How plants fine tune their natural chemica...( LA JOLLA CA Even closely related pl...)

LA JOLLA, CA Even closely related plants produce their own natural chemical cocktails, each set uniquely adapted to the individual plant's specific habitat. Comparing anti-fungals produced by tobacco and henbane, researchers at the Salk Institute for Biological Studies discovered that only a few mutations in a key enzyme are enough to shift the whole output to an entirely new product mixture. Making fewer changes led to a mixture of henbane and tobacco-specific molecules and even so-called "chemical hybrids," explaining how plants can tinker with their natural chemical factories and adjust their product line to a changing environment without shutting down intracellular chemical factories completely.

The findings not only gave the Salk scientists a glimpse of the plants' evolutionary past, but may help them fine-tune the production of natural and environmentally friendly fungicides and pesticides as well as new flavors and fragrances by turning "enzymatic knobs" in the right direction.

Trying to make the best of their real estate, plants rely on an impressive arsenal of volatile and nonvolatile molecules, which diffuse easily through the membranes of the cells that produce them to communicate and interact with the outside world. Often highly aromatic and exceedingly specific for a particular ecological niche, these chemicals attract pollinators, summon natural predators of pests, defend against competitors or, through their antimicrobial properties, protect against natural plant pathogens such as fungi and bacteria.

"Most people are familiar with the word biodiversity, but 'chemodiversity,'the extraordinary tapestry of natural chemicals found in plantsis just as important for life, the appearance of new species and the survival of many different ecosystems on the earth," says Howard Hughes Medical Institute investigator Joseph P. Noel, Ph.D, director of the Jack H. Skirball Center for Chemical Biology and Proteomics, who led the stud
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