GmTIR1/GmAFB3-based auxin perception regulated by miR393 modulates soybean nodulation
GmTIR1/GmAFB3-based auxin perception regulated by miR393 modulates soybean nodulation
复制标题
miR393 调控的基于 GmTIR1/GmAFB3 的生长素感知调节大豆结瘤
DOI：
10.1111/nph.14632
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发表时间：
2017-07-01
期刊：
影响因子：
9.4
通讯作者：
Li, Xia
中科院分区：
文献类型：
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作者：
Cai, Zhaoming;Wang, Youning;Li, Xia
生长素在豆科植物的结瘤中起着重要的作用。然而，生长素信号调控根瘤形成的机制在很大程度上是未知的。特别是，生长素受体及其调控在决定性结节发育中的作用仍然难以捉摸。我们检测了生长素受体GmTIR1/GmAFB3基因在大豆中的表达模式。我们分析了GmTIR1/AFB3在根瘤菌侵染和根瘤数量调控中的作用，并检测了miR393在根瘤形成过程中的作用及其与GmTIR1/AFB3的关系。结果表明，GmTIR1和GmAFB3基因在结瘤过程中表现出不同的表达模式，过表达GmTIR1基因可显著增加结节的屈曲灶和最终结节的数量。miR393家族对GmTIR1/AFB3基因进行转录后切割，miR393家族成员的敲除显著增加根瘤菌感染和根瘤菌数量。在miR393切割位点过度表达抗miR393切割的GmTIR1C突变形式导致感染灶和结节数量进一步增加，这表明mir33s通过直接靶向GmTIR1C来调节结节。本研究表明，gmtir1和gmafb3介导的生长素信号通路受miR393的时空调控，在大豆根瘤发育中起着至关重要的作用。
Auxins play important roles in the nodulation of legumes. However, the mechanism by which auxin signaling regulates root nodulation is largely unknown. In particular, the role of auxin receptors and their regulation in determinate nodule development remains elusive.We checked the expression pattern of the auxin receptor GmTIR1/GmAFB3 genes in soybean. We analyzed the functions of GmTIR1/AFB3 in the regulation of rhizobial infection and nodule number, and also tested the functions of miR393 during nodulation and its relationship with GmTIR1/AFB3.The results showed that GmTIR1 and GmAFB3 genes exhibit diverse expression patterns during nodulation and overexpression of GmTIR1 genes significantly increased inflection foci and eventual nodule number. GmTIR1/AFB3 genes were post-transcriptionally cleaved by miR393 family and knock-down of the miR393 family members significantly increased rhizobial infection and the nodule number. Overexpression of the mutated form of GmTIR1C at the miR393 cleavage site that is resistant to miR393 cleavage led to a further increase in the number of infection foci and nodules, suggesting that miR393s modulate nodulation by directly targeting GmTIR1C.This study demonstrated that GmTIR1-and GmAFB3-mediated auxin signaling, that is spatio-temporally regulated by miR393, plays a crucial role in determinate nodule development in soybean.