miR398 and miR408 are up-regulated in response to water deficit in Medicago truncatula
miR398 and miR408 are up-regulated in response to water deficit in Medicago truncatula
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DOI：
10.1007/s00425-009-1078-0
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发表时间：
2010-02-01
期刊：
影响因子：
4.3
通讯作者：
dos Santos, Dulce Metelo
中科院分区：
文献类型：
--
作者：
Trindade, Ines;Capitao, Claudio;dos Santos, Dulce Metelo
植物microRNAs参与了多种非生物胁迫反应。我们鉴定了几个在水分胁迫下表现出差异表达的保守的microRNAs：miR169只在根中下调，miR398a/b和miR408在地上部和根中都强烈上调。MiR169在根中的下调与其靶MtHAP2-1转录本的积累无关，这表明它的调控可能不是在mRNA水平上发生的，或者可能取决于其他调控机制，这些机制在缺水条件下不涉及miRNA。MiR398a/b和miR408的上调以及它们各自编码铜蛋白COX5b(线粒体细胞色素c氧化酶5b亚基)和植物蓝蛋白的靶基因的明显下调，突显了这些miRNAs参与了对水分胁迫的响应。此外，在水分亏缺期间，miR398的上调与铜超氧化物歧化酶CSD1的下调呈负相关。MiR398a/b和miR408对铜蛋白编码基因的调控表明铜的动态平衡与元胞藻对渐进性水分亏缺的适应之间存在联系。
Plant microRNAs have been implicated in various abiotic stress responses. We identified several conserved microRNAs that showed differential expression in Medicago truncatula plants subjected to water deficit: miR169 is down-regulated only in the roots and miR398a/b and miR408 are strongly up-regulated in both shoots and roots. Down-regulation of miR169 in the roots did not correlate with accumulation of its target MtHAP2-1 transcripts, suggesting that its regulation may not occur at the mRNA level or may depend on other regulatory mechanisms, which do not involve this miRNA, in water-deficit conditions. The up-regulation of miR398a/b and miR408 and the clear down-regulation of their respective target genes, which encode the copper proteins COX5b (subunit 5b of mitochondrial cytochrome c oxidase) and plantacyanin, highlight the involvement of these miRNAs in response to water deprivation in M. truncatula. Also, miR398 up-regulation is inversely correlated with the down-regulation of copper superoxide dismutase, CSD1, during water deficit. The regulation of genes encoding copper proteins by miR398a/b and miR408 suggests a link between copper homeostasis and M. truncatula adaptation to progressive water deficit.