甜菊不同叶龄叶片细胞ATPase活性的定位

在甜菊幼叶细胞中,ATPase活性定位于质膜、液泡、胞间连丝、细胞间隙及细胞壁的某些部位上。成熟叶细胞的液泡ATPase活性增强,而质膜ATPase活性减弱。当叶片接近衰老时,除叶绿体片层膜上表现较弱的ATPase活性外,其它部位的ATPase活性丧失。

Localization of ATPase Activity in the Different-Staged Leaf Cells of Stevia rebaudiana Bertoni

Using the cytochemical method of lead phosphate precipitation, the ultrastruc- ture localization of adenosine triphosphatase (ATPase) activity in the different- staged leaf cells of Stevia rebaudiana Bertoni was investigated. The ATPase activity in the young leaf cells was localized on plasmolemma, tonoplast, vacuolar sap, plasmodesmata, intercellular spaces and some sites of cell wall. When the leaves got mature, the ATPase activity in tonoplast and vacuolar sap tended to increase, at plasmolemma, while, markly reduced or almost inactivated. In the aging leaves, it was found that there was the reaction of ATPase activity in choroplast lamellae, but no ATPase activity in other parts of the cell. The relationship of the vacuolar ATPase with the vacuolar transport and accumulation of stevioside was discussed.