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ARS Home » Southeast Area » Stuttgart, Arkansas » Dale Bumpers National Rice Research Center » Research » Publications at this Location » Publication #285805
Title: DNA methylation affected by male sterile cytoplasm in rice (Oryza sativa L.)

Author
item XU, PEIZHOU - Sichuan University
item Yan, Wengui
item HE, JING - Sichuan University
item LI, YUN - Chengdu Institute
item ZHANG, HONGYU - Sichuan University
item PENG, HAI - Sichuan University
item WU, XIANJUN - Sichuan University

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/22/2012
Publication Date: 1/6/2013
Citation: Xu, P., Yan, W., He, J., Li, Y., Zhang, H., Peng, H., Wu, X. 2013. DNA methylation affected by male sterile cytoplasm in rice (Oryza sativa L.). Molecular Breeding. 31:719-727.

Interpretive Summary: Male sterile cytoplasm plays an important role in hybrid rice and cytoplasmic effects are sufficiently documented. DNA methylation that is an epigenetic event that alters gene expression and affects cell function has been studied for numerous aspects in rice. However, no reports are available on DNA methylation affected by male sterile cytoplasm in hybrid rice. In this study, a methylation sensitive amplified polymorphism (MSAP) technique was adapted to characterize DNA methylation for four male sterile cytoplasms that were widely commercialized in China. Site b1 and b3 were fully methylated only in all the maintainer lines, while b2 was fully methylated only in all the male sterile lines. These results implied a relationship of DNA methylation at these sites specifically with male sterile cytoplasms, as well as male sterility since the only difference between male sterile and maintainer lines was the cytoplasm. Furthermore, a pronounced variation was observed among the experimental materials, which associated with genetic distance between cytoplasmic donor and nucleus donor cultivars.

Technical Abstract: Male sterile cytoplasm plays an important role in hybrid rice and cytoplasmic effects are sufficiently documented. However, no reports are available on DNA methylation affected by male sterile cytoplasm in hybrid rice. We used a methylation sensitive amplified polymorphism (MSAP) technique to characterize DNA methylation for four male sterile cytoplasms that were widely commercialized in China. In total, 12 pairs of selective primers in combinations of EcoRI and MspI/HpaII amplified 350 bands among four male sterile (A) lines and the corresponding maintainer (B) lines. Site b1 and b3 were fully methylated only in all the B lines, while b2 was fully methylated only in all the A lines. These results implied a relationship of DNA methylation at these sites specifically with male sterile cytoplasms, as well as male sterility since the only difference between A and B lines was the cytoplasm. The DNA methylation was largely affected by male sterile cytoplasms. WA-type and Yinshui-type cytoplasms affected the methylation much greater than G-type and D-type cytoplasms as indicated by the number and degree of methylated sites, ratio of methylated sites, fully methylated sites, ratio of fully methylated sites, and polymorphism between A and B lines for these cytoplasms. The genetic distance between the cytoplasm and nucleus for the WA-type is much greater than for G- and D-types because the former is between wild and cultivated species and the latter is within indica subspecies between African and Asian cultivars. This difference in genetic distance may be responsible for the variation in methylation which we observed.