Faculty Member

Profile

Research Interests

Understanding molecular regulation of low phosphate adaptations

My lab’s focus is on finding novel genes and understanding their functions in cellular signaling in response to limiting Phosphorus (P) conditions. Plants activate a diverse set of responses to face P scarcity and consequently alter physiological, biochemical and developmental processes. We are targeting P solubilizing enzymes, membrane remodeling genes and root development to improve resource acquisition and utilization in rice and chickpea. We employ modern tools of genomics like transcriptomics, metabolomics, phenomics, transgenesis and gene editing to pinpoint candidate genes for improving plant performance in low P input system.

Current Research

Beyond Photosynthesis: The Chloroplast's Adaptations help plants thrive in phosphate scarcity

Plants have the incredible ability to produce their own food, thanks to chloroplasts. These organelles also help plants thrive in environments with low phosphate levels. One of the most impressive ways chloroplasts do this is by using galactolipids, which are lipids that don't require phosphate.

Phosphate is a crucial nutrient for many cellular processes, including photosynthesis. However, many soils and environments have sub-optimal levels of phosphate, leading to poor plant growth and crop yield. Chloroplastic membranes thylakoid/envelope are the most abundant cellular membranes in plants. Galactolipids make up most of the glycerolipids in chloroplast membranes, accounting for over 80% of the total lipids. When phosphate levels are low, plants further break down phosphate lipids, phospholipids and increase the production of galactolipids. This process, called membrane lipid remodeling, enables plant cells to maintain their structural integrity and function even when phosphate is limited (Verma et al., 2021 Plant Physiology & Biochemistry).

Understanding and manipulating this intriguing display of cellular P reutilization is our strategy for generating environment-resilient crops. We are targeting several enzymes of this pathway like GDPDs (Mehra et al., Plant Cell & Environment), MGDGs (Verma et al., 2021; JXB) and DGDGs to understand their roles in rice using biochemistry, molecular biology, transgenesis and genome editing approach.

Gene-editing for exploring the role of P-related genes and creating novel gene variants

CRISPR/Cas9 and new emerging gene-editing tools have revolutionized the field of genomics. No other method has given such a control over changing the gene functions in plants. We are utilizing gene editing in rice to knock out genes, create new alleles and alter transcriptional regulation of phosphate transport and signaling genes. We have used sgRNA and multiplexing strategies in manipulating different genes involved in P-related signalling. Some of the successful stories from our lab include the characterization of the rice citrate transporter, OsCT1, for its role in Pi uptake and metal distribution (Panchal et al., 2023; Plant Journal); demonstration of marker-free gene-edited lines carrying only an SNP in MGD3 synthase gene, OsMGD3 a phospholipid remodelling gene in rice (Verma et al., 2022; Journal of Experimental Botany) and revealing a novel role for rice PAP3b gene in phosphate homeostasis (Bhadouria et al., 2023; Plant Cell & Physiology). We have also been able to raise gene-edited lines using DNA-free Ribo-Nucleo Protein (RNP) system in rice. The lab is interested in testing new tools for making precise gene-editing in rice genes for improving plant response to challenging environments.

Looking underground: Understanding Roots for future plants

Roots, often neglected by plant researchers, have the potential for crop production in future challenging environments. Plants with efficient roots adapted to the local environment can sustain crop yield in soils with minimum water and fertilizer inputs.  Our focus is on identifying the root traits that enable plants to tolerate soil mineral deficiencies. Research has shown that root hairs, which are responsible for half of the total phosphate uptake, are highly responsive to low phosphorus deficiencies (Giri et al., 2018 Nature Communications; Bhosale & Giri et al., 2018, Nature Communications). We have studied this response in rice and chickpeas using cutting-edge techniques such as high-throughput root phenotyping, gene editing, GWAS, and transcriptomics (Kohli et al., 2020 FIGE; Kohli et al., 2021 Plant Cell & Environment). We are also investigating how roots respond to other abiotic stresses using advanced molecular and genetic techniques. Our research has the potential to improve our understanding of root responses to abiotic stresses, which is crucial for sustainable agriculture

Purple Acid Phosphatases (PAPs): enzymes with dynamic roles

This colorful set of enzymes named so due to their purple color in aqueous solution, play diverse roles in plants besides their key role in organic-P solubilization inside and outside the cell. PAPs fall under the larger category of Acid Phosphatase (APase) and may regulate cellular signaling or influence processes like P-remobilization, senescence, seed phosphate loading, ROS detoxification, carbon metabolism by the virtue of their signaling and enzymatic activities (Mehra et al., 2017; Bhadouria et al., 2017). Besides their transcriptional regulation by environmental stresses, PAPs are subjected to extensive post-translational modifications to execute their actions. Another class of APase known as Halo Acid Dehalogenases (HADs) is hydrolases with strong catalytic activity (Pandey et al., 2017). We are interested in discovering new APases, finding their biochemical attributes and engineering them with enhanced biochemical activity for manipulating their biological actions towards crop improvement for low input production.

Transgenics with PAP21b are more efficient than WT in P limited soils

Ongoing projects:

1. Beyond Transgenic Plants: Use of Precise Genome Editing for Improving Plant Growth Under Low Phosphorous Input. Funded by: DBT-Indo-Swiss joint project


2. Unlinking phosphate deficiency responses from their adverse effects on growth in rice. Funder under: Swarna Jayanti Fellowship


3. Targeting Pup1 independent mechanisms for improving low soil phosphorus tolerance and use-efficiency in rice. Funded by: DBT NIPGR-IIRR, joint research project