Yaoyao Huang;Xiangzhuo Xing;Jinyu Jin;Yun Tang;Lian Ding;Aiping Song;Sumei Chen;Fadi Chen;Jiafu Jiang;Weimin Fan

College of Horticulture and Landscape, Yunnan Agriculture University, Kunming, Yunnan 650201, China; State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China;State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China;State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu 210095, Chin

cmbhlh110;flowering;a novel;regulate;chrysanthemum;heli

Basic helix–loop–helix (bHLH) transcription factor gene family in plants controls various growth and development aspects; however, the actual roles of these genes in flowering plants are not well known. In this study, a novel bHLH protein CmbHLH110 was found to interact with CmERF110 by in vitro and in vivo experiments, a chrysanthemum ERF110 homolog that acts as a positive flowering regulator. In addition, CmbHLH110 was also found to regulate the flowering of chrysanthemums, overexpression of CmbHLH110 causes chrysanthemums to flower earlier, and suppressed CmbHLH110 leads to delayed flowering. Furthermore, the loss-of-function Arabidopsis mutant of its homologue PERICYCLE FACTOR TYPE-A 5 (PFA5) had a noticeable late flowering phenotype, and CmbHLH110 completely complemented the late flowering phenotype of the pfa5 mutant, whereas heterologous overexpression of CmbHLH110 in Arabidopsis Col-0 caused early flowering. Transcriptome sequencing revealed significant differential expression of flowering-related and circadian clock-related genes in transgenic chrysanthemum. Therefore, we concluded that CmbHLH110, as a novel flowering regulator, could interact with CmERF110 to regulate flowering in chrysanthemum.