| To study the effect on expressions of PM H+-ATPase, Ca2+-ATPase and V-ATPase with ABA treatment in vitro, apple fruit and grape berry were used in the experiment. Immuno-gold electron microscopy and western blotting showed that, first, PM H+-ATPase, 99.7 KDa, enriched on plasmalemma and less on vacuole membrane, got to its peak of quantity at early stage of fruit development; Second, Ca2+-ATPase was observed on almost all the membrane systems and reached the maximum content during the middle stage of fruit development. Antibody recognized a band of 121.1 KDa in apple fruit microsomes, while two bands of 112.3 KDa and 100.6 KDa respectively in grape fruit microsomes, which changed similarly at each developing stage; Third, The location of V-ATPase was on vacuole membrane, plasmalemma and vacuole membrane , which showed the lowest density in the middle stage with its subunits keeping reacting contrarily to each other all through the fruit development, that is, for example, in apple fruit, the content of connecting subunit whose molecular mass was 62.2 KDa, decreased continuously from the early stage to the harvest stage contrast to the deepening density of the band of 71.3 KDa, the catalysis subunit. In grape berry, however, the changing principles on homologous subunits were completely opposite to the rules found in apple fruit. ABA mainly induced the expressions of catalysis subunits of V-ATPase, which resulted in a remarkable rise on density of gold particles, particularly on plasmalemma, except for the plasmalemma of sieve elements with nacreous cell wall; and last, ABA treatment in vitro could raise the contents of all the enzymes above mentioned at different degrees.In conclusion, PM H+-ATPase and Ca2+-ATPase reached their highest content at early and middle developmental stage respectively, compared to the lowest content of V-ATPase at middle stage of the fruit development. In vitro, ABA treatment induced the expressions of ATPase.
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