A Moso bamboo gene VQ28 confers salt tolerance to transgenic Arabidopsis plants.

Abstract

Overexpression ofPeVQ28in Arabidopsis regulated the expression of salt/ABA-responsive genes and indicated thatPeVQ28may affect the ABA synthesis induced by stress in plants by regulating salt tolerance. Plant-specific VQ proteins, which contain a conserved short FxxhVQxhTG amino acid sequence motif, play an important role in abiotic stress responses, but their functions have not been previously studied in Moso bamboo (Phyllostachys edulis). In this study, real-time quantitative PCR analysis indicated that expression of PeVQ28 was induced by salt and abscisic acid stresses. A subcellular localization experiment showed that PeVQ28 was localized in the nuclei of tobacco leaf cells. Yeast two-hybrid and bimolecular fluorescence complementation analyses indicated that PeVQ28 and WRKY83 interactions occurred in the nucleus. The PeVQ28-overexpressing Arabidopsis lines showed increased resistance to salt stress and enhanced sensitivity to ABA. Compared with wild-type plants under salt stress, PeVQ28-transgenic plants had lower malondialdehyde and higher proline contents, which might enhance stress tolerance. Overexpression of PeVQ28 in Arabidopsis enhanced expression of salt- and ABA-responsive genes. These results suggest that PeVQ28 functions in the positive regulation of salt tolerance mediated by an ABA-dependent signaling pathway.