Cold stress is a major abiotic factor that inhibits soybean (Glycine max (Linn.) Merr.) yield. MicroRNAs (miRNAs) are prevalent endogenous gene regulators in eukaryotes that can cleave target messenger RNAs and play essential roles in soybean cold response. In this study, 105 genes, including 22 pentatricopeptide repeat (PPR) genes and 4 growth-related genes, were predicted to be the target genes of soybean miRNA miR1508a (gma-miR1508a). The expression of gma-miR1508a was induced by cold treatment but inhibited by drought stress. Compared to the wild type (WT), the overexpression of gma-miR1508a in soybean plants resulted in dwarfing and thick cell walls. Gma-miR1508a transgenic plants exhibited cold tolerance at the germination and young seedling stages, and soluble sugar content was 58.7% higher than that of WT plants under cold stress. The gma-miR1508a transgenic lines showed lower survival rates and greater leaf water loss compared to the WT under drought treatment, which indicated that gma-miR1508a reduced drought resistance in soybean. Transcript abundances of 2 PPR and 4 growth-related predicted target genes decreased in gma-miR1508a transgenic plants. In the above six genes, the expression patterns of Glyma.16G162100 (PPR) and Glyma.17G065400 (xyloglucan endo-trans-glucosylase/hydrolase, XTH) showed opposite trends with gma-miR1508a under cold conditions. 5′-Rapid amplification of complementary DNA ends (5′-RACE) assays of Glyma.16G162100 revealed that the cleavage sites of gma-miR1508a are located at the 15th and 21st nucleotides of the complementary region. This study demonstrated that gma-miR1508a confers dwarfing, cold tolerance, and drought sensitivity in soybean.

低温胁迫是抑制大豆（Glycine max（Linn。）Merr。）产量的主要非生物因子。微小RNA（miRNA）是真核生物中普遍存在的内源基因调节剂，可以裂解靶信使RNA，并在大豆冷反应中发挥重要作用。在这项研究中，预测了105个基因，包括22个五肽重复（PPR）基因和4个与生长相关的基因，是大豆miRNA miR1508a（gma-miR1508a）的目标基因。低温处理诱导了gma-miR1508a的表达，但干旱胁迫抑制了其表达。与野生型（WT）相比，大豆植物中gma-miR1508a的过度表达导致矮化和厚壁细胞。Gma-miR1508a转基因植物在发芽和幼苗期表现出耐寒性，冷胁迫下的可溶性糖含量比野生型植物高58.7％。的GMA-miR1508a转基因品系显示出较低的存活率和更大叶失水相比下干旱处理的WT，这表明GMA-miR1508a大豆降低抗旱性。在gma-miR1508a转基因植物中，2个PPR和4个与生长相关的预测靶基因的转录本丰度降低。另外，在上述六种基因，的表达模式Glyma.16G162100（PPR）和Glyma.17G06540​​0（木葡聚糖内切反式glucosylase /水解酶，XTH）在寒冷条件下与gma-miR1508a呈现相反的趋势。Glyma.16G162100的5'-互补DNA末端快速扩增（5'-RACE）分析表明，gma-miR1508a的切割位点位于互补区的第15和21位核苷酸。这项研究表明，gma-miR1508a赋予大豆矮化，耐寒性和干旱敏感性。