小柯机器人

近日，福建农林大学杨贞标等研究人员合作发现，ABL和TMK是细胞外生长素的共同受体。相关论文于2023年11月17日在线发表在《细胞》期刊上。

研究人员表示，几十年来，人们一直在争论细胞外对植物必需的植物激素——生长素的感知。生长素结合蛋白1（ABP1）与五种重要的跨膜激酶（TMK）发生物理相互作用，被认为是细胞外生长素受体，但由于abp1基因敲除突变体缺乏明显的形态表型，其作用受到争议。

研究人员发现了两个新的生长素结合蛋白ABL1和ABL2，它们定位于细胞外，以植物生长素依赖的方式直接与TMK的胞外结构域相互作用。此外，功能冗余的ABL1和ABL2在基因上与TMK相互作用，其功能与ABP1重叠，但又独立于ABP1。重要的是，TMK1的胞外结构域本身也能结合植物生长素，并与ABP1或ABL1在植物生长素结合方面产生协同作用。因此，这些研究结果发现，生长素受体ABL1和ABL2的功能与ABP1重叠但又不同，它们与TMK一起作为细胞外生长素的共同受体发挥作用。

附：英文原文

Title: ABLs and TMKs are co-receptors for extracellular auxin

Author: Yongqiang Yu, Wenxin Tang, Wenwei Lin, Wei Li, Xiang Zhou, Ying Li, Rong Chen, Rui Zheng, Guochen Qin, Wenhan Cao, Patricio Pérez-Henríquez, Rongfeng Huang, Jun Ma, Qiqi Qiu, Ziwei Xu, Ailing Zou, Juncheng Lin, Liwen Jiang, Tongda Xu, Zhenbiao Yang

Issue&Volume: 2023-11-17

Abstract: Extracellular perception of auxin, an essential phytohormone in plants, has been debated for decades. Auxin-binding protein 1 (ABP1) physically interacts with quintessential transmembrane kinases (TMKs) and was proposed to act as an extracellular auxin receptor, but its role was disputed because abp1 knockout mutants lack obvious morphological phenotypes. Here, we identified two new auxin-binding proteins, ABL1 and ABL2, that are localized to the apoplast and directly interact with the extracellular domain of TMKs in an auxin-dependent manner. Furthermore, functionally redundant ABL1 and ABL2 genetically interact with TMKs and exhibit functions that overlap with those of ABP1 as well as being independent of ABP1. Importantly, the extracellular domain of TMK1 itself binds auxin and synergizes with either ABP1 or ABL1 in auxin binding. Thus, our findings discovered auxin receptors ABL1 and ABL2 having functions overlapping with but distinct from ABP1 and acting together with TMKs as co-receptors for extracellular auxin.

DOI: 10.1016/j.cell.2023.10.017

Source: https://www.cell.com/cell/fulltext/S0092-8674(23)01134-0