Yu Xinhai, Jiao Tongtong, Liu Changfeng, Zhang Hexin, Liu Yanxi, Zhang Chunyu, Wu Ming, Guo Liquan
College of Life Sciences, Jilin Agricultural University, Changchun 130118, China.
Jilin Institute of Biology, Changchun 130012, China.
Plants (Basel). 2025 Jul 1;14(13):2015. doi: 10.3390/plants14132015.
Blue light is a significant environmental cue influencing plant photomorphogenesis and regulating plant growth and development. The COP9 signaling complex (CSN), a multi-subunit protein complex, plays a pivotal role in regulating photomorphogenesis, with CSN2 being identified as a key subunit essential for the assembly and function of the CSN. This study investigated the role of OsCSN2 in rice under blue-light conditions. Utilizing knockout (KO) mutant plants and transgenic overexpression (OE) lines for wild-type (WT) and mutated versions of OsCSN2, we observed significant suppression of the overall seedling phenotype under blue light, indicating that OsCSN2 acts as a negative regulator of blue light-mediated morphogenesis. Further analysis revealed that exogenous application of gibberellin (GA) and the GA synthesis inhibitor paclobutrazol (PAC) modulated seedling elongation in response to blue light, particularly affecting plant height, coleoptile, and first incomplete leaf length without altering root growth. This suggests that OsCSN2 mediates the inhibitory effects of blue light on aboveground development through the gibberellin signaling pathway. On day 9, the analyses of endogenous GA levels combined with Western blotting (WB) and quantitative real-time PCR (qRT-PCR) revealed that OsCSN2 senses blue light signals through cryptochrome 2 (CRY2), influences the expression of and , and highlights its role in the photoreceptive signaling pathway. This regulation ultimately influences the degradation of SLR1 within the GA signaling pathway, affecting rice seedling growth and development. Our findings also highlight the differential roles of OsCSN1 and OsCSN2 within the CSN in modulating rice seedling photomorphogenesis, thereby providing new insights into the intricate regulatory mechanisms governing plant responses to blue light.
蓝光是影响植物光形态建成以及调节植物生长发育的重要环境信号。COP9信号复合体（CSN）是一种多亚基蛋白复合体，在调节光形态建成中起关键作用，其中CSN2被确定为CSN组装和功能所必需的关键亚基。本研究调查了蓝光条件下水稻中OsCSN2的作用。利用野生型（WT）和突变型OsCSN2的敲除（KO）突变体植株和转基因过表达（OE）株系，我们观察到蓝光下整体幼苗表型受到显著抑制，这表明OsCSN2作为蓝光介导的形态建成的负调控因子发挥作用。进一步分析表明，外源施加赤霉素（GA）和GA合成抑制剂多效唑（PAC）可调节蓝光响应下的幼苗伸长，尤其影响株高、胚芽鞘和第一片不完全叶的长度，而不改变根的生长。这表明OsCSN2通过赤霉素信号通路介导蓝光对地上部发育的抑制作用。在第9天，对内源GA水平的分析结合蛋白质免疫印迹（WB）和定量实时聚合酶链反应（qRT-PCR）表明，OsCSN2通过隐花色素2（CRY2）感知蓝光信号，影响 和 的表达，并突出了其在光感受信号通路中的作用。这种调节最终影响GA信号通路中SLR1的降解，从而影响水稻幼苗的生长发育。我们的研究结果还突出了CSN中OsCSN1和OsCSN2在调节水稻幼苗光形态建成中的不同作用，从而为植物对蓝光响应的复杂调控机制提供了新的见解。
