Catabolism of strigolactones by a carboxylesterase
Catabolism of strigolactones by a carboxylesterase
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DOI：
10.1038/s41477-021-01011-y
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发表时间：
2021-11
期刊：
影响因子：
18
通讯作者：
E. Xu;Liang Chai;Shiqi Zhang;Ruixue Yu;Xixi Zhang;Chongyi Xu;Yuxin Hu
中科院分区：
文献类型：
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作者：
E. Xu;Liang Chai;Shiqi Zhang;Ruixue Yu;Xixi Zhang;Chongyi Xu;Yuxin Hu
Strigolactones(SLS)是类胡萝卜素衍生的植物激素，控制着植物枝条的分枝和寄主植物与共生真菌或根寄生植物之间的通讯。广泛的研究已经确定了参与SL生物合成和信号转导的关键成分，而内源SLS在植物中的分解代谢或失活在很大程度上仍不清楚。在这里，我们报告了拟南芥羧酸酯酶15(AtCXE15)及其同源物作为SLS的有效水解酶的功能。我们发现，AtCXE15的过表达通过抑制SL抑制的腋芽生长促进了枝条的分枝。我们进一步证明了AtCXE15在体外和植物中都能结合和有效地降解SLS。我们还提供了证据表明，AtCXE15能够催化不同的SL类似物的水解，并且这种依赖于CXE15的SLS的分解代谢在种子植物中进化上是保守的。这些结果揭示了植物体内SLS稳态调节的催化机制，这也为调控内源SLS从而调控作物和观赏植物的构型提供了一条合理的途径。
Strigolactones (SLs) are carotenoid-derived plant hormones that control shoot branching and communications between host plants and symbiotic fungi or root parasitic plants. Extensive studies have identified the key components participating in SL biosynthesis and signalling, whereas the catabolism or deactivation of endogenous SLs in planta remains largely unknown. Here, we report that theArabidopsiscarboxylesterase 15 (AtCXE15) and its orthologues function as efficient hydrolases of SLs. We show that overexpression ofAtCXE15promotes shoot branching by dampening SL-inhibited axillary bud outgrowth. We further demonstrate that AtCXE15 could bind and efficiently hydrolyse SLs both in vitro and in planta. We also provide evidence that AtCXE15 is capable of catalysing hydrolysis of diverse SL analogues and that such CXE15-dependent catabolism of SLs is evolutionarily conserved in seed plants. These results disclose a catalytic mechanism underlying homoeostatic regulation of SLs in plants, which also provides a rational approach to spatial-temporally manipulate the endogenous SLs and thus architecture of crops and ornamental plants.