The Wheat E Subunit of V-Type H(+)-ATPase Is Involved in the Plant Response to Osmotic Stress

The vacuolar type H(+)-ATPase (V-type H(+)-ATPase) plays important roles in establishing an electrochemical H(+)-gradient across tonoplast, energizing Na(+) sequestration into the central vacuole, and enhancing salt stress tolerance in plants. In this paper, a putative E subunit of the V-type H(+)-ATPase gene, W36 was isolated from stress-induced wheat de novo transcriptome sequencing combining with 5'-RACE and RT-PCR methods. The full-length of W36 gene was 1097 bp, which contained a 681 bp open reading frame (ORF) and encoded 227 amino acids. Southern blot analysis indicated that W36 was a single-copy gene. The quantitative real-time PCR (qRT-PCR) analysis revealed that the expression level of W36 could be upregulated by drought, cold, salt, and exogenous ABA treatment. A subcellular localization assay showed that the W36 protein accumulated in the cytoplasm. Isolation of the W36 promoter revealed some cis-acting elements responding to abiotic stresses. Transgenic Arabidopsis plants overexpressing W36 were enhanced salt and mannitol tolerance. These results indicate that W36 is involved in the plant response to osmotic stress.