Three type-B response regulators, ARR1, ARR10 and ARR12, play essential but redundant roles in cytokinin signal transduction throughout the life cycle of Arabidopsis thaliana
Three type-B response regulators, ARR1, ARR10 and ARR12, play essential but redundant roles in cytokinin signal transduction throughout the life cycle of Arabidopsis thaliana
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DOI：
10.1093/pcp/pcm165
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发表时间：
2008-01-01
影响因子：
4.9
通讯作者：
Mizuno, Takeshi
中科院分区：
文献类型：
--
作者：
Ishida, Kai;Yamashino, Takafumi;Mizuno, Takeshi
拟南芥有11个成员属于典型的b型ARR（真实反应调节因子）家族。其中，7个高度同源的成员似乎也在水稻（Oryza sativa）中保守，但其他成员则不保守。结果表明，这7种ARRs通常作为dna结合转录因子参与高等植物磷酸化介导的细胞分裂素信号转导网络。为了深入了解细胞分裂素相关的b型ARRs的功能，我们之前研究了arr1 arr10 arr12三重突变体，并报道了它表现出生长迟缓和血管发育异常。基于这一事实，在这里，我们试图通过参考细胞分裂素相关表型，在整个生命周期中深入表征突变体。我们发现，观察到的arr1、arr10、arr12的细胞分裂素相关表型非常严重，与某些ahk2、ahk3、ahk4/cre1三突变体的表型高度相似，这些突变体实际上没有细胞分裂素受体来传播磷接力信号转导网络。在属于细胞分裂素相关b型ARR亚家族的7个ARR成员中，ARR1、ARR10和ARR12共同在细胞分裂素信号转导中起重要（或一般）作用。因此，其他b型ARRs （ARR2, ARR11， ARR14和ARR18）可能在植物中发挥更具体的空间和时间作用。
Arabidopsis thaliana has 11 members belonging to the typical type-B ARR (authentic response regulator) family. Among them, seven highly homologous members appear also to be conserved in rice (Oryza sativa), but others are not. It was suggested that these seven ARRs are commonly implicated as DNA-binding transcription factors in the phosphorelay-mediated cytokinin signal transduction network in higher plants. To gain an insight into the functions of the cytokinin-associated type-B ARRs, we previously investigated an arr1 arr10 arr12 triple mutant and reported that it exhibited stunted growth and abnormality in vascular development. Based on this fact, here we attempted to characterize the mutant intensively with reference to cytokinin-associated phenotypes through the life cycle. We showed that the observed cytokinin-associated phenotypes of arr1 arr10 arr12 were very severe and highly analogous to those observed for certain ahk2 ahk3 ahk4/cre1 triple mutants, which have virtually no cytokinin receptor to propagate the phosphorelay signal transduction network. Among the seven ARR members belonging to the cytokinin-associated type-B ARR subfamily, it was thus suggested that ARR1, ARR10 and ARR12 together play essential (or general) roles in cytokinin signal transduction. It is therefore conceivable that the other type-B ARRs (ARR2, ARR11, ARR14 and ARR18) might play more specific roles spatially and temporally in plants.