Divergence in the Enzymatic Activities of a Tomato and Solanum pennellii Alcohol Acyltransferase Impacts Fruit Volatile Ester Composition
Divergence in the Enzymatic Activities of a Tomato and Solanum pennellii Alcohol Acyltransferase Impacts Fruit Volatile Ester Composition
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DOI：
10.1016/j.molp.2014.11.007
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发表时间：
2015-01-05
期刊：
影响因子：
27.5
通讯作者：
Klee, Harry J.
中科院分区：
文献类型：
--
作者：
Goulet, Charles;Kamiyoshihara, Yusuke;Klee, Harry J.
番茄果实积累了一系列不同的挥发物，包括多种酯。番茄果实中的酯类挥发物含量相对较低，而与番茄密切相关的植物龙葵的酯类挥发物含量要丰富得多。这两个物种之间的酯含量也有质的差异。我们先前已经证明，非特异性酯酶的高表达是番茄果实相对于彭尼利果实总酯含量较低的关键。在这里，我们表明，酯组成的质量差异是成熟相关的酒精酰基转移酶(AAT1)酶活性差异的结果。Pennellii菌株AAT1比番茄菌株AAT1对所有测试的酒精都有更高的效率。这两种酶在底物偏好上有差异，这解释了在挥发物中观察到的变化。结果表明，两个相关物种是如何进化到通过调节酯的合成和降解的平衡来精确调整其挥发性含量的。
Tomato fruits accumulate a diverse set of volatiles including multiple esters. The content of ester volatiles is relatively low in tomato fruits (Solanum lycopersicum) and far more abundant in the closely related species Solanum pennellii. There are also qualitative variations in ester content between the two species. We have previously shown that high expression of a non-specific esterase is critical for the low overall ester content of S. lycopersicum fruit relative to S. pennellii fruit. Here, we show that qualitative differences in ester composition are the consequence of divergence in enzymatic activity of a ripening-related alcohol acyltransferase (AAT1). The S. pennellii AAT1 is more efficient than the tomato AAT1 for all the alcohols tested. The two enzymes have differences in their substrate preferences that explain the variations observed in the volatiles. The results illustrate how two related species have evolved to precisely adjust their volatile content by modulating the balance of the synthesis and degradation of esters.