Barman, Ananya2018-02-122023-10-192018-02-122023-10-192017ROLL NO. 11610630https://gyan.iitg.ac.in/handle/123456789/899Supervisors: Ranjan Tamuli and Utpal BoraThe universal second messenger Ca2+ plays a central role in intracellular signaling in eukaryotes. Neurospora crassa is a naturally occurring filamentous fungus extensively used as a model organism to understand different aspects of biological processes including the Ca2+ signaling machinery. However, only a few Ca2+ signaling genes have been studied so far in N. crassa and detailed knowledge about its Ca2+ signaling components has remained largely unknown. Therefore, in my Ph.D thesis work, I have studied the cellular roles of three important Ca2+ signaling genes phospholipase C-1 (plc-1), secretory phospholipase A2 (sPLA2), and calcium proton exchanger-1 (cpe-1) in N. crassa. I found that the plc-1, splA2, and cpe-1 genes are involved in the regulation of [Ca2+]c, carotenoid accumulation, survival under stress conditions, and acquisition of induced thermotolerance in N. crassa. Studies on the double mutants of plc-1, splA2, and cpe-1 revealed that they synthetically regulate growth, aerial hyphae, biomass accumulation, conidial germination, carotenoid accumulation, fertility, Ca2+ stress tolerance, UV survival, oxidative stress survival, and acquisition of thermotolerance induced by heat shock. I have shown that the signaling functions of the plc-1, splA2, and cpe-1 genes are independent of cAMP mechanism.enBIOSCIENCES AND BIOENGINEERINGThesis