MiR397b regulates both lignin content and seed number in Arabidopsis via modulating a laccase involved in lignin biosynthesis.
MiR397b regulates both lignin content and seed number in Arabidopsis via modulating a laccase involved in lignin biosynthesis.
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DOI：
10.1111/pbi.12222
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发表时间：
2014-10
影响因子：
13.8
通讯作者：
Cong-Ying Wang;Shengchun Zhang;Yang Yu;Yu-Chun Luo;Qing Liu;Changliang Ju;Yu-Chan Zhang;L. Qu;W. J. Lucas;Xiaojing Wang;Yue‐Qin Chen
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文献类型：
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作者：
Cong-Ying Wang;Shengchun Zhang;Yang Yu;Yu-Chun Luo;Qing Liu;Changliang Ju;Yu-Chan Zhang;L. Qu;W. J. Lucas;Xiaojing Wang;Yue‐Qin Chen
植物漆酶（LAC）属于蓝铜氧化酶家族，能将单木质素转化为木质素.最近的研究已经确定了microRNA参与这一过程;然而，植物漆酶的生理功能和调节仍然知之甚少。在这里，我们表明，漆酶基因，LAC 4，由microRNA，miR 397 b，控制木质素的生物合成和种子产量在拟南芥。在转基因植物中，miR 397 b（OXmiR 397 b）的过表达减少了木质素沉积。血管和纤维的次生壁厚度在OXmiR 397 b系中减少，并且胡萝卜素亚基和愈创木基亚基都减少，导致血管组织弱化。相反，miR 397 b抗性漆酶mRNA的过表达导致相反的表型。过表达miR 397 b的植物发育出多于两个花序芽，并且具有增加的角果数和角果长度，导致更高的种子数。此外，在这些miR 397 b过表达植物中形成了增大的种子和更多的种子。该研究表明，miR 397通过调节漆酶基因介导的发育可能是显花植物中的一种常见机制，miR 397对漆酶的调节可能是具有较少木质素的工程植物生物质生产的潜力。
Plant laccase (LAC) enzymes belong to the blue copper oxidase family and polymerize monolignols into lignin. Recent studies have established the involvement of microRNAs in this process; however, physiological functions and regulation of plant laccases remain poorly understood. Here, we show that a laccase gene, LAC4, regulated by a microRNA, miR397b, controls both lignin biosynthesis and seed yield in Arabidopsis. In transgenic plants, overexpression of miR397b (OXmiR397b) reduced lignin deposition. The secondary wall thickness of vessels and the fibres was reduced in the OXmiR397b line, and both syringyl and guaiacyl subunits are decreased, leading to weakening of vascular tissues. In contrast, overexpression of miR397b-resistant laccase mRNA results in an opposite phenotype. Plants overexpressing miR397b develop more than two inflorescence shoots and have an increased silique number and silique length, resulting in higher seed numbers. In addition, enlarged seeds and more seeds are formed in these miR397b overexpression plants. The study suggests that miR397-mediated development via regulating laccase genes might be a common mechanism in flowering plants and that the modulation of laccase by miR397 may be potential for engineering plant biomass production with less lignin.