Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Guangzhou 510316, China.
Int J Mol Sci. 2021 Dec 28;23(1):287. doi: 10.3390/ijms23010287.
Cryptochrome 1 and 2 (CRY1 and CRY2) are blue light receptors involved in the regulation of hypocotyl elongation, cotyledon expansion, and flowering time in . Two cryptochrome-interacting proteins, Blue-light Inhibitor of Cryptochrome 1 and 2 (BIC1 and BIC2), have been found in . BIC1 plays critical roles in suppressing the physiological activities of CRY2, which include the blue light-dependent dimerization, phosphorylation, photobody formation, and degradation process, but the functional characterization of BIC protein in other crops has not yet been performed. To investigate the function of BIC protein in rice (), two homologous genes of and , namely and (), were identified. The overexpression of and led to increased leaf sheath length, whereas mutations in displayed shorter leaf sheath in a blue light intensity-dependent manner. OsBIC1 regulated blue light-induced leaf sheath elongation through direct interaction with OsCRY1a, OsCRY1b, and OsCRY2 (OsCRYs). Longitudinal sections of the second leaf sheath demonstrated that OsBIC1 and OsCRYs controlled leaf sheath length by influencing the ratio of epidermal cells with different lengths. RNA-sequencing (RNA-seq) and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) analysis further proved that OsBIC1 and OsCRYs regulated similar transcriptome changes in regulating Gibberellic Acids (GA)-responsive pathway. Taken together, these results suggested that OsBIC1 and OsCRYs worked together to regulate epidermal cell elongation and control blue light-induced leaf sheath elongation through the GA-responsive pathway.
CRY1 和 CRY2（CRY1 和 CRY2）是参与调节下胚轴伸长、子叶扩张和开花时间的蓝光受体。在 中发现了两种与隐花色素相互作用的蛋白，蓝光抑制隐花色素 1 和 2（BIC1 和 BIC2）。BIC1 在抑制 CRY2 的生理活性方面起着关键作用，包括蓝光依赖性二聚化、磷酸化、光体形成和降解过程，但 BIC 蛋白在其他作物中的功能特征尚未得到研究。为了研究 BIC 蛋白在水稻（）中的功能，鉴定了 和 的两个同源基因，即 和 （）。过表达 和 导致叶片鞘长度增加，而 的突变以蓝光强度依赖的方式显示较短的叶片鞘。OsBIC1 通过与 OsCRY1a、OsCRY1b 和 OsCRY2（OsCRYs）直接相互作用来调节蓝光诱导的叶片鞘伸长。第二叶片鞘的纵截面表明，OsBIC1 和 OsCRYs 通过影响具有不同长度的表皮细胞的比例来控制叶片鞘的长度。RNA 测序（RNA-seq）和定量实时聚合酶链反应（qRT-PCR）分析进一步证明，OsBIC1 和 OsCRYs 通过调节赤霉素（GA）反应途径来调节相似的转录组变化。综上所述，这些结果表明，OsBIC1 和 OsCRYs 通过 GA 反应途径共同作用，调节表皮细胞伸长，控制蓝光诱导的叶片鞘伸长。
