Researchers at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) have identified a set of promising genes in chickpea that could play a key role in the plant's defense against dry root rot (DRR), a devastating fungal disease.

Led by Dr. Mamta Sharma, the team has now explained the mechanism of DRR at the molecular level. They found the involvement of endochitinase and PR-3-type chitinase (CHI III) genes in delaying the progression of DRR. DRR is caused by Rhizoctonia bataticola, a soil-borne fungus that kills plant tissues and uses the dead matter to sustain itself. Such pathogens are termed necrotrophic. While Fusarium wilt in chickpea has traditionally been the concern of plant health experts, DRR has emerged over the past decade as a major threat in the heart of India's chickpea-producing regions.

The team studied DRR susceptibility in two cultivars (BG 212 and JG 11) in high soil moisture and low temperature conditions, as well as in low soil moisture and high temperature conditions. The disease susceptibility was higher in the second set of conditions. They then studied the differential gene expression of several stress-responsive genes in chickpea and found the significant overexpression of genes encoding for the enzymes endochitinase and PR-3-type chitinase implicated their role in the plant's defense mechanism. "These genes are very active in the early stages of the disease, particularly under low soil moisture conditions, and have concluded that they contribute to delaying the progression," said Mr. Sharath Chandran, a Senior Research Fellow at ICRISAT and the study's first author.

For more details, read the new release on the ICRISAT Happenings Newsletter.