摘要
为研究CMS核质互作的分子机理,将甘蓝型油菜(Brassica napus L.)和白菜(B.campestris L.ssp.chinensis Makino)杂交并连续回交6代获得白菜OguCMS,在与保持系花药细胞学比较的基础上,运用cDNA-AFLP筛选得到白菜OguCMS早、中期花蕾提早表达的MYB-like差异片段,利用RACE克隆得到该片段的cDNA全长,命名为BcMYBogu(GenBank登录号:EF127861),对其氨基酸序列和表达特征进行研究。结果表明,白菜OguCMS绒毡层在四分体后增生,高度液泡化,导致小孢子花粉外壁异常,细胞质同外壁分离并降解;花药变白;BcMYBogu具有典型的MYBDNA结合域—W残基和SH[AL]QKY[RF]基序;系统进化分析显示BcMYBogu与AtMYB26,AtMYB32和AtMYB4等聚类在同一分枝;RT-PCR分析表明BcMYBogu在莲座叶、花茎和花蕾中均有表达,但在OguCMS花蕾中表达量显著上升。由此推测BcMYBogu是一个新的与白菜OguCMS相关的MYB家族新成员。
In the attempt to elucidate the molecular mechanism of CMS. Ogura cytoplasmic male sterile （OguCMS） lines were obtained in Chinese cabbage after interspecific hybridization between Brassica. napus L. OguCMS and B. campestris ssp. chinensis followed by recurrent backcross with B. campestris ssp. chinensis as the pollen donor. The CMS lines were significantly characterized by the whitish anther and indehiscence of anther. The tapetal hypertrophy with excess vacuolation was the first observed defective soon after the tetrad stage, subsequently the microspores defected in pollen wall formation, and later the cytoplasm detached from the exine wall and underwent degeneration. With aid of cDNA-AFLP and RACE approaches, we cloned the BcMYBogu（GenBank accession No： EF127861） in Chinese cabbage, which is premature expressed in early and middle stage floral buds of OguCMS lines, and predicted to encode a novel protein with a DNA binding domain： SH[AL]QKY[RF] motif at the N-terminus. Phylogenetic comparison revealed that the BcMYBogu was clustered with AtMYB32, AtMYB26 and AtMYB4, which were indicated to be involved in male sterility in Arabidopsis thaliana. The BcMYBogu transcript was detected in rosette leaves, floral buds and stems by RT-PCR analysis. Compared with the maintainer, the expression level of BcMYBogu was increased in these organs, especially in floral buds of OguCMS lines. Our investigation suggests that BcMYBogu is a new member of the MYB family involved in male sterility in Chinese cabbage.
出处
《遗传》
CAS
CSCD
北大核心
2007年第5期621-628,共8页
Hereditas（Beijing)
基金
浙江省自然科学基金(编号:Y304180)
浙江省重大科技项目(编号:2005C12019-02)资助~~
