Overexpression of the Chrysanthemum lavandulifolium ROS1 gene promotes flowering in Arabidopsis thaliana by reducing the methylation level of CONSTANS

• Published in: Plant science (Limerick) Vol. 342; p. 112019
• Main Authors: Shi, Zhongya, Zhao, Wenqian, Li, Chenran, Tan, Wenchao, Zhu, Yifei, Han, Yanchao, Ai, Penghui, Li, Zhongai, Wang, Zicheng
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.05.2024
• Subjects: Chrysanthemum lavandulifolium; CONSTANS (CO); DNA demethylation; Flowering time; Promoter methylation; RELEASE OF SILENCING 1 (ROS1); CONSTANS (CO); DNA demethylation; Promoter methylation; Chrysanthemum lavandulifolium; Flowering time; RELEASE OF SILENCING 1 (ROS1)
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2024.112019

DNA demethylation is involved in the regulation of flowering in plants, yet the underlying molecular mechanisms remain largely unexplored. The RELEASE OF SILENCING 1 (ROS1) gene, encoding a DNA demethyltransferase, plays key roles in many developmental processes. In this study, the ROS1 gene was isolated from Chrysanthemum lavandulifolium, where it was strongly expressed in the leaves, buds and flowers. Overexpression of the ClROS1 gene caused an early flowering phenotype in Arabidopsis thaliana. RNA-seq analysis of the transgenic plants revealed that differentially expressed genes (DEGs) were significantly enriched in the circadian rhythm pathway and that the positive regulator of flowering, CONSTANS (CO), was up-regulated. Additionally, whole-genome bisulphite sequencing (WGBS), PCR following methylation-dependent digestion with the enzyme McrBC, and bisulfite sequencing PCR (BSP) confirmed that the methylation level of the AtCO promoter was reduced, specifically in CG context. Overall, our results demonstrated that ClROS1 accelerates flowering by reducing the methylation level of the AtCO promoter. These findings clarify the epigenetic mechanism by which ClROS1-mediated DNA demethylation regulates flowering. •ClROS1, a DNA demethyltransferase, was isolated from Chrysanthemum lavandulifolium.•Overexpression of ClROS1 in Arabidopsis promoted flowering.•Overexpression of ClROS1 decreased the genome-wide methylation level of transgenic plants.•ClROS1-mediated DNA demethylation regulates flowering by reducing the methylation level of the AtCO promoter.