Effect of male sterile and fertile cytoplasm on nuclear DNA methylation in hybrid rice 

Asif Ali, Yun Li, Hui Chen, Peizhou Xu, Hongyu Zhang, Xiaoqiong Chen, Liao Yongxiang, Shaohong Fu, Tingkai Wu, Muhammad Zafar Iqbal, Muhammad Umer Farooq , Xianjun Wu*

Acta Physiologiae Plantarum（IF=1.438），2019，41：81

https://link.springer.com/article/10.1007/s11738-019-2874-1

Abstract

Nucleus-controlled fertility restoration and cytoplasmic male sterility are important mechanisms to exploit heterosis. However, the effect of DNA methylation on cytoplasmic-nuclear interaction is not well understood yet. The current study used a methylation-sensitive amplified polymorphism to characterize polymorphism in nuclear DNA methylation among cytoplasmic male sterile line (D62A), corresponding maintainer line (D62B), and two F1 hybrids (D62A × R527 and D62B × R527). In results, 495 fragments were amplified between the parental D62A and D62B lines. The total methylation (double + single-stranded) and full methylation (double-stranded) rates of D62A (33.13%, 24.24%) both were found to be lower than that of corresponding maintainer D62B (33.94%, 24.85%). Analysis of methylation revealed that male sterile line D62A was less methylated than that of corresponding maintainer line D62B in all methylation types I, II and III. A total of 516 fragments were amplified between two F1 hybrids (D62A × R527 and D62B × R527). The total methylation in both hybrids (D62A × R527 and D62B × R527) was identical (34.69%). While full methylation rates for D62A × R527 and D62B × R527 were 25.78% and 25.58%, respectively, that is non-significant. Moreover, polymorphism in DNA methylation was found higher in F1 hybrids (5.43%) than parents (4.24%). These results implied that different cytoplasm leads to changes in nuclear DNA methylation and sterile cytoplasm has reduced the effect on nuclear methylation than non-sterile cytoplasm. Current study explains the interaction between cytoplasmic male sterility and DNA methylation which may contribute to further research.