Malate Plays a Crucial Role in Starch Metabolism, Ripening, and Soluble Solid Content of Tomato Fruit and Affects Postharvest Softening
Malate Plays a Crucial Role in Starch Metabolism, Ripening, and Soluble Solid Content of Tomato Fruit and Affects Postharvest Softening
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DOI：
10.1105/tpc.109.072231
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发表时间：
2011-01-01
期刊：
影响因子：
11.6
通讯作者：
Fernie, Alisdair R.
中科院分区：
文献类型：
--
作者：
Centeno, Danilo C.;Osorio, Sonia;Fernie, Alisdair R.
尽管事实上，水果的有机酸含量被认为是其最重要的商业品质性状之一，当由消费者进行评估时，关于有机酸代谢对水果本身的生理重要性的了解相对较少。在这里，我们评估的效果修改苹果酸代谢的水果特定的方式，通过减少线粒体苹果酸脱氢酶或脱氢酶的活动，通过有针对性的反义方法在番茄（番茄）。虽然这些遗传扰动对水果总产量的影响相对较小，但它们对水果代谢产生了巨大的影响，以及采后货架期和对细菌感染的敏感性发生了意想不到的变化。详细的表征表明，成熟的速度基本上是不变的，但含有较高的苹果酸线的特点是较低水平的瞬时淀粉和较低的可溶性糖含量在收获时，而那些具有较低的苹果酸含有较高水平的这些碳水化合物。ADP-葡萄糖焦磷酸化酶的活化状态分析表明，它与过渡淀粉的积累。与质体苹果酸脱氢酶的活化状态改变和转基因品系的色素生物合成改变一起，这些结果表明表型是由于细胞氧化还原状态改变。综合数据揭示了苹果酸代谢在番茄果实代谢和发育中的重要性，并证实了瞬时淀粉在该物种农艺产量测定中的重要性。
Despite the fact that the organic acid content of a fruit is regarded as one of its most commercially important quality traits when assessed by the consumer, relatively little is known concerning the physiological importance of organic acid metabolism for the fruit itself. Here, we evaluate the effect of modifying malate metabolism in a fruit-specific manner, by reduction of the activities of either mitochondrial malate dehydrogenase or fumarase, via targeted antisense approaches in tomato (Solanum lycopersicum). While these genetic perturbations had relatively little effect on the total fruit yield, they had dramatic consequences for fruit metabolism, as well as unanticipated changes in postharvest shelf life and susceptibility to bacterial infection. Detailed characterization suggested that the rate of ripening was essentially unaltered but that lines containing higher malate were characterized by lower levels of transitory starch and a lower soluble sugars content at harvest, whereas those with lower malate contained higher levels of these carbohydrates. Analysis of the activation state of ADP-glucose pyrophosphorylase revealed that it correlated with the accumulation of transitory starch. Taken together with the altered activation state of the plastidial malate dehydrogenase and the modified pigment biosynthesis of the transgenic lines, these results suggest that the phenotypes are due to an altered cellular redox status. The combined data reveal the importance of malate metabolism in tomato fruit metabolism and development and confirm the importance of transitory starch in the determination of agronomic yield in this species.