黄瓜AG-like基因CsMADS24在花器官发育中的功能分析

Cucumber (Cucumis sativus L.) is an important vegetable crop, the research on cucumber floral organ is significant in theory and practice. AG-like gene belonging to MADS-box gene family, which plays an important role in stamen, carpel and ovule development, however, its function in cucumber is poorly understood. Our previous studies revealed only CsMADS24 belonged to AG-like gene in cucumber, and mainly expressed in early female flower. CsMADS24 over-expression vector transformed into wild-type Arabidopsis, the first whorl sepal ectopically developed to carpelloid structure, the second whorl petal transformed into stamineous structure, suggested that CsMADS24 might be closely related to cucumber flower development. This study is based on the previous work，by in situ hybrid to analyse CsMADS24 temporal and spatial expression patterns, over-expression and RNAi techniques to further study its function. Through this research, we expect to reveal the relationship of CsMADS24 gene with cucumber flower development in theory, to lay foundation for cucumber genetic improvement in application.

黄瓜（Cucumis sativus L.）是重要的蔬菜作物，对黄瓜花器官的研究具有一定的理论和实践意义。AG-like基因属MADS-box基因家族，在拟南芥雄蕊、心皮及胚珠的发育中起重要作用，其在黄瓜中的功能尚不清楚。我们前期研究发现，黄瓜中仅CsMADS24归属AG-like基因，主要在幼期雌花中表达。构建CsMADS24的过表达载体并转化拟南芥，第一轮萼片异生出心皮状的结构，第二轮花瓣部分转变为雄蕊状的结构，暗示CsMADS24基因可能与黄瓜花的发育密切相关。本研究拟在已有的工作基础上，采用原位杂交来研究该基因的时空表达模式，结合过表达、RNAi等技术来进一步研究该基因的功能。通过本项目研究，可望在理论上揭示CsMADS24与黄瓜花器官发育之间的关系，在应用上为黄瓜的遗传改良奠定基础。

黄瓜是重要的蔬菜作物，对黄瓜花器官的研究将为阐明黄瓜生殖发育机制及遗传改良提供基础。AG-like基因属MADS-box基因家族，在雄蕊、心皮及胚珠的发育中起重要作用。经全基因扫描发现，黄瓜中仅CsMADS24归属AG-like，构建CsMADS24的过表达载体并转化拟南芥，第一轮的萼片异生出心皮状的结构，第二轮的花瓣部分转变为雄蕊状的结构，呈现AG类基因的异位表达表型。组织表达谱分析发现，CsMADS24特异在黄瓜雌花中表达。原位杂交分析表明，CsMADS24基因在黄瓜雄花第9和10时期的雄蕊中检测到信号。过表达CsMADS24基因黄瓜植株表型变化较为明显，节位出现多雄多雌现象，单节位雌雄最高达5雌和17雄。RNA干扰CsMADS24基因黄瓜植株的根、茎、叶和低节位花在小苗时期均没有明显变化。这些结果表明，CsMADS24基因可能参与了黄瓜花蕾的发育过程。