A phosphoinositide‐specific phospholipase C pathway elicits stress‐induced Ca²⁺ signals and confers salt tolerance to rice

Abstract

In animal cells, phospholipase C (PLC) isoforms predominantly hydrolyze phosphatidylinositol-4,5-biphosphates [PtdIns(4,5)P ] into the second messengers diacylglycerol (DAG) and inositol 1,4,5-trisphosphate [Ins(1,4,5)P ] to regulate diverse biological processes. By contrast, the molecular mechanisms and physiological significance of PLC signaling in plants still awaits full elucidation. Here, we identified a rice (Oryza sativa cv) PI-PLC, OsPLC1, which preferred to hydrolyze phosphatidylinositol-4-phosphate (PtdIns4P) and elicited stress-induced Ca signals regulating salt tolerance. Analysis by ion chromatography revealed that the concentration of PtdIns4P was c. 28 times of that of PtdIns(4,5)P in shoots. OsPLC1 not only converted PtdIns(4,5)P but also - and even more efficiently - converted PtdIns4P into DAG and Ins(1,4,5)P in vitro and in vivo. Salt stress induced the recruitment of OsPLC1 from cytoplasm to plasma membrane, where it hydrolyzed PtdIns4P. The stress-induced Ca signaling was dependent on OsPLC1, and the PLC-mediated Ca signaling was essential for controlling Na accumulation in leaf blades, thus establishing whole plant salt tolerance. Our work identifies a conversion pathway and physiological function for PtdIns4P pools in rice and reveals the connection between phosphoinositides and Ca signals mediated by PLC during salt stress responses.

Phosphatidylinositol‐hydrolyzing phospholipase C4 modulates rice response to salt and drought

“…AtPLC3 and AtPLC9 positively regulate thermos‐tolerance in Arabidopsis (Liu et al, ; Zheng et al, ). Because PI‐PLC was first indicated in hyperosmotic stress response in Arabidopsis (Hirayama, Ohto, Mizoguchi, & Shinozaki, ), several studies have found that increased expression of specific PLCs could improve salt and/or drought tolerance (Georges et al, ; Li et al, ; Tripathy et al, ; Wang et al, ). However, the mechanism by which PI‐PLCs mediate the stress response is not well understood.…”

MicroRNA-449a Inhibition Protects H9C2 Cells Against Hypoxia/Reoxygenation-Induced Injury by Targeting the Notch-1 Signaling Pathway

“…Recently, these molecules have been implicated in several processes of direct relevance to the heart, including cardiac development, cardiac hypertrophy, heart failure, and angiogenesis [10-13]. The altered expression patterns of several miRNAs in myocardium have been confirmed in the setting of ischemia, raising the possibility that miRNAs might affect cardiac function after AMI [14].…”

De Novo Transcriptome Sequencing and the Hypothetical Cold Response Mode of Saussurea involucrata in Extreme Cold Environments

“…The PLCs act on phosphatidylinositol 4,5-bisphosphate, generating inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). IP3 triggers Ca +2 releases from internal stores [50]. The Phosphoinositide phospholipase C 7 , Phospholipase D p1 are induced by cold in the Arabidopsis (Available online: ; Available online: ) and the Phospholipase A1-II 5 is a cold responsive gene in the Oryza (Available online: ).…”