Prof. S. Rajagopal was elected fellow to the Indian National Science Academy (INSA), New Delhi w.e.f. 1st January 2023 for his significant contributions to the area of photosynthesis with emphasis on the bioenergetics and acclimation of chloroplasts. His research lab at the Department of Plant Sciences, School of Life Sciences, University of Hyderabad (UoH) studied in detail the structural and organizational dynamics of photosystems (PS) and light-harvesting complexes (LHC) in Chlamydomonas reinhardtii and Arabidopsis thaliana. His lab used proteomics and metabolomics-based approaches to dissect the abiotic stress-responsive events in chloroplasts.
He discovered that under fluctuating light, the LHCB2 subunit undergoes phosphorylation triggering the dissociation of LHCII from PS II and eventual migration to PSI, a phenomenon called state transitions. Under temperature and salt stresses too, state transitions constituted an important protective strategy.
Prof. Rajagopal further studied the influence of high light and iron deficiency on the organization of photosynthetic apparatus and proposed a structural model of PSI. He emphasized that aggregation of LHCII complexes helped C. reinhardtii to acclimate to abiotic stress through non-photochemical quenching mediated by LHC stress-related protein. His findings on the physiological and molecular basis of abiotic stress acclimation could pave the way for designing sustenance strategies of photosynthesis under limiting conditions.
Prof. Rajagopal has also been working on the structural properties and regulation of purified proteins.