Vacuolar membrane H+-ATPase cˋˋ subunit gene (ThVHAcˋˋ1) from Tamarix hispida Willd improves salt stress tolerance

Abstract

The plant vacuolar H+-ATPase (V-ATPase) is a multisubunit complex. In addition to performing basic housekeeping functions, this complex is also involved in abiotic stress resistance in plants. In this study, a V-ATPase cˋˋ subunit gene (ThVHAcˋˋ1) from Tamarix hispida Willd was cloned with a 534-bp ORF. Sequence analysis showed that the ThVHAcˋˋ1 protein contains four transmembrane helices and lacks a signal peptide. qRT-PCR results showed that ThVHAcˋˋ1 was primarily induced by treatments of NaCl, NaHCO3, PEG6000, CdCl2 or ABA in roots, stems and leaves of T. hispida. The expression pattern of ThVHAcˋˋ1 was significantly different from that of ThVHAc1 (a V-ATPase c subunit in T. hispida). Furthermore, the cell survival rates and density (OD600) results showed that the transgenic yeast overexpressing ThVHAcˋˋ1 exhibited increased tolerance to the above-mentioned abiotic stresses. In addition, the overexpression of ThVHAcˋˋ1 confers salt tolerance to transgenic Arabidopsis plants by improving the ROS content and decreasing the accumulation of O2− and H2O2. Similarly, the homologous transformation of the ThVHAcˋˋ1 gene into T. hispida also improved salt tolerance. Our results suggest that the ThVHAcˋˋ1 gene plays an important role in plant stress tolerance.