Newly Explored Rice Gene Could Help "Blast"
Killer Fungus By Erin Peabody
Rice plants could soon be getting their own version of "caller
ID." Agricultural Research Service
scientists are providing plants of this important world crop with the genetic
tools needed to recognize and identify incoming attacks from the damaging
pathogen known as rice blast. The fungus, Magnaporthe grisea, causes
rice yield losses of up 30 percent each year worldwide.
Two-thirds of the global population relies on rice. And while
many farmers around the world are growing record amounts of the staple
grain--thanks to new rice varieties and advances in nutrient and pest
management--they can't compete with the blast fungus' will to survive.
According to ARS chemist Sally Leong, blast is so adaptable that
it can defeat a rice cultivar, specially bred to resist the fungus, after just
one growing season. Leong works at the agency's
Cereal Crops Research
Unit in Madison, Wis.
Trying to escape the tug-of-war scenario that rice breeders find
themselves in when searching for new, blast-resistant plants every one to three
years, Leong is working to arm important rice varieties with more certain,
long-lasting genetic advantages.
She's been studying two key genes--one from a resistant rice
cultivar and one from the M. grisea pathogen--to understand precisely
how hardy rice plants defend themselves when confronted with infectious spores
of the blast fungus. Early recognition of the fungal perpetrator is key to
successful plant protection.
Having evolved alongside each other in many parts of the world,
rice and its blast pathogen possess genes with a unique history. As such, a
rice plant will launch a strong defense response against M. grisea if
its resistance gene matches a related, counter-resistance gene in the fungus.
Leong is developing rice plants with the resistance gene. She
and colleagues are also researching how to optimally apply the M.
griseaa gene to already-resistant rice plants to achieve even greater
blast-readiness in rice.
about the research in the August issue of Agricultural Research magazine,
available online at:
ARS is the U.S. Department of
Agriculture's chief scientific research agency.