Differential Expression of Mitogen Activated Protein Kinase (MAPK) and Stress-Related Genes in Rice Overexpressing MPK3 and MPK6 under Abiotic Stress

Abstract

Plants being sessile have ability to adapt themselves in constantly changing and challenging environment by perceiving external/internal cues and transducing them down to the nucleus for appropriate cellular reorganization. Activation of mitogen-activated protein kinases (MAPKs) is a common reaction of plant cells towards such cues in development-related signal transduction pathways. The downstream events after the activation of MAPKs are largely unknown in plants. In the present study, we examined the effect of arsenic, salt and drought stress on growth parameters and transcript profiling of MAPKs, silicon transporters andstress responsivegenes in transgenic rice overexpressing OsMPK3 and OsMPK6 under the control of a dexamethasone (DEX)-inducible promoter, and possible role MAPKs in stress tolerance. Our results revealed that OsMPK3 and OsMPK6 overexpressing lines under arsenic stress and drought stress enhanced the transcript level of stress responsive genes, encoding enzymes superoxide dismutase, ascorbate peroxidase, glutamine synthetase and aldehyde oxidase. Upregulation in transcripts profiling of three silicon transporter genes OsLsi1, OsLsi2 and OsLsi6 showed improved stress tolerance ability of OsMPK3 and OsMPK6 overexpressing lines by effective absorption of silicon. The fundamental knowledge about the function of MPK3 and MPK6, important member of MAPKs family may also lead to an engineered plant tolerant to various abiotic and biotic stresses.