Novel functions of the Arabidopsis transcription factor TCP5 in petal development and ethylene biosynthesis

First author: Sam W. van Es; Affiliations: Wageningen University and Research (瓦赫宁根大学): Wageningen, The Netherlands

Corresponding author: Richard G.H. Immink

The flowers of most dicotyledons have petals that, together with the sepals, initially protect the reproductive organs. Later during development petals are required to open the flower and to attract pollinators. This diverse set of functions demands tight temporal and spatial regulation of petal development. We studied the functioning of the Arabidopsis thaliana TCP5‐like transcription factors (TFs) in petals. Overexpression of TCP5 in petal epidermal cells (表皮细胞) results in smaller petals, whereas tcp5 tcp13 tcp17 triple knockout lines have wider petals with an increased surface area. Comprehensive expression studies revealed effects of TCP5‐like TFs on the expression of genes related to the cell cycle, growth regulation and organ growth. Additionally, the ethylene biosynthesis genes 1‐amino‐cyclopropane‐1‐carboxylate (ACC) synthase 2 (ACS2; 1-氨基环丙烷-1-羧酸(ACC)合酶) and ACC oxidase 2 (ACO2) and several ETHYLENE RESPONSE FACTORS (ERFs) are found to be differentially expressed in TCP5 mutant and overexpression lines. Chromatin immunoprecipitation–quantitative PCR showed direct binding of TCP5 to the ACS2 locus in vivo. Ethylene is known to influence cell elongation, and the petal phenotype of the tcp5 tcp13 tcp17 mutant could be complemented by treatment of the plants with an ethylene pathway inhibitor. Taken together, this reveals a novel role for TCP5‐like TFs in the regulation of ethylene‐mediated petal development and growth.

大多数双子叶的花有花瓣，与萼片一起起初保护植物的生殖器官。在发育到一定阶段之后，花瓣会张开，并吸引授粉者。花瓣在不同时期行使不同的功能需要在花瓣的发育过程中有时间和空间的精确调控。本文研究了拟南芥中TCP5‐like转录因子在花瓣发育过程中的作用。在花瓣的表皮细胞中过表达TCP5基因会导致花瓣变小，而tcp5 tcp13 tcp17三突变体则具有更加宽的花瓣，整个花瓣的表面积增加。通过比较的表达研究，作者发现TCP5‐like转录因子影响的基因与细胞周期、生长调控以及器官生长相关。另外，乙烯1-氨基环丙烷-1-羧酸（ACC）合酶编码基因ACS2、ACC氧化酶编码基因ACO2和一些乙烯响应因子ERFs在TCP5突变体和过表达株系中存在差异表达。染色质免疫共沉淀实时定量PCR显示体内环境下TCP5会直接结合到ACS2位点。乙烯已知可以影响细胞伸长，而且tcp5 tcp13 tcp17三突变体的花瓣表型能够通过对植物外施乙烯通路抑制剂来恢复。综上，本文的研究揭示了TCP5‐like转录因子在乙烯介导的花瓣发育和生长过程中扮演的新的调控作用。

通讯：Richard G.H. Immink (https://www.wur.nl/en/Persons/Richard-Immink.htm)

研究方向：植物开花及器官发育相关的分子机理。

doi: https://doi.org/10.1111/tpj.13904

Journal: the plant journal

First Published date: 25 April, 2018

（P.S. 欢迎关注微信公众号：微信号Plant_Frontiers）