叶黄素支链1/环类/增殖细胞因子1(TCP)转录因子控制多种植物生长和发育的多个方面。然而,据报道,很少有基因通过其特定的结合位点直接被它们靶向和调控,然后揭示它们在植物中的功能。通过随机结合位点选择(RBSS)鉴定TCP2的共有DNA结合位点基序。TCP2识别的DNA含有基序G(G/T)GGNCC(A/C),与其他TCP结构域蛋白结合的基序表现出高度一致性。因此,该基序被认为是TCP2的特异性DNA结合位点。昼夜节律时钟相关1(CCA1)和早花3(ELF3)随后被认为是潜在的靶基因,原因是含有相似的TCP2结合位点或核心结合位点GGNCC,并且发现TCP2通过DNA结合受到正调节。表型分析结果表明,TCP2的突变和过表达导致了叶片形态发生的变异,特别是TCP2、4和10的双重或三重突变。TCPs的突变导致开花后期。最后,显示TCP2通过介导茉莉酸信号通路影响下胚轴伸长。总的来说,这些结果为今后旨在区分TCP2的靶基因和阐明TCP2在植物生长发育中的重要作用的研究提供了基础。
TEOSINTE BRANCHED 1/CYCLOIDEA/PROLIFERATING CELL FACTOR 1 (TCP) transcription factors control multiple aspects of growth and development in various plant species. However, few genes were reported to be directly targeted and regulated by them through their specific binding sites, and then uncover their functions in plants. A
consensus DNA-binding site motif of TCP2 was identified by random binding site selection (RBSS). DNA recognized by TCP2 contained the motif G(G/T)GGNCC(A/C), which showed high consistency with motifs bound by other TCP domain proteins. Consequently, this motif was regarded as the specific DNA-binding sites of TCP2. Circadian clock associated 1 (CCA1) and EARLY FLOWERING 3 (ELF3) were subsequently considered as potential target genes owing to the containing of the similar TCP2 binding sites or core binding sites GGNCC and found to be positively regulated by TCP2 via DNA binding. Phenotype analysis results showed that mutation and over-expression of TCP2 resulted in variations in leaf
morphogenesis, especially the double or triple mutations of TCP2, 4 and 10. Mutations in TCPs caused late flowering. Finally, TCP2 was shown to influence hypocotyl elongation by mediating the jasmonate signaling pathway. Overall, these results provide a basis for future studies aimed at distinguishing the target genes of TCP2 and elucidating the important roles of TCP2 in plant growth and development.