Cloning and Expression Analysis of Mlo Gene from Pericallis hybrida B. Nord.

The full-length Mlo gene was obtained by reverse transcription polymerase chain reaction （RT-PCR） and RACE. The result of sequence analysis indicated that M/o gene from Pericallis hybrida B. Nord. contained about 1296bp open reading frame and encoded 431 amino acids. According to the comparison of the exogenous gene sequences by BLAST analysis and phylogenetic analysis, Mlo gene shared over 85% nucleotide homology and 98% amino acid homology. Finally, through semi-quantitative-PCR and fluorescence quantitative analysis, we found that Mlo gene showed the highest expression levels in leaves and the lowest in roots after inoculated with powdery mildew pathogen for different days.

瓜叶菊‘大花’Mlo基因RNAi载体的构建及其遗传转化研究

为进一步研究瓜叶菊Mlo基因的功能以及为将来获得具有广谱与持久的白粉菌抗性瓜叶菊种质资源奠定基础,以瓜叶菊(Pericallis hybrida B.Nord)‘大花’为试验材料,克隆瓜叶菊‘大花’Mlo基因保守片段,构建了瓜叶菊‘大花’RNAi载体;同时构建了瓜叶菊‘大花’高频再生体系;并利用根癌农杆菌介导法转化瓜叶菊‘大花’进而建立了遗传转化体系。经酶切鉴定,成功构建了Mlo基因的RNAi载体质粒pTCK303-mlo-RNAi,构建了瓜叶菊‘大花’高频再生体系,最终确定瓜叶菊‘大花’最佳愈伤诱导培养基为:MS+6-BA 2.4mg/L+NAA 1.0mg/L+KT 0.3mg/L+2,4-D 1.0mg/L;瓜叶菊‘大花’愈伤组织的分化培养最适培养基为:MS+6-BA 2.0mg/L+NAA0.1mg/L;瓜叶菊‘大花’生根培养的最佳培养基为1/2MS+NAA 0.5mg·L-1,并且初步探索了瓜叶菊‘大花’Mlo基因转化体系。