CLE42 delays leaf senescence by antagonizing ethylene pathway in Arabidopsis

第一作者：Yi Zhang

第一单位：北京林业大学

通讯作者：Zhonghai Li

 Abstarct 

背景+问题：Leaf senescence is the final stage of leaf development and is influenced by numerous internal and environmental factors. CLE family peptides are plant-specific peptide hormones that regulate various developmental processes. However, the role of CLE in regulating Arabidopsis leaf senescence remains unclear. 

叶片衰老是叶片发育的最后一个阶段，受到多种内在和外界环境因素的影响。CLE家族多肽是一类植物特异的多肽类激素，调控多种发育进程。但是，CLE在拟南芥叶片衰老中的作用还不清楚。

主要发现：Here, we found that CLE42 is a negative regulator of leaf senescence by using a CRISPR/Cas9-produced CLE mutant collection. 

本文中，作者通过CRISPR/Cas9介导的CLE敲除突变，发现CLE42是叶片衰老的负调控因子。

结果1-突变体、过表达、外施CLE42：The cle42 mutant displayed earlier senescence phenotypes, while overexpression of CLE42 delayed age-dependent and dark-induced leaf senescence. Moreover, application of the synthesized 12-aa peptide (CLE42p) also delayed leaf senescence under natural and dark conditions. 

cle42突变体表现出更早的叶片衰老，而过表达CLE42延迟了年龄依赖型和黑暗诱导的叶片衰老。此外，外施人工合成的CLE42同样能够延缓自然条件和黑暗处理下的叶片衰老。

结果2-CLE42与CLE41/44功能冗余：CLE42 and CLE41/44 displayed functional redundancy in leaf senescence, and the cle41 cle42 cle44 triple mutant displayed more pronounced earlier senescence phenotypes than any single mutant. 

CLE42和CLE41/44在叶片衰老方面存在功能冗余，cle41 cle42 cle44三突变体要比任何一个单突都要表现出更加明显的叶片衰老表型。

结果3-CLE42抑制乙烯通路：Analysis of differentially expressed genes obtained by RNA-Seq methodology revealed that ethylene pathway was suppressed by overexpressing CLE42. Moreover, CLE42 suppressed ethylene biosynthesis and thus promoted the protein accumulation of EBF, which in turn decreased the function of EIN3. Accordingly, mutation of EIN3/EIL1 or overexpression of EBF1 suppressed the earlier senescence phenotypes of the cle42 mutant. 

通过对CLE42过表达植株的RNA-seq分析显示，乙烯通路明显被抑制。此外，CLE42抑制了乙烯的生物合成，从而促进了EBF的蛋白积累，转而降低了EIN3的功能。相应的，EIN3/EIL1的突变或者EBF1的过表达能够抑制cle42突变体的叶片提早衰老表型。

结论：Together, our results reveal that the CLE peptide hormone regulates leaf senescence by communicating with ethylene pathway.

综上，本文的研究揭示了CLE多肽激素通过乙烯通路，作用于叶片衰老的调控。

** 李中海 **

doi: https://doi.org/10.1111/nph.18154

Journal: New Phytologist

First Published: April 09, 2022