Institute of Crop Science, Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou, 310058, China.
Henan Agricultural Radio and Television School, Zhengzhou, 450008, China.
Plant Sci. 2021 Jan;302:110728. doi: 10.1016/j.plantsci.2020.110728. Epub 2020 Oct 24.
Rice is one of the most important food crops in the world. Breeding high-yield, multi-resistant and high-quality varieties has always been the goal of rice breeding. Rice tiller, panicle architecture and grain size are the constituent factors of yield, which are regulated by both genetic and environmental factors, including miRNAs, transcription factors, and downstream target genes. Previous studies have shown that SPL (SQUAMOSA PROMOTER BINDING-LIKE) transcription factors can control rice tiller, panicle architecture and grain size, which were regulated by miR156, miR529 and miR535. In this study, we obtained miR529a target mimicry (miR529a-MIMIC) transgenic plants to investigate plant phenotypes, physiological and molecular characteristics together with miR529a overexpression (miR529a-OE) and wild type (WT) to explore the function of miR529a and its SPL target genes in rice. We found that OsSPL2, OsSPL17 and OsSPL18 at seedling stage were regulated by miR529a, but there had complicated mechanism to control plant height. OsSPL2, OsSPL16, OsSPL17 and SPL18 at tillering stage were regulated by miR529a to control plant height and tiller number. And panicle architecture and grain size were controlled by miR529a through altering the expression of all five target genes OsSPL2, OsSPL7, OsSPL14, OsSPL16, OsSPL17 and OsSPL18. Our study suggested that miR529a might control rice growth and development by regulating different SPL target genes at different stages, which could provide a new method to improve rice yield by regulating miR529a and its SPL target genes.
水稻是世界上最重要的粮食作物之一。培育高产、多抗、优质品种一直是水稻育种的目标。水稻分蘖、穗型和粒型是产量的构成因素，受遗传和环境因素的调控，包括 miRNA、转录因子和下游靶基因。先前的研究表明，SPL（SQUAMOSA PROMOTER BINDING-LIKE）转录因子可以控制水稻分蘖、穗型和粒型，这些是由 miR156、miR529 和 miR535 调控的。在本研究中，我们获得了 miR529a 靶标模拟物（miR529a-MIMIC）转基因植物，以研究植物表型、生理和分子特征，同时还研究了 miR529a 过表达（miR529a-OE）和野生型（WT），以探讨 miR529a 及其 SPL 靶基因在水稻中的功能。我们发现，幼苗期的 OsSPL2、OsSPL17 和 OsSPL18 受 miR529a 调控，但调控植株高度的机制较为复杂。分蘖期的 OsSPL2、OsSPL16、OsSPL17 和 SPL18 受 miR529a 调控，从而控制植株高度和分蘖数。穗型和粒型则通过改变五个靶基因 OsSPL2、OsSPL7、OsSPL14、OsSPL16、OsSPL17 和 OsSPL18 的表达来控制。我们的研究表明，miR529a 可能通过在不同阶段调控不同的 SPL 靶基因来控制水稻的生长和发育，这为通过调控 miR529a 及其 SPL 靶基因来提高水稻产量提供了一种新方法。
