Characterization of an acyltransferase capable of synthesizing benzylbenzoate and other volatile esters in flowers and damaged leaves of Clarkia breweri
Characterization of an acyltransferase capable of synthesizing benzylbenzoate and other volatile esters in flowers and damaged leaves of Clarkia breweri
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DOI：
10.1104/pp.006460
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发表时间：
2002-09-01
期刊：
影响因子：
7.4
通讯作者：
Pichersky, E
中科院分区：
文献类型：
--
作者：
D'Auria, JC;Chen, F;Pichersky, E
从750个啤酒花表达序列标签中筛选出一个编码456个氨基酸的蛋白质的cDNA，其序列与植物酰基转移酶具有相当的相似性。该cDNA在大肠杆菌中表达，所产生的蛋白质编码苯甲酰辅酶A（CoA）：苯甲醇苯甲酰转移酶（BEBT）。BEBT催化苯甲酸苄酯的形成，苯甲酸苄酯是C.它具有啤酒花的香味，但它也具有与许多其他醇和酰基辅酶A的活性。BEBT基因在花的不同部位均有表达，在柱头的RNA转录水平最高，而在正常条件下的叶片中没有表达。然而，BEBT的表达诱导受损叶片，达到最大值后6小时发生损害。我们还表明，在这里，一个密切相关的烟草（烟草）基因先前被诱导叶片后，受到植物病原细菌的挑战也有BEBT活性，而最相似的蛋白质BEBT在拟南芥蛋白质组不使用苯甲酰辅酶A作为底物，而是可以使用乙酰辅酶A催化形成的顺式-3-己烯-1-基乙酸酯，绿叶挥发物。
A cDNA encoding a protein with 456 amino acids whose sequence shows considerable similarity to plant acyltransferases was identified among 750 Clarkia breweri flower expressed sequence tags. The cDNA was expressed in Escherichia coli, and the protein produced was shown to encode the enzyme benzoyl-coenzyme A (CoA):benzyl alcohol benzoyl transferase (BEBT). BEBT catalyzes the formation of benzylbenzoate, a minor constituent of the C. breweri floral aroma, but it also has activity with a number of other alcohols and acyl CoAs. The BEBT gene is expressed in different parts of the flowers with maximal RNA transcript levels in the stigma, and no expression was observed in the leaves under normal conditions. However, BEBT expression was induced in damaged leaves, reaching a maximum 6 h after damage occurred. We also show here that a closely related tobacco (Nicotiana tabacum) gene previously shown to be induced in leaves after being challenged by phytopathogenic bacteria also has BEBT activity, whereas the most similar protein to BEBT in the Arabidopsis proteome does not use benzoyl CoA as a substrate and instead can use acetyl CoA to catalyze the formation of cis-3-hexen-1-yl acetate, a green-leaf volatile.