miRNA164-directed cleavage of ZmNAC1 confers lateral root development in maize (Zea mays L.).
miRNA164-directed cleavage of ZmNAC1 confers lateral root development in maize (Zea mays L.).
复制标题
miRNA164 定向切割 ZmNAC1 赋予玉米侧根发育 (Zea mays L.)
DOI：
10.1186/1471-2229-12-220
复制
发表时间：
2012-11-21
影响因子：
5.3
通讯作者：
Yao Y
中科院分区：
文献类型：
--
作者：
Li J;Guo G;Guo W;Guo G;Tong D;Ni Z;Sun Q;Yao Y
背景
MicroRNA是一类小的非编码RNA，其通过结合靶mRNA来调节基因表达，这导致切割或翻译抑制。NAC蛋白包括NAM、ATAF和CUC，是植物特异性转录因子家族，在发育和胁迫调节中具有不同的作用。据报道，miR 164负调控NAC 1的表达，这反过来又影响侧根发育在拟南芥;然而，很少有人知道玉米NAC家族和miR 164参与侧根发育。
结果
我们收集了175个具有NAC结构域的玉米转录本。其中，7个ZmNAC是miR 164调节的推定靶标。我们从2个玉米自交系87-1和综3中分离到一个基因，命名为TC 258020（命名为ZmNAC 1）。ZmNAC 1在根中具有高表达水平，并且相对于87-1在宗3中显示出更高的丰度（1.8倍），87-1比宗3具有更少的侧根。在重组自交系群体中，ZmNAC 1的表达量与侧根密度呈显著相关。过表达ZmNAC 1的转基因拟南芥与野生型相比侧根增加。这些结果表明，ZmNAC 1在侧根发育中发挥了重要作用。等位基因表达分析表明，反式调控元件是87-1和Zong 3中ZmNAC 1差异表达的主要介质，进一步分析表明miR 164是一个引导内源ZmNAC 1 mRNA切割的反式元件。成熟miR 164和miR 164前体在87-1中的表达均高于Zong 3，这与ZmNAC 1的表达模式相反。此外，等位基因测定显示顺式调节元件最可能影响Zm-miR 164 b的表达模式。GUS检测结果表明，Zm-miR 164 b启动子在87-1中的GUS活性高于在综3中的GUS活性。此外，我们检测了miR 164 b在RIL群体中的表达，结果表明miR 164 b在含有87-1启动子的RIL中的表达水平高于含有Zong 3启动子的RIL。
结论
我们的研究结果表明，玉米中miR 164 b启动子活性的差异导致成熟miR 164的不同表达模式的一种可能途径，该成熟miR 164负调控87-1和Zong 3中ZmNAC 1的表达，从而导致显著不同的侧根表型。
Background
MicroRNAs are a class of small, non-coding RNAs that regulate gene expression by binding target mRNA, which leads to cleavage or translational inhibition. The NAC proteins, which include NAM, ATAF, and CUC, are a plant-specific transcription factor family with diverse roles in development and stress regulation. It has been reported that miR164 negatively regulates NAC1 expression, which in turn affects lateral root development in Arabidopsis; however, little is known about the involvement of the maize NAC family and miR164 in lateral root development.
Results
We collected 175 maize transcripts with NAC domains. Of these, 7 ZmNACs were putative targets for regulation by miR164. We isolated one gene, called TC258020 (designated ZmNAC1) from 2 maize inbred lines, 87-1 and Zong3. ZmNAC1 had a high expression level in roots and showed higher abundance (1.8 fold) in Zong3 relative to 87-1, which had less lateral roots than Zong3. There was a significant correlation between the expression level of ZmNAC1 and the lateral root density in the recombinant inbred line (RIL) population. Transgenic Arabidopsis that overexpressed ZmNAC1 had increased lateral roots in comparison to the wild type. These findings suggest that ZmNAC1 played a significant role in lateral root development. An allelic expression assay showed that trans-regulatory elements were the dominant mediators of ZmNAC1 differential expression in 87-1 and Zong3, and further analysis revealed that miR164 was a trans-element that guided the cleavage of endogenous ZmNAC1 mRNA. Both mature miR164 and miR164 precursors had higher expression in 87-1 than Zong3, which was the opposite of the expression pattern of ZmNAC1. Additionally, the allelic assay showed that the cis-regulatory element most likely affected Zm-miR164b's expression pattern. A β-glucuronidase (GUS) assay showed that the Zm-miR164b promoter had higher GUS activity in 87-1 than in Zong3. In addition, we detected miR164b expression in the RIL population, and the results indicated that miR164b had a higher expression level in the RILs containing 87-1 promoter than those containing Zong3 promoter.
Conclusion
Our results indicate one possible pathway in maize by which differences in miR164b promoter activity resulted in a different expression pattern for mature miR164 which negatively regulates ZmNAC1 expression in 87-1 and Zong3, thereby contributing to a significantly different lateral root phenotype.
登录
查看更多内容
影响因子：
4.1
作者：
Ooka, H;Satoh, K;Kikuchi, S
通讯作者：
Kikuchi, S
影响因子：
5.1
作者：
Collinge, M;Boller, T
通讯作者：
Boller, T
影响因子：
11.4
作者：
Mallory, AC;Reinhart, BJ;Bartel, DP
通讯作者：
Bartel, DP
影响因子：
7.2
作者：
Clough, SJ;Bent, AF
通讯作者：
Bent, AF
影响因子：
11.6
作者：
Guo, HS;Xie, Q;Chua, NH
通讯作者：
Chua, NH