Wu Xiaoyun, Li Junzhuo, Wen Xiaohui, Zhang Qiuling, Dai Silan
Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, School of Landscape Architecture, Beijing Forestry University, Beijing, China.
Genomics and Genetic Engineering Laboratory of Ornamental Plants, Department of Horticulture, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
Front Plant Sci. 2023 Sep 29;14:1276123. doi: 10.3389/fpls.2023.1276123. eCollection 2023.
TCP proteins, part of the transcription factors specific to plants, are recognized for their involvement in various aspects of plant growth and development. Nevertheless, a thorough investigation of in , a prominent ancestral species of cultivated chrysanthemum and an excellent model material for investigating ray floret (RF) and disc floret (DF) development in , remains unexplored yet. Herein, a comprehensive study was performed to analyze the genome-wide distribution of in . In total, 39 in were identified, showing uneven distribution on 8 chromosomes. Phylogenetic and gene structural analyses revealed that were grouped into classes I and II. The class II genes were subdivided into two subclades, the CIN and CYC/TB1 subclades, with members of each clade having similar conserved motifs and gene structures. Four CIN subclade genes (, , , and ) contained the potential miR319 target sites. Promoter analysis revealed that had numerous -regulatory elements associated with phytohormone responses, stress responses, and plant growth/development. The expression patterns of during capitulum development and in two different florets were determined using RNA-seq and qRT-PCR. The expression levels of s varied in six development stages of capitula; 25 out of the 36 genes were specifically expressed in flowers. Additionally, we identified six key genes, which belong to the class II TCP subclade, with markedly upregulated expression in RFs compared with DFs, and these genes exhibited similar expression patterns in the two florets of species. It is speculated that they may be responsible for RFs and DFs development. Subcellular localization and transactivation activity analyses of six candidate genes demonstrated that all of them were localized in the nucleus, while three exhibited self-activation activities. This research provided a better understanding of in and laid a foundation for unraveling the mechanism by which important involved in the capitulum development.
TCP蛋白是植物特有的转录因子的一部分，因其参与植物生长发育的各个方面而受到认可。然而，对栽培菊花的一个重要祖先物种以及研究其舌状花（RF）和管状花（DF）发育的优良模式材料[此处原文缺失具体物种名]的全面研究仍未开展。在此，进行了一项综合研究以分析[此处原文缺失具体物种名]中TCP蛋白在全基因组中的分布。总共在[此处原文缺失具体物种名]中鉴定出39个TCP蛋白，它们在8条染色体上分布不均。系统发育和基因结构分析表明，TCP蛋白被分为I类和II类。II类基因又细分为两个亚分支，即CIN和CYC/TB1亚分支，每个分支的成员具有相似的保守基序和基因结构。四个CIN亚分支基因（[此处原文缺失具体基因名]）含有潜在的miR319靶位点。启动子分析表明，TCP蛋白具有许多与植物激素反应、胁迫反应和植物生长/发育相关的顺式调控元件。利用RNA测序和qRT-PCR确定了TCP蛋白在头状花序发育过程中以及在两种不同小花中的表达模式。TCP蛋白的表达水平在头状花序的六个发育阶段有所不同；36个TCP基因中有25个在花中特异性表达。此外，我们鉴定出六个关键的TCP基因，它们属于II类TCP亚分支，与管状花相比，在舌状花中的表达明显上调，并且这些基因在[此处原文缺失具体物种名]的两种小花中表现出相似的表达模式。推测它们可能对头状花序中舌状花和管状花的发育负责。对六个候选基因的亚细胞定位和反式激活活性分析表明，它们都定位于细胞核，而其中三个具有自激活活性。这项研究为更好地理解[此处原文缺失具体物种名]中的TCP蛋白奠定了基础，并为揭示重要的TCP蛋白参与头状花序发育的机制奠定了基础。
