Developmental roles of Auxin Binding Protein 1 in Arabidopsis thaliana
Developmental roles of Auxin Binding Protein 1 in Arabidopsis thaliana
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DOI：
10.1016/j.plantsci.2020.110750
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发表时间：
2021-02-01
期刊：
影响因子：
5.2
通讯作者：
Friml, Jiri
中科院分区：
文献类型：
--
作者：
Gelova, Zuzana;Gallei, Michelle;Friml, Jiri
生长素是一种重要的植物生长调节剂，但目前关于生长素感知和信号传递的模型不能解释生长素的全部效应，特别是那些与快速反应相关的生长素效应。生长素结合蛋白1(ABP1)是生长素感知机制的一个可能的候选成分，它在植物中的功能尚不清楚。在这里，我们结合表达分析和功能获得和丧失的方法来分析ABP1在植物发育中的作用。ABP1表现出广泛的表达，很大程度上与转录生长素反应活性重叠，但不受其调控。此外，ABP1活性对于转录生长素信号不是必需的。植物遗传分析表明，abp1功能缺失突变体的发育基本正常，抽苔过程中有少量缺陷。另一方面，ABP1功能获得等位基因显示出广泛的生长发育缺陷，包括根和下胚轴的生长和弯曲、侧根和叶的发育、抽苔以及对热胁迫的反应。在细胞水平上，ABP1功能获得导致生长素对PIN极性分布的影响减弱，并影响对BFA敏感的PIN细胞内聚集。功能获得分析表明ABP1广泛参与植物发育，但机制仍不清楚，可能在abp1功能缺失突变体中被功能冗余所掩盖。
Auxin is a major plant growth regulator, but current models on auxin perception and signaling cannot explain the whole plethora of auxin effects, in particular those associated with rapid responses. A possible candidate for a component of additional auxin perception mechanisms is the AUXIN BINDING PROTEIN 1 (ABP1), whose function in planta remains unclear.Here we combined expression analysis with gain- and loss-of-function approaches to analyze the role of ABP1 in plant development. ABP1 shows a broad expression largely overlapping with, but not regulated by, transcriptional auxin response activity. Furthermore, ABP1 activity is not essential for the transcriptional auxin signaling. Genetic in planta analysis revealed that abp1 loss-of-function mutants show largely normal development with minor defects in bolting. On the other hand, ABP1 gain-of-function alleles show a broad range of growth and developmental defects, including root and hypocotyl growth and bending, lateral root and leaf development, bolting, as well as response to heat stress. At the cellular level, ABP1 gain-of-function leads to impaired auxin effect on PIN polar distribution and affects BFA-sensitive PIN intracellular aggregation.The gain-of-function analysis suggests a broad, but still mechanistically unclear involvement of ABP1 in plant development, possibly masked in abp1 loss-of-function mutants by a functional redundancy.