Abstract
Plasma membrane (PM) H+-ATPase is an enzyme mainly related to the membrane transport in plants. PM H+-ATPase is involved in many physiological functions,mineral nutrition, metabolite translocation and cellular growth. In Nicotiana plumbaginifolia and Arabidopsis, PM H+-ATPases are encoded by a family of about 10 genes, organized into five subfamilies. It is suggested that each PM H+-ATPase isoforms in fact function in different cells and tissues or at different metabolic states and under different environmental conditions. Flowers of Portulaca generally open in response to a temperature rise and a light exporsure. We had reported that Vanadate-sensitive ATPase activity in crude microsome fraction of petal increased during the dark period just before the flower-opening and flower-opening process induced by light irradiation. One of the main factors of these changes was the increase of enzyme amount. In this study, we isolated 4 new PM H+-ATPase genes from petals. They were classified into the subfamily II and their time-course expression profiles and organ specific ones were investigated. We now examine about the effects of light and temperature condition on their expression.
