水稻愈伤组织形成过程中甲基化对OsMAPK2的表达调控  

DNA methylation-mediated regulation of OsMAPK2 gene expression in rice callus formation

作　　者：王文国[1] 李锐[1] 朱珈仪[1] 王胜华[1] 陈放[1] 

机构地区：[1]四川大学生命科学学院,生物资源与生态环境教育部重点实验室,成都610064

出　　处：《遗传》2010年第12期1275-1280,共6页Hereditas（Beijing)

摘　　要：利用MSAP方法从经过5-azaC处理和未处理的水稻愈伤组织中获得了1个存在甲基化位点的片段。测序后比对分析表明,该片段为水稻MAPK家族OsMAPK2基因的5′端区域。该基因5′端区域有一个CpG岛,与拟南芥AtMAPK12基因序列高度相似。利用实时定量PCR和HpaII-McrBC PCR分析了在水稻芽段受生长素刺激后形成愈伤组织过程中OsMAPK2基因的表达与甲基化的关系。结果表明:该基因表达量与基因5′端甲基化水平相对应,甲基化调控基因的表达。在愈伤组织形成过程中2.0mg/L的2,4-D诱导该基因5′端区域去甲基化,使基因表达,而长时间(100h)的诱导后或导致重新甲基化,基因表达量降低;低浓度的2,4-D(0.5和1.0mg/L)也可以产生同样的趋势,但是基因的表达量低于2.0mg/L的2,4-D的诱导;高浓度的2,4-D(5.0mg/L)可以在较短的时间内完成对基因的诱导和抑制。A DNA segment with DNA methylation site was detected from rice callus with or without 5-azaC treatment by MSAP. This segment was located on the first exon of gene OsMAPK2 and its 5-non-coding region. Gene OsMAPK2 had a CpG island in the 5-region and was homologous to AtMAPK12. Real-time quantitative PCR and Hpa II-McrBC PCR were conducted to detect the gene expression and DNA methylation of OsMAPK2 in the process of callus formation. The results showed that the DNA methylation was able to control the expression of OsMAPK2. The additon of 2.0 mg/L 2,4-D could induce DNA demethylation in the 5-region and activate the expression of OsMAPK2 gene. However,after long-time stimu-lation（100 h） ,the gene was methylated again,and the gene expression level was decreased. The trends of DNA methylation and gene expression stimulated by low concentrations of 2,4-D（0.5 and 1.0 mg/L） were similar to 2.0 mg/L 2,4-D,but the expression levels in each time point were low. On the other hand,high concentration of 2,4-D（5.0 mg/L） completed the processes of induction and suppression of the gene in a shorter time.

关 键 词：水稻 愈伤组织 甲基化 OsMAPK2 生长素 

分 类 号：S511[农业科学—作物学]