“…The salt-tolerant phenotype was explained by an increased capacity for Na + uptake into vacuoles, and drought resistance was attributed to an enhanced vacuolar osmoregulatory capacity (Gaxiola et al, 2001(Gaxiola et al, , 2002. It has been subsequently demonstrated that overexpression of AVP1 and other plant type I H + -PPase genes can increase both salt and drought tolerance in diverse systems, including tobacco (Nicotiana tabacum; Gao et al, 2006), cotton (Gossypium hirsutum; Lv et al, 2008Lv et al, , 2009, alfalfa (Medicago sativa; Bao et al, 2008), maize (Zea mays; Li et al, 2008), and creeping bentgrass (Agrostis stolonifera; Li et al, 2010). Interestingly, a study on the variation of salinity tolerance in Arabidopsis ecotypes reported a positive relationship between salt tolerance and AVP1 expression (Jha et al, 2010).…”