The function of the pseudo phosphotransfer proteins has diverged between rice and Arabidopsis

第一作者：John Vaughan‐Hirsch

第一单位：英国诺丁汉大学

通讯作者：Joseph J. Kieber

 Abstract 

背景回顾：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.

细胞分裂素信号转导：The cytokinin signaling pathway is a phosphorelay comprised of the histidine kinase receptors (HKs), the authentic histidine phosphotransfer proteins (AHPs), and the type‐B Response Regulators (RRs).

负调节子：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.

主要研究：Here, we describe the role of the rice PHP genes.

结果1-系统发育分析：Phylogenic analysis indicates that the PHPs are generally first found in the genomes of gymnosperms and that they arose independently in monocots and dicots.

结果2-遗传互补试验：Consistent with this, the three rice PHPs fail to complement an Arabidopsis php mutant (aphp1/ahp6).

结果3-水稻PHP功能：Disruption of the three rice PHPs results 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 triple php mutant affects multiple aspects of rice growth and development, including shoot morphology, panicle architecture and seed fill.

结果4-水稻与拟南芥PHP功能差异：In contrast to Arabidopsis, disruption of the rice PHPs does 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.

 通讯作者 

**Joseph J. Kieber**

doi: https://doi.org/10.1111/tpj.15156

Journal: the plant journal

Published date: Jan 09, 2021