An ancestral allele of grapevine transcription factor MYB14 promotes plant defence.
An ancestral allele of grapevine transcription factor MYB14 promotes plant defence.
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DOI：
10.1093/jxb/erv569
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发表时间：
2016-03
影响因子：
6.9
通讯作者：
Nick P
中科院分区：
文献类型：
--
作者：
Duan D;Fischer S;Merz P;Bogs J;Riemann M;Nick P
在抗病葡萄属樟子松中芪类化合物诱导表达增加的分子机制可以通过MYB 14启动子的诱导表达增加来解释。芪合酶是植物抗毒素白藜芦醇合成的关键酶。欧洲野生葡萄藤种葡萄属sylvestris的一些克隆几乎已经灭绝，它们在不同形式的压力下积累了更多的白藜芦醇。在目前的研究中，我们问的诱导芪合酶的转录Hoe 29，其中一个具有升高的芪诱导，可能是由于转录因子MYB 14的诱导升高。Hoe 29和Ke 83（第二个芪诱导型基因型）的MYB 14启动子具有不同的区域，并应用于启动子-报告系统。我们发现，芪合酶诱导与这两种基因型的MYB 14转录诱导的差异相关。这两个等位基因诱导UV在启动子-报告基因测定，但只有MYB 14启动子Hoe 29诱导flg 22，与芪合酶表达的供体基因型，其中都响应于UV，但只有Hoe 29是响应于霜霉病葡萄在防御过程中。我们绘制了上游信号，发现RboH依赖的氧化爆发，钙离子内流，MAPK级联，茉莉酸激活MYB 14启动子，而水杨酸是无效的。我们的数据表明MYB 14启动子的Hoe 29等位基因具有作为抗性育种的候选靶标的潜力。
The molecular mechanisms underlying the elevated inducibility of stilbene in pathogen-resistant Vitis sylvestris can be explained by the increased inducibility of the MYB14 promoter. Stilbene synthase is a key enzyme for the production of the phytoalexin resveratrol. Some clones of Vitis sylvestris, a wild European grapevine species which is almost extinct, have been shown to accumulate more resveratrol in response to different forms of stress. In the current study, we asked whether the induction of stilbene synthase transcripts in Hoe29, one of the V. sylvestris clones with elevated stilbene inducibility, might result from the elevated induction of the transcription factor MYB14. The MYB14 promoter of Hoe29 and of Ke83 (a second stilbene-inducible genotype) harboured distinct regions and were applied to a promoter–reporter system. We show that stilbene synthase inducibility correlates with differences in the induction of MYB14 transcripts for these two genotypes. Both alleles were induced by UV in a promoter–reporter assay, but only the MYB14 promoter from Hoe29 was induced by flg22, consistent with the stilbene synthase expression of the donor genotypes, where both respond to UV but only Hoe29 is responsive to Plasmopara viticola during defence. We mapped upstream signals and found that a RboH-dependent oxidative burst, calcium influx, a MAPK cascade, and jasmonate activated the MYB14 promoter, whereas salicylic acid was ineffective. Our data suggest that the Hoe29 allele of the MYB14 promoter has potential as a candidate target for resistance breeding.