Flowering plants downsized DNA to take over world

The abrupt origin and rapid diversification of the flowering plants during the Cretaceous has long been considered an “abominable mystery.” While the cause of their high diversity has been attributed largely to coevolution with pollinators and herbivores, their ability to outcompete the previously dominant ferns and gymnosperms has been the subject of many hypotheses. Common among these is that the angiosperms alone developed leaves with smaller, more numerous stomata and more highly branching venation networks that enable higher rates of transpiration, photosynthesis, and growth. Yet, how angiosperms pack their leaves with smaller, more abundant stomata and more veins is unknown but linked—we show—to simple biophysical constraints on cell size. Only angiosperm lineages underwent rapid genome downsizing during the early Cretaceous period, which facilitated the reductions in cell size necessary to pack more veins and stomata into their leaves, effectively bringing actual primary productivity closer to its maximum potential. Thus, the angiosperms’ heightened competitive abilities are due in no small part to genome downsizing.

read the paper

Article in Quanta Magazine

Rip Van Winkle effect allows plants to survive

image source

Scores of plant species are capable of living dormant under the soil for up to 20 years, enabling them to survive through difficult times, a new study has found.

An international team of academics has found that at least 114 plant species from 24 different plant families, from widespread locations and ecological communities around the world, are capable of prolonged dormancy as adult plants, remaining alive in the soil but not emerging from the ground every spring. This behaviour enables them not only to survive through difficult times, but to make the best of adversity. … more

Shefferson Lab for Plant Fungal Evolutionary Ecology

Giant tree forests need 59″ rain per year to form

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Tree canopies come in two main heights ~82′ and 131′. They form in tropical and temperate regions but only if the yearly rainfall is consistently 59″ or more


Rainforests are among the most charismatic as well as the most endangered ecosystems of the world. However, whereas the effects of climate change on tropical forests resilience is a focus of intense research,the conditions for their equally impressive temperate counterparts remain poorly understood,and it remains unclear whether tropical and temperate rainforests have fundamental similarities or not.Here we use new global data from high precision laser altimetry equipment on satellites to reveal for the first time that across climate zones ‘giant forests’ are a distinct and universal phenomenon, reflected in a separate mode of canopy height (~40m) world-wide. Occurrence of these giant forests (cut-off height > 25 m) is negatively correlated to variability in rainfall and temperature. We also demonstrate that their distribution is sharply limited to situations with a mean annual precipitation above a threshold of 1500 mm that is surprisingly universal across tropical and temperate climates. The total area with such precipitation levels is projected to increase by ~4 million km2globally. Our results thus imply that strategic management could in principle facilitate the expansion of giant forests, securing critically endangered biodiversity as well as carbon storage in selected regions

A Global Climate Niche forGiant Trees

Nepenthes Ampullaria

This is my most unusual plant. It is a lowland, swamp loving Nepenthes that was a carnivore and has switched to a detritivore diet. Though they don’t mind an occasional bug. The pitchers have enzymes and bacteria to break down and digest leaves, insects and insect larvea. The pitcher fluid is more basic than is found in other Nepenthes. Many insects will make homes for themselves in the pitchers.

I started with a batch of seeds I purchased on eBay. The first couple years growth is very slow, they make up for it the third year.

They are native to the rainforests of Malaysia and Indonesia. You’ll often see them at food stands, the pitchers stuffed with rice. I’ve also seen them called ‘monkey cups’.

In Malaysia a tea made from the roots is used to treat dysentery.

Keep them warm 60’F-80’F humid, wet and out of direct sunlight. I’ve done best growing them in orchid baskets full of sphagnum moss. I seat the baskets in a clear pot and keep an inch or so of water in there. Only use distilled water, they are sensitive to chemicals in drinking water.

I found started Nepenthes seeds in terrariums on top of peat moss works best.

Nepenthes ampullaria are most strongly related to Bicalcarata. Ampullarias are most easily identified by the tiny, narrow lid on the pitcher. There is a large variation in pitcher size, colors are solid green or green speckled with red.

Some leaves do not have pitchers, but instead grow tendrils.



The fluids of Nepenthes pitcher plants are habitats to many specialized animals known as inquilines, which facilitate the conversion of prey protein into pitcher-absorbable nitrogen forms such as ammonium. Xenoplatyura beaveri (Diptera: Mycetophilidae) is a predatory dipteran inquiline that inhabits the pitchers of Nepenthes ampullaria. Larvae of X. beaveri construct sticky webs over the fluid surface of N. ampullaria to ensnare emerging adult dipteran inquilines.

Our results show that a terrestrial, inquiline predator can contribute significantly to nutrient sequestration in the phytotelma it inhabits, and suggest that this interaction has a net mutualistic outcome for both species.

Tomato plants turn munching caterpillars into cannibals



It turns out that cannibalism is widespread among the insects that otherwise spend their time munching on plants. “It often starts with one caterpillar biting another one in the rear, which then oozes,” said University of Wisconsin–Madison’s John Orrock in a press release describing his work. “And it goes downhill from there. At the end of the day, somebody gets eaten.”

It’s considered a stress response to a lack of food. What surprised Orrock was that this behavior sometimes took place on plants. You know, the things these caterpillars are supposed to be eating. If the food’s right there, why would these insects be turning on each other?

It all comes back to the chemicals a plant releases to say “watch out, I’m being eaten.” This is typically some chemical relative of jasmonic acid, a regulator of plant stress responses. While jasmonic acid can be used to coordinate a plant’s own response to stress, it also gets out into the environment and alerts other plants that something stressful is going on.

Paper:
Induced defences in plants reduce herbivory by increasing cannibalism

More info:
Jasmonic acid distribution and action in plants: Regulation during development and response to biotic and abiotic stress

Slime mold (Fuligo septica)

Yellow plasmodium, more commonly known as dog vomit slime mold is actually a fungus.

Grows on decaying wood and leaves, in the shade. Most of its life is spent as a single cell. When warm and humid the cells creep together to form a single unit. The cells lock into each other like keys in a lock. The unit then follows light sources and moves in search of bacteria, yeasts and other fungi to eat. By pulsing it can send the food throughout itself.

Slime molds leave a trail of slime behind which acts as memory. When they find the slime they move to explore a new area rather than re-search an area they’ve cleaned.

Reproduces by breaking back apart into multiple cells that are moved by the wind to begin new units when the weather conditions are right.

Slime molds have been placed in mazes with various food sources, they connect together and hunt out the food which is then fed to the entire unit through the tube network it creates in itself. If the food is placed on a map in large cities a highway system develops to transport the food that looks spooky similar to our own highways. Slime molds can find the most efficient routes through a maze.

Slime molds have been with us about 600 million years and were the inspiration for the movie ‘The Blob’.

Dodder vine (Cuscuta pentagona)

Dodder vine

Dodder vine is an amazing plant, it is orange rather than green due to its lack of chlorophyl, it can’t make its own food.

Instead the dodder vine hatches in the spring from a seed and very slowly moves in a circle searching the air for beta-myrcene a volatile chemical emitted into the air by tomatoes and other plants. When it picks up the scent of beta-myrcene it grows in the direction of the odor until it finds the plant emitting it.

Once it reaches the plant it tightly winds itself around the plant, sinking roots into the host plant. The roots then suck up the juices in the host plant to feed itself. The host plant will then wilt and die.

Dodder vine also appears to exchange RNA with the host plant. Whether this is a way of exchanging information with the host plant or a way to reprogram it, much the way viruses reprogram our DNA is unknown.

Plants use RNA as a way to send messages through out the plant. When a dodder vine attacks a plant some of the plant’s RNA gets sucked up by the dodder vine. The dodder vine can then read the RNA to better evaluate how to attack the host.

Professor Neelima Sinha and colleagues at the UC Davis Section of Plant Biology studied dodder vines growing on tomato plants in the lab. They found that RNA molecules from the host could be found in the dodder up to a foot (30 cm) from the point where the parasite had plumbed itself into the host.

Plants often use small RNA molecules as messengers between different parts of the plant. In a paper published in Science in 2001, Sinha’s group showed that RNA could travel from a graft into the rest of the plant and affect leaf shape. Plants can also use specific RNAs to fight off viruses. . . [ read more Plant Parasite Wiretaps Host ]

Dodder is a member of the Morning Glory family.

It has very tiny leaves that are more like scales than leaves and tiny white flowers.

It is considered an invasive plant and a threat to the local ecology in Texas.

A new method of plant communication?
Genomic-scale exchange of mRNA between a parasitic plant and its host
YouTube video of dodder vine locating and reaching for a tomato plant
Dodder management guide lines