%0 Journal Article
%T Osmotic Stress Induces the Expression of VvMAP Kinase Gene in Grapevine (Vitis vinifera L.)
%A Samia Daldoul
%A Michael Hoefer
%A Ahmed Mliki
%J Journal of Botany
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/737035
%X Abiotic stress adversely affects the growth of grapevine plants. In order to study the early expression changes of genes particularly involved in signal transduction upon salt and drought stresses in grapevines, ESTs derived from a suppressive subtractive hybridization approach (SSH) were selected for expression studies. We were particularly interested in the expression behaviour of the MAP kinase cDNA clone identified by differential screening of the salt-stressed SSH libraries. Interestingly, VvMAP kinase transcript showed a differential expression towards salt and drought treatment in the salt tolerant cultivar Razegui. The upregulation of this transcript was confirmed by RNA blot analysis. Our results revealed that the VvMAP kinase gene could be classified as an osmotic stress responsive gene as its expression was induced by salinity and drought. Furthermore, our study provides the basis for future research on the diverse signaling pathways mediated by MAPKs in grapevine. 1. Introduction Salt and drought stresses are a severe constraint to crop production, and plants that undergo water deficit manifest a wide range of behaviors, ranging from high sensitivity to tolerance. Grapevine (V. vinifera L.) is economically important for Tunisian agriculture but, due to climate variability and environmental changes, yield and quality of the commonly grown grapevine varieties are impaired. Although the responses of plants to osmotic stress have been extensively studied at the physiological and biochemical levels, the perception and intracellular transmission mechanisms remain largely unknown. Due to their sessile habit, plants are exposed to a variety of environmental stresses. Thus, their responses and adaptation to environmental constraints must be communicated in a specific manner from outside of the cell to the inside, and ultimately to the nucleus, where changes in gene expression may occur. Therefore, plant adaptation to salinity requires the regulation of the expression of various genes which could encode for protein kinases and phospholipases, or transcription factors. Mitogen-activated protein kinases (MAPKs) are one of the important proteins involved in the signal transduction of extracellular information to intracellular targets and play a crucial role in the response to biotic and abiotic stresses [1]. Several plant protein kinases were found to be activated by osmotic stress [2]. It was shown that only one specific MAPK is activated by cold and drought stress in alfalfa plants (N6). Several MAP kinases were identified from different plant species
%U http://www.hindawi.com/journals/jb/2012/737035/