Scientists from US Department of Agriculture (USDA) studied the genes of
ancient grasses and found a gene that could save wheat from Ug99 (Puccina
graminis), a notorious type of stem rust that keeps on evolving.

USDA Agricultural Research Service (ARS) scientist Matt Rouse and colleagues
studied a variety of ancient grasses such as einkorn wheat, emmer wheat, and
goatgrass. Rouse and team found the gene Sr35 which confers resistance to
the stem rust. To search for the position of Sr35 in the wheat genome, the
research team conducted various knock-out experiments. In one set of mutant
plants, they knocked out the cloned sequences and found it made those plants
susceptible to Ug99. In another set of mutant plants, they inserted the same
sequences into previously susceptible plants and found it made them
resistant.

This marked the first time that scientists managed to isolate and clone a
Ug99 resistance gene. The results would help scientists to easily insert
useful genes into wheat varieties.

[www.ars.usda.gov]