DNA甲基化对水稻花药培养过程中黄化的影响

Impacts of DNA methylation on etiolation in rice anther culture

花药培养是一种常见的植物组织培养技术,其培养过程中易产生黄化苗,从DNA甲基化的角度探究水稻花药培养中幼苗高频黄化的机制。结果表明:水稻花药培养产生的黄化苗叶绿素含量降低,叶绿体形态异常。黄化苗基因组DNA甲基化水平明显升高。进一步分析发现绿苗和黄化苗差异甲基化基因主要富集在光合作用相关的途径。通过转录组分析发现,LOC_Os04g58200(OsPORA)、LOC_Os01g01280(OsTLP27)、LOC_Os06g01850(OsLFNR1)、LOC_Os11g01140(OsNPH1a)、LOC_Os02g15640(OsPYL3)、LOC_Os12g08830、LOC_Os07g053600、LOC_Os06g40640(OsAld-Y)和LOC_Os07g01769个与光合作用相关的基因表达量发生改变,且甲基化水平也发生变化。综上,水稻花药培养过程中由于DNA甲基化而抑制光合作用中相关基因的表达,从而导致黄化苗的产生。

Anther cultivation is a common plant tissue culture technique with great significance in rice breeding.However,many etiolated seedlings are easy to produce during the anther cultivation,and the reasons for their formation have not been reported.In this study,the mechanism of high-frequency etiolated seedlings in rice anther cultivation was analyzed from the perspective of DNA methylation.The results showed that the chlorophyll content of etiolated seedlings produced by rice anther cultivation was reduced,and the chloroplast morphology was abnormal.The level of DNA methylation in the genome of etiolated seedlings was significantly increased.Further analysis found that the differential methylation genes of green seedlings and etiolated seedlings were mainly enriched in photosynthesis-related pathways.The expression levels and methylation levels of the following genes had undergone correlation changes,such as LOC_Os04g58200(OsPORA),LOC_Os01g01280(OsTLP27),LOC_Os06g01850(OsLFNR1),LOC_Os11g01140(OsNPH1a),LOC_Os02g15640(OsPYL3),LOC_Os12g08830,LOC_Os07g053600,LOC_Os06g40640(OsAld-Y)and LOC_Os07g01760,which were associated with photosynthesis.It is shown that DNA methylation inhibits the expression of relevant genes in photosynthesis during rice anther cultivation,resulting in the production of etiolated seedlings.