The two-component system is involved in several developmental events and different responses to the environment. Histidine-containing phosphotransfer proteins (HPs) play a critical role in transferring the phosphoryl group in the nucleus and regulating downstream effectors. Two authentic-HPs (OsAHPs) and three pseudo-HPs (OsPHPs) have been identified in rice. The conserved phosphorylation residue does not occur in OsPHPs, which are proposed as negative regulators in the cytokinin two-component system. One of the OsPHPs, OsPHP3, in rice is highly expressed at root caps. However, the roles of OsPHP3 have not been investigated in rice. We detected two major alternative splicing mRNAs of OsPHP3 and determined the expression in response to different environmental stimuli. The ratio of the two major alternative splicing OsPHP3 variants was significantly altered in response to a light signal and tissue specificity. Additionally, the results also indicated the positive regulation of auxin in the transcription of OsPHP3 in the root, and the ratio of the expression of the two major alternative splicing OsPHP3s was altered. OsPHP3 was also involved in auxin- and cytokinin-regulated lateral root development. Collectively, these results indicate a possible regulation of alternative splicing OsPHP3 isoforms by light and their roles in rice lateral root development.

中文翻译：

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水稻中假组氨酸磷酸转移蛋白 3 的光调控选择性剪接

两部分系统涉及几个发展事件和对环境的不同反应。含组氨酸的磷酸转移蛋白 (HPs) 在转移细胞核中的磷酰基和调节下游效应器方面起着关键作用。已在水稻中鉴定出两种真实 HPs (OsAHPs) 和三种伪 HPs (OsPHPs)。OsPHPs 中不存在保守的磷酸化残基，OsPHPs 被提议作为细胞分裂素双组分系统中的负调节剂。水稻中的一种 OsPHP，OsPHP3，在根冠处高度表达。然而，尚未研究 OsPHP3 在水稻中的作用。我们检测到 OsPHP3 的两个主要选择性剪接 mRNA，并确定了响应不同环境刺激的表达。响应光信号和组织特异性，两种主要选择性剪接 OsPHP3 变体的比率发生了显着变化。此外，结果还表明生长素在根中OsPHP3的转录中具有正调控作用，两种主要选择性剪接OsPHP3s的表达比例发生了改变。OsPHP3 还参与生长素和细胞分裂素调节的侧根发育。总的来说，这些结果表明光对选择性剪接 OsPHP3 异构体的可能调节及其在水稻侧根发育中的作用。并且改变了两个主要选择性剪接OsPHP3s的表达比例。OsPHP3 还参与生长素和细胞分裂素调节的侧根发育。总的来说，这些结果表明光对选择性剪接 OsPHP3 异构体的可能调节及其在水稻侧根发育中的作用。并且改变了两个主要选择性剪接OsPHP3s的表达比例。OsPHP3 还参与生长素和细胞分裂素调节的侧根发育。总的来说，这些结果表明光对选择性剪接 OsPHP3 异构体的可能调节及其在水稻侧根发育中的作用。