Loss-of-function of vacuolar-type H+ pyrophosphatase gene lead to reduce in stomatal aperture and density

Abstract

Abstract Transgenic plants over-expressing vacuolar H+ type pyrophosphatase (V-PPase) gene were reported to display drought resistance, reduced vacuolar pH and raised stomatal conductance. To further understand the role of V-PPase on stomatal regulation, loss- and gain-of-function approaches were combined for analysing relationship between stomatal aperture and V-PPase gene expression. Homozygous mutants of this gene were isolated by polymerase chain reaction (PCR) method. BCECF-AM fluorescence probe was used for detecting cellular pH. The result here indicated that Arabidopsis plant lines over-expressing of V-PPase gene displayed raised stomatal aperture. Both of stomatal aperture and density of homozygous vpp mutants were less than that of control plants. In addition, cellular pH of guard cells in vpp mutants was higher than control evidently. In general, our results suggested that V-PPase activity regulates stomatal aperture by changing guard cell pH.