Investigating inducible short-chain alcohol dehydrogenases/reductases clarifies rice oryzalexin biosynthesis.
Investigating inducible short-chain alcohol dehydrogenases/reductases clarifies rice oryzalexin biosynthesis.
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DOI：
10.1111/tpj.13249
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发表时间：
2016-10
期刊：
影响因子：
--
通讯作者：
Peters RJ
中科院分区：
文献类型：
--
作者：
Kitaoka N;Wu Y;Zi J;Peters RJ
水稻（Oryza sativa）产生多种与labdane相关的二萜，作为植物抗毒素和化感化学物质。这些重要天然产物的生产已部分阐明。然而，在许多这些二萜化合物中发现的负责产生酮基的氧化酶在很大程度上仍然未知。迄今为止，只有一种短链醇脱氢酶/还原酶（sdr）被提出催化该途径的最后一步，并已被表征。而水稻含有bbb220个sdr，只有5个转录被证明是由真菌细胞壁激发子几丁质诱导的。这包括莫内酯A合成酶（OsMAS/SDR110C- ms1），其他四个都属于同一个SDR110C家族，进一步表明在二萜类生物合成中起作用。在这里，首先使用简化的底物类似物进行生化表征，以表明潜在的功能，然后通过对关键生物合成中间体的进一步分析来支持。然后采用动力学研究来进一步阐明这些作用。令人惊讶的是，OsSDR110C-MS2更有效地催化最终氧化产生之前分配给OsMAS/SDR110C-MS1的内酯A，我们推测后一种SDR可能具有替代功能。另一方面，其中两种sdr明显参与了米zalexin的生物合成，OsSDR110C-MI3容易氧化米zalexin D的3α-羟基，而OsSDR110C-MS3也可以氧化伴生的7β-羟基。然后，这些sdr一起从水稻抗毒素D产生水稻抗毒素A - C，基本上完成了水稻植物抗毒素家族的生物合成。
Rice (Oryza sativa) produces a variety of labdane-related diterpenoids as phytoalexins and allelochemicals. The production of these important natural products has been partially elucidated. However, the oxidases responsible for production of the keto groups found in many of these diterpenoids have largely remained unknown. Only one short-chain alcohol dehydrogenase/reductases (SDRs), which has been proposed to catalyze the last step in such a pathway, has been characterized to-date. While rice contains >220 SDRs, only the transcription of five has been shown to be induced by the fungal cell wall elicitor chitin. This includes the momilactone A synthase (OsMAS/SDR110C-MS1), with the other four all falling in the same SDR110C family, further suggesting roles in diterpenoid biosynthesis. Here biochemical characterization with simplified substrate analogs was first used to indicate potential functions, which were then supported by further analyses with key biosynthetic intermediates. Kinetic studies were then employed to further clarify these roles. Surprisingly, OsSDR110C-MS2 more efficiently catalyzes the final oxidation to produce momilactone A that was previously assigned to OsMAS/SDR110C-MS1, and we speculate that this latter SDR may have an alternative function instead. On the other hand, two of these SDRs clearly appear to act in oryzalexin biosynthesis, with OsSDR110C-MI3 readily oxidizing the 3α-hydroxyl of oryzalexin D, while OsSDR110C-MS3 can also oxidize the accompanying 7β-hydroxyl. Together, these SDRs then serve to produce oryzalexins A – C from oryzalexin D, essentially completing elucidation of the biosynthesis of this family of rice phytoalexins.
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影响因子：
5.1
作者：
Persson, Bengt;Kallberg, Yvonne;Bray, James E.;Bruford, Elspeth;Dellaporta, Stephen L.;Favia, Angelo D.;Gonzalez Duarte, Roser;Jornvall, Hans;Kavanagh, Kathryn L.;Kedishvili, Natalia;Kisiela, Michael;Maserk, Edmund;Mindnich, Rebekka;Orchard, Sandra;Penning, Trevor M.;Thornton, Janet M.;Adamski, Jerzy;Oppermann, Udo
通讯作者：
Oppermann, Udo
影响因子：
4.8
作者：
Shimura, Kazuhiro;Okada, Atsushi;Yamane, Hisakazu
通讯作者：
Yamane, Hisakazu
影响因子：
7.2
作者：
Schmelz, Eric A.;Huffaker, Alisa;Peters, Reuben J.
通讯作者：
Peters, Reuben J.
影响因子：
3.5
作者：
Wu Y;Hillwig ML;Wang Q;Peters RJ
通讯作者：
Peters RJ
影响因子：
23.9
作者：
Zi J;Mafu S;Peters RJ
通讯作者：
Peters RJ