兰科植物具有相当独特的花部形态，由外向内分别为花萼、花瓣、唇瓣和合蕊柱，部分兰花之花萼和花瓣形状极为相似，兰花花型上最大的特色之一为具有由花瓣高度特化而成的唇瓣，并且铁皮石斛还具有管状花萼。因此，兰科中铁皮石斛花被的研究对于了解被子植物花被的起源和演化过程具有重要意义。.申请者已经从铁皮石斛的转录组和基因组序列中筛选到A、B和E类MADS-box EST片段，在高等真双子叶植物花器官中，这些基因主要控制花被发育。.本项目进一步通过蛋白质互作、基因表达、转基因和进化分析等方法，首次在铁皮石斛中对花被发育相关的A、B和E类MADS-box基因进行研究，探索A、B和E类MADS-box表达模式和功能演化以及花萼、花瓣和唇瓣的发育，对正确理解花器官产生的机制以及深入了解花器官发育在进化过程中的多样性具有重要的意义。

Orchids is unique floral morphology includes sepal, petal, labellum (or lip) and gynostemium (or column) from outer to inner. Among them, some of the sepal and petal are similar to each other, while it is one of the most distinctive features of a highly modified petal part and is called the labellum，and is tubular sepal in Dendrobium candidum (Orchidaceae) as well. Therefore, It is an important species of a perianth D. candidum in relation to understanding the origin and evolution of angiosperm perianth..Based on the transcriptome and genome sequencing, we have obtained the A, B,E-class MADS-box transcription factor homologues EST isolated from D. candidum, which control petal and stamen identity in floral organ of the higher eudicots. .In the current project, methods of proteins interaction, gene expression, transgene will be performed and phylogenetic trees will be reconstructed.The A, B, E-class MADS-box genes of perianth development will be studied in D. candidum for the first time. The expression and functional evolution of A, B, E-class MADS-box transcription factors isolated from D. candidum and sepal, petaloid and labellum development will be explored. It is very important to correctly understand the origin and evolution of the perianth, and deep understand the origin and diversification of flowers in angiosperms.