Tuesday, July 27, 2010

Wonders of Nature

Here is one, from Science.

An excerpt.

“When the leaves they depend on turn a deathly yellow in the fall, leaf miner moths (Phyllonorycter blancardella) perform CPR. Even as the rest of the leaf wilts, the patch surrounding a leaf miner larva stays a bright and photosynthetically active green. Now, a new study shows that these green islands spark to life thanks to bacteria living within the grubs themselves.

“Like mammals, many insects host internal microbes called endosymbionts that help them digest meals, often passing these friends from generation to generation. Insect endosymbionts have also proven themselves keen inventors, developing new defenses for their hosts. "The more we look at endosymbionts in insects, the more people find interesting and new functions," says ecologist David Giron of the Université François Rabelais in Tours, France.

“It seemed possible to Giron that bacteria like those in the genus Wolbachia, which dwell in leaf miners, could also rewire plant metabolism. Many microbes, including Wolbachia, carry a gene also found in plants that spurs some plant cells to make hormones called cytokinins, he says. Cytokinins, which delay death in plant cells, can spur green islands on their own and are plentiful in leaf-miner islands.”