Research Projects

Dry root rot (DRR) is a destructive disease caused by a broad-spectrum fungal pathogen called Macrophomina phaseolina. This disease affects over 500 plant species, including economically important crops like chickpea. DRR has a significant impact on chickpea yield in India, and current efforts to develop plant resistance to the disease have not been entirely successful. The objective of this project is to investigate non-host resistance (NHR) mechanisms to the pathogen and use the findings to enhance chickpea resistance to the disease under abiotic stress conditions. Previous studies have explored host resistance to the DRR pathogen, but NHR mechanisms have not been well-understood. The project aims to identify non-host plants of M. phaseolina through extensive literature analysis and field trial observations. The potential non-hosts will be screened for DRR infection using the blotter paper technique, which has been standardized in the lab. Once potential non-hosts are identified, the research team will investigate the mechanisms of NHR by observing the various stages of M. phaseolina infection in root tissue using confocal microscopy. They will also examine the role of nutrient deprivation to the pathogen as a mechanism of non-host resistance. Previous research has shown that metabolites, antimicrobial compounds, transporters/mechanisms limiting nutrient availability to the pathogen can be an effective way to restrict its growth inside a non-host. To understand the molecular changes induced by DRR infection in the non-host plant, the research team will perform transcriptome analysis using a suitable approach with a focus on genes related to primary and secondary metabolism. They will also perform a parallel experiment to investigate the dynamics of primary and secondary metabolic changes during chickpea-M. phaseolina interaction using GC/MS. The integrative analysis of the transcriptome and metabolome will enable identification of key pathways involved in NHR, leading to the identification of genes having a role in NHR. To determine the role of genes in NHR, the research team will manipulate gene expression using hairy root transformation. In planta pathogen load and fungal colonization will be estimated, and the role of the identified gene in host defense against M. phaseolina will be extensively characterized. Finally, the resistance of transgenic plants to DRR will be analyzed in the presence of abiotic stress conditions to determine the effectiveness of the gene in conferring DRR resistance under extreme environments. In summary, the project aims to explore the mechanisms of non-host resistance to the DRR pathogen and use the findings to enhance chickpea resistance to the disease under abiotic stress conditions. By identifying potential non-hosts, investigating the mechanisms of NHR, and characterizing key genes, this project will contribute to the development of more effective strategies for managing DRR and protecting chickpea yield.