Molecular cloning and expression analysis of four turmeric MAP kinase genes in response to abiotic stresses and phytohormones

Abstract

Plant mitogen activated protein kinase (MAPK) cascades comprise a complex network playing a major role in regulating extracellular stimuli as well as developmental processes. The present study involves cloning four MAPKs (ClMPK1, 3, 4 and 5) from Curcuma longa. All four ClMPKs have fully canonical motifs of MAPK and each is represented by a single copy in the turmeric genome. The analysis of exon-intron junctions revealed conserved nature of ClMPKs across different plant groups. The RT-qPCR analysis showed their expression in mature plant tissues. The transcript analysis using the RT-qPCR shows that the four ClMPKs were differentially regulated by cold, salinity, and drought stresses. ClMPK4 showed a significant upregulation in the presence of NaCl, polyethylene glycol, and mannitol. The time-course expression analysis revealed a marked accumulation of ClMPK1 and ClMPK4 transcripts after mechanical wounding or applications of abscisic acid, H2O2, methyl jasmonate, and salicylic acid. ClMPK5 showed a unique and pronounced expression in response to hexavalent chromium (CrVI). © 2014 Springer Science+Business Media Dordrecht.