摘要
【目的】利用棉花无短绒突变体GZnn为材料,分离与棉花纤维发育相关的重要基因,从而揭示棉花纤维发育的分子机理。【方法】通过扫描电镜观察GZnn与其近等基因系TM-1在纤维发育上的差别;采用差异显示RT-PCR方法寻找GZnn与TM-1之间的差异表达片段,并进行相应分析。【结果】用扫描电镜观察突变体GZnn与TM-1的胚珠表面纤维细胞起始发生的情况,发现GZnn不仅在纤维细胞发生和延伸上延迟,而且纤维细胞总数也明显减少。利用差异显示PCR进行比较筛选,获得了12个差异表达的EST片段,其中,DS3只特异性地在GZnn开花前(-3～0DPA)的胚珠中特异表达,而在其近等基因系TM-1中没有表达,推测DS3可能是一个纤维启动过程中的MYB类负调控转录因子。【结论】本研究利用棉花无短绒突变体GZnn发现,棉纤维细胞在早期分化和形态建成过程中大量基因表达,对其中的关键基因的表达模式和功能开展深入研究将有助于阐明棉纤维分化发育的分子机理,为棉花遗传改良提供理论基础。
[ Objective ] This study aims to compare the transcript profiles between the cotton fuzzless mutant and its isogenic line in order to identify the genes which are involved in cotton fiber development. [ Method ] Scanning electron microscope （SEM） was used to observe the differential fiber developmental patterns between the fuzzless mutant GZnn and its isogenic line TM-1, and differential display PCR was employed to identify the differentially expressed genes. These resulting fragments were sequenced and analyzed by BLASTx. [ Result ] Using SEM to examine the cellular events of fiber cell development in the mutant GZnn, it was found that not only the process of fiber cell formation and elongation delayed, but also the fiber number reduced in the mutant in comparison with TM-1. By using differential display RT-PCR, 12 differentially expressed cDNA fragments were obtained, among which DS3 showed high degree of similarity to myb family transcription factors and was expressed exclusively in ovule before anthesis （-3-0 DPA） in the mutant, but not in that of TM-1. Therefore, DS3 might be a negative regulator during fiber initiation. [Conclusion] A large number of genes were expressed specifically during cotton fiber initiation and development. Further investigations on the genes which play key roles during this process are of help to understand the molecular mechanisms underlying the differentiation and development of cotton fibers, and this will contribute to cotton genetic improvement.
出处
《中国农业科学》
CAS
CSCD
北大核心
2009年第3期790-797,共8页
Scientia Agricultura Sinica
基金
国家重点基础研究发展计划“973”(2004CB117300)
