Research Projects

Heavy-metal contamination is one of the major abiotic stress factors that, by negatively affecting plant growth and development, severely limit agricultural productivity worldwide and pose health risks to both humans and animals when accumulated in food crops. Role of G-proteins have been established during various abiotic stress responses like high light intensity, temperature, salinity and drought. In terms of metal stress response much data is not available, selected set of G protein subunits mutants have been tested and showed altered sensitivity towards cadmium (Urano et al., 2016). Meta-analyses of more than 20 transcriptomic data sets associated with nutrient stresses or G protein mutations revealed agb1 mutant had altered metal ion profiles and exhibited severe growth arrest under zinc stress, and aberrant root waving under iron and zinc stresses, while the Gα-null mutation attenuated leaf chlorosis under iron deficiency in both Arabidopsis and rice (Wu et al., 2020). N-MYC DOWN-REGULATED-LIKE (NDL) discovered as an interacting partner of the AGB1/AGG dimer. NDL1-AGB1 proteins act in a signaling pathway that modulates root auxin transport and auxin gradients in part by affecting the levels of auxin transport facilitators (Mudgil et al., 2009). NDRG1, animal counterpart of NDL1 is classified as a metastasis repressor and stress response protein. NDRG1 and its human ortholog are induced by nickel, cadmium, and hypoxia (Merlot et al., 2019; Wimmer et al., 2005; Cangul, 2004). Though both in animal and plants NDL proteins indicated to play important role during various kinds of stress responses but their molecular mechanism/s of action are still a mystery. Recently stress analysis of the NDL members in conjunction with AGB1 in Arabidopsis showed differential expression patterns, collectively, all three members showed a role during dehydration stress (Rymaszewski et al., 2017; Katiyar and Mudgil, 2019). We established that NDL1 acts as a modulator in salt stress response and works downstream of AGB1 (Gupta et al. 2021). NDL1-AGB1 module has established role of in salinity and dehydration stress, metal stress related findings on them from animals and plants, and detailed analysis of the G protein interactome with respect to metal stress related interacting components of NDL1-AGB1 module prompted us to propose potential important role of this module in heavy metal stress management as well. Thus, the objective of the current project is to unravel the role of NDL1-AGB1 proteins and their mechanism of action in response to metal stress. Towards this we have performed detailed in-silico analysis of NDL1-AGB1 interactome. Our preliminary results revealed five interactors with predicted role during altered metal stress responses. Detailed molecular analysis of the metal stress response of NDL1-AGB1 module and their metal stress related interactors would be important to discover the still unexplored molecular pathways of metal stress signaling.