Plants

Nick Stockton asks, at Wired, why didn’t the ice ages that began at 800,000 ago just remain? What reversed the cooling trend? A new study, published today in Nature Geoscience, has a hypothesis what that something was: plants. Or, more specifically, a complicated process in which plants wear down certain kinds of rocks, and how those rocks remove carbon dioxide from the atmosphere as they wear down—leaving just enough CO2 out there to trap solar warmth, and gradually bring summer back. More. Most ecology on the planet actually depends on plants. Everything seems organized around them, including temperatures. See also: How plants see, hear, smell, and respond without animal sense organs Follow UD News at Twitter!

From Jef Akst at The Scientist: While animal cells undergo two rounds of reprogramming during reproduction to wipe clear most of the methyl marks that decorate their DNA and histones, plants leave their epigenomes largely intact from one generation to the next. In plants, this results in epialleles—stably inherited alleles encoded by methylation, rather than by gene sequence—that control subtle phenotypes, such as timing of flowering or fruit ripening. Most of the differences [between individuals] that we see are caused by genetic variation,” says Colot. “But it’s not all caused by genetic variation. What would be caused by this epigenetic variation could be as important.” Whether these epialleles can be adaptively altered by the environment remains a matter of debate, Read More ›

From Josh Gabbatiss at BBC: In their experiments, Appel and Cocroft found that recordings of the munching noises produced by caterpillars caused plants to flood their leaves with chemical defences designed to ward off attackers. “We showed that plants responded to an ecologically-relevant ‘sound’ with an ecologically-relevant response,” says Cocroft. … For example, despite lacking eyes, plants such as Arabidopsis possess at least 11 types of photoreceptor, compared to our measly four. This means that, in a way, their vision is more complex than ours. Plants have different priorities, and their sensory systems reflect this. As Chamovitz points out in his book: “light for a plant is much more than a signal; light is food.” More. The article cautions, refreshingly, Read More ›

From ScienceDaily: The research was carried out by a team of scientists at BGI, Zheijiang University and the Chinese Academy of Sciences, who tackled and analyzed an exceptionally large genome, totalling more than 10 billion DNA “letters.” Ginkgo is considered a “living fossil,” meaning its form and structure have changed very little in the 270 million years since it first came into existence. Given its longevity as a species and unique position in the evolutionary tree of life, the ginkgo genome will provide an extensive resource for studies concerning plant defenses against insects and pathogens, and research investigating early events in tree evolution and in evolution overall. … The ginkgo genome stretches over more than 10 Gb, which is 80 Read More ›

From forester Peter Wohlleben at Daily Mail: There’s increasing evidence to show that trees are able to communicate with each other. More than that, trees can learn. If that’s true — and my experience as a forester convinces me it is — then they must be able to store and transmit information. And scientists are beginning to ask: is it possible that trees possess intelligence, and memories, and emotions? So, to cut to the quick, do trees have brains? It sounds incredible, but when you discover how trees talk to each other, feel pain, nurture each other, even care for their close relatives and organise themselves into communities, it’s hard to be sceptical.More. No one familiar with the area now Read More ›

Someone found out that lichens involve more than one fungus with the algae?: “The findings overthrow the two-organism paradigm,” says Sarah Watkinson from the University of Oxford. “Textbook definitions of lichens may have to be revised.” “It makes lichens all the more remarkable,” adds Nick Talbot from the University of Exeter. “We now see that they require two different kinds of fungi and an algal species. If the right combination meet together on a rock or twig, then a lichen will form, and this will result in the large and complex plant-like organisms that we see on trees and rocks very commonly. The mechanism by which this symbiotic association occurs is completely unknown and remains a real mystery.” More. If that’s Read More ›

A reader sent this link to a free 2013 paper in Genome Biol Evol wherein we read: Although once said to be “junk,” or “parasitic,” DNA (Doolittle and Sapienza 1980; Orgel and Crick 1980), a recent large and rapid accumulation of evidence indicates that transposable elements (TEs) have been a significant factor in the evolution of a wide range of eukaryotic taxa (Bennetzen 2000; Kazazian 2004; Biémont and Vieira 2006; Feschotte and Pritham 2007; Bohne et al. 2008; Hua-Van et al. 2011). We have proposed TEs as powerful facilitators of evolution (Oliver and Greene 2009), formalized this proposal into the TE-Thrust hypothesis (Oliver and Greene 2011), and more recently, expanded and strengthened this hypothesis (Oliver and Greene 2012). More. But Read More ›

Dumps photosynthesis. From New Scientist: A newly discovered Japanese plant spends most of its life hidden underground and steals nutrients from fungi rather than getting its energy from the sun. … The plant’s stem is about 3-9 centimetres long and has between nine and 15 purple star-shaped flowers, which push up above the ground. Suetsugu has named it Sciaphila yakushimensis after the island. The plant can’t photosynthesise and, like other mycoheterotrophs, steals the carbon it needs from a fungal host. The parasitic plant attracts strands of mycorrhizal fungus into its many hairy roots and then feeds off fungus growing inside the roots. … Because it doesn’t rely on photosynthesising the sun’s light for its energy, it can stay underground, reducing Read More ›

Richard Mabey, author of The Cabaret of Plants: Forty Thousand Years of Plant Life and the Human Imagination, was interviewed recently by National Geographic: There Is Such a Thing as Plant Intelligence … We tend to judge plants not as autonomous organisms but in terms of what they can do for us. But they’re astonishing in their own right and deserve to be given the same ethical status as animals. … It’s long been known that the trees in a forest are connected by mycorrhizal fungi. This means fungi that live symbiotically with the roots of forest trees. The forest trees can’t grow without them because they haven’t got enough access to the minerals in the soil, and the fungi Read More ›

To wipe ou memory of stress. From New Scientist: Some plants have “long-term memory”. For instance, Arrhenatherum elatius, a perennial grass species common in Europe, seems to remember drought and is better able to defend against damage from excessive sunlight than plants that haven’t been through an earlier drought. … Plants can preserve such memories across generations, at times via epigenetic mechanisms, which influence whether or not genes are expressed. Ah, a mechanism. If the plant is not using a brain, what is it using? But when Peter Crisp at the Australian National University in Canberra and his colleagues scoured the literature for examples of such memory of stressful events, they found that memory is more the exception rather than Read More ›

From Salk Institute: Grafted plants’ genomes can communicate with each other Agricultural grafting dates back nearly 3,000 years. By trial and error, people from ancient China to ancient Greece realized that joining a cut branch from one plant onto the stalk of another could improve the quality of crops. Now, researchers at the Salk Institute and Cambridge University have used this ancient practice, combined with modern genetic research, to show that grafted plants can share epigenetic traits, according to a new paper published the week of January 18, 2016 in the Proceedings of the National Academy of Sciences. … “Grafting is something done often in the commercial world, and yet, we really don’t completely understand the consequences for the two Read More ›

Generally, coal is assumed to have originated in the lignin of Carboniferous forests, but now a new theory has been introduced: From The Economist: The trees of the Carboniferous were not like those of today. Moreover, which types of tree predominated varied over the vast span of time that it covered. One pertinent observation Dr Boyce and his team make is that the peak of coal formation coincided with the dominance of a group called the lycopsids. Yet lycopsid trunks were composed mostly of tissue called periderm, which corresponds to modern bark and contains little lignin. Forests that existed both before and after these lycopsid woods (but before the supposed evolution of lignin-digesting fungi) had many more lignin-rich species in Read More ›

From ScienceDaily: Plants crawled onto land earlier than we give them credit, genetic evidence suggests Plant biologists agree that it all began with green algae. At some point in our planet’s history, the common ancestor of trees, ferns, and flowers developed an alternating life cycle–presumably allowing their offspring to float inland and conquer Earth. But on December 16 in Trends in Plant Science, Danish scientists argue that some green algae had been hanging out on land hundreds of millions of years before this adaptation and that land plants actually evolved from terrestrial, not aquatic, algae. Botanists have suspected this possibility since 1980, but supporters have lacked proof. Now, Carlsberg Laboratory’s Jesper Harholt and University of Copenhagen’s Øjvind Moestrup and Peter Read More ›

From Science Daily: New fossil evidence shows that Australia’s fire-prone shrubland open vegetation originated at least 70 million years ago — 40-50 million years earlier than previously thought. The findings, published online ahead of print in the American Journal of Botany, reject prevailing wisdom that Australia was covered with rainforest until 40 million years ago, and that currently dominant native vegetation types evolved after that on a drying continent with increasing fire. “Amazingly, we think part of the ancient vegetation was similar to what you can now see in south-western Australia, and there were even a couple of leaf bits that look just like Banksia,” says Dr Carpenter. “Banksia is one of Australia’s most iconic native plants and is very Read More ›

From ScienceDaily: Ancient alga knew how to survive on land before it left water and evolved into the first plant Up until now it had been assumed that the alga evolved the capability to source essential nutrients for its survival after it arrived on land by forming a close association with a beneficial fungi called arbuscular mycorrhiza (AM), which still exists today and which helps plant roots obtain nutrients and water from soil in exchange for carbon. The previous discovery of 450 million year old fossilised spores similar to the spores of the AM fungi suggests this fungi would have been present in the environment encountered by the first land plants. Remnants of prehistoric fungi have also been found inside Read More ›