Changes in acidity and in proton transport at the tonoplast of grape berries during development
Changes in acidity and in proton transport at the tonoplast of grape berries during development
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DOI：
10.1007/s004250000472
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发表时间：
2001-05
期刊：
影响因子：
4.3
通讯作者：
N. Terrier;F. Sauvage;A. Ageorges;C. Romieu
中科院分区：
文献类型：
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作者：
N. Terrier;F. Sauvage;A. Ageorges;C. Romieu
与许多水果一样，葡萄浆果（葡萄属viniferaL.）成熟导致苹果酸的强烈分解。使用膜组分，我们测试的假设，酸度的变化导致苹果酸液泡分解。两个主要的液泡泵无机焦磷酸酶（V-PPase; EC 3.6.1.1）和液泡ATP酶（V-ATP酶; EC 3.6.1.3）的水解活性在整个发育过程中增加，在成熟过程中加速，如通过Western印迹和转录表达分析所证实的。V-PPase活性与V-ATPase活性的比值始终有利于V-PPase，并达到最大值。在成熟过程中，阴离子运输速率显著增加。成熟前，液泡膜被动透性较低，成熟后上升。我们的数据表明，液泡膜渗漏显着增加成熟过程中。这种泄漏可能是苹果酸分解的主要原因，由于氧化磷酸化无法面对增加的能量需求而放大。
As in many fruits, the induction of grape berry (Vitis viniferaL.) ripening results in intense breakdown of malic acid. Using membrane fractions, we tested the hypothesis that changes in acidity resulted from malate vacuolar decompartmentation. The hydrolytic activities of the two primary vacuolar pumps inorganic pyrophosphatase (V-PPase; EC 3.6.1.1) and vacuolar ATPase (V-ATPase; EC 3.6.1.3) increased throughout development with an acceleration during ripening, as confirmed by Western blotting and analysis of transcript expression. The ratio of V-PPase activity to V-ATPase activity was always in favour of V-PPase and reached its maximum value atvéraison. The rate of anion transport strongly increased during ripening. Before ripening, tonoplast passive permeability was low, but rose during ripening. Our data indicate that tonoplast leakage dramatically increased during ripening. This leakage is probably the prime cause of malate decompartmentation, amplified by the incapacity of oxidative phosphorylation to face increased energy demand.