玉米光周期反应及一个相关基因的克隆

【目的】研究玉米的光周期反应，克隆出玉米中的EMF同源基因并研究其表达模式。【方法】以热带玉米自交系CML288和温带玉米自交系黄早四为材料，研究了它们在9 h和15 h光周期处理后的反应和热带自交系CML288在不同时期两种日照挪动处理下的光周期反应。通过RT-PCR法克隆到一个玉米上的EMF同源基因，并检测了该基因在经过不同光周期处理的自交系CML288、黄早四及其F1的不同生长时期茎尖中的表达。【结果】 CML288对光周期的反应非常敏感，黄早四相对不敏感。CML288在短日照条件下7片叶时期是光周期反应的敏感时期，在长日照条件下9片叶时期是光周期反应的敏感时期。推测新克隆的cDNA序列含有完整的1 881bp的开放阅读框，编码一条约71kD的多肽，包含626个氨基酸残基，编码的蛋白质有一个C2H2型锌指结构区,两个核定位信号区和一个酸性区，可能是DAN结合蛋白，Northern杂交显示，其在茎尖和叶片中均有表达。经不同光周期处理后，该基因在2个自交系及F1不同生长时期茎尖中的表达情况不同。【结论】克隆到的基因其功能可能与促进营养生长和抑制生殖生长有关。

Response to Photoperiodical Variation and the Clone of a Photoperiod-Related Gene in Maize

Objective] The aim of the research is to study the response to photoperiodical variation, clone the EMF gene in maize and study the expression pattern of this gene. Method] CML288, a tropical inbred line, and Huanzao4, a temperate inbred line, were used as materials to study the response to photoperiodical variation in maize. The two inbred lines were grown in 2 different controlled photoperiod rhythms, 9 h and 15 h. And some CML288 plants grew at one level of photoperiod and then were transferred to the other photoperiodical level at different stages. Developmental stages and leaf numbers were recorded. A photoperiod related gene was cloned using RT-PCR. The expression of the gene in different treated materials was studied. Result] Results showed that CML288 was very sensitive to photoperiodical variation, but Huangzao4 was not. The seven-leaf stage is the most sensitive period for CML288 under short-day condition, and the nine-leaf stage on long-day condition. The cloned novel gene contains an open reading frame of 188 lbp encoding a putative DNA binding protein of 626 amino acids, which was possessed of a C2H2-type zinc finger motif, two putative nuclear localization signals and an acidic cluster. It expressed or did not differ from different materials. Conclusion] The function of the gene might be maintained vegetative development by repressing the flower program genes. Northern blot revealed that it expresses both in the SAM and leaf.