Ren Wenqing, Wu Feijie, Bai Jinjuan, Li Xiaorong, Yang Xi, Xue Wanxin, Liu Heng, He Yuke
1National Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Fenglin Road 300, Shanghai, 200032 China.
2Graduate School of the Chinese Academy of Sciences, Shanghai, 200032 China.
Hortic Res. 2020 Jan 1;7:1. doi: 10.1038/s41438-019-0222-7. eCollection 2020.
() in encodes a double-stranded RNA-binding protein needed for proper miRNA maturation, and its null mutant shows a typical leaf-incurvature phenotype. In Chinese cabbage, (), a close homolog of , is differentially expressed in juvenile leaves, which are flat, and in adult leaves, which display extreme incurvature. BcpLH lacks protein-protein interaction domains and is much shorter than HYL1. To test whether is associated with defects in microRNA (miRNA) biogenesis and leaf flatness, we enhanced and repressed the activity of by transgenics and investigated -dependent miRNAs and plant morphology. BcpLH promoted miRNA biogenesis by the proper processing of primary miRNAs. downregulation via antisense decreased a specific subset of miRNAs and increased the activities of their target genes, causing upward curvature of rosette leaves and early leaf incurvature, concurrent with the enlargement, earliness, and round-to-oval shape transition of leafy heads. Moreover, BcpLH-dependent miRNAs in Chinese cabbage are not the same as HYL1-dependent miRNAs in Arabidopsis. We suggest that controls a specific subset of miRNAs in Chinese cabbage and coordinates the direction, extent, and timing of leaf curvature during head formation in .
（）在拟南芥中编码一种双链RNA结合蛋白，该蛋白是miRNA正常成熟所必需的，其缺失突变体表现出典型的叶片内弯表型。在大白菜中，BcpLH（），即HYL1的一个紧密同源物，在扁平的幼叶和表现出极度内弯的成叶中差异表达。BcpLH缺乏蛋白质-蛋白质相互作用结构域，且比HYL1短得多。为了测试BcpLH是否与微小RNA（miRNA）生物合成缺陷和叶片扁平度有关，我们通过转基因增强和抑制了BcpLH的活性，并研究了依赖BcpLH的miRNA和植物形态。BcpLH通过对初级miRNA的适当加工促进miRNA生物合成。通过反义技术下调BcpLH降低了特定miRNA子集的水平，并增加了其靶基因的活性，导致莲座叶向上弯曲和叶片早期内弯，同时伴有叶球的增大、早熟以及形状从圆形到椭圆形的转变。此外，大白菜中依赖BcpLH的miRNA与拟南芥中依赖HYL1的miRNA不同。我们认为BcpLH控制大白菜中特定的miRNA子集，并在大白菜叶球形成过程中协调叶片弯曲的方向、程度和时间。
