Dr Jawahar Singh

My current research at SLCU centres on root nodule symbiosis in cowpea (Vigna unguiculata), a legume that fixes atmospheric nitrogen through partnership with Bradyrhizobium bacteria. Using single-nucleus RNA-seq (~60,000 nuclei), I have built the first cell-type-resolved transcriptional atlas of the cowpea nodule, identifying novel cell types including a Purine Processing Zone central to ureide biosynthesis — the nitrogen currency of determinate legumes. In parallel, bulk RNA-seq across a nodulation time series has revealed stage-specific gene regulatory networks governing infection, organogenesis, and nitrogen metabolism. I am also using CRISPR-Cas9 and hairy root transformation to functionally characterize key transcription factors and membrane biogenesis genes that control symbiotic efficiency. This work is funded by ENSA and the Bill & Melinda Gates Foundation, with the broader goal of engineering cowpea and soybean varieties that fix more nitrogen with less fertilizer input.

Prior to Cambridge, I was a DGAPA Postdoctoral Fellow at UNAM, Mexico, in the lab of Prof. Oswaldo Valdés-López, where I made the first direct demonstration that a PHR1-type transcription factor binds the NIN promoter in Phaseolus vulgaris — establishing phosphate availability as a gatekeeper for nodulation commitment (Plant and Cell Physiology, 2025). Before that, my PhD at NIPGR, New Delhi, under Prof. Praveen K. Verma focused on genome-wide characterization of LysM receptor-like kinases in chickpea and their role in Nod factor perception.