Shanghai JiaoTong University, School of Agriculture and Biology, Shanghai 200240, China.
Plant Physiol. 2010 Aug;153(4):1759-70. doi: 10.1104/pp.110.156950. Epub 2010 May 27.
MicroRNAs (miRNAs) are important regulators of plant growth and development. Previously, we identified a group of conserved and novel miRNA families from soybean (Glycine max) roots. Many of these miRNAs are specifically induced during soybean-Bradyrhizobium japonicum interactions. Here, we examined the gene expression levels of six families of novel miRNAs and investigated their functions in nodule development. We used northern-blot analyses to study the tissue specificity and time course of miRNA expression. Transgenic expression of miR482, miR1512, and miR1515 led to significant increases of nodule numbers, while root length, lateral root density, and the number of nodule primordia were not altered in all tested miRNA lines. We also found differential expression of these miRNAs in nonnodulating and supernodulating soybean mutants. The expression levels of 22 predicted target genes regulated by six novel miRNAs were studied by real-time polymerase chain reaction and quantitative real-time polymerase chain reaction. These results suggested that miRNAs play important roles in soybean nodule development.
MicroRNAs (miRNAs) 是植物生长和发育的重要调控因子。之前，我们从大豆 (Glycine max) 根中鉴定了一组保守和新的 miRNA 家族。这些 miRNA 中有许多在大豆-根瘤菌 (Bradyrhizobium japonicum) 互作过程中特异性诱导表达。在这里，我们检测了六个新 miRNA 家族的基因表达水平，并研究了它们在根瘤发育中的功能。我们使用 northern-blot 分析来研究 miRNA 表达的组织特异性和时间进程。miR482、miR1512 和 miR1515 的转基因表达导致根瘤数量显著增加，而在所有测试的 miRNA 株系中，根长、侧根密度和根瘤原基数量没有改变。我们还发现这些 miRNA 在非结瘤和超结瘤大豆突变体中的表达水平存在差异。通过实时聚合酶链反应和定量实时聚合酶链反应研究了 22 个受六个新 miRNA 调控的预测靶基因的表达水平。这些结果表明 miRNA 在大豆根瘤发育中发挥重要作用。
