Multiple genes recruited from hormone pathways partition maize diterpenoid defences
Multiple genes recruited from hormone pathways partition maize diterpenoid defences
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DOI：
10.1038/s41477-019-0509-6
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发表时间：
2019-10-01
期刊：
影响因子：
18
通讯作者：
Schmelz, Eric A.
中科院分区：
文献类型：
--
作者：
Ding, Yezhang;Murphy, Katherine M.;Schmelz, Eric A.
复制和分歧的主要途径基因的植物专门的代谢进化的基础，然而，机制分区平行激素和防御途径往往是推测。例如，主要途径中间体对映贝壳杉烯对于赤霉素生物合成是必需的，并且也是玉米抗生素的建议前体。通过整合转录共调控模式，全基因组关联研究，组合酶分析，蛋白质组学和有针对性的突变体分析，我们表明，玉米贝壳杉酯素的生物合成收益通过位置异构体的内异贝壳杉烯形成的二萜合酶对招募赤霉素代谢。氧化和随后的去饱和的ent-异贝壳杉烯由三个混杂的细胞色素P450和一个新的类固醇5 α还原酶间接产生主要的ent-贝壳杉烯相关的抗生素镰刀菌茎腐病抗性所需的。来自多个重复的贝壳杉烯代谢基因的途径分支的分歧和差异表达最小化初级代谢的失调，通过迂回生物合成的对映贝壳杉烯相关的抗生素，而不生产生长激素前体在防御。
Duplication and divergence of primary pathway genes underlie the evolution of plant specialized metabolism; however, mechanisms partitioning parallel hormone and defence pathways are often speculative. For example, the primary pathway intermediate ent-kaurene is essential for gibberellin biosynthesis and is also a proposed precursor for maize antibiotics. By integrating transcriptional coregulation patterns, genome-wide association studies, combinatorial enzyme assays, proteomics and targeted mutant analyses, we show that maize kauralexin biosynthesis proceeds via the positional isomer ent-isokaurene formed by a diterpene synthase pair recruited from gibberellin metabolism. The oxygenation and subsequent desaturation of ent-isokaurene by three promiscuous cytochrome P45Os and a new steroid 5 alpha reductase indirectly yields predominant ent-kaurene-associated antibiotics required for Fusarium stalk rot resistance. The divergence and differential expression of pathway branches derived from multiple duplicated hormone-metabolic genes minimizes dysregulation of primary metabolism via the circuitous biosynthesis of ent-kaurene-related antibiotics without the production of growth hormone precursors during defence.