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利用同源序列法,本实验以拟南芥DNA去甲基化酶ROS1的序列成功在玉米Maize Sequence网站获得玉米同源序列,并利用生物信息学的方法对其序列进行预测分析.显示,玉米ROS1包括3个拷贝,且同源性比较接近,酸性不稳定的可溶性亲水蛋白,不含信号序列,均具有DNA-glycosylase,HhH-GPD-domain,HTH-base-excis_C及RRM-DME结构域,但是ROS1-3不具有Perm-CXXC结构域,系统进化分析发现与单子叶植物谷子、小麦和高粱关系较近.为进一步分析其功能,本实验以盐胁迫下耐盐玉米自交系为材料,Real-time qRT-PCR定量检测该酶DNA-glycosylase功能结构域表达水平.发现,盐浓度为200 mmol/L时表达量最高,与对照相比差异显著.该实验说明玉米ROS1去甲基化酶可能参与逆境胁迫下玉米的甲基化调控机制.“,”In order to obtain homologous sequences of maize,the amino acid sequences of DNA demethylation enzyme ROS1 of Arabidopsis thaliana ROS1 were used.Through bio-informatic predication and analysis,the results showed that the DNA de-methylationase ROS 1 of maize contained 3 copies which had similar homology.They were all soluble hydrophilic acid labile proteins with no signal sequences.As well as all copies contained DNA-glycosylase,HhH-GDP-domain,HTH-base-excis_C and RRM DME domain structure.However,ROS1-3 didn't have Perm-CXXC domain structure.Phylogenetic analysis showed that ROS 1 of maize was closed to the monocots,such as Setaria italica,Triticum aestivum and Sorghum bicolor.In addition,to further analyze the function of ROS1,we used salt tolerant maize inbred lines as materials to detecte the expression level of the functional domain,DNA-glycosylase by real-time qRT-PCR under salt stress.We found that the quantity of ROS1 gene expression was significant increasing under 200 mmol/L salt stress.This study indicated that DNA methylation enzyme ROS 1 of maize might play a remarkable role in DNA methylation regulatory mechanism under abiotic stress.