State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.
Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
Plant Sci. 2022 Dec;325:111465. doi: 10.1016/j.plantsci.2022.111465. Epub 2022 Sep 22.
MiR396s play important roles in regulating plant growth and stress response, and great potential for crop yield promotion was anticipated. For more comprehensive and precise understanding of miR396s in Poaceae, we analyzed the phylogenetic linkage, gene expression, and chromosomal distribution of miR396s in this study. Although the mature miR396s' sequences were mostly conserved, differential expression patterns and chromosomal distribution were found among Poaceae species including the major cereal crops rice, wheat, and maize. Consistently, in comparison with rice, wheat and maize plants transformed with the target mimicry construct of miR396 (MIM396) exhibited differential effects on grain size and disease resistance. While the TaMIM396 plants showed increased grain size, panicle length and sensitivity to B. graminis, the ZmMIM396 plants didn't show obvious changes in grain size and disease resistance. In Addition, several GROWTH-REGULATING FACTOR (GRF) genes in wheat and maize were repressed by miR396s, which could be reversed by MIM396, confirming the conserved regulatory roles of miR396 on GRFs. While providing new solution to enhance grain yield in wheat and revealing potential regulatory variations of miR396s in controlling grain size and disease resistance in different crops, this study gives clues to further explore miR396s' functions in other Poaceae species.
miR396s 在调控植物生长和应激反应中发挥着重要作用，预计对提高作物产量有很大的潜力。为了更全面、更准确地了解禾本科植物中的 miR396s，我们在本研究中分析了 miR396s 的系统发育关系、基因表达和染色体分布。尽管成熟 miR396s 的序列大多保守，但在包括主要粮食作物水稻、小麦和玉米在内的禾本科物种中发现了差异表达模式和染色体分布。一致的是，与水稻相比，转化为 miR396 靶标模拟物（MIM396）的小麦和玉米植株对籽粒大小和抗病性表现出不同的影响。虽然 TaMIM396 植株表现出籽粒增大、穗长增加和对禾谷镰刀菌的敏感性增加，但 ZmMIM396 植株在籽粒大小和抗病性方面没有明显变化。此外，小麦和玉米中的几个生长调节因子（GRF）基因被 miR396s 抑制，而 MIM396 可以逆转这种抑制，证实了 miR396 对 GRFs 的保守调控作用。本研究为提高小麦的籽粒产量提供了新的解决方案，并揭示了 miR396s 在控制不同作物籽粒大小和抗病性方面的潜在调控差异，为进一步探索 miR396s 在其他禾本科物种中的功能提供了线索。
