Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, September 23, 1994                   TAG: 9409240063
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A2   EDITION: METRO 
SOURCE: ASSOCIATED PRESS
DATELINE: WASHINGTON                                 LENGTH: Medium

NEW GENE FIGHTS CROP DISEASES

``It's a discovery that brings us up to a whole new level of understanding,'' said Dr. Brian Staskawicz of the University of California at Berkeley, who isolated one of the genes.

Staskawicz and a separate team of Harvard researchers led by Dr. Fred Ausubel each isolated the RPS2 gene from a member of the mustard family, Arabidopsis thaliana. This gene fights off a serious bacterial infection.

Simultaneously, Dr. Barbara Baker and colleagues at Berkeley and the Agriculture Department isolated the N gene from tobacco, the first gene ever cloned that defends a plant against a virus.

The three teams report their discoveries in today's issues of the journals Science and Cell.

The researchers predict that within three years they may know enough from these genes to start fighting plant diseases without the chemicals and crossbreeding farmers now rely on.

Importantly, these genes - and a newly discovered fungus-fighting gene from flax called L6 - are related.

``That's the really exciting part,'' Staskawicz said. ``We've basically discovered a new class of genes that can recognize a diverse group of pathogens.''

All three genes are from unrelated plants and work on totally separate types of diseases. But when the researchers compared the sequences of proteins and amino acids that make a gene unique, they found startling similarities. In fact, some sequences were identical.

Such broad resistance within a single family of genes signals that the genes will be easy to transfer into other plants. That means scientists could one day, with just a little genetic engineering, protect any plant from bacterial, viral and fungal infections.