Abstract:Understanding molecular mechanisms of salt tolerance is beneficial to molecular breeding for salt tolerance in Maize. Previous studies on Arabidopsis revealed that the Na+/H+ antiporter conferring salt tolerance depends on the proton gradients established by proton pumps. H+-ATPase and H+-pyrophosphatase pump cytoplasmic H+ across the vacuolar membrane into the vacuole, generate the H+ gradient, and power secondary active transporters of inorganic ions and organic acids. Therefore, in this study a gene from maize based on AVP1 of Arabidopsis by the homology-based cloning was cloning. Blast searches indicated that this gene encodes a vacuolar membrane pyrophosphatase (VPP)-like protein belonging to the H_PPase superfamily, therefore named as ZmVPP1. The cDNA contains an uninterrupted open reading frame of 2301 bp, coding for a polypeptide of 766 amino acids. Multiple sequences alignment revealed that the protein is highly conserved in the plants. Real-time quantitative PCR was used to analyze expression patterns of ZmVPP1 in different organs and under different stresses. We found that ZmVPP1 was mainly expressed in mature leaves but lower in reproductive organs such as young ear, indicating that ZmVPP1 may play some roles in sequestration of Na+ in the vacuole of mature leaves and protect young tissues. Expression under dehydration, PEG, NaCl, cold and ABA showed that ZmVPP1 was response to the stresses rather than ABA. The results suggest that ZmVPP1 is involved in salt tolerance.