Abstract

Ethylene is a gaseous hormone that affects many processes of plant growth and development. During vascular development, ethylene positively regulates cambial cell division in parallel with tracheary element differentiation inhibitory factor (TDIF) peptide signaling. In this study, we identified an ethylene overproducing mutant, acs7-d, exhibiting enhanced cambial activity and reduced wall development in fiber cells. Using genetic analysis, we found that ethylene signaling is necessary for the phenotypes of enhanced cambial cell division as well as defects in stem elongation and fiber cell wall development. Further, the cambial cell proliferation phenotype of acs7-d depends on WOX4, indicating that the two parallel pathways, ethylene and TDIF signaling, converge at WOX4 in regulating cambium activity. Gene expression analysis showed that ethylene impedes fiber cell wall biosynthesis through a conserved hierarchical transcriptional regulation. These results advance our understanding of the molecular mechanisms of ethylene in regulating vascular meristem activity.

中文翻译：

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ACS7 的激活会影响血管发育，并证明乙烯合成与形成层活性之间存在联系。

摘要

乙烯是一种气态激素，影响植物生长发育的许多过程。在血管发育过程中，乙烯与气管元件分化抑制因子 (TDIF) 肽信号传导平行地正向调节形成层细胞分裂。在这项研究中，我们鉴定了一种乙烯过量产生突变体acs7-d，其在纤维细胞中表现出增强的形成层活性和减少的壁发育。使用遗传分析，我们发现乙烯信号传导对于增强的形成层细胞分裂的表型以及茎伸长和纤维细胞壁发育的缺陷是必需的。此外，acs7-d的形成层细胞增殖表型依赖于 WOX4，表明乙烯和 TDIF 信号这两个平行通路在 WOX4 处会聚以调节形成层活性。基因表达分析表明，乙烯通过保守的分级转录调控阻碍纤维细胞壁的生物合成。这些结果促进了我们对乙烯调节血管分生组织活性的分子机制的理解。