水稻单C_2H_2型锌指基因ZOS2-01的表达与功能分析

Expressional and Functional Analysis of a Single C_2H_2 Zinc Finger Gene ZOS2-01 in Rice (Oryza sativa L.)

拟南芥超雄基因(SUPERMAN,SUP)是一个单C2H2锌指基因。该基因突变后会造成雌蕊同源转化为雄蕊,正常的心皮发育受阻,因此SUP在控制花第3/4轮边界的建立和胚珠的发育中起重要作用。为了探知水稻中的SUP同源基因是否也存在类似的功能,我们根据拟南芥SUP的功能结构域,从水稻中克隆了一个与SUP类似基因,命名为ZOS2-01,并对其表达和功能进行了分析。结果表明,ZOS2-01与拟南芥的SUP和矮牵牛的PhSUP1在系统进化树上处于同一分支且与SUP的功能结构域完全相同。定量PCR和GUS表达分析表明,除胚乳外,ZOS2-01几乎在所有组织和器官中表达,但在幼穗中的表达量最高,暗示它可能参与了水稻的营养生长和花器官发育的调节。然而,采用RNA干扰和过量表达的方法减少和增加ZOS2-01的表达并没有明显影响水稻的生长发育,转基因水稻的营养生长正常,花器官发育也没有明显异常且结实正常。这些结果表明,尽管水稻ZOS2-01与拟南芥SUP具有相同的功能结构域,但它们的表达和功能可能已出现了分化,或者水稻中存在多个功能冗余的SUP类似基因。

Ababidopsis SUPERMAN （SUP） gene encodes a single C2H2 zinc finger gene.Mutation of this gene may block the normal carpel development and results in homeotic transformation of carpels into stamens.So SUP plays a key role in maintaining the boundary between floral whorls 3 and 4 and ovule development in Arabidopsis.In order to understand whether the SUP homologous gene in rice shares similar functions,we isolated a SUP-like gene in rice,named ZOS2-01,according to the functional domain of SUP,and characterized its expression and function.The results indicated that ZOS2-01,SUP and PhSUP1 belong to the same clade in the phylogenetic tree and the functional domain in ZOS2-01 is completely the same as that in SUP.Quantitative RT-PCR and GUS expression analyses showed that ZOS2-01 is expressed in all tissues and organs except endosperm,with the strongest expression in young panicles,implying that ZOS2-01 might be probably involved in the regulation of vegetative growth and floral organ development in rice.However,decrease and increase of ZOS2-01 expression mediated by RNA interference and over-expression did not exhibit obvious influence on rice growth and development.The transgenic plants showed normal vegetative growth,normal floral organ development and normal seed production.These results suggest that although rice ZOS2-01 and Arabidopsis SUP have the same functional domain,they might have diverged in expression and function,or there might be several SUP-like genes with redundant functions in rice.