Is losing ethylene a losing game?
Is losing ethylene a losing game?
复制标题
失去乙烯是一场失败的游戏吗？
DOI：
10.1016/j.molp.2022.03.005
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发表时间：
2022
期刊：
影响因子：
27.5
通讯作者：
Chang, Caren
中科院分区：
文献类型：
--
作者：
Van de Poel, Bram;Chang, Caren
It is well established that the gaseous plant hormone ethylene modulates growth and development and mediates responses to biotic and abiotic stresses. Seed plants produce ethylene from S-adenosyl-L-methionine, which is converted to 1-aminocyclopropane-1-carboxylic acid (ACC) by ACC synthase (ACS); ACC is then converted to ethylene by a dedicated enzyme, ACC oxidase (ACO)(Figure 1 A). Many seed plant genomes carry multiple ACO homologs, allowing for spatiotemporal fine-tuning of ethylene biosynthesis. Non-seed plants (eg, ferns, bryophytes) lack ACO homologs (Li et al., 2018) and produce ethylene presumably by an unknown non-ACC-dependent pathway. Numerous responses to ethylene have been identified by treating plants with exogenous ethylene. However, the removal of internally synthesized ethylene is required to determine the roles of endogenous ethylene.Li et al.(2022a) recently reported in Molecular Plant the creation of ‘‘ethylene-free’’Arabidopsis mutants that are unable to produce detectable levels of ethylene, as a result of knocking out all five ACO genes using CRISPR/Cas9 technology. In the same issue, Heydlauff et al.(2022) genetically crossed Arabidopsis aco T-DNA insertion lines to generate an aco quadruple mutant that is heterozygous for a fifth aco mutation. Both papers investigated the role of ethylene in aspects of reproduction; Li et al.(2022a) focused on programmed cell death/degeneration of the synergid cells, while Heydlauff et al.(2022) focused on the roles of the ethylene transcription factor ETHYLENE-INSENSITIVE3 (EIN3) in endosperm and seed development. It was previously reported that ethylene is required to initiate programmed cell death of the synergid cells, and can even bypass the fertilization requirement (V ölz et al., 2013). However, surprisingly, Li et al.(2022a) showed that the aco quintuple knockout mutants have normal synergid cell death, indicating that ethylene is not necessarily required in this process (Figure 1 B). Even so, they found that ethyleneindependent cell death of the persistent synergid cell requires EIN3 and its homolog EIN3-LIKE1 (EIL1)(Li et al., 2022a).
