Grain legumes represent major food crops cultivated and consumed in India and other developing countries owing to their high nutritional value and important role in maintaining the ecosystem. Powdery mildew is one of the most devastating fungal diseases limiting legume productivity in India. 

These obligate biotrophs alter plant cellular architecture and metabolism to acquire nutrients via specialized feeding structures (haustoria) while limiting plant defense responses. Chemical treatments used to control the disease are neither economical nor environmentally friendly. 

Furthermore, despite the availability of a few powdery mildew resistant legume varieties, identity of the genes conferring resistance and knowledge of the underlying molecular events is limited. One of our primary goals is to identify novel host processes and the underlying genes that impact powdery mildew growth without an associated yield penalty. 

For this, we employ functional genomics, metabolomics, cell biology and reverse genetics tools to study Medicago truncatula/pea-Erysiphe pisi interaction as a model to identify host resistance and susceptibility factors that impact powdery mildew disease progression at different infection stages.

 We envision that factors limiting pathogen growth at different developmental stages would be more difficult to overcome than resistance based on a single mechanism, or mechanisms governed by a single gene. Our long-term goal is to utilize these genes as molecular targets to engineer durable resistance in legumes of agronomic import.

Another major area of focus is to elucidate how these obligate biotrophic fungi utilize ‘effector’ proteins to suppress host immunity and modulate host metabolism to divert nutrients from the plant to fuel growth and reproduction. 

For this, we utilize genomics, transcriptomics, and RNAi-based reverse genetics tools to decipher the role of candidate fungal effectors in pea powdery mildew pathogenesis. 

Functionally relevant pathogen effectors are targeted for silencing using transgenic methods as well as non-transgenic, nanocarrier-based smart delivery systems.