Identification of an aromatic aldehyde synthase involved in indole-3-acetic acid biosynthesis in the galling sawfly (Pontania sp.) and screening of an inhibitor
Identification of an aromatic aldehyde synthase involved in indole-3-acetic acid biosynthesis in the galling sawfly (Pontania sp.) and screening of an inhibitor
复制标题
DOI：
10.1016/j.ibmb.2021.103639
复制
发表时间：
2021-08-23
影响因子：
3.8
通讯作者：
Suzuki, Yoshihito
中科院分区：
文献类型：
--
作者：
Miyata, Umi;Arakawa, Kenta;Suzuki, Yoshihito
3-吲哚乙酸 (IAA) 是一种植物激素生长素，可能参与昆虫瘿诱导。我们之前提出IAA生物合成途径为Trp->吲哚-3-乙醛肟->吲哚-3-乙醛(IAAld)->IAA或Trp->IAAld->IAA。在这项研究中，我们使用异源蛋白质表达系统调查了负责限速步骤的瘿锯蝇酶，并鉴定了 PonAAS2（一种芳香醛合酶），可催化色氨酸转化为 IAAld。 PonAAS2基因在含有高浓度IAA的早中期幼虫中高表达，但在秋季从虫瘿中逃逸且含有极低浓度IAA的幼虫中，表达水平几乎可以忽略不计。通过筛选化学文库获得的PonAAS2抑制剂可抑制叶蜂酶溶液中IAA的产生80%，表明该酶在叶蜂IAA生物合成中的重要作用。
Indole-3-acetic acid (IAA), a phytohormone auxin, may be involved in insect gall induction. We previously proposed that the IAA biosynthetic pathway is Trp -> indole-3-acetaldoxime -> indole-3-acetaldehyde (IAAld) -> IAA or Trp -> IAAld -> IAA. In this study, we surveyed galling sawfly enzymes responsible for the rate-limiting steps using a heterologous protein expression system and identified PonAAS2, an aromatic aldehyde synthase, that catalyzed the conversion of Trp to IAAld. The PonAAS2 gene was highly expressed in early- and mid-stage larvae that contained high concentrations of IAA, but the expression level was almost negligible in larvae that had escaped from their gall in autumn and contained very low concentrations of IAA. An inhibitor of PonAAS2, obtained by screening a chemical library, inhibited IAA production in sawfly enzyme solution by 80%, suggesting the important role of this enzyme in IAA biosynthesis in sawfly.