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Article|01 Sep 2021|OPEN
DNA methylation is involved in sexual differentiation and sex chromosome evolution in the dioecious plant garden asparagus
Shu-Fen Li1, Can-Can Lv1, Li-Na Lan1, Kai-Lu Jiang1, Yu-Lan Zhang1, Ning Li1, Chuan-Liang Deng1 & Wu-Jun Gao1,
1College of Life Sciences, Henan Normal University, Xinxiang 453007, China

Horticulture Research 8,
Article number: 198 (2021)
doi: 10.1038/hortres.2021.198
Views: 47

Received: 29 Mar 2021
Revised: 25 May 2021
Accepted: 01 Jun 2021
Published online: 01 Sep 2021

Abstract

DNA methylation is a crucial regulatory mechanism in many biological processes. However, limited studies have dissected the contribution of DNA methylation to sexual differentiation in dioecious plants. In this study, we investigated the variances in methylation and transcriptional patterns of male and female flowers of garden asparagus. Compared with male flowers, female flowers at the same stages showed higher levels of DNA methylation. Both male and female flowers gained DNA methylation globally from the premeiotic to meiotic stages. Detailed analysis revealed that the increased DNA methylation was largely due to increased CHH methylation. Correlation analysis of differentially expressed genes and differentially methylated regions suggested that DNA methylation might not have contributed to the expression variation of the sex-determining genes SOFF and TDF1 but probably played important roles in sexual differentiation and flower development of garden asparagus. The upregulated genes AoMS1, AoLAP3, AoAMS, and AoLAP5 with varied methylated CHH regions might have been involved in sexual differentiation and flower development of garden asparagus. Plant hormone signaling genes and transcription factor genes also participated in sexual differentiation and flower development with potential epigenetic regulation. In addition, the CG and CHG methylation levels in the Y chromosome were notably higher than those in the X chromosome, implying that DNA methylation might have been involved in Y chromosome evolution. These data provide insights into the epigenetic modification of sexual differentiation and flower development and improve our understanding of sex chromosome evolution in garden asparagus.