Herself’s Houston Garden

Plants emit compounds to both attract and repel insects. Plants planted near rhododendrons can absorb and emit chemicals given off by rhododendrons to protect themselves from insects.

Scandinavian Scientists have discovered that a species of tree defends itself from herbivore attack by using chemicals emitted by neighbouring plants. The study, published today in New Phytologist, reveals how a species of birch tree adsorbs chemical compounds from neighbouring marsh tea plants, Rhondodendron tomentosum, in a unique ‘defence by neighbour strategy.’

The team from Finland, led by Prof. Jarmo Holopainen from the University of Eastern Finland, were conducting studies into emissions of forest and peat land plants when they discovered previously unreported compounds for mountain birch from their foliage emissions. The compounds were emitted by a species of rhododendron growing nearby.

“It is well known that many plant species start to emit chemical compounds after damage by herbivores,” said the co-author Dr. Sari Himanen, from Agrifood Research Finland. “In an earlier study we accessed the compounds emitted from mountain birch following Moth feeding damage and we found that some of the trees growing next to Rhondodendron tomentosum also emitted residual amounts of the compounds ledene, ledol and palustrol. This resulted in the idea to experimentally test whether these sticky semivolatiles could actually protect neighbouring birch trees from the attention of attacking herbivores such as feeding moths. Based on experimentation in the field, in a natural habitat and in the laboratory, we discovered that a novel, potentially also ecologically meaningful effect for neighbour-emitted foliage-adsorbed semi-volatiles might take place in a boreal environment.”

Plant emissions can have several roles, including the attraction or deterrence of herbivores. Some cause an indirect defence by attracting a herbivorous natural enemy, but it is extraordinary for one plant to benefit directly from another plant’s emissions.

Read more Plants discover the benefits of good neighbors in strategy against herbivores

Paper
Herbivore and neighbour effects on tundra plants depend on species identity, nutrient availability and local environmental conditions

Back in Boston I had a quince that came with our home outside my office window. It was the first plant to flower every spring and my favorite.

Last fall I found a Cameo Quince and put it outside my office window down here in Houston. It was the first plant to bloom in the garden this year.

We are really at the lower edge of where it will grow ( zone 5a-8b ) and I’m not sure how well it will do in the summer but I couldn’t resist giving it a try.

This quince is planted in part shade but it will do well in full sun.

Chaenomeles cameo quince does not have the thorns many other quinces do.

In a cold winter quince will drop its leaves, this one retained its leaves all winter.

Watering needs are average.

Needs little pruning to keep its shape. Quince will reach about 5′ tall by 6′ wide.

Quince was a staple in Victorian gardens. The fruit must be cooked before eating. It was commonly baked in pies that are similar to apple pies.

Plants grown in soils low in phosphates grow hairy roots in the search for nutrients. Now scientists have discovered the gene that turns on hairy roots and hope to use it to develop food crops that will grow in poor soils or with less fertilizer.

When crops such as barley and wheat are grown on soils containing small amounts of phosphate it is known that those plants with long hairs on their roots give higher yields than those with short hairs. Similarly, long-haired beans grown on the nutrient-poor tropical soils of Central America do much better than short haired varieties.

Root hairs burrow into the soil like tiny ‘mining machines’ releasing acids and other scouring chemicals that crack open rocky minerals releasing valuable nutrients, such as iron and phosphate, that are necessary for plant growth.

Now, for the first time, scientists have found the mechanism that controls the growth of these specialised nutrient-excavating cells. They discovered that a master regulatory gene called RSL4 acts like a switch; hair cells grow when the gene is turned on and growth stops when it is off. read more

More information:
A basic helix-loop-helix transcription factor controls cell growth and size in root hairs
Discovery of nutrient mining machine in plants

It would seem trees are not as dumb as they first appear. When wasps try to lay eggs from outside the flower with out pollinating the flower, instead of inside the flower while spreading pollen the trees drop the fruit containing the baby wasps to death.

While trees often drop unpollinated flowers, they will often hold onto the galls containing the wasps and provide themselves with a future generation of pollinators.

Figs and fig wasps have evolved to help each other out: Fig wasps lay their eggs inside the fruit where the wasp larvae can safely develop, and in return, the wasps pollinate the figs.

But what happens when a wasp lays its eggs but fails to pollinate the fig?

The trees get even by dropping those figs to the ground, killing the baby wasps inside, reports a Cornell University and Smithsonian Tropical Research Institute study published in the Proceedings of the Royal Society B (published online Jan. 13). ( read more read more about tree retaliation )

More information
Abstract
Download the paper (pdf)