Chinese scientists said yesterday that they had identified a plant gene which can help fight rice blast, a major global disease that savages crops and reduces the use of harmful pesticides. Rice blast is a fungus and a major crop irritant worldwide including China. It can destroy grain production up to half. Scientists estimate that it destroys global rice to an extent that is enough to feed 85 million people annually. Experts estimate that rice blast causes the loss of 3 million tons of rice in China every year. The cost to control the disease is vast with an extensive use of pesticides. It is a threat to the environment and food security. The scientists have been looking for disease-resistant genes that would not only control rice blast but also protect the environment and public health.

The team in 2006 identified a gene, Pigm, which has broad-spectrum resistance. The scientists then spent a decade to analyze the mechanism of the gene locus and found it encodes two proteins, PigmR and PigmS. PigmR can defend disease but leads to a drop in production, while PigmS can raise grain production but inhibits the resistance effect of PigmR. The two proteins result a good balance by controlling the disease and maintaining good production. By fully understanding the gene, one can guide seed companies and breeders. So far, over 30 domestic companies and breeders have used discovery for molecular breeding to allow new rice varieties with better disease resistance effects but ideal production.