Cloning and functional analysis of wheat V-H plus -ATPase subunit genes

The root microsomal proteomes of salt-tolerant and salt-sensitive wheat lines under salt stress were analyzed by two-dimensional electrophoresis and mass spectrum. A wheat V-H+-ATPase E subunit protein was obtained whose expression was enhanced by salt stress. In silicon cloning identified the full-length cDNA sequences of nine subunits and partial cDNA sequences of two subunits of wheat V-H+-ATPase. The expression profiles of these V-H+-ATPase subunits in roots and leaves of both salt-tolerant and salt-sensitive wheat lines under salt and abscisic acid (ABA) stress were analyzed. The results indicate that the coordinated enhancement of the expression of V-H+-ATPase subunits under salt and ABA stress is an important factor determining improved salt tolerance in wheat. The expression of these subunits was tissue-specific. Overexpression of the E subunit by transgenic Arabidopsis thaliana was able to enhance seed germination, root growth and adult seedling growth under salt stress.