A single residue change in the product of the chrysanthemum gene TPL1-2 leads to a failure in its repression of flowering

• Published in: Plant science (Limerick) Vol. 285; pp. 165 - 174
• Main Authors: Zhang, Zixin, Hu, Qian, Cheng, Hua, Cheng, Peilei, Liu, Yanan, Liu, Weixin, Xing, Xiaojuan, Chen, Sumei, Chen, Fadi, Jiang, Jiafu
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.08.2019
• Subjects: Arabidopsis; Chrysanthemum - genetics; Chrysanthemum - growth & development; Chrysanthemum - physiology; Constitutive expression; Flowers - growth & development; Gene Expression Profiling; Gene Expression Regulation, Plant - genetics; Genes, Plant - genetics; Genes, Plant - physiology; Plant Proteins - genetics; Plant Proteins - physiology; Plants, Genetically Modified; Point mutation; Protein interaction; Protein structure; qRT-PCR; Real-Time Polymerase Chain Reaction; Sequence Analysis, DNA; Time Factors; Two-Hybrid System Techniques; Constitutive expression; Protein interaction; Protein structure; Point mutation; qRT-PCR
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2019.04.027

•The product of TPL1-2 contributes to the regulation of flowering in chrysanthemum. The TPL1-2 transgenic lines flowered around 15 days later than WT plants，while the mut-TPL1-2 (N176H) flowered earlier.•The flowering-related genes FT, TSF, FUL and AP1 were all more strongly transcribed in the mutant transgene expressors than in the wild type transgene expressors.•Y2H and FLuCI experiments were shown to be capable of interacting with the WT form and its own, while TPL1-2 showed weak interaction on its own. It is speculated that the change may caused by the conformational change of protein structure.. The TPL/TPR co-repressor is involved in many plant signaling pathways, including those regulating the switch from vegetative to reproductive growth. Here, a TPL homolog (TPL 1-2) was isolated from chrysanthemum. Its product was found to be deposited in the nucleus. The abundance of TPL1-2 transcript varied across the plant, with its highest level being recorded in the stem apex, and its lowest in the root and stem. In the leaf, the abundance of TPL1-2 transcript was highest at dusk in plants exposed to long days, and at dawn in those exposed to short days. Site-directed mutagenesis was used to induce an N176H mutation in TPL1-2. The constitutive expression in Arabidopsis thaliana of the wild type and the mutated alleles of TPL1-2 had a contrasting effect on flowering time, with the mutant transgene expressors flowering later than the wild type transgene expressors. The flowering-related genes FT, TSF, FUL and AP1 were all more strongly transcribed in the mutant transgene expressors than in the wild type transgene expressors.