OsBBX14 promotes photomorphogenesis in rice by activating OsHY5L1 expression under blue light conditions
OsBBX14 promotes photomorphogenesis in rice by activating OsHY5L1 expression under blue light conditions
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DOI：
10.1016/j.plantsci.2019.04.017
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发表时间：
2019-07-01
期刊：
影响因子：
5.2
通讯作者：
Xie, Xianzhi
中科院分区：
文献类型：
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作者：
Bai, Bo;Lu, Nannan;Xie, Xianzhi
据报道，在水稻中，OsBBX 14是一种B-box（BBX）转录因子，可以延迟抽穗。在此，我们发现OsBBX 14正调控水稻光形态建成。OsBBX 14过表达植株（OsBBX 14-OX）对光敏感，尤其是蓝光，表现出矮化现象，而OsBBX 14敲除植株（osbbx 14）在蓝光下比野生型植株高。组织学分析表明，观察到的侏儒症主要是由于细胞长度减少。此外，OsBBX 14丰度（mRNA和蛋白水平）的影响，不同的光波长在时间依赖性的方式。在OsBBX 14-OX株系中，拟南芥同源基因HY 5Ls（LONG HYPOCOTYL 5 LIKE）和ELIPs（EARLY LIGHT-INDUCIBLE PROTEIN）的表达水平显著上调，这两个基因在光信号通路中起正调控作用。相反，与细胞壁组织和矮化相关的基因在OsBBX 14-OX系中表达下调。染色质免疫沉淀（ChIP）实验证实OsBBX 14与HY 5L 1（LONG HYPOCOTYL 5 LIKE 1）启动子的T/G-box结合。LUC互补成像（LCI）结果表明OsBBX 14与OsBBX 2蛋白存在物理相互作用。总体而言，OsBBX 14可能通过直接或间接调控HY 5L 1等与细胞壁组织和矮化相关基因的表达，促进蓝光诱导的光形态建成。
In rice, OsBBX14, a B-box (BBX) transcription factor, reportedly delays heading. Here, we revealed that OsBBX14 positively regulates rice photomorphogenesis. The OsBBX14-overexpressing (OsBBX14-OX) seedlings were hypersensitive to light, especially blue light, and exhibited dwarfism, while the OsBBX14 knock-out plants (osbbx14) were taller than wild-type plants under blue light. Histological analyses indicated that the observed dwarfism was mainly due to decreased cell length. Additionally, OsBBX14 abundance (mRNA and protein levels) was influenced by different light wavelengths in a time-dependent manner. The expression levels of HY5Ls (LONG HYPOCOTYL 5 LIKE) and ELIPs (EARLY LIGHT-INDUCIBLE PROTEIN) genes, whose Arabidopsis thaliana homologs function as positive regulators in the light signaling pathway, were significantly upregulated in OsBBX14-OX lines. In contrast, the expression of genes related to cell wall organization and dwarfism was downregulated in OsBBX14-OX lines. Chromatin immunoprecipitation (ChIP) assays confirmed that OsBBX14 binds to the T/G-box of HY5L1 (LONG HYPOCOTYL 5 LIKE 1) promoter. LUC complementation imaging (LCI) results suggested that OsBBX14 had physical interaction with OsCRY2 protein. Collectively, in response to blue light, OsBBX14 promotes photomorphogenesis, probably by directly or indirectly regulating the expression of HY5L1 or other genes related to cell wall organization and dwarfism.