Activated expression of AtEDT1/HDG11 promotes lateral root formation in Arabidopsis mutant edt1 by upregulating jasmonate biosynthesis
Activated expression of AtEDT1/HDG11 promotes lateral root formation in Arabidopsis mutant edt1 by upregulating jasmonate biosynthesis
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DOI：
10.1111/jipb.12347
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发表时间：
2015-12-01
影响因子：
11.4
通讯作者：
Xiang, Cheng-Bin
中科院分区：
文献类型：
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作者：
Cai, Xiao-Teng;Xu, Ping;Xiang, Cheng-Bin
根系构型对植物吸收水分和养分至关重要。我们以前报道edt 1（edt 1D）突变体与改变根结构，有助于显着的抗旱性。然而，其潜在的分子机制还不清楚。在这里，我们报告的机制之一EDT 1/HDG 11赋予改变根结构。野生型和edt 1D根转录组的比较表明，在edt 1D根中，茉莉酸生物合成和信号转导途径的基因表达量显著增加，并通过定量RT-PCR得到证实。进一步分析表明，EDT 1/HDG 11作为转录因子直接结合于编码JA生物合成中四种关键酶的AOS、AOC 3、OPR 3和OPDL 1启动子中的HD结合位点。我们发现，茉莉酸水平显着升高edt 1D根与野生型相比，随后。另外，edt 1D侧根原基中生长素的积累量明显高于野生型。edt 1D opcl 1双突变体的遗传分析也表明HDG 11在调节LR形成中部分依赖于JA。综上所述，过量表达EDT 1/HDG 11通过直接上调编码JA生物合成酶的几个基因的表达来激活生长素信号传导并促进侧根形成，从而增加了edt 1D根部的JA水平。
Root architecture is crucial for plants to absorb water and nutrients. We previously reported edt1 (edt1D) mutant with altered root architecture that contributes significantly to drought resistance. However, the underlying molecular mechanisms are not well understood. Here we report one of the mechanisms underlying EDT1/HDG11-conferred altered root architecture. Root transcriptome comparison between the wild type and edt1D revealed that the upregulated genes involved in jasmonate biosynthesis and signaling pathway were enriched in edt1D root, which were confirmed by quantitative RT-PCR. Further analysis showed that EDT1/HDG11, as a transcription factor, bound directly to the HD binding sites in the promoters of AOS, AOC3, OPR3, and OPCL1, which encode four key enzymes in JA biosynthesis. We found that the jasmonic acid level was significantly elevated in edt1D root compared with that in the wild type subsequently. In addition, more auxin accumulation was observed in the lateral root primordium of edt1D compared with that of wild type. Genetic analysis of edt1D opcl1 double mutant also showed that HDG11 was partially dependent on JA in regulating LR formation. Taken together, overexpression of EDT1/HDG11 increases JA level in the root of edt1D by directly upregulating the expressions of several genes encoding JA biosynthesis enzymes to activate auxin signaling and promote lateral root formation.