The Hidden World of Plants: Survival & Evolution | SLICE SCIENCE | FULL DOC

In their fight for survival, plants reveal sophisticated and sometimes Machiavellian strategies. In case of attack, they can massively deploy chemical weapons. They form alliances with a multitude of species or manipulate others, such as insects and birds. In the unceasing battle between those that eat and those that get eaten, plants have incredibly creative resources which have inspired many films. They poison, fake and create fear. Plants aren't what you might think. Seen up close and even very, very close, nature takes on a whole other dimension. Our eye only sees the outlines of plants, a branch with leaves, a flower, the silhouettes of trees. If we could look much closer and go into that intimate space, we would discover a disturbing, stunning complexity. This green chaos, covered with what looks like the eyes of snails, is in reality the surface of the leaf of an ordinary tree, enlarged hundreds of times through digital 3D microscopes. Today, scientific imagery enables us to see plants like never before, and we find, in awe, that the world of plants remains largely a mystery to us. Our world, and that of plants, is one of never-ending change, sometimes brutal. For plants, responding correctly to the signals of the environment is a question of life and death. This happens right from the beginning. Take a seed. It must be able to interpret temperature variations, or the plant may never come to life. Nature sends seeds a host of signals, sometimes contradictory. In the heart of winter, a few days exceptionally warm and sunny might let it believe it is the start of spring. If the seed was just a mechanism with no flexibility, it would be taken by surprise with such mistaken signals. In reality, it is rare that premature growth is killed by the cold. How is it that most seeds resist the temptation to sprout during a series of warm winter days? At the University of Birmingham, George Bassel is studying how, and under what conditions, the seed of thalecress, a star plant in laboratories, germinates and decides when the moment has come to push its sprout out of its protective shell to start the adventure of life. To make its decision, does the seed rely on the equivalent of an internal meteorological station giving a reliable forecast of upcoming good weather? Typically in a plant, decisions are reached broadly across the body of the plant. And unusually in the case of the seed, there is a small subset of cells within the root tip that are deciding whether or not to germinate. This small subset of cells that we call the decision-making center. When the weather is getting warmer, the decision center of the seed, colored in red here, is on permanent alert. The seeds are receiving many signals from the environment and they have to condense all of these signals into a single decision. Do I germinate or do I not? So the solution seeds have found is to produce two hormones. One, which is the sleeping-promoting, dormancy-promoting hormone, abscisic acid. And the other one, which is the awakening, germination-promoting hormone, gibberellic acid. So you have these two hormones and the seed has an antagonism, a fight between the two. And whichever one is the dominant one is making the decision for the seed. The cells of the decision center are on the outer edge of the seed, here colored in blue, and sensitive to cold. As long as the young sprouts risk freezing, these cells secrete sleep hormones and the seed stays dormant. When the ground gets warmer, the peripheral cells stay passive, while the interior cells at the center produce growth hormones, here colored in orange, which push the seed to wake up. Contradictory signals, grow, don't grow, can succeed each other for days on end without any action until the growth hormone is durably predominant and the sprout will form. Some seeds need unpredictable and cataclysmic events in order to germinate. We now know the molecule produced by smoke is perceived by seeds, and we also know that this molecule is leading to the stimulation of the germination-promoting hormone, gibberellic acid, causing the seeds to wake up. Many indigenous peoples have known about the dynamics of fire for thousands of years. They like controlled burn-offs, which give a boost to nature. Australian aborigines periodically burn specific land. The fire cleans the ground and the seeds of 30 or so species of plant, quietly waiting for the signal, immediately spring to life. And another benefit is having had that plant material be burned, there will be more nutrients in the soil for the plant to then grow. In some climates, seeds wait silently for the right conditions to sprout, and they can wait for a long time, a very long time. The ability of a seed to stay dormant and not germinate depends upon how long it can stay alive. So a seed could stay dormant for a year, five years, even 5,000 years is possible. Recently, we have an example of a 32,000-year-old seed coming back to life. The only limiting factor is whether or not the seed is able to stay alive. So within the soil, the seed is in fact still alive, it is still breathing, albeit at a very, very low rate, you can imagine like a hibernation. Tough, able to patiently wait centuries for a fleeting moment, sorting out the true from the false. Are seeds intelligent? I don't believe seeds are geniuses. Plants are receiving signals from the environment and performing computations, not unlike a computer might do, and performing logical operations in order to make their decisions. So I look at a plant more like a computer than I do a genius. If seeds aren't, strictly speaking, intelligent, they are logical. Evolution has given them extraordinarily ingenious systems to extend their field and colonise new territory. For plants to produce their seeds, they have first to be fertilised by pollen. Evolution has found extraordinary solutions. These red capsules are fern pollen, highly magnified by an electronic microscope. Pollen is male seed, equivalent to mammal spermatoza. Since ferns are immobile, miniscule arms catapult their pollen into the air. They drift on the wind and fertilise other ferns, which can be far away. To avoid rapid dehydration and death during their trip towards the plant they will fertilise, these organisms, although microscopic, fold in upon themselves like origami. The folds and furrows form a shell, which retains the water they need to arrive at their destination alive. During spring flowering, pollen forms clouds of dust which carry and spread life. Being sedentary is a constraint, but it hasn't stopped plants from invading all land where life is possible. How can they reproduce and mingle their genes to avoid degeneration when they are rooted down? Many take advantage of those who can move freely. Insects, birds, mammals and all of those we call pollinators. But for a pollinator to go from one flower to another, it needs some kind of motivation. To attract the key holders of their lives, plants deploy resources that are extraordinarily diverse. Some flowers have flamboyant colours. Others release irresistible perfumes. Yet others produce delicious nectars. And it works. As soon as the flowers open, pollinators mass in numbers, loaded with the fertilising pollen harvested on other flowers of the same species. Orchards don't risk sending their pollen into the air. The ophrys displays the colours, forms and even the scent of female bees. It is so convincing in its disguise that male bees believe it and copulate with the flower, thinking they are copulating with females of their own species. Since they are covered with the pollen of other ophrys that they have visited shortly before, the male bees rarely fertilise, but they fertilise a flower and not an insect. To resolve complex problems, some plants, such as wild tobacco, don't just use one pollinator, but two species, which come one after the other, according to the state of the plant. The unexpected twists and turns of the pollination of wild tobacco attracted the attention of the researchers at the Max Planck Institute in Germany. For his research, Ian Baldwin cultivates plants that originally come from tropical American regions. Wild tobacco is pollinated by a specific pollinator. This moth visits the flowers at night and nectars on those flowers. But when it nectars, it also lays an egg, and that egg turns into a voracious caterpillar that devours the plant. Our research has been focused on trying to understand how the plant solves this difficult dilemma of having both a good guy and a bad guy as its interactor. Tobacco flowers open at the end of the day. They point their aromatic petals towards the sky to attract moths called tobacco moths or hawk moths. The precise placing of the flower petals allows the long horn of pollinators easy access to the sugary pistils. During the visit, the horn of the hawk moth is loaded with pollen. Ah, Danny looks like they're ready for a good night of pollinations. Ian and Danny are raising hawk moths. At sunset, they watch the behavior of the moths in the greenhouse where the tobacco plots are in flower. When the horn of the hawk moth slides into the petals to siphon off the nectar, it leaves grains of pollen harvested in visits to other tobacco flowers. The flower is fertilized, but instead of leaving, the moth sits on one of the leaves of the tobacco plant and lays eggs. Ian has counted up to a dozen eggs on each leaf of some of the plants available to the moths from his breed. With the hawk moth, wild tobacco has an efficient pollinator. Unfortunately, the eggs turn into voracious caterpillars which immediately devour the very plant that fed their parent. The black growth on their back has led to their nickname of horned caterpillars. Strangely, these very hungry caterpillars don't seem to suffer from the poisonous nicotine in the tobacco leaves. They double in weight each day. Everything is eaten, even the flowers. The scientists consider the plant endangered after a week of constant attack by the caterpillars and when 20% of the plant's leaf surface is damaged. If danger is present, the wild tobacco plant dramatically changes its behavior. The flowers open by day instead of at night. When the hawk moth makes its nightly rounds, the flowers are now closed. The moth leaves without drinking the nectar and without laying eggs. A second step moves into action, just as surprising as the first. Wild tobacco finds a replacement for the rude moth, the elegant hummingbird. The logic is, if it can switch to the hummingbird, why doesn't it always stay with the hummingbird? Because the hummingbird doesn't lay caterpillar eggs, it lays hummingbird eggs. And the hummingbird eggs don't hatch into caterpillars that eat the plant. Wild tobacco takes its chances with the dangers of the hawk moth because the moth offers something that the inoffensive hummingbird doesn't offer. Hummingbirds fly in short distances and only bring in pollen from a small number of plants nearby. The hawk moth, it's like a frequent flyer. It flies 500 kilometers a night. It can pick up pollen from all over the western United States and bring in pollen mixtures that are diverse. Wild tobacco risks being eaten to death to take advantage of a genetic pool that ensures its strength. This risk-benefit evaluation proves that some plants take the long term into account. Plants are a banquet for many species, from the microscopic aphid to the tallest giraffe. How to defend against these hordes of teeth, jaws and beaks that are constantly trying to eat them? Evolution has equipped plants with all sorts of defensive weapons, from the most basic to the most sophisticated. These fine growths, which spring from different parts of the plant and look like hairs, are called trichomes. Some trichomes form an impassable barrier. Highly dense, they prevent pathogenic microorganisms from gaining access to vulnerable parts of the plant. Other trichomes, like those that cover the leaves of beans, are like planks full of nails for adventurous attackers to impale themselves upon. Cannabis trichomes have a ball-shaped head, which contains a repulsive substance for unwanted visitors. The thorns of the acacia discourage large grazing animals by inflicting painful wounds to the lips and mouth. For the acacia, the problem is that giraffes and kudu don't care about the razor-sharp thorns. When a kudu or a giraffe comes to graze on it, the acacia develops a defense in depth which is even more surprising and efficient than the thorns. Its leaves release ethylene, a volatile gas that immediately triggers the production of tannin, not just by the acacia which has been attacked, but also by neighboring trees. Tannin is a chemical compound that drives off pathogenic microbes and upsets the herbivores. Kudu and giraffes can't take it and go elsewhere to graze. How does the acacia know if a giraffe or kudu attacks its leaves? Recent scientific studies have revealed that any wound to the plant triggers an electric signal, as we can see in this exceptional sequence filmed at very high speed. The speed of propagation of the signal is approximately 6 centimeters a minute, far below that of humankind, where the speed can reach 80 meters a second. It may seem surprising, but plants and humans share a neurotransmitter, glutamate. Plants are different to us, they don't have a nervous system, they don't have nerves. But in common with us, they produce glutamate and plants produce that molecule and others when they're bitten by caterpillars and other insects. The glutamate and other molecules activate electrical signals that travel through the veins of the leaf, from one leaf to the other. More surprisingly, the plant can identify which type of attacker is at work. The alert reaction is far more intense if the leaves are eaten by a caterpillar than if they are cut by a blade or ripped by a tool. The secret of this distinction is that plants react to the saliva. If the alert is stronger, it's because the plant has been taught by evolution that ravaging caterpillars are many and forever hungry. Edward Farmer is studying the function of electric signals emitted by plants under attack by a predator. He places electrodes on the leaves of Thalecress, whose scientific name is Arabidopsis thaliana. We use Arabidopsis in our laboratory because it grows very quickly and we can share what we learn in Arabidopsis with hundreds of other laboratories throughout the world. Under attack, Thalecress undergoes stress, which in turn triggers its defence system. Detailed understanding of the electrical activity of an injured Thalecress will help us understand its defence system. Edward Farmer needs an agent that will measure electrical activity in the plant's cells and that agent will be a common aphid. The researcher will transform the aphid into a living mobile electrode. To do this, he attaches a very thin copper wire to its back. Put the electrode on. Very good. Up a bit. And the aphid becomes a guinea pig. Move it up a little bit. More on top of the insect. Over it. Yeah, yeah. Good. That's it. There we see it. Yeah, yeah, yeah. That's good. An earthing wire is buried in the pot. When the connected aphid perforates the leaf cells, the aphid will transmit the electrical signals of the plant. These are captured by the copper wire attached to the aphid. The ordinary electrical activity of the plant appears clearly. OK, Jing, the aphid's feeding on plant number one. It looks really good. We can go ahead and inflict the wound. This is where the experiment really begins. The plant reacts to its wound by sending an electric signal. This is the peak on the recording. This signal spreads to other leaves of the plant and this triggers the secretion of a hormone known as jasminite. When an insect bites a leaf and glutamate is made, electrical signals travel to the other leaf and they cause the other leaf to produce a hormone called jasminite. The hormone is active, the plant becomes defended, the leaf is no longer digestible, insects can't eat it and they leave. Jasminite is more concentrated at the plant's centre, where new tender leaves are formed. These are more attractive for insects and need higher levels of protection. A priority because they ensure the plant's growth. Levels of jasminite are lower further out from the centre of the plant. The older leaves are less crucial for the plant. Comparing two groups of thalecress confirms the role of jasminite in the plant's defence system. So these plants here are normal, wild-type plants, perfectly capable of defending themselves. They make jasminite, they have been attacked by insects, but they're not being eaten quickly. In this box here, these plants have been mutated, they lack the ability to make jasminite and they've been badly damaged. Jasminite secreted due to an attack triggers the production of a bitter taste and unbearable odours for ravaging insects. This flood of aromas is not unsimilar to what grass exhales when being mowed. Who would have thought, before the recent research of Ted Turling revealed it, that good old country sweet corn also uses chemical defences, but not to repel its aggressors. When threatened, our familiar corn is so Machiavellian that its sense shivers up your spine and has inspired writers of horror and science fiction movies. Corn is regularly attacked by Spodoptera, the caterpillar of a moth that is invasive and never stops eating. Spodoptera has a predator, a little wasp called Euplectrus, whose fragile appearance hides a killer with horrifying methods. Corn knows this and when Spodoptera attacks it, calls the killer. In the blink of an eye, the wasp injects a droplet of eggs into the caterpillar's body. The eggs quickly hatch and give birth to larvae which grow by devouring the Spodoptera from the inside out. In space, no one can hear you scream, says one of the characters in the movie, Alien. Here, the wasp answers the call of the corn. When we started this research, we thought that what would be the faeces of the caterpillars that is attracting these parasitic wasps. But when we started looking at this in more detail, we found that it's actually the plants that are actively starting to produce volatile compounds that form an odour that is very attractive to these parasitic wasps. It takes a few hours for the attacked corn to produce and liberate in the surrounding air these wasp-attracting scents. Neighbours to the plant under attack perceive the warning signal. In turn, they reproduce it and the signal travels to the wasps lying in ambush. These olfactive signals target caterpillars with the precision of a GPS. Smaller plants are most vulnerable to these caterpillars. In fact, one caterpillar can completely destroy and kill one plant. So that's why the smaller plants will benefit the most from these signals. Small plants emit many more compounds, much larger quantities of these compounds than larger plants. To test the efficiency of this defence system, corn has been genetically modified to not react when attacked by caterpillars. The result is spectacular. The field of corn that cannot call the wasps for help is eaten right down to its roots. Plants release volatile compounds specific to each pest that attacks them. And surprisingly, these airborne molecules also attract the specific predator for that pest. In this way, plants can count on wasps, but also on ladybirds and bugs which swallow up aphids in large quantities. The more and more that we start to understand the language of plants, each different insect induces a different response in the plant, a different bouquet of volatiles. That means that there's sort of an odorous fingerprint that we can tap into. We should be able to develop sensors that can then perceive these odours and tell us what is going on with the plant. Ted Terling's team has developed an artificial nose which identifies the principal airborne substances released by plants under attack. This prototype will be improved and reduced in size before practical field use. We hope that eventually we can put on robots that then go through the field smelling the plants and tell a farmer which plant is under attack by a caterpillar. The fight between plants and their pests is like a never-ending series. In the game of if you attack me, I'll call your enemy who will kill you, other insects have found surprisingly unusual answers. In this way, Ted Terling's and a Chinese team have recently discovered that little white flies, the aureoles, can alter the message sent by the plants they attack. It's one of those amazing adaptations in insects that allow them to circumvent the defences of plants by making the plant think that they're under attack by something else. The alert message that they send out suggests that they're under attack by a pathogen and not by an insect. And that's why the neighbouring plant will start defending itself against the pathogen and not against white flies. White flies may seem insignificant at first sight but they attack and damage over 600 different species of plants. So this is what they call the co-evolutionary arms race between plants and insects. And obviously, in this particular case, the insects are ahead of the game. But we can expect that certain plants have already adapted to that and they launched the right defence. We haven't discovered that yet. Or that in the future, in nature, the plants that are now being fooled will have evolved different mechanisms to launch the correct defences against white flies as well. It's an intense game of chess played out between plants and insects. What's at stake is species survival. Each partner being constantly forced to evolve and adapt by diversifying and improving their tactics. It's well known that birds use trees. They serve as ladders, hiding places for lovemaking and for nesting. But it's far well less known that trees also use birds. As corn calls in killer wasps for help, trees infested by colonies of caterpillars call birds to their aid. When the leaf is fully developed, they're attacked by caterpillars that are already quite large. Birds are attracted in search of food. At this moment, the large caterpillars are an important source of nutrition. But we're in a slightly different context. We're studying a lot earlier in time, at a stage when the caterpillars have only just hatched. They've started to eat the bud from the inside. The freshly hatched caterpillars are less than a millimetre long. The tree must have extremely good senses to detect their presence and send out a warning signal. Samuel Caro has built an aviary in a Y shape. At the end of one of the corridors, he places a healthy young oak tree. On the other corridor, he places a young oak tree on which he releases 20 just-hatched caterpillars. The two trees are hidden by a white cover so they cannot be seen. Samuel places a bird in the nesting platform of the third corridor of the aviary and actions the fans which send the airborne compounds produced by the two trees toward the bird. Off you go, hop! The bird takes flight and chooses one of the two trees. Samuel Caro repeats the experiment a hundred times and almost all the birds fly blindly to the oak infested with caterpillars. This isn't pure chance. The infested tree is secreting chemical compounds that signal to the birds that it has food. These micro scents attract the birds to zones where there is a future abundance of caterpillars. They are more prone to build their nests in the area and reproduce more, reproduce earlier, lay more eggs and in that way act as a pressure on the caterpillars and get rid of the predators for this tree. By encouraging the birds to move into the neighborhood the oaks ensure long-term protection. With each invasion, the buds produce an aromatic call and the birds fly in. Samuel Caro has synthesized the airborne compounds released by the infected oak buds. We took this aromatic bouquet into the wild spreading it about the nesting zones where the birds might reproduce and we saw that in total there were more eggs laid in the zones with artificial aromas no doubt because they thought there would be a large amount of food two, three or four weeks later. For a long time science didn't know about the complex links and signals that plants have between each other but also with insects, birds and perhaps with mammals. Industrial chemical pesticides were a simple answer efficient and profitable for getting rid of pests. Today the continued degradation of soil is bringing agriculture towards finding other solutions. We can imagine that in the future we can combine the presence of these nesting platforms with alarm scents produced by the trees to strongly attract insect-eating birds and so act as an integrated biological defense system and avoid the massive use of pesticides. If plants use several surprisingly efficient strategies of defense above ground what is going on underground in the roots? The earth is crawling with life worms, acari, springtails, centipedes, bacteria and many other species still yet to be discovered. All of this busy world tirelessly moves between the roots of plants and the mycelium of mushrooms that weave beneath our feet a dense and interwoven network. Fungi appeared 450 million years ago and have colonized all terrestrial and aquatic environments. It's thought that without them the first plants could not have conquered dry land. Plants and fungi have been partners for a long time Here we have an incredibly diverse range of decomposers. Degrading fungi which represent 40% of the forest's biodiversity. They break down tree trunks, branches and dead leaves and thanks to that decomposing activity of degrading they feed the soil where the mycorrhizal fungi absorb the elements necessary for tree growth. Seps, amanita muscaria, chanterelles, russulae, gerol, milk cap fungi, bolles and many others because the family of mycorrhizal fungi is large. They are the fruit of underground organisms called mycelia a network of filaments that explore vast surfaces in search of food. Microbiologist at the French NRI Research Centre Francis Martin studies how plants benefit from underground ecosystems. Here we have a very nice sep. It's probably connected via a mycelian system underground to this young oak. Here it's spectacular. You can see the mycorrhizal root lightly coloured red and then we have one here, orange, probably another mycorrhizal fungus installed on the root system. So this oak is interacting with dozens of different symbiotic fungi forming mycorrhizal structures with different forms and colours with probably different functions. One of the essential functions of these sleeve-like structures is to protect the roots of plants from springtails, roundworms and other tiny little creatures that seek to eat them. The other function is to weave a dense network of filaments uniting fungal mycelia and plant roots. This network bond prepares the soil as it contains nutriments necessary for both plants and fungi. What is surprising is that the health of this forest surrounding us depends on this little structure we call mycorrhiza, symbiosis between plants and fungi. Through mycorrhiza, fungi supply plants with rare minerals like phosphorus and nitrogen which they capture in the soil along with other nutrients. In exchange, the fungi receive sugars from plant photosynthesis which, not having chlorophyll, they can't make themselves. Laboratory observation by confocal microscope allows us to understand the symbiotic fusion of the mycelium filaments and plant roots. Here we're in the soil, the network of mycorrhizal fungi. All these green filaments colonise the whole of the root surface in red and end up by forming a mycorrhiza cap here in green. Here we can clearly see the fungi filaments which surround the root forming a kind of sock and then this network of filaments which penetrate the root and burrow between the cells to the heart of the root. Through this fusional connection with the mycorrhiza plants make close and fertile bonds with many fungal mycelia and with very many and varied colonies of bacteria. In green are the bacteria that jump, twitch and run along the highways of fungal mycorrhizal filaments. This allows the bacteria to move a long way which they couldn't do without the fungus. The bacterial population that proliferate in the soil are to plants what intestinal microbes are to humans. Two plants have similar relations with the bacteria which surround them as we do to our own. Soil is like a digestive tube. There is flora in the soil made of microorganisms and the plant is able to search out and select useful bacteria for itself. Useful especially to improve soil fertility but also useful to protect itself from diseases and climatic changes. To appreciate the influence of bacteria on the development of pulses like for example corn or beans the French Enroy Centre has built an entirely automised experimental platform. Plant development is measured in highly controlled conditions. Lionel Ranger and his team grow corn plots in pots filled with soil where the number and diversity of bacteria is precisely dosed. Through very high definition cameras the pockets of bacteria are easy to quantify and qualify in the images. Here we truly discover the root of the plant and on that root if we look closely we can see little balls called nodes. In these nodes are millions of bacteria which are raised by the plant and in return these bacteria feed the plant because they are capable of capturing atmospheric nitrogen, nitrogen in the air and transform it in a way that the plant can assimilate it. It's a win-win partnership. The plant feeds the bacteria and the bacteria feed the plant. The more variety and quantity of bacteria the more prosperous the plants. The shape and dimension of the pockets vary according to the type of plant. In the same way that the mycorrhizae secrete hormones to attract fungal mycelia the root nodes secrete hormones to attract bacteria. Once the bacteria are enclosed in the nodes or capsules of the roots the plant modifies them. They change shape, grow longer and their metabolism alters. Instead of feeding on diverse substances the encapsuled bacteria now only feed on atmospheric nitrogen which they turn into nitrogen the plant can assimilate as a fertilizer. At INRA France we have shown that if the micro biodiversity is reduced in the soil plant development is reduced. We've also shown that if fertilizer is added to the soil where there is less biodiversity the plant still won't develop as well as it would if there was more biodiversity. So if we compare fertilizer to biodiversity it's better to have a more biodiversified soil than to add fertilizer. These win-win partnerships between plants and bacteria are already used in agriculture especially for pulse cultures and that allows us to bring nitrogen in a natural way and limit the use of chemical fertilizers. In agricultural systems which are poorer, less fertile, notably in Africa this simply allows agriculture to happen. To develop plants where they couldn't survive before because the soils weren't fertile enough. And one of the first applications is the development of the Great Green Wall in South Sahel which has allowed a whole zone to be reforested limiting the expansion of the desert. In the heart of the forest there are thousands of species of mushrooms interacting with the trees. It's a permanent dialogue. Unfortunately in the farm just beside it massive use of pesticides has eliminated all microbial life. The plants are alone and no longer talk. It's completely silent. For the first time in the history of industrial farming harvests of cultivated crops have stopped increasing. Confronted with environmental constraints and the limits of selection our agriculture is at a dead end. A new biological approach offers a new perspective for progress one that remains to be fully explored. Hopefully in the future mycorrhizal symbiosis and nitrogen fixing symbiosis will be developed by humankind to help plants adapt to climate change. The discoveries over the past few years have considerably improved our vision of the plant world. The closer we look at them the more plants become familiar to us. Perhaps one day we'll stop seeing them as objects that can be infinitely cut, exploited and transformed and see them for what they are precious allies without which we would be lost.