摘要
作为转录因子 ,MADS框蛋白基因在植物花器官发育中有着重要的功能。为研究棉花花器官发育的分子机理 ,以棉花花器官突变体CHV1(cottonhomeoticvariant)和徐州 14 2正常植株为材料 ,利用棉花EST数据库资料 ,通过EST序列整合 ,从陆地棉徐州 14 2花蕾中克隆出一个MADS框蛋白的编码区段 ,GenBank登录号为AF5 3896 5。该片段 (GhMADS1)长 713bp ,包含一个 711bp的开放阅读框 ,推导的氨基酸序列 (2 36个氨基酸 )与葡萄、烟草、矮牵牛、拟南芥和金鱼草等的AGL2组MADS框蛋白有很高的序列相似性。系统进化分析同样将Gh MADS1基因归入AGL2组MADS框蛋白。RT PCR分析显示 ,该基因在陆地棉的花瓣、雄蕊、胚珠和纤维中表达 ,特别是在花瓣中表达量最高 ,而在根、茎、叶等营养器官和棉花同源异型突变体CHV1(所有花器官均变为苞叶状叶性器官 )的变异花蕾中不表达。
As a kind of transcription factors,MADS-box protein plays an important role in various cellular processes,especially in the development of floral organs. Based on the contig analysis of the cotton ESTs,the coding region of a cotton MADS-box protein (GhMADS1) was obtained by RT-PCR from floral buds of cotton (G. hirsutum). The cloned fragment of 713 bp (GhMADS1,GenBank accession no. AF538965) contains an open reading frame of 711 bp,coding a polypeptide of 236 amino acids. It was demonstrated that the deduced GhMADS1 protein was highly homologous to the AGL2 group of MADS-box proteins from Vitis vinifera,Nicotiana sylvestris,Petunia hybrida,Arabidopsis thaliana and Antirrhinum majus.Phylogenetic analysis also indicated that GhMADS1 belongs to the AGL2 group of MADS-box proteins. RT-PCR analysis showed that GhMADS1 gene expressed in petals,stamens,ovules and fibers,but not in roots,stems,leaves,bracts and sepals. The strongest expression of GhMADS1 gene was detected in petals. But in floral buds of a cotton homeotic mutant (CHV1),whose floral organs are all converted to bract leaf-like organs,the transcript of GhMADS1 gene was not detected. It was proposed that GhMADS1 gene would be crucial to the development of cotton floral organs.
基金
国家自然科学基金资助项目 (批准号 :3 0 0 70 485 )~~
