Function of the pseudo phosphotransfer proteins has diverged between rice and Arabidopsis
Function of the pseudo phosphotransfer proteins has diverged between rice and Arabidopsis
复制标题
水稻和拟南芥中假磷酸转移蛋白的功能存在差异
DOI：
10.1111/tpj.15156
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Šimura, Jan
中科院分区：
文献类型：
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作者：
Vaughan‐Hirsch, John;Tallerday, Emily J.;Burr, Christian A.;Hodgens, Charlie;Boeshore, Samantha L.;Beaver, Kevin;Melling, Allison;Sari, Kartika;Kerr, Ian D.;Šimura, Jan
植物激素细胞分裂素在植物生长发育的几乎所有方面都起着重要作用。细胞分裂素信号主要在双子叶植物模式拟南芥中进行研究，在单子叶植物中进行的工作相对较少，单子叶植物包括水稻（Oryza sativa）和其他具有农业重要性的谷物。细胞分裂素信号通路是由组氨酸激酶受体、真正的组氨酸磷酸转移蛋白（AHPs）和B型反应调节因子（RR）组成的磷酸中继。细胞分裂素信号传导的两个负调节因子已经被鉴定：A型RR，其是细胞分裂素初级应答基因，和假组氨酸磷酸转移蛋白（PHPs），其缺乏磷酸转移所需的His残基。在这里，我们描述了水稻PHP基因的作用。系统发育分析表明，PHPs通常首先在裸子植物的基因组中发现，并且它们在单子叶植物和双子叶植物中独立出现。与此相一致，三个水稻PHPs不能互补一个拟南芥突变体（aphp 1/ahp 6）。三种水稻PHPs的破坏导致与这些元件一致的分子表型，这些元件作为细胞分裂素信号传导的负调控因子，包括诱导许多A型RR和细胞分裂素氧化酶基因。该突变体影响水稻生长发育的多个方面，包括地上部形态、穗构型和籽粒充实。与拟南芥相反，水稻PHPs的破坏不影响根维管格局，这表明虽然单子叶植物和双子叶植物之间的关键信号网络的许多方面是保守的，但至少一些细胞分裂素信号元件的作用是不同的。
The phytohormone cytokinin plays a significant role in nearly all aspects of plant growth and development. Cytokinin signaling has primarily been studied in the dicot model Arabidopsis, with relatively little work done in monocots, which include rice (Oryza sativa) and other cereals of agronomic importance. The cytokinin signaling pathway is a phosphorelay comprised of the histidine kinase receptors, the authentic histidine phosphotransfer proteins (AHPs) and type‐B response regulators (RRs). Two negative regulators of cytokinin signaling have been identified: the type‐A RRs, which are cytokinin primary response genes, and the pseudo histidine phosphotransfer proteins (PHPs), which lack the His residue required for phosphorelay. Here, we describe the role of the ricePHPgenes. Phylogenic analysis indicates that the PHPs are generally first found in the genomes of gymnosperms and that they arose independently in monocots and dicots. Consistent with this, the three ricePHPsfail to complement an Arabidopsisphpmutant (aphp1/ahp6). Disruption of the three ricePHPsresults in a molecular phenotype consistent with these elements acting as negative regulators of cytokinin signaling, including the induction of a number of type‐A RR and cytokinin oxidase genes. The triplephpmutant affects multiple aspects of rice growth and development, including shoot morphology, panicle architecture, and seed fill. In contrast to Arabidopsis, disruption of the ricePHPsdoes not affect root vascular patterning, suggesting that while many aspects of key signaling networks are conserved between monocots and dicots, the roles of at least some cytokinin signaling elements are distinct.