1 00:00:06,000 --> 00:00:09,880 Of all life on Earth, there's something more mysterious 2 00:00:09,880 --> 00:00:13,120 yet more vital to our survival than anything else. 3 00:00:15,920 --> 00:00:17,760 Its birth is violent. 4 00:00:19,360 --> 00:00:21,520 Much of its life is hidden underground. 5 00:00:25,320 --> 00:00:28,960 And only at the end of its life cycle does it reveal its identity. 6 00:00:31,480 --> 00:00:32,680 The mushroom. 7 00:00:39,600 --> 00:00:42,120 I'm Professor Richard Fortey. 8 00:00:42,120 --> 00:00:45,040 'I've been fascinated by mushrooms all my life.' 9 00:00:45,040 --> 00:00:46,480 Nice find. 10 00:00:46,480 --> 00:00:51,200 'I love to collect and study them.' 11 00:00:51,200 --> 00:00:54,760 Many people think of mushrooms just as something to eat, 12 00:00:54,760 --> 00:00:58,600 or maybe as decoration in folk tales. 13 00:00:58,600 --> 00:01:00,680 But nothing could be further from the truth. 14 00:01:02,400 --> 00:01:05,560 They have a secret life so magical, 15 00:01:05,560 --> 00:01:07,400 so weird, 16 00:01:07,400 --> 00:01:10,200 that it defies imagination, 17 00:01:10,200 --> 00:01:13,040 and I'm going to reveal it as never before. 18 00:01:17,200 --> 00:01:22,520 I've set up my own lab to unlock the mysteries of mushrooms. 19 00:01:22,520 --> 00:01:23,880 Oh, look at that! 20 00:01:23,880 --> 00:01:25,520 They're like geysers. 21 00:01:27,080 --> 00:01:29,840 I'll discover their astonishing powers. 22 00:01:31,080 --> 00:01:33,840 What makes them the fastest... 23 00:01:33,840 --> 00:01:35,120 the largest... 24 00:01:36,800 --> 00:01:39,960 ..and some of the deadliest living things on the planet. 25 00:01:41,600 --> 00:01:45,320 Half a cap will kill you and kill you slowly and painfully. 26 00:01:47,120 --> 00:01:51,000 And I'll meet the people turning those powers to our advantage 27 00:01:51,000 --> 00:01:53,320 to create new medicines 28 00:01:53,320 --> 00:01:55,280 and new materials. 29 00:01:55,280 --> 00:01:58,080 The innovation we have here is the future of energy production 30 00:01:58,080 --> 00:02:00,400 and even devices and products like your iPhone. 31 00:02:02,320 --> 00:02:05,640 To discover what gives mushrooms their extraordinary abilities, 32 00:02:05,640 --> 00:02:09,800 I'm going to follow their story from birth, through life, to death. 33 00:02:11,120 --> 00:02:15,200 A story so strange it seems almost alien, 34 00:02:15,200 --> 00:02:19,720 yet it will reveal why mushrooms are crucial to all life on Earth, 35 00:02:19,720 --> 00:02:24,120 and why they have a powerful connection to you and me. 36 00:02:37,360 --> 00:02:40,800 The only place many of us encounter mushrooms is here. 37 00:02:44,000 --> 00:02:46,280 Cultivated edible varieties like these, 38 00:02:46,280 --> 00:02:50,120 are all most of us think about when it comes to mushrooms. 39 00:02:50,120 --> 00:02:52,280 We Brits can't get enough. 40 00:02:52,280 --> 00:02:55,200 It's a multimillion pound business in the UK. 41 00:02:57,240 --> 00:02:59,440 But there's so much more to mushrooms 42 00:02:59,440 --> 00:03:03,640 than this fine example in the fresh food counter. 43 00:03:03,640 --> 00:03:08,000 This mushroom is just one species from an enormous kingdom, 44 00:03:08,000 --> 00:03:09,680 the kingdom of the fungi... 45 00:03:10,800 --> 00:03:14,080 ..and fungi are hidden away in all kinds of food products 46 00:03:14,080 --> 00:03:16,800 in this supermarket in ways you wouldn't expect. 47 00:03:20,960 --> 00:03:24,160 Look hard enough and every aisle reveals evidence 48 00:03:24,160 --> 00:03:26,440 of how fungi underpin modern living. 49 00:03:27,880 --> 00:03:29,280 Cheese. 50 00:03:30,560 --> 00:03:33,920 My favourite Stilton cheese, well, it's blue, 51 00:03:33,920 --> 00:03:36,080 and the blue is a fungus. 52 00:03:37,440 --> 00:03:40,080 A lot of fizzy drinks have citric acid in them, 53 00:03:40,080 --> 00:03:42,920 and that's produced by a fungus called Aspergillus niger 54 00:03:42,920 --> 00:03:44,840 in huge quantities. 55 00:03:44,840 --> 00:03:49,680 Many detergents also contain citric acid, just like fizzy drinks. 56 00:03:49,680 --> 00:03:53,360 Ah, here's soy sauce, bread, 57 00:03:53,360 --> 00:03:56,680 Quorn, chocolate, fruit juices. 58 00:03:56,680 --> 00:03:58,800 Well, sometimes they have a bitter taste, 59 00:03:58,800 --> 00:04:01,000 which can be removed by another fungus. 60 00:04:02,320 --> 00:04:04,080 Salmon, red salmon. 61 00:04:04,080 --> 00:04:05,640 The red colour, I'm afraid, 62 00:04:05,640 --> 00:04:08,480 is sometimes due to a fungus called Phaffia. 63 00:04:09,640 --> 00:04:12,080 Some of the protein in pet foods, 64 00:04:12,080 --> 00:04:16,720 which keeps your animals healthy is actually produced by fungi. 65 00:04:18,280 --> 00:04:20,160 And, of course, booze. 66 00:04:20,160 --> 00:04:23,240 The fermenting activity of Saccharomyces, 67 00:04:23,240 --> 00:04:25,880 turning sugars into alcohol. 68 00:04:33,520 --> 00:04:37,120 Clearly, our supermarket shop just wouldn't be the same without fungi. 69 00:04:37,120 --> 00:04:40,400 They're hidden away in all sorts of ways in the products. 70 00:04:40,400 --> 00:04:44,400 They must have a series of special biochemical tricks up their sleeve. 71 00:04:47,120 --> 00:04:50,400 But how exactly is it that they seem to turn up everywhere 72 00:04:50,400 --> 00:04:52,600 and affect so many parts of our lives? 73 00:04:55,480 --> 00:04:58,720 To begin to answer that question, I'm going to a place 74 00:04:58,720 --> 00:05:01,760 where I encounter fungi in all their forms. 75 00:05:03,720 --> 00:05:07,560 Head out into any woodland like this one in the Scottish Borders, 76 00:05:07,560 --> 00:05:09,200 and if you look hard enough, 77 00:05:09,200 --> 00:05:11,840 you'll start finding them everywhere. 78 00:05:23,000 --> 00:05:26,280 To me, they're fascinating. 79 00:05:26,280 --> 00:05:29,440 Some may think they look like any other plant, 80 00:05:29,440 --> 00:05:32,640 but in fact, they're a different organism altogether. 81 00:05:34,760 --> 00:05:37,320 Fungi evolved as a kingdom in their own right, 82 00:05:37,320 --> 00:05:40,400 distinct from plants and animals, 83 00:05:40,400 --> 00:05:43,840 over one and a half billion years ago. 84 00:05:43,840 --> 00:05:45,200 It's thought that in variety, 85 00:05:45,200 --> 00:05:47,680 they outnumber plants by at least ten to one. 86 00:05:49,320 --> 00:05:52,240 And searching for them is my favourite pastime. 87 00:05:55,760 --> 00:05:59,840 Some people might think of autumn as a rather gloomy time of year, 88 00:05:59,840 --> 00:06:02,520 but for me, it's pure joy. 89 00:06:02,520 --> 00:06:04,920 I can take my basket, I can go into the woods... 90 00:06:05,960 --> 00:06:08,800 ..and I can do my mushroom foraying. 91 00:06:08,800 --> 00:06:10,600 I've been doing it for decades. 92 00:06:11,680 --> 00:06:12,960 What's the thrill of it? 93 00:06:12,960 --> 00:06:16,680 Well, to the left of the path, to the right of the path, 94 00:06:16,680 --> 00:06:19,480 dozens of different kinds of fungi are erupting. 95 00:06:20,560 --> 00:06:25,560 But, I suppose, the most primeval feeling, the basic one, 96 00:06:25,560 --> 00:06:29,440 is still the thrill of discovery, the thrill of the chase. 97 00:06:35,040 --> 00:06:39,320 You may not realise that what we call the mushroom is, in fact, 98 00:06:39,320 --> 00:06:41,280 just one type of fungus. 99 00:06:41,280 --> 00:06:43,880 It's the form that we are most familiar with 100 00:06:43,880 --> 00:06:46,400 and it's certainly the easiest to recognise. 101 00:06:49,360 --> 00:06:51,840 The head of a mushroom is its cap. 102 00:06:56,360 --> 00:06:58,160 And many have a stalk. 103 00:07:01,880 --> 00:07:03,840 Look underneath the cap, 104 00:07:03,840 --> 00:07:07,680 and you'll often find a set of sharp ridges known as gills. 105 00:07:07,680 --> 00:07:09,520 Ah-ha! 106 00:07:09,520 --> 00:07:14,200 Well, now, this is, of course, the archetypal mushroom. 107 00:07:14,200 --> 00:07:18,280 It's the one that the gnomes sit on top of. 108 00:07:18,280 --> 00:07:19,920 It's the fly agaric. 109 00:07:19,920 --> 00:07:23,840 I can see other species really, really close to hand. 110 00:07:23,840 --> 00:07:28,200 This is the king of the edible mushrooms, the cep, 111 00:07:28,200 --> 00:07:29,560 the penny bun, 112 00:07:29,560 --> 00:07:30,920 porcini. 113 00:07:30,920 --> 00:07:33,800 The fact that it's got so many names is a measure 114 00:07:33,800 --> 00:07:37,840 of just how highly regarded it is as an edible fungus. 115 00:07:37,840 --> 00:07:39,120 It's one of the best. 116 00:07:41,520 --> 00:07:43,760 'But as well as the quintessential mushroom...' 117 00:07:43,760 --> 00:07:45,040 Bit hazardous. 118 00:07:45,040 --> 00:07:48,680 '..if you look a little harder, you'll find a host of other fungi 119 00:07:48,680 --> 00:07:50,760 'that don't look like mushrooms at all.' 120 00:07:52,000 --> 00:07:55,080 Ah, well, now, here's something completely different. 121 00:07:55,080 --> 00:07:58,280 Perhaps doesn't look like a fungus at first sight to people. 122 00:07:58,280 --> 00:07:59,760 It's one of the coral fungi. 123 00:08:00,960 --> 00:08:02,760 This is an ear fungus. 124 00:08:02,760 --> 00:08:07,280 They're still fungi but they're very, very different sort of fungi. 125 00:08:07,280 --> 00:08:09,240 Yellow brain fungus. 126 00:08:09,240 --> 00:08:11,760 Doesn't look like anything from this Earth, really, does it? 127 00:08:13,000 --> 00:08:14,640 It's the beefsteak fungus. 128 00:08:15,920 --> 00:08:19,400 And you can see why - it looks a bit like raw liver. 129 00:08:21,640 --> 00:08:25,680 'In fact, this organism can take so many weird and wonderful forms, 130 00:08:25,680 --> 00:08:27,720 'knowing what it is you're looking at 131 00:08:27,720 --> 00:08:32,720 'can sometimes be a challenge, even for an experienced forayer like me.' 132 00:08:32,720 --> 00:08:36,520 Wow, now, that is something really weird. 133 00:08:36,520 --> 00:08:38,480 I'm not quite sure what's going on. 134 00:08:38,480 --> 00:08:41,520 It's absolutely extraordinary. That's one coming back to the lab. 135 00:08:44,040 --> 00:08:48,600 Almost every foray I go on, I find something new and intriguing. 136 00:08:48,600 --> 00:08:52,360 Time to take a closer look at exactly what's in my basket. 137 00:08:55,320 --> 00:08:58,440 This is our specially-built mushroom lab 138 00:08:58,440 --> 00:09:00,640 where I'll be unlocking the mysteries of fungi 139 00:09:00,640 --> 00:09:03,640 with the help of mycologist Dr Patrick Hickey. 140 00:09:03,640 --> 00:09:05,680 Well, this is quite a set-up you've got here. 141 00:09:07,360 --> 00:09:09,880 Their first secret is their identity. 142 00:09:11,000 --> 00:09:14,040 So here we are with our haul back from the woods, 143 00:09:14,040 --> 00:09:16,400 and what a variety we've got in the basket. 144 00:09:16,400 --> 00:09:19,400 Of course, we notice things like the colour, of course. 145 00:09:19,400 --> 00:09:20,640 The smell. 146 00:09:20,640 --> 00:09:24,480 Oh, yeah, that's got a really sweet smell to it, very sweet odour. 147 00:09:24,480 --> 00:09:27,720 So fungus identification uses all your senses. 148 00:09:27,720 --> 00:09:30,000 It's a very sensory experience. 149 00:09:30,000 --> 00:09:32,440 But there's another way we can really narrow down 150 00:09:32,440 --> 00:09:35,600 the mystery of a mushroom and positively identify it 151 00:09:35,600 --> 00:09:38,080 and that's by doing something called a spore print. 152 00:09:38,080 --> 00:09:41,040 Every mushroom has its own unique spore print 153 00:09:41,040 --> 00:09:43,640 and to do a spore print, we cut the stem off, 154 00:09:43,640 --> 00:09:46,440 and then place the cap onto a piece of paper 155 00:09:46,440 --> 00:09:48,280 and just leave it for a few hours. 156 00:09:48,280 --> 00:09:50,840 When you come back and lift it up, 157 00:09:50,840 --> 00:09:53,840 you'll see the mushroom has deposited a layer of spores 158 00:09:53,840 --> 00:09:55,640 and they look just like fingerprints. 159 00:09:55,640 --> 00:09:58,120 It's a bit like taking a fingerprint from a mushroom. 160 00:09:59,320 --> 00:10:02,720 These spores are like the seeds of a mushroom 161 00:10:02,720 --> 00:10:06,360 and the patterns they create can reveal some surprises, 162 00:10:06,360 --> 00:10:10,120 even when two mushrooms appear to look the same. 163 00:10:10,120 --> 00:10:12,520 So here we've got two similar looking... 164 00:10:12,520 --> 00:10:15,200 Almost the same, yeah. ..white mushrooms, 165 00:10:15,200 --> 00:10:18,640 but reveal the spores - one's startlingly white 166 00:10:18,640 --> 00:10:21,040 and the other's very black. 167 00:10:21,040 --> 00:10:24,080 Yeah, it's a key in the identification of the mushroom. 168 00:10:30,280 --> 00:10:32,320 So we have such a variety of colours. 169 00:10:32,320 --> 00:10:34,640 We've got a sort of purple here. 170 00:10:34,640 --> 00:10:36,880 We've got cream, we've got white, 171 00:10:36,880 --> 00:10:41,800 very pure white, rust brown, even pinkish. Yeah. 172 00:10:41,800 --> 00:10:44,840 And I have to say what a beautiful pattern it makes too. 173 00:10:44,840 --> 00:10:47,360 I mean, aesthetically, extremely pleasing. 174 00:10:47,360 --> 00:10:50,480 They're wonderful. They're just like the silhouettes of a mushroom, 175 00:10:50,480 --> 00:10:54,240 and that colour of the spore print is unique to that type of mushroom 176 00:10:54,240 --> 00:10:57,160 and they don't change throughout the mushroom's life cycle. 177 00:11:00,640 --> 00:11:02,320 The spore prints reveal 178 00:11:02,320 --> 00:11:07,280 that mushrooms are more varied and complex than they might appear. 179 00:11:07,280 --> 00:11:10,640 Their world is mysterious and little known, 180 00:11:10,640 --> 00:11:14,960 yet they have the power to affect our lives in unexpected ways. 181 00:11:14,960 --> 00:11:17,600 One of the most striking displays of that power 182 00:11:17,600 --> 00:11:20,360 takes us to the most unlikely place. 183 00:11:29,000 --> 00:11:32,960 This is Mark Gilchrist, a consultant pharmacist 184 00:11:32,960 --> 00:11:35,240 at St Mary's Hospital, London. 185 00:11:35,240 --> 00:11:38,880 He spends much of his day administering and prescribing 186 00:11:38,880 --> 00:11:42,240 the most widely-used type of drug on the planet - 187 00:11:42,240 --> 00:11:43,720 antibiotics. 188 00:11:47,200 --> 00:11:49,480 Antibiotics are tremendously important 189 00:11:49,480 --> 00:11:51,800 in our fight against infection. 190 00:11:51,800 --> 00:11:55,280 Up to about 30% of patients within a hospital setting 191 00:11:55,280 --> 00:11:57,280 can be on antibiotics at any one time 192 00:11:57,280 --> 00:11:59,520 and that's used to treat things like pneumonias 193 00:11:59,520 --> 00:12:01,760 to simple skin and soft tissue infections 194 00:12:01,760 --> 00:12:04,840 and prevent surgical site infections post operatively. 195 00:12:07,080 --> 00:12:10,640 The invention of antibiotics has been a game changer 196 00:12:10,640 --> 00:12:13,800 for medicine and mankind. 197 00:12:13,800 --> 00:12:15,480 And we owe it all to fungi. 198 00:12:21,280 --> 00:12:24,520 In 1928, scientist Alexander Fleming 199 00:12:24,520 --> 00:12:26,720 was carrying out research at St Mary's. 200 00:12:27,880 --> 00:12:31,240 He was studying the staphylococcus bacterium, 201 00:12:31,240 --> 00:12:35,360 and left some samples on his desk, before heading off on holiday, 202 00:12:35,360 --> 00:12:38,560 expecting them to grow and develop while he was away. 203 00:12:40,480 --> 00:12:43,840 When Fleming returned from his holiday to resume his research 204 00:12:43,840 --> 00:12:46,680 on bacteria here in this lab, 205 00:12:46,680 --> 00:12:48,720 he noticed something extraordinary. 206 00:12:50,400 --> 00:12:53,640 His bacteria samples were dead. 207 00:12:53,640 --> 00:12:56,160 They had been completely destroyed by fungi. 208 00:12:57,680 --> 00:13:00,320 Intrigued by why this had happened, 209 00:13:00,320 --> 00:13:02,560 Fleming examined his samples further. 210 00:13:04,200 --> 00:13:08,640 He realised that a fungus spore, possibly from a lab below, 211 00:13:08,640 --> 00:13:11,760 must have landed on the gel plate and germinated. 212 00:13:14,640 --> 00:13:18,520 The spore had rapidly started to feed on the contents of the dish, 213 00:13:18,520 --> 00:13:21,240 starving and ultimately killing the bacteria. 214 00:13:22,880 --> 00:13:25,400 The significance wasn't lost on Fleming. 215 00:13:25,400 --> 00:13:28,320 This could be a new way to fight bacterial infection 216 00:13:28,320 --> 00:13:30,040 inside the human body. 217 00:13:31,800 --> 00:13:36,040 His discovery led to the creation of the world's first antibiotic - 218 00:13:36,040 --> 00:13:37,360 penicillin. 219 00:13:38,880 --> 00:13:43,160 And it only happened thanks to some tiny spores from a fungus, 220 00:13:43,160 --> 00:13:44,400 carried on the breeze. 221 00:13:46,240 --> 00:13:49,880 But to understand how those spores came to be there at all, 222 00:13:49,880 --> 00:13:54,240 we need to delve deeper into the secret world of fungi, 223 00:13:54,240 --> 00:13:57,320 right back to the start of their life cycle, 224 00:13:57,320 --> 00:13:59,960 to the moment a new fungus begins. 225 00:14:12,880 --> 00:14:14,280 I've come to Scotland 226 00:14:14,280 --> 00:14:18,120 to see something I've always wanted to see but never have, 227 00:14:18,120 --> 00:14:21,200 although I've rehearsed it many times in my mind's eye. 228 00:14:24,000 --> 00:14:27,640 This is one of the largest mushroom farms in the UK, 229 00:14:27,640 --> 00:14:29,880 and inside each of these polytunnels, 230 00:14:29,880 --> 00:14:33,800 there's a spectacular natural phenomenon taking place - 231 00:14:33,800 --> 00:14:35,200 the birth of fungi. 232 00:14:48,200 --> 00:14:51,600 It's a magical process, normally invisible, 233 00:14:51,600 --> 00:14:55,920 but tonight I'm going to see it clearly for the first time. 234 00:14:59,640 --> 00:15:01,360 Well, to a mushroom person, of course, 235 00:15:01,360 --> 00:15:04,080 this is like being in heaven, 236 00:15:04,080 --> 00:15:09,480 and everywhere you look, it's extraordinary - 237 00:15:09,480 --> 00:15:13,360 this laser torch picks out little white specks. 238 00:15:13,360 --> 00:15:16,280 They're so numerous. This is like shining a beam 239 00:15:16,280 --> 00:15:18,200 up into the Milky Way. 240 00:15:18,200 --> 00:15:22,480 Billions upon billions of spores in the air all around us, 241 00:15:22,480 --> 00:15:26,040 and they're ubiquitous, so they're going up to the ceiling 242 00:15:26,040 --> 00:15:27,640 they're going out the door, 243 00:15:27,640 --> 00:15:29,840 they're doubtless going into my lungs. 244 00:15:32,920 --> 00:15:39,000 If you want a graphic demonstration of how prolific mushrooms are, 245 00:15:39,000 --> 00:15:40,280 here it is. 246 00:15:47,240 --> 00:15:50,320 So this is how most fungi begin life. 247 00:15:51,520 --> 00:15:56,240 The mushroom spews out many millions of spores every hour, 248 00:15:56,240 --> 00:15:58,520 for as long as it remains above the ground... 249 00:15:59,720 --> 00:16:03,320 ..each of them carrying the potential to be a new fungus. 250 00:16:04,960 --> 00:16:07,360 It's mesmerising to watch, 251 00:16:07,360 --> 00:16:10,200 but I want to know exactly what's going on here 252 00:16:10,200 --> 00:16:13,400 and to do that, I'll need more than a laser light. 253 00:16:15,680 --> 00:16:17,360 Back in the mushroom lab, 254 00:16:17,360 --> 00:16:21,400 Patrick can reveal the hidden mechanisms of mushroom birth. 255 00:16:21,400 --> 00:16:23,800 A mushroom, also known as a fruiting body, 256 00:16:23,800 --> 00:16:26,880 really is just the reproductive structure of a fungus 257 00:16:26,880 --> 00:16:29,840 and its sole purpose is to produce spores. 258 00:16:29,840 --> 00:16:31,760 So to look at these in more detail, 259 00:16:31,760 --> 00:16:35,000 what I'm going to do is take a very thin section 260 00:16:35,000 --> 00:16:36,840 through this mushroom cap 261 00:16:36,840 --> 00:16:40,320 and put it onto a microscope slide. 262 00:16:46,000 --> 00:16:48,320 There we go... Ah! 263 00:16:48,320 --> 00:16:50,560 That's the business, isn't it? 264 00:16:50,560 --> 00:16:55,120 Yeah, so the large cylindrical kind of clear part of the cell 265 00:16:55,120 --> 00:16:59,840 is the basidium and those little spiky bits protruding from it 266 00:16:59,840 --> 00:17:03,040 are called the sterigmata and they hold the spores in place. 267 00:17:03,040 --> 00:17:05,560 Now, eventually, when those spores are fully ripened, 268 00:17:05,560 --> 00:17:08,240 they'll drop off into that air space between the gills, 269 00:17:08,240 --> 00:17:10,040 and fall down from the mushroom. 270 00:17:10,040 --> 00:17:12,360 That whole structure, including the spores, 271 00:17:12,360 --> 00:17:15,080 is about the width of a human hair, and, remember, these gills 272 00:17:15,080 --> 00:17:18,160 are packed with them. They're completely lined with a layer 273 00:17:18,160 --> 00:17:20,560 of these basidia continually producing spores. 274 00:17:20,560 --> 00:17:22,520 It's a production line. 275 00:17:22,520 --> 00:17:25,440 It's an extraordinary thought, isn't it? This tiny object, 276 00:17:25,440 --> 00:17:28,280 just a few thousandths of a millimetre long, 277 00:17:28,280 --> 00:17:31,240 contains the potentiality for a new mushroom colony. 278 00:17:31,240 --> 00:17:32,440 Exactly. 279 00:17:34,080 --> 00:17:38,400 This constant production line, forming and releasing spores, 280 00:17:38,400 --> 00:17:42,880 is exactly what I saw so vividly in action at the mushroom farm. 281 00:17:42,880 --> 00:17:46,120 But that's just one way mushrooms can spread their spores. 282 00:17:46,120 --> 00:17:48,760 Others do it in a completely different way. 283 00:17:50,360 --> 00:17:53,400 This is an orange peel fungus, 284 00:17:53,400 --> 00:17:55,080 and it's part of a large group 285 00:17:55,080 --> 00:17:59,240 that fire their spores vertically, with explosive results, 286 00:17:59,240 --> 00:18:03,160 as we can see here when the action is slowed down 600 times. 287 00:18:11,960 --> 00:18:13,560 Oh, look at that! 288 00:18:13,560 --> 00:18:15,760 They're like geysers erupting. 289 00:18:19,880 --> 00:18:23,320 The spores are incredibly prolific. Throughout the course of a day, 290 00:18:23,320 --> 00:18:26,200 each fungus might be capable of producing over a million spores 291 00:18:26,200 --> 00:18:28,480 and over the lifetime of that fungus, 292 00:18:28,480 --> 00:18:30,720 we're into tens to hundreds of millions. 293 00:18:37,720 --> 00:18:41,760 Well, that's extraordinary footage. I've never, ever seen anything 294 00:18:41,760 --> 00:18:45,680 so graphically displaying the way fungi get rid of their spores. 295 00:18:45,680 --> 00:18:47,640 It's a truly impressive fungus. 296 00:18:53,800 --> 00:18:58,040 These fungi can reload and fire time and time again, 297 00:18:58,040 --> 00:18:59,960 often for many days on end. 298 00:19:02,280 --> 00:19:03,680 And how that works 299 00:19:03,680 --> 00:19:06,320 was a brilliant discovery made by someone you wouldn't expect. 300 00:19:14,760 --> 00:19:19,120 Beatrix Potter is famous for penning The Tale Of Peter Rabbit, 301 00:19:19,120 --> 00:19:20,640 but what's less well known, 302 00:19:20,640 --> 00:19:23,800 is that she was one of the leading mushroom biologists of her time. 303 00:19:25,760 --> 00:19:29,120 Both Potter and pioneering biologist Arthur Buller 304 00:19:29,120 --> 00:19:31,560 spent much of their lives trying to find out 305 00:19:31,560 --> 00:19:34,160 how some mushrooms release their spores. 306 00:19:38,360 --> 00:19:41,520 They discovered that a tiny drop of fluid, 307 00:19:41,520 --> 00:19:45,560 now known as Buller's drop, forms at the base of every spore. 308 00:19:49,880 --> 00:19:53,080 As the spore ripens and begins to detach, 309 00:19:53,080 --> 00:19:56,400 the Buller's drop fuses with a second tiny water droplet 310 00:19:56,400 --> 00:19:59,200 that forms at the side of the spore. 311 00:19:59,200 --> 00:20:02,840 Like two raindrops joining together on a windowpane, 312 00:20:02,840 --> 00:20:06,400 this fusion causes a rapid shift in mass 313 00:20:06,400 --> 00:20:09,600 that dislodges the spore in such a spectacular fashion. 314 00:20:14,600 --> 00:20:17,360 This microscopic process all takes place 315 00:20:17,360 --> 00:20:19,960 in a few millionths of a second 316 00:20:19,960 --> 00:20:22,160 and is key to how many fungi reproduce. 317 00:20:23,440 --> 00:20:26,760 But of them all, there's one particular species 318 00:20:26,760 --> 00:20:28,120 that's a record breaker. 319 00:20:30,600 --> 00:20:33,320 You may think that the fastest organism on the planet 320 00:20:33,320 --> 00:20:36,440 is a cheetah or maybe a peregrine falcon, 321 00:20:36,440 --> 00:20:38,400 but you'd be wrong. 322 00:20:38,400 --> 00:20:41,520 Allowing for scale, the speediest organism on the planet 323 00:20:41,520 --> 00:20:43,880 is actually a tiny fungus. 324 00:20:43,880 --> 00:20:46,280 It grows on top of cowpats. 325 00:20:47,440 --> 00:20:53,600 It's called Pilobolus crystallinus, or the "Hat Thrower" fungus, 326 00:20:53,600 --> 00:20:56,400 and no other species demonstrates better 327 00:20:56,400 --> 00:20:58,960 the importance of the spore release mechanism. 328 00:21:02,920 --> 00:21:07,120 This little fungus feeds on the dung of herbivores, 329 00:21:07,120 --> 00:21:11,080 but when the supply of nutrients from one pile has been exhausted, 330 00:21:11,080 --> 00:21:12,680 it needs to move on, 331 00:21:12,680 --> 00:21:16,000 and to do that, it has to get out of the dung 332 00:21:16,000 --> 00:21:18,280 and onto new blades of grass. 333 00:21:18,280 --> 00:21:20,080 That's the equivalent of you or I 334 00:21:20,080 --> 00:21:23,440 trying to throw a tennis ball over the Eiffel Tower. 335 00:21:23,440 --> 00:21:25,600 But, then, you or I can't do this. 336 00:21:25,600 --> 00:21:28,040 BANG 337 00:21:28,040 --> 00:21:30,560 MUSIC: "Zorba's Dance" by Mikis Theodorakis 338 00:21:34,360 --> 00:21:37,800 Using water drop acceleration, these spore capsules, 339 00:21:37,800 --> 00:21:41,040 seen as little black hats, can be fired at a speed 340 00:21:41,040 --> 00:21:45,400 of up to 40mph in just two millionths of a second, 341 00:21:45,400 --> 00:21:48,680 pulling an astonishing 20,000 Gs in the process. 342 00:21:49,840 --> 00:21:52,240 BANG 343 00:21:52,240 --> 00:21:55,080 The little "Hat Thrower" fungus is a wonderful example 344 00:21:55,080 --> 00:21:58,160 of the sophistication of fungus evolution. 345 00:21:58,160 --> 00:22:01,840 It throws its spore body more than a thousand times its own length 346 00:22:01,840 --> 00:22:04,520 into clear grass, away from cowpats, 347 00:22:04,520 --> 00:22:07,520 so that the cows will come along, graze the grass, 348 00:22:07,520 --> 00:22:11,480 incorporate the spores and so propagate another generation. 349 00:22:14,640 --> 00:22:17,800 The "Hat Thrower" shows just how ingenious fungi are 350 00:22:17,800 --> 00:22:19,520 when it comes to reproduction. 351 00:22:20,680 --> 00:22:24,320 They will go to extraordinary lengths to ensure their own future. 352 00:22:26,240 --> 00:22:30,120 It's the key to why fungi have become such a dominant life form 353 00:22:30,120 --> 00:22:33,920 with such vast numbers of species all over the planet. 354 00:22:37,560 --> 00:22:43,080 And it's certainly a talent to which humankind owes a great deal. 355 00:22:47,000 --> 00:22:51,840 But as impressive as spore dispersal might be, 356 00:22:51,840 --> 00:22:55,040 it's just the beginning of the fungus's life story. 357 00:22:56,200 --> 00:22:59,760 It's the next stage that truly reveals why they are 358 00:22:59,760 --> 00:23:02,000 so vital to all life on Earth. 359 00:23:03,840 --> 00:23:08,040 So far we've just been looking at the fruit body of the mushroom. 360 00:23:08,040 --> 00:23:11,920 Indeed, I suppose to most people they think that IS the mushroom. 361 00:23:12,960 --> 00:23:14,680 But it's only part of the story. 362 00:23:15,800 --> 00:23:18,560 To discover how mushrooms relate 363 00:23:18,560 --> 00:23:21,680 to so many other organisms on our planet, 364 00:23:21,680 --> 00:23:25,400 we have to go further, we have to go underground. 365 00:23:35,760 --> 00:23:38,240 You'd be forgiven for thinking that what we see 366 00:23:38,240 --> 00:23:41,440 above the ground is the main part of the fungus... 367 00:23:42,840 --> 00:23:47,640 ..but, in fact, the vast majority of the organism is hidden underground. 368 00:23:47,640 --> 00:23:51,520 It's a huge web of tiny threads, spreading out in search of food. 369 00:23:54,080 --> 00:23:56,920 And the only way many fungi can get what they need, 370 00:23:56,920 --> 00:24:00,080 is by attaching themselves to other organisms, 371 00:24:00,080 --> 00:24:03,000 and engaging in a two-way exchange of nutrients. 372 00:24:06,840 --> 00:24:09,560 It's a process that results in one of the most complex, 373 00:24:09,560 --> 00:24:12,440 yet crucial relationships in the natural world. 374 00:24:16,760 --> 00:24:18,960 To discover how this works, 375 00:24:18,960 --> 00:24:22,320 I'm meeting Kew Gardens mycologist Bryn Dentinger. 376 00:24:25,000 --> 00:24:28,760 Anywhere from 70% to 90% of all plants on Earth 377 00:24:28,760 --> 00:24:33,160 will form a very special intimate relationship with fungi 378 00:24:33,160 --> 00:24:37,080 and the fungi will attach themselves to the plant roots, 379 00:24:37,080 --> 00:24:39,680 either directly penetrating the roots 380 00:24:39,680 --> 00:24:42,840 or sometimes they will form sheaths on the outside 381 00:24:42,840 --> 00:24:45,400 that will envelop the root like a kind of glove. 382 00:24:46,760 --> 00:24:49,040 This is where the nutrient exchange takes place 383 00:24:49,040 --> 00:24:50,840 between the fungus and the root. 384 00:24:54,880 --> 00:24:58,600 This nutrient exchange works both ways. 385 00:24:58,600 --> 00:25:03,000 The fungus feeds on sugars from the plant that it needs to grow 386 00:25:03,000 --> 00:25:05,480 and in return gives back water and minerals 387 00:25:05,480 --> 00:25:08,200 that the planet is unable to absorb enough of itself. 388 00:25:11,160 --> 00:25:14,720 I'm going to lift up this pine seedling here 389 00:25:14,720 --> 00:25:18,120 and you can see, where I'm pointing with my pinkie, that white fuzz. 390 00:25:18,120 --> 00:25:19,360 Oh, yeah, OK. 391 00:25:19,360 --> 00:25:21,200 Those are the fungal filaments 392 00:25:21,200 --> 00:25:25,000 and it is completely covering the roots of this pine tree right here. 393 00:25:26,400 --> 00:25:29,440 And it extends over a much larger surface area 394 00:25:29,440 --> 00:25:31,840 than the roots can possibly cover, 395 00:25:31,840 --> 00:25:34,800 and this gives them access to all kinds of nutrients 396 00:25:34,800 --> 00:25:36,720 and water, even, from the soil, 397 00:25:36,720 --> 00:25:40,000 so they can extract nitrogen and phosphorous, in particular, 398 00:25:40,000 --> 00:25:41,360 from the soil, 399 00:25:41,360 --> 00:25:43,440 and provide those to the plant, 400 00:25:43,440 --> 00:25:46,640 which the plant will then exchange for sugars 401 00:25:46,640 --> 00:25:48,560 that it produces through photosynthesis. 402 00:25:48,560 --> 00:25:50,800 And the two together make for a better plant? 403 00:25:50,800 --> 00:25:53,640 A better plant and a better fungus, healthier soil. 404 00:25:53,640 --> 00:25:56,480 So it's a win-win situation for both? 405 00:25:56,480 --> 00:25:58,360 It's a win-win situation for both partners 406 00:25:58,360 --> 00:25:59,920 and, in fact, for the entire world. 407 00:26:02,080 --> 00:26:05,320 'We're going to look for evidence of this vital relationship, 408 00:26:05,320 --> 00:26:07,000 'in the wild.' 409 00:26:07,000 --> 00:26:08,360 Well, we can't see them, 410 00:26:08,360 --> 00:26:12,320 but, all around us there are these unseen fungal partners. 411 00:26:12,320 --> 00:26:16,160 They're invisible to us when we just take a nice stroll along a path, 412 00:26:16,160 --> 00:26:17,920 but they're all around us. 413 00:26:17,920 --> 00:26:19,520 Shall we have a go? Let's do it. 414 00:26:21,400 --> 00:26:22,640 I think I've got some. 415 00:26:25,240 --> 00:26:28,880 Well, I mean, you don't have to search for it. 416 00:26:28,880 --> 00:26:32,440 You can see the white tips here. It's very obvious, yeah. 417 00:26:32,440 --> 00:26:36,360 But every one of these tiny little, side-branching roots 418 00:26:36,360 --> 00:26:37,560 is covered in fungus. 419 00:26:41,480 --> 00:26:44,520 There's a fascinating and fundamental relationship 420 00:26:44,520 --> 00:26:47,240 between fungi and land plants, 421 00:26:47,240 --> 00:26:51,680 not just here in Kew and every park in Britain, but in every field. 422 00:26:51,680 --> 00:26:54,480 Without this relationship, plants couldn't thrive. 423 00:26:54,480 --> 00:26:57,720 It's impossible to overstate its importance. 424 00:27:00,160 --> 00:27:02,960 So how exactly does this hidden process happen? 425 00:27:05,840 --> 00:27:09,560 To find out, Patrick has been capturing it in action, 426 00:27:09,560 --> 00:27:12,280 starting from the moment a spore hits the ground. 427 00:27:14,040 --> 00:27:16,760 The primary mission of a fungal spore is to feed 428 00:27:16,760 --> 00:27:18,920 and find food resources. 429 00:27:18,920 --> 00:27:23,400 Now, under the right conditions, the spore starts to germinate and grow. 430 00:27:23,400 --> 00:27:26,400 That's what we can see here. We've placed some spores 431 00:27:26,400 --> 00:27:30,320 into a drop of water and as you can see, they're starting to swell. 432 00:27:30,320 --> 00:27:32,920 There's a little bit of movement starting to go on inside. 433 00:27:32,920 --> 00:27:36,240 Oh, yeah. And already you can see this little bud emerging, 434 00:27:36,240 --> 00:27:39,320 and that little bud is the beginnings of a fungal hypha. 435 00:27:39,320 --> 00:27:41,560 So, what is a hypha? 436 00:27:41,560 --> 00:27:44,880 The hypha is the feeding part of a fungus, the feeding tube, 437 00:27:44,880 --> 00:27:48,000 and the hypha goes in search of water and food 438 00:27:48,000 --> 00:27:50,080 and will continue growing and branching 439 00:27:50,080 --> 00:27:53,280 until it eventually establishes a colony, a fungal colony. 440 00:27:53,280 --> 00:27:54,840 Does it grow very fast? 441 00:27:54,840 --> 00:27:58,160 Once a hypha finds its food source, it can develop very quickly 442 00:27:58,160 --> 00:28:00,040 and form what we call a mycelium. 443 00:28:01,360 --> 00:28:06,640 A mycelium is the scientific name for the fungus's feeding network. 444 00:28:06,640 --> 00:28:09,480 Here magnified 500 times, 445 00:28:09,480 --> 00:28:13,520 we can see one starting to form as many hyphae begin to web together. 446 00:28:15,000 --> 00:28:17,640 Essentially, it is a fungus's root system, 447 00:28:17,640 --> 00:28:20,640 a complex series of feeding tubes. 448 00:28:20,640 --> 00:28:24,680 It's not unlike a microscopic human digestive system, 449 00:28:24,680 --> 00:28:27,000 processing food that allows it to grow. 450 00:28:28,280 --> 00:28:33,080 Within these tubes are the nutrients that are a fungus's entire future. 451 00:28:33,080 --> 00:28:34,920 And you can see the network forming now. 452 00:28:34,920 --> 00:28:37,120 Yeah, and this is in the centre of the colony. 453 00:28:37,120 --> 00:28:40,200 You have this branched network that keeps on feeding nutrients 454 00:28:40,200 --> 00:28:43,040 through the colony and sharing its water and resources. 455 00:28:43,040 --> 00:28:45,360 And that's only half a millimetre square? 456 00:28:45,360 --> 00:28:47,920 Roughly half a millimetre is the sort of field of view 457 00:28:47,920 --> 00:28:49,120 that we're looking at here 458 00:28:49,120 --> 00:28:50,720 and it's very much like a road network - 459 00:28:50,720 --> 00:28:52,440 we've got these kind of main motorways, 460 00:28:52,440 --> 00:28:54,360 we've got lots of little side routes in there 461 00:28:54,360 --> 00:28:58,560 and we've got flow of nutrients, water and it's very dynamic. 462 00:28:58,560 --> 00:29:00,680 For example, if I was to break one of these tracks, 463 00:29:00,680 --> 00:29:03,560 the fungus would very quickly adapt and form new connections. 464 00:29:03,560 --> 00:29:06,200 And form new connections and new routes. Mmm. 465 00:29:06,200 --> 00:29:08,400 It's extraordinary how bustling it is. 466 00:29:08,400 --> 00:29:11,200 Of course I can now see what we saw with Bryn Dentinger - 467 00:29:11,200 --> 00:29:15,200 how efficient these hyphae are at gathering nutrients 468 00:29:15,200 --> 00:29:16,760 and moving through the soil. 469 00:29:16,760 --> 00:29:19,720 Absolutely, and even in the most dry soil environments, 470 00:29:19,720 --> 00:29:22,600 fungi are able to draw up the moisture from the soil 471 00:29:22,600 --> 00:29:25,760 and transfer it into the plants through this co-operation. 472 00:29:25,760 --> 00:29:28,400 It is extraordinary, extraordinary footage. 473 00:29:30,480 --> 00:29:34,200 Although the mycelium is almost entirely invisible to us, 474 00:29:34,200 --> 00:29:36,880 it makes up the vast majority of the organism. 475 00:29:38,040 --> 00:29:40,440 And its size can be truly breathtaking. 476 00:29:41,600 --> 00:29:44,960 So big, in fact, it can often extend for miles. 477 00:29:48,840 --> 00:29:53,560 The biggest organism in the world is not the blue whale, 478 00:29:53,560 --> 00:30:00,400 but a mycelium that spreads across an incredible 2,384 acres 479 00:30:00,400 --> 00:30:02,720 in Oregon's Blue Mountains. 480 00:30:04,000 --> 00:30:07,600 It's called Armillaria mellea, or the honey fungus, 481 00:30:07,600 --> 00:30:11,440 and this example is thought to be over 2,000 years old. 482 00:30:13,440 --> 00:30:16,960 It's a mind-boggling example of how far a mycelium can grow. 483 00:30:19,320 --> 00:30:24,800 But it also reveals just how destructive a feeding fungus can be. 484 00:30:26,040 --> 00:30:29,040 These are clumps of honey fungus. 485 00:30:29,040 --> 00:30:31,920 It's the same fungus that spread inexorably 486 00:30:31,920 --> 00:30:34,640 through the forests of Oregon 487 00:30:34,640 --> 00:30:38,040 and it demonstrates a very different, some would say sinister, 488 00:30:38,040 --> 00:30:41,160 relationship between mycelium and trees. 489 00:30:44,360 --> 00:30:46,680 Unlike the balanced nutrient exchange 490 00:30:46,680 --> 00:30:50,320 that we see between most fungi and their plant partners, 491 00:30:50,320 --> 00:30:56,160 honey fungus takes much more from its host than it gives. 492 00:30:56,160 --> 00:30:58,920 It consumes all the sugars it needs, 493 00:30:58,920 --> 00:31:01,520 but crucially doesn't give back enough water and nutrients 494 00:31:01,520 --> 00:31:03,280 to help the tree grow properly. 495 00:31:04,840 --> 00:31:08,960 As a result, the greedy mycelium of this fungus thrives, 496 00:31:08,960 --> 00:31:11,400 while the tree slowly weakens. 497 00:31:14,080 --> 00:31:16,680 Honey fungus is a slow killer. 498 00:31:16,680 --> 00:31:20,320 It advances from tree to tree on hidden threads. 499 00:31:20,320 --> 00:31:23,880 As our tree population ages and some sickens, 500 00:31:23,880 --> 00:31:26,960 the rise of honey fungus is inexorable. 501 00:31:30,200 --> 00:31:33,320 But it's not the biggest threat to our plants and trees. 502 00:31:33,320 --> 00:31:37,880 There's another species of fungus whose hunger is even more deadly. 503 00:31:39,560 --> 00:31:42,600 I've come to Norfolk to find evidence of a fungus 504 00:31:42,600 --> 00:31:44,640 that's very difficult to see, 505 00:31:44,640 --> 00:31:46,680 but whose eating habits 506 00:31:46,680 --> 00:31:51,760 are threatening to wipe out one of Britain's oldest trees. 507 00:31:51,760 --> 00:31:55,600 Just a few years ago, a new killer arrived in Britain - 508 00:31:55,600 --> 00:31:56,960 ash dieback disease, 509 00:31:56,960 --> 00:32:00,760 or Chalara fraxinea, to give it its scientific name. 510 00:32:00,760 --> 00:32:03,920 And no fungus better demonstrates 511 00:32:03,920 --> 00:32:06,040 the greed of mycelium for nourishment... 512 00:32:07,560 --> 00:32:10,040 ..and if it has its way, maybe, 513 00:32:10,040 --> 00:32:12,720 magnificent forest trees like this ash 514 00:32:12,720 --> 00:32:14,760 may yet become just a part of history. 515 00:32:19,000 --> 00:32:20,920 David Bole knows all too well 516 00:32:20,920 --> 00:32:23,440 just how destructive this fungus has become. 517 00:32:23,440 --> 00:32:27,080 And there's quite a lot of dieback in here, isn't there? 518 00:32:27,080 --> 00:32:28,360 Yeah. 519 00:32:28,360 --> 00:32:31,760 This is one of the first woods where we discovered it. 520 00:32:31,760 --> 00:32:35,920 What we're finding now is that there's over 500 cases 521 00:32:35,920 --> 00:32:39,960 in the wider environment and as we do more in-depth surveys, 522 00:32:39,960 --> 00:32:42,120 more and more cases are coming to the fore. 523 00:32:42,120 --> 00:32:44,240 Take me through the symptoms. 524 00:32:44,240 --> 00:32:48,080 Well, the first thing to look for is this, the black leaves, 525 00:32:48,080 --> 00:32:49,240 which we've got here 526 00:32:49,240 --> 00:32:53,680 and we've got a really good example on this little, young tree here. 527 00:32:53,680 --> 00:32:55,960 The leaves have died but they're black. 528 00:32:55,960 --> 00:32:59,160 They really don't look healthy and they're hanging onto the tree. 529 00:32:59,160 --> 00:33:01,000 I notice they die from the top too, 530 00:33:01,000 --> 00:33:03,600 so they're dead up here but still green down here. 531 00:33:03,600 --> 00:33:06,120 Yes, you know, it's called dieback and that's a good way 532 00:33:06,120 --> 00:33:08,800 to think of it - we have the tree slowly dying back. 533 00:33:09,920 --> 00:33:14,000 Other symptoms are these diamond-shaped lesions. 534 00:33:14,000 --> 00:33:17,440 The fungus lands on the leaves, the mycelia come in, 535 00:33:17,440 --> 00:33:21,880 and works its way up and down the cells of the tree 536 00:33:21,880 --> 00:33:25,480 and forms these very particular diamond-shaped lesions. 537 00:33:27,760 --> 00:33:31,480 This process is rather eerily called necrotrophy, 538 00:33:31,480 --> 00:33:33,760 which means eating the dead. 539 00:33:33,760 --> 00:33:35,840 The feeding hyphae of ash dieback 540 00:33:35,840 --> 00:33:37,960 attach themselves to their tree hosts 541 00:33:37,960 --> 00:33:40,200 in the same way as other fungi, 542 00:33:40,200 --> 00:33:43,800 but they obtain their sugars without providing any nutrients 543 00:33:43,800 --> 00:33:45,240 or water in return. 544 00:33:47,080 --> 00:33:49,640 It's all one-way traffic 545 00:33:49,640 --> 00:33:51,080 and has a fatal outcome. 546 00:33:53,880 --> 00:33:55,160 OK. 547 00:33:55,160 --> 00:33:57,120 OK, so let's just have a look inside. 548 00:33:58,240 --> 00:34:00,640 Oh, yeah. You can see discolouration. 549 00:34:00,640 --> 00:34:02,560 It's absolutely patent. 550 00:34:02,560 --> 00:34:07,080 So the disease has entered here and this is the fungal mycelia, 551 00:34:07,080 --> 00:34:09,840 which are starting to work its way inside the tree. 552 00:34:09,840 --> 00:34:12,000 The mycelia get inside all the cells 553 00:34:12,000 --> 00:34:14,480 that transport the water up and down the tree 554 00:34:14,480 --> 00:34:16,360 and stop the water transport 555 00:34:16,360 --> 00:34:19,640 and so the tree effectively dies of thirst, if you like. 556 00:34:26,840 --> 00:34:31,080 It's a sad end to one of our most beautiful and elegant forest trees. 557 00:34:31,080 --> 00:34:33,120 It really, really is, yes. 558 00:34:33,120 --> 00:34:35,640 I mean, we'll probably lose a generation of ash 559 00:34:35,640 --> 00:34:37,760 but let's hope we see that coming back. 560 00:34:40,800 --> 00:34:44,400 Ash dieback demonstrates just what happens when the delicate balance 561 00:34:44,400 --> 00:34:47,320 between plant and fungus gets out of kilter... 562 00:34:48,600 --> 00:34:50,920 ..and that's what allows this disease 563 00:34:50,920 --> 00:34:52,600 to spread so far and so fast. 564 00:34:55,600 --> 00:35:00,040 It also shows just what a voracious eater fungal mycelium can be. 565 00:35:01,680 --> 00:35:03,760 But though this unstoppable appetite 566 00:35:03,760 --> 00:35:06,160 can be deadly in the natural world, 567 00:35:06,160 --> 00:35:10,520 some scientists are looking to turn it to our advantage. 568 00:35:25,040 --> 00:35:30,120 This is Eben Bayer, an entrepreneur based in New York. 569 00:35:30,120 --> 00:35:33,160 He noticed something intriguing that happens 570 00:35:33,160 --> 00:35:36,600 when some mycelium spreads out in search of food. 571 00:35:39,680 --> 00:35:42,120 First time I saw mycelium in action was holding 572 00:35:42,120 --> 00:35:44,840 clumps of woodchips together on my family farm 573 00:35:44,840 --> 00:35:46,560 and rather than falling apart, 574 00:35:46,560 --> 00:35:49,880 they'd be held together by these white fibre strands. 575 00:35:49,880 --> 00:35:53,000 One night, sitting at home on my futon in my apartment, 576 00:35:53,000 --> 00:35:56,280 I got this crazy idea about, "Hey, mycelium seems to grow, 577 00:35:56,280 --> 00:35:58,680 "and glue the forest floor together. 578 00:35:58,680 --> 00:36:00,360 "Maybe we can use it as a glue." 579 00:36:03,520 --> 00:36:08,040 Eben saw huge potential in this binding property of mycelium. 580 00:36:08,040 --> 00:36:11,120 He used it to create a new kind of packaging, 581 00:36:11,120 --> 00:36:13,400 one that he believes could, ultimately, 582 00:36:13,400 --> 00:36:16,800 become an eco-friendly alternative to some plastics. 583 00:36:19,280 --> 00:36:22,280 Just in packaging alone, there's like billions of dollars 584 00:36:22,280 --> 00:36:23,960 of Styrofoam used every year, 585 00:36:23,960 --> 00:36:27,800 somewhere between $3.5 and $5 billion of styrene, 586 00:36:27,800 --> 00:36:30,680 and the biggest issue with plastics is at their end of life 587 00:36:30,680 --> 00:36:33,280 and with our material, you get something that, 588 00:36:33,280 --> 00:36:36,040 at the end of its useful life, can be composted, right. 589 00:36:36,040 --> 00:36:39,600 Your packaging becomes a nutrient for your neighbourhood, not a pollutant. 590 00:36:41,600 --> 00:36:45,320 To make his new material, Eben mimics what happens in nature. 591 00:36:46,400 --> 00:36:50,960 He takes some ground corn stalks and seeds them with fungus spores. 592 00:36:50,960 --> 00:36:54,560 The spores germinate, and begin to feed on the stalks, 593 00:36:54,560 --> 00:37:00,240 breaking down and digesting them, so the mycelium can start to grow. 594 00:37:00,240 --> 00:37:03,880 The mixture is then placed inside a mould and left 595 00:37:03,880 --> 00:37:06,600 for the mycelium to perform its biological magic. 596 00:37:08,120 --> 00:37:12,040 So, they'll sit on a rack like this for anywhere from 24 to 72 hours. 597 00:37:12,040 --> 00:37:14,200 It doesn't look like anything's happening, 598 00:37:14,200 --> 00:37:15,960 but the mycelium is already going to work, 599 00:37:15,960 --> 00:37:18,520 growing and extending out from every one of these particles 600 00:37:18,520 --> 00:37:20,440 and building a strong, tough network. 601 00:37:20,440 --> 00:37:23,280 And within 24 hours, this part will look a little white 602 00:37:23,280 --> 00:37:26,240 and that's the mycelium gluing everything together. 603 00:37:32,560 --> 00:37:35,200 So this is a finished corner block. 604 00:37:35,200 --> 00:37:38,000 It's been grown in our production process, it's been moulded 605 00:37:38,000 --> 00:37:41,800 and all of this came from that loosie-goosie agricultural by-product 606 00:37:41,800 --> 00:37:43,000 you saw at the beginning. 607 00:37:43,000 --> 00:37:44,320 Pretty incredible, huh? 608 00:37:49,560 --> 00:37:51,400 What we've done with mycelium here, 609 00:37:51,400 --> 00:37:53,760 which is basically leveraging a living organism 610 00:37:53,760 --> 00:37:55,400 to create really great technology, 611 00:37:55,400 --> 00:37:58,000 is where the excitement is, that's where the innovation is 612 00:37:58,000 --> 00:38:00,840 and that's where the solutions are going to be for the next 100 years. 613 00:38:03,680 --> 00:38:07,840 So the mushroom mycelium could help us tackle the global problem 614 00:38:07,840 --> 00:38:09,560 of plastic waste. 615 00:38:09,560 --> 00:38:12,880 But Eben's work also demonstrates another important trait 616 00:38:12,880 --> 00:38:14,280 of the feeding mycelium. 617 00:38:16,720 --> 00:38:19,720 While some fungi feed on living organisms, 618 00:38:19,720 --> 00:38:23,560 others only eat those that are dead. 619 00:38:23,560 --> 00:38:27,760 These fungi are able to break down and digest organic waste 620 00:38:27,760 --> 00:38:30,480 and in doing so, recycle it. 621 00:38:32,200 --> 00:38:34,720 This process is called saprotrophy 622 00:38:34,720 --> 00:38:38,280 and it's absolutely vital in the natural world. 623 00:38:39,640 --> 00:38:43,280 In this damp wood, the litter of leaves, 624 00:38:43,280 --> 00:38:47,160 indeed, every twig, is being consumed by mycelium, 625 00:38:47,160 --> 00:38:50,320 that breaks down the cellulose and other compounds. 626 00:38:50,320 --> 00:38:51,320 Even... 627 00:38:52,520 --> 00:38:55,160 Even wood can be digested by fungi. 628 00:38:55,160 --> 00:38:58,600 The hard lining that gives the wood its strength 629 00:38:58,600 --> 00:39:03,800 can be consumed and the wood reduced to little more than rubble. 630 00:39:03,800 --> 00:39:07,720 Were it not for the relentless activity of mycelium, in fact, 631 00:39:07,720 --> 00:39:13,800 the whole planet would be covered with a mass of undigested scrub. 632 00:39:17,840 --> 00:39:21,840 It's hard to overstate the importance of saprotrophic fungi. 633 00:39:21,840 --> 00:39:25,720 They have successfully recycled the world's natural waste 634 00:39:25,720 --> 00:39:28,560 for hundreds of millions of years, 635 00:39:28,560 --> 00:39:32,720 making entire ecosystems habitable for animal and plant life. 636 00:39:34,040 --> 00:39:36,360 So how do they achieve this crucial trick? 637 00:39:40,200 --> 00:39:43,120 So, Patrick, let's talk rot. 638 00:39:43,120 --> 00:39:45,240 Few people realise just how important 639 00:39:45,240 --> 00:39:48,520 those saprotropes fungi are in nature. 640 00:39:48,520 --> 00:39:49,920 How does it work? 641 00:39:49,920 --> 00:39:52,160 Well, fungi are really quite invasive. 642 00:39:52,160 --> 00:39:55,600 The fungi have this mycelium, which penetrates deep into the waste 643 00:39:55,600 --> 00:39:57,840 and unlike us, where our stomachs are internal, 644 00:39:57,840 --> 00:40:01,840 the fungi secrete their digestive juices out into the environment 645 00:40:01,840 --> 00:40:05,240 and start breaking down the complex molecules, 646 00:40:05,240 --> 00:40:08,080 things like cellulose, into more simple forms. 647 00:40:08,080 --> 00:40:10,640 This is via a myriad of those little hyphal threads. 648 00:40:10,640 --> 00:40:11,840 That's right. 649 00:40:11,840 --> 00:40:14,880 And to demonstrate just how effective saprotrophic fungi are 650 00:40:14,880 --> 00:40:16,720 at breaking down organic matter, 651 00:40:16,720 --> 00:40:19,760 I've put several days of kitchen waste into this beaker 652 00:40:19,760 --> 00:40:21,680 and I've filmed it over two weeks 653 00:40:21,680 --> 00:40:24,440 to see just how quickly it goes down, it rots down. 654 00:40:25,800 --> 00:40:28,680 SQUELCHING 655 00:40:29,680 --> 00:40:32,320 So there it is, just sort of sinking down. 656 00:40:32,320 --> 00:40:36,160 Yeah. Lots of juice exuding from the vegetables. 657 00:40:36,160 --> 00:40:39,520 So the invisible threads of the mycelium are getting in there, 658 00:40:39,520 --> 00:40:42,440 breaking vegetables and the other organic waste, 659 00:40:42,440 --> 00:40:44,120 into something they can use. 660 00:40:45,960 --> 00:40:47,680 The other important thing to note here 661 00:40:47,680 --> 00:40:50,040 is that when all these vegetables did go into the beaker, 662 00:40:50,040 --> 00:40:52,760 they already had spores on them, so they were already pre-seeded 663 00:40:52,760 --> 00:40:54,960 with the spores. Because spores are everywhere. 664 00:40:54,960 --> 00:40:57,560 Exactly, when you bring the food back from the supermarket, 665 00:40:57,560 --> 00:41:00,960 it'll already have a coating of a whole cocktail of different spores 666 00:41:00,960 --> 00:41:03,760 and as soon as those fungi are in a slightly warm environment, 667 00:41:03,760 --> 00:41:06,160 it becomes quite a feeding frenzy, if you like. 668 00:41:09,920 --> 00:41:13,600 So, Richard, I'm going to show you the results of the one 669 00:41:13,600 --> 00:41:15,240 that I prepared two weeks ago. 670 00:41:17,200 --> 00:41:20,080 Well, it couldn't be much clearer than that. 671 00:41:20,080 --> 00:41:22,840 Yeah. Look how far it's gone down. This was the start point and... 672 00:41:22,840 --> 00:41:24,360 At least a third. 673 00:41:24,360 --> 00:41:27,520 ..it's gone down about a third and I'd expect, within another two weeks, 674 00:41:27,520 --> 00:41:29,240 to be almost to the bottom. 675 00:41:29,240 --> 00:41:31,080 If this process wasn't happening 676 00:41:31,080 --> 00:41:33,400 we would just be surrounded by organic waste matter. 677 00:41:33,400 --> 00:41:35,400 Heaps of vegetables. Exactly. 678 00:41:35,400 --> 00:41:38,760 What it does show is just what makes the fungi 679 00:41:38,760 --> 00:41:43,720 such efficient seekers after... scavengers after nutrition. 680 00:41:43,720 --> 00:41:45,520 Yep. 681 00:41:45,520 --> 00:41:47,680 Extraordinary. 682 00:41:47,680 --> 00:41:51,160 The brilliant way the mycelium of a saprotrophic fungus 683 00:41:51,160 --> 00:41:55,840 uses digestive juices just like humans to break down waste 684 00:41:55,840 --> 00:41:59,320 makes it a recycling machine like no other. 685 00:41:59,320 --> 00:42:02,440 And it doesn't stop there. 686 00:42:02,440 --> 00:42:05,560 For as saprotrophic fungi recycle organic matter, 687 00:42:05,560 --> 00:42:10,040 they're performing a key role in creating healthy soil, 688 00:42:10,040 --> 00:42:15,240 soil that can, in turn, sustain new plant life 689 00:42:15,240 --> 00:42:18,600 and that's also a home for a host of other life forms, 690 00:42:18,600 --> 00:42:21,400 tiny micro-organisms that live within it. 691 00:42:22,520 --> 00:42:24,200 And for some fungi, 692 00:42:24,200 --> 00:42:28,960 the arrival of these new guests is just another feeding opportunity. 693 00:42:30,760 --> 00:42:34,280 These oyster mushrooms, or Pleurotus, 694 00:42:34,280 --> 00:42:38,600 have mycelium that breaks down the wood in rotting logs. 695 00:42:39,920 --> 00:42:41,760 They're quite efficient at doing this, 696 00:42:41,760 --> 00:42:45,680 but they have a shortage of one essential element, nitrogen 697 00:42:45,680 --> 00:42:47,720 and to make good this deficiency, 698 00:42:47,720 --> 00:42:49,520 they've evolved a very special trick. 699 00:42:54,520 --> 00:42:56,800 From the end of some of its hyphae, 700 00:42:56,800 --> 00:42:59,440 the oyster mushroom emits tiny lassos 701 00:42:59,440 --> 00:43:01,880 that secrete a powerful toxin. 702 00:43:01,880 --> 00:43:03,600 And it does this for one reason... 703 00:43:05,400 --> 00:43:07,760 ..nematode worms. 704 00:43:07,760 --> 00:43:10,960 These tiny organisms live within the logs 705 00:43:10,960 --> 00:43:12,520 and happen to be rich in the nitrogen 706 00:43:12,520 --> 00:43:14,560 that the hungry mushroom needs. 707 00:43:15,880 --> 00:43:19,640 The oyster mushroom lures the nematodes towards their tiny lassos 708 00:43:19,640 --> 00:43:21,120 before enveloping them. 709 00:43:22,600 --> 00:43:26,000 Once trapped, it's curtains for the little worm, 710 00:43:26,000 --> 00:43:28,000 and dinner for the mushroom 711 00:43:28,000 --> 00:43:30,520 as it gets the nitrogen-rich fluid it needs. 712 00:43:33,000 --> 00:43:36,840 The oyster mushroom's rather gruesome feeding trick 713 00:43:36,840 --> 00:43:41,480 demonstrates yet again just how sophisticated a fungus can be 714 00:43:41,480 --> 00:43:43,880 when it comes to getting the food it needs. 715 00:43:49,560 --> 00:43:53,600 It's a talent that, once again, we humans are looking to harness. 716 00:43:57,080 --> 00:44:00,480 Over in Washington State, mycologist Paul Stamets 717 00:44:00,480 --> 00:44:03,920 has turned to our hungry friend the oyster mushroom, 718 00:44:03,920 --> 00:44:06,560 in the hope he can use it on a truly grand scale - 719 00:44:06,560 --> 00:44:10,520 to tackle some of our most pressing environmental problems, 720 00:44:10,520 --> 00:44:12,600 such as chemical pollution. 721 00:44:15,920 --> 00:44:20,760 One of my great realisations in life is that habitats have immune systems 722 00:44:20,760 --> 00:44:22,240 just like we do, 723 00:44:22,240 --> 00:44:25,480 but mushrooms are the bridges between the two. 724 00:44:25,480 --> 00:44:29,760 These things unravel and break down large molecules into smaller ones 725 00:44:29,760 --> 00:44:33,040 that are very useful for other members in the ecological community. 726 00:44:34,120 --> 00:44:39,000 The course of that decomposition, has many different properties 727 00:44:39,000 --> 00:44:40,960 that we can use for breaking down toxic waste. 728 00:44:42,560 --> 00:44:44,200 That looks good. 729 00:44:44,200 --> 00:44:46,600 Paul discovered that mushroom mycelium 730 00:44:46,600 --> 00:44:51,160 can break down the hydrocarbons present in much chemical waste. 731 00:44:51,160 --> 00:44:54,240 It's a process he calls bioremediation. 732 00:44:54,240 --> 00:44:57,480 The mushroom is greedily eating the pollutants away. 733 00:45:05,800 --> 00:45:08,080 It looks convincing in the lab, 734 00:45:08,080 --> 00:45:10,480 but does it work in practice? 735 00:45:10,480 --> 00:45:14,440 Paul's theory was recently put to the test on an industrial level 736 00:45:14,440 --> 00:45:17,120 when a heavily-polluted petrochemical site 737 00:45:17,120 --> 00:45:19,640 was seeded with oyster mushroom mycelium. 738 00:45:21,360 --> 00:45:24,080 The work was carried out by environmental engineer 739 00:45:24,080 --> 00:45:25,080 Howard Sprouse. 740 00:45:26,720 --> 00:45:28,880 Yeah, bring her down a little for me. 741 00:45:28,880 --> 00:45:33,160 After just two days, the team found that their polluted pile 742 00:45:33,160 --> 00:45:36,480 had been transformed by the mushroom mycelium 743 00:45:36,480 --> 00:45:38,680 and was now teeming with new life. 744 00:45:40,040 --> 00:45:45,240 Well, this is interesting. We've got lots of worms in here now. 745 00:45:45,240 --> 00:45:46,920 That's a good sign. 746 00:45:46,920 --> 00:45:50,440 If it drops any more, we're going to be able to use this soil anywhere. 747 00:45:52,280 --> 00:45:54,320 The contaminate has gone... 748 00:45:55,480 --> 00:46:00,040 ..the decomposition process that the fungi have started 749 00:46:00,040 --> 00:46:04,200 is continued by other soil microorganisms 750 00:46:04,200 --> 00:46:07,760 and you end up with soil that's richer than it was when you started. 751 00:46:11,640 --> 00:46:14,760 Paul's study shows that oyster mushroom mycelium 752 00:46:14,760 --> 00:46:17,480 can not only digest chemical waste - 753 00:46:17,480 --> 00:46:20,720 it also manages to create an entirely new ecosystem 754 00:46:20,720 --> 00:46:22,880 in the process. 755 00:46:22,880 --> 00:46:27,960 At a time when the Earth is suffering from toxin exposure, 756 00:46:27,960 --> 00:46:32,680 erosion of habitats, overpopulation, 757 00:46:32,680 --> 00:46:35,960 deforestation, loss of soil integrity... 758 00:46:37,640 --> 00:46:41,920 ..mushrooms present themselves with unique properties 759 00:46:41,920 --> 00:46:46,520 that can address all those problems with a single group, 760 00:46:46,520 --> 00:46:48,720 and that's what I find so exciting - 761 00:46:48,720 --> 00:46:51,360 that the solutions are literally underfoot. 762 00:46:55,240 --> 00:46:57,440 Paul's work shows just how great 763 00:46:57,440 --> 00:46:59,800 the potential of fungus mycelium might be. 764 00:47:01,720 --> 00:47:05,920 Its hidden underground threads act upon their natural environment 765 00:47:05,920 --> 00:47:09,680 in truly remarkable ways we are only now beginning to realise. 766 00:47:12,320 --> 00:47:14,320 But as vital as it could be to us, 767 00:47:14,320 --> 00:47:17,640 the mycelium's feeding quest has one simple goal... 768 00:47:19,680 --> 00:47:21,600 ..to produce its fruiting body... 769 00:47:22,840 --> 00:47:26,080 ..bringing the organism to the end of its life cycle. 770 00:47:31,400 --> 00:47:35,600 We've seen how mycelium can form complex feeding webs 771 00:47:35,600 --> 00:47:39,200 and how the mycelium underpins so many of Earth's ecosystems... 772 00:47:40,840 --> 00:47:44,600 ..yet that mycelium itself has only one purpose... 773 00:47:45,920 --> 00:47:51,960 ..to fulfil its own life cycle and to lead once again to the mushroom. 774 00:48:00,040 --> 00:48:04,200 For the fungus, this final stage simply means reproduction 775 00:48:04,200 --> 00:48:06,400 and the dispersal of billions of spores. 776 00:48:07,560 --> 00:48:09,440 'But for another species, 777 00:48:09,440 --> 00:48:12,560 'it's just the beginning of its relationship with fungi.' 778 00:48:12,560 --> 00:48:13,880 Nice find. 779 00:48:13,880 --> 00:48:16,240 'And that species is us.' 780 00:48:16,240 --> 00:48:17,520 Ah. 781 00:48:17,520 --> 00:48:19,520 The sulphur tuft. 782 00:48:19,520 --> 00:48:20,480 Very abundant. 783 00:48:21,560 --> 00:48:23,800 Very inedible. 784 00:48:23,800 --> 00:48:26,440 'Its mythical status in folklore and magic 785 00:48:26,440 --> 00:48:31,120 'has made the mushroom an object of both fascination and fear.' 786 00:48:31,120 --> 00:48:33,560 Well, now, this is a troublemaker. 787 00:48:34,640 --> 00:48:37,520 'And sometimes that fear can be for good reason.' 788 00:48:38,880 --> 00:48:43,120 Poison pie is, as its name suggests, not a good thing to eat. 789 00:48:46,400 --> 00:48:47,960 Go out into any woodland 790 00:48:47,960 --> 00:48:51,920 and you're likely to encounter a wide range of poisonous fungi 791 00:48:51,920 --> 00:48:55,280 that you certainly would not want on your dinner plate. 792 00:48:55,280 --> 00:48:58,200 People get a big nervous about this one... 793 00:48:58,200 --> 00:48:59,920 the Sickener. 794 00:48:59,920 --> 00:49:02,680 Well, the name tells you everything. You don't want to eat it. 795 00:49:05,440 --> 00:49:07,880 The notion that fungi can be poisonous 796 00:49:07,880 --> 00:49:09,920 is what frightens us most about them. 797 00:49:13,760 --> 00:49:17,920 This is the most poisonous mushroom known to man. 798 00:49:17,920 --> 00:49:19,480 It's the death cap. 799 00:49:19,480 --> 00:49:22,400 People have eaten it, apparently in mistake for a field mushroom. 800 00:49:22,400 --> 00:49:24,160 I can't think how. 801 00:49:24,160 --> 00:49:28,520 But they'd have cause to regret it, because half a cap of one of these 802 00:49:28,520 --> 00:49:31,200 is enough to kill a grown man, 803 00:49:31,200 --> 00:49:32,960 and slowly, 804 00:49:32,960 --> 00:49:34,080 and painfully. 805 00:49:39,000 --> 00:49:41,200 I've been a field mycologist for many years 806 00:49:41,200 --> 00:49:45,600 and know to avoid dangerous mushrooms like the death cap, 807 00:49:45,600 --> 00:49:49,840 but their toxicity does raise an interesting question - 808 00:49:49,840 --> 00:49:52,800 what is it that gives mushrooms the power to kill? 809 00:49:54,600 --> 00:49:57,760 To explore this, I've come back to the lab once final time. 810 00:49:59,360 --> 00:50:03,720 Every fungus will have a cocktail of different chemicals within it, 811 00:50:03,720 --> 00:50:06,800 and depending on what type it is, there's various different types 812 00:50:06,800 --> 00:50:10,360 of poisonous chemicals which are present in these mushrooms. 813 00:50:10,360 --> 00:50:14,320 Possibly one of the worst ones is something like the destroying angel. 814 00:50:14,320 --> 00:50:16,440 Or the death cap, which is its close relative. 815 00:50:16,440 --> 00:50:20,200 Or the death cap, and those have a substance called amatoxins, 816 00:50:20,200 --> 00:50:22,680 which are deadly toxic. 817 00:50:22,680 --> 00:50:26,280 You'd only have to eat one or two of these to be completely poisoned. 818 00:50:26,280 --> 00:50:29,800 You'll end up with liver failure, kidney failure and death 819 00:50:29,800 --> 00:50:33,040 and it's a really quite nasty way to go. 820 00:50:33,040 --> 00:50:37,480 So we know that mushrooms are toxic, but why are they toxic? 821 00:50:37,480 --> 00:50:40,920 Well, there's a theory that mushrooms evolved to become toxic 822 00:50:40,920 --> 00:50:43,960 in order to discourage predators from eating them, 823 00:50:43,960 --> 00:50:46,200 but I'm not sure that's exactly the case, 824 00:50:46,200 --> 00:50:50,280 so I've set up a little test with a selection of mushrooms 825 00:50:50,280 --> 00:50:52,960 and we've brought in a guest to do the test for us. 826 00:50:56,200 --> 00:51:00,400 Patrick has offered a selection of five mushrooms to a hungry slug, 827 00:51:00,400 --> 00:51:03,200 one of which is poisonous to humans. 828 00:51:03,200 --> 00:51:04,480 But which will it prefer? 829 00:51:06,400 --> 00:51:08,720 After a look around and having a nibble of one or two, 830 00:51:08,720 --> 00:51:10,720 he seems to have settled on this one. 831 00:51:10,720 --> 00:51:14,040 Oh, the sulphur tuft, which is famously bitter and poisonous. 832 00:51:14,040 --> 00:51:16,120 Yeah, it doesn't seem to bother the slug 833 00:51:16,120 --> 00:51:19,960 and, in fact, he seems to be having a tasty meal on the gills, there. 834 00:51:19,960 --> 00:51:23,440 So what we've seen is certainly not in support of the idea 835 00:51:23,440 --> 00:51:26,320 that fungi are kind of protecting themselves from being eaten 836 00:51:26,320 --> 00:51:29,880 until mature. In fact, you could argue that that mushroom 837 00:51:29,880 --> 00:51:32,160 actually wants to be eaten, 838 00:51:32,160 --> 00:51:34,760 so what's it all about? 839 00:51:34,760 --> 00:51:36,520 I think, really, the bigger picture 840 00:51:36,520 --> 00:51:38,800 is the diversity within the fungal kingdom, 841 00:51:38,800 --> 00:51:42,400 in that the fungi produce thousands of different chemicals 842 00:51:42,400 --> 00:51:45,320 and it just so happens that some of those are toxic to us, 843 00:51:45,320 --> 00:51:48,520 whereas they might not be toxic to something like a slug or an insect. 844 00:51:48,520 --> 00:51:51,880 In fact, it may be a very important food source for those animals. 845 00:51:51,880 --> 00:51:55,360 So you've just got a huge spectrum of different types of chemicals. 846 00:51:55,360 --> 00:51:57,320 And we're only just beginning to explore 847 00:51:57,320 --> 00:51:59,560 the implications of some of these. Absolutely. 848 00:52:02,960 --> 00:52:05,400 We don't yet fully understand why some fungi 849 00:52:05,400 --> 00:52:08,040 have such a potent effect on us. 850 00:52:08,040 --> 00:52:09,440 More research is needed. 851 00:52:11,280 --> 00:52:13,360 But, already, we're beginning to exploit 852 00:52:13,360 --> 00:52:17,600 some of their seemingly sinister behaviours for our own benefit. 853 00:52:18,880 --> 00:52:21,280 Can I introduce you to cordyceps? 854 00:52:21,280 --> 00:52:24,560 These are dried specimens of a very famous fungus, 855 00:52:24,560 --> 00:52:28,600 famous in Chinese medicine for curing all manner of ills. 856 00:52:28,600 --> 00:52:32,160 It's a curious fungus with a strange, parasitic lifestyle. 857 00:52:35,880 --> 00:52:39,320 Unlike most fungi, it doesn't feed on dead matter 858 00:52:39,320 --> 00:52:41,880 but instead seeks out a very different host. 859 00:52:43,840 --> 00:52:46,600 Like something out of science fiction, 860 00:52:46,600 --> 00:52:49,920 this fungus grows inside insects, 861 00:52:49,920 --> 00:52:53,680 slowly killing them until the fruiting body is ready to emerge. 862 00:53:01,680 --> 00:53:05,680 But despite its rather, alien life habits, 863 00:53:05,680 --> 00:53:08,400 the chemicals concealed inside the cordyceps 864 00:53:08,400 --> 00:53:11,600 may yet prove crucial to a major medical breakthrough. 865 00:53:15,120 --> 00:53:18,800 Doctor Cornelia De Moor from the University of Nottingham 866 00:53:18,800 --> 00:53:22,080 is using this little mushroom in a cutting-edge treatment 867 00:53:22,080 --> 00:53:24,440 for one of our most feared diseases - 868 00:53:24,440 --> 00:53:25,920 cancer. 869 00:53:29,080 --> 00:53:34,600 So in cordyceps there are very high levels of this cordycepin. 870 00:53:35,600 --> 00:53:37,160 And cordycepin is a compound 871 00:53:37,160 --> 00:53:39,200 that is actually only very slightly changed 872 00:53:39,200 --> 00:53:43,280 from a very common compound that you find in all cells called adenosine. 873 00:53:43,280 --> 00:53:45,760 It's only one oxygen difference. 874 00:53:45,760 --> 00:53:48,960 But for some reason, only cordyceps fungi make cordycepin 875 00:53:48,960 --> 00:53:51,640 while all organisms make adenosine. 876 00:53:53,600 --> 00:53:58,240 This unique compound produced by cordyceps has long been of interest 877 00:53:58,240 --> 00:54:02,440 to alternative medicine in the treatment of cancerous tumours. 878 00:54:02,440 --> 00:54:07,080 But how it worked was never clear and Cornelia was keen to find out. 879 00:54:10,320 --> 00:54:13,880 What surprised us immensely the first time we treated cells 880 00:54:13,880 --> 00:54:17,680 with cordycepin is when we put cordycepin on cells like that, 881 00:54:17,680 --> 00:54:21,240 they changed shape into cells like that 882 00:54:21,240 --> 00:54:26,640 in which the little grains are gone and the cells start to shrink. 883 00:54:26,640 --> 00:54:28,320 So when we saw this, 884 00:54:28,320 --> 00:54:32,120 we knew there was something quite fundamental happening to the cells 885 00:54:32,120 --> 00:54:35,040 and that then led to our later discoveries 886 00:54:35,040 --> 00:54:36,600 on the affects of cordycepin. 887 00:54:41,720 --> 00:54:43,920 Cornelia knew that with any cancer, 888 00:54:43,920 --> 00:54:47,320 in order for the individual cells to multiply and grow, 889 00:54:47,320 --> 00:54:49,280 they must join themselves together 890 00:54:49,280 --> 00:54:53,640 using tiny stems called poly-A tails. 891 00:54:53,640 --> 00:54:56,640 And it's here that she has discovered that cordycepin 892 00:54:56,640 --> 00:54:57,960 plays a crucial role. 893 00:54:59,640 --> 00:55:02,760 So we've been doing some work on breast cancer cells, 894 00:55:02,760 --> 00:55:05,240 which we've been treating with cordycepin, 895 00:55:05,240 --> 00:55:08,720 and what we're seeing is that the cordycepin appears to stop 896 00:55:08,720 --> 00:55:11,080 the making of the long poly-A tail. 897 00:55:11,080 --> 00:55:13,120 So it might not kill the cell 898 00:55:13,120 --> 00:55:17,960 but the most important thing - it stops the growth of the cancer cell, 899 00:55:17,960 --> 00:55:21,800 by cutting off the machinery that is necessary for cell growth. 900 00:55:23,400 --> 00:55:26,520 It is a completely new mechanism for a cancer drug, 901 00:55:26,520 --> 00:55:30,520 so all other cancer drugs work on completely different principles, 902 00:55:30,520 --> 00:55:33,160 not on inhibiting this polyadenylation, 903 00:55:33,160 --> 00:55:36,480 so it could be the first of a new class of drugs, 904 00:55:36,480 --> 00:55:39,640 not only for cancer, but also for inflammatory diseases. 905 00:55:42,560 --> 00:55:45,640 Medical breakthroughs, from Fleming's penicillin 906 00:55:45,640 --> 00:55:49,920 to cutting edge cancer research, reveal an extraordinary truth. 907 00:55:50,960 --> 00:55:53,520 The cells of fungi have the ability 908 00:55:53,520 --> 00:55:56,840 to interact with our own cells on a profound level... 909 00:55:59,680 --> 00:56:03,600 ..to alter them in ways that affect our health, even our survival. 910 00:56:05,920 --> 00:56:07,480 And this is a powerful clue 911 00:56:07,480 --> 00:56:12,040 to the true relationship between fungi and us. 912 00:56:12,040 --> 00:56:15,680 Time and again, we seem to discover deep biological connections 913 00:56:15,680 --> 00:56:18,160 between ourselves and the fungi. 914 00:56:19,360 --> 00:56:21,960 But what could we have in common with a mushroom? 915 00:56:23,440 --> 00:56:26,080 To find out the answer, we have to delve deep 916 00:56:26,080 --> 00:56:28,240 into our own evolutionary history. 917 00:56:30,920 --> 00:56:35,360 As we've seen, fungi are neither plant nor animal. 918 00:56:35,360 --> 00:56:37,440 Early in the story of life on Earth, 919 00:56:37,440 --> 00:56:42,640 they established themselves as a kingdom in their own right. 920 00:56:42,640 --> 00:56:46,240 But it's the moment when this happened that is truly significant. 921 00:56:48,400 --> 00:56:51,840 At the point when plants and animals diverged, 922 00:56:51,840 --> 00:56:54,440 the fungi were still part of that animal branch. 923 00:56:56,280 --> 00:56:58,960 It was not until about ten million years later 924 00:56:58,960 --> 00:57:01,360 that they began their own evolutionary journey 925 00:57:01,360 --> 00:57:02,800 as a distinct kingdom. 926 00:57:03,880 --> 00:57:08,760 This explains why they have retained a number of key biological traits 927 00:57:08,760 --> 00:57:12,600 that make them much more animal than plant, much more like us. 928 00:57:16,000 --> 00:57:18,680 Traits we've seen time and time again, 929 00:57:18,680 --> 00:57:21,400 as we've explored their fascinating life cycle... 930 00:57:22,720 --> 00:57:26,000 ..from the explosive way that they release their spores... 931 00:57:27,480 --> 00:57:32,120 ..to the way they feed and digest other organisms, much as we do. 932 00:57:33,280 --> 00:57:34,920 At every stage of their life, 933 00:57:34,920 --> 00:57:38,560 fungi reveal just how much like us they are. 934 00:57:38,560 --> 00:57:42,000 It's a powerful connection, that explains why we work 935 00:57:42,000 --> 00:57:43,640 so well together. 936 00:57:43,640 --> 00:57:47,880 So we are all much more mushroom than you could ever imagine. 937 00:57:49,040 --> 00:57:53,360 And because of this close affinity, sometimes the fungi work with us, 938 00:57:53,360 --> 00:57:55,400 and even sometimes against us... 939 00:57:56,600 --> 00:58:00,200 ..and that is the true magic of mushrooms.