【目的】对辣椒差减文库中挑选出的4个育性相关候选基因进行克隆与表达分析,探讨其与辣椒细胞核雄性不育的关系。【方法】通过半定量RT-PCR技术分析候选EST在辣椒可育株和不育株中的表达情况。利用RACE技术获得4个育性相关基因的cDNA全长,结合生物信息学方法进行序列比对和蛋白理化性质分析。采用半定量RT-PCR检测基因在不同器官(花药、子房、花瓣、萼片和叶片)和花药小孢子不同发育时期(四分体时期、单核早中期、单核靠边期和双核期)的表达量。【结果】根据比对注释结果,将4个基因分别命名为CaSEP1、CaPROF、CaOle e 6和CaPCP。CaSEP1全长1 108 bp,编码221个氨基酸,含有一个MADS结构域和一个K结构域;CaPROF全长767 bp,编码131个氨基酸,含有一个PROF结构域;CaOle e 6全长523 bp,编码85个氨基酸,含有一个Ole e 6结构域;CaPCP全长563 bp,编码66个氨基酸。氨基酸序列比对及系统发育树分析表明,CaSEP1与番茄SEP1的氨基酸序列相似性最高,并且亲缘关系最近;CaPROF与茄科作物烟草和番茄的前纤维蛋白相似性较高,且与番茄的前纤维蛋白亲缘关系最近;CaOle e 6与番茄中的对应蛋白存在一定的相似性,亲缘关系也最近;CaPCP则与茶树中的对应蛋白相似性最高,亲缘关系最近。表达分析显示,CaSEP1在可育株花药、子房、花瓣等花器官中表达量一致,且高于萼片和叶片;CaPROF在可育株花药中的表达明显高于叶片,在其他器官中不表达;CaOle e6在可育株花药中的表达明显高于其他器官;CaPCP只在可育株的花药中表达。CaSEP1在可育株小孢子不同发育时期表现为先逐渐升高,至单核靠边期达到最高,而后在双核期表达量明显下降,在不育株中则表现为伴随着小孢子发育表达量逐渐升高;该基因在四分体时期两材料的表达量相当,在单核早中期和单核靠边期可育株中的表达量明显高于不育株,而双核期可�
Fertility restoration of cytoplasmic male-sterility in pepper (Capsicum annuum L.) is useful for commercial production of hybrid seeds. However, the mechanism of fertility restoration has not been determined. We previously constructed a cDNA library and identified some genes related to fertility restoration in pepper using suppression subtractive hybridization technology. In this study, the expression patterns of 20 genes were investigated using semi-quantitative RT-PCR. Three genes expressed only in restorer lines, but not in sterility lines. Four genes expressed only in anther, but not in other organs. Among these 7 genes, the clone TG31 was observed to specifically express in anther of restorer lines. The work described here provides a comprehensive overview on the expression pattern of the genes that are induced by restorer alleles in pepper. It will also contribute to the current understanding of molecular networks for the regulation of fertility restoration.
Pepper flowers are hermaphroditic; the plant's male sterility trait is characterized by its inability to produce pollen grains. In the ABC model of flower development, B-function genes play roles in petal and stamen development in the angiosperm. In this study, a B-class gene designated as PAP3 (Gen Bank accession no. HM104635) was isolated in pepper. The gene encoded 226 amino acids and shared high similarity with the MADS-box protein family, with a conservative MADS domain and semiconservative K domain. Furthermore, the expression of PAP3 was abundant only in petals and anthers but not in leaves. A functional study employing virus-induced gene silencing(VIGS) showed that knockdown of PAP3 led to the shriveling of pollen grains and male sterility; however, it did not affect petal development. These results suggest an essential role for PAP3 in the development of the pepper stamen and in contributing to the variation of floral traits.
