蝴蝶蘭GAMYB binding protein是從PCR篩選扣減式基因庫篩選高溫逆境下表現的基因。GA訊息傳遞在植物生長和發育扮演重要角色。首先利用RT-PCR與5’RACE的方式獲得全長為2552 bp的cDNA並命名為PaGAMYBBP。預期的蛋白質具有一個從第205到368胺基酸高度保留的SKIP/SNW domain。SKIP/SNW domain存在許多細胞核蛋白質中，例如果蠅染色質。PaGAMYBBP mRNA在蝴蝶蘭葉片與花苞中的表現沒有差異。蝴蝶蘭植株以10-4 M的GA處理PaGAMYBBP mRNA的表現會受到抑制。PaGAMYBBP mRNA的表現在高溫處理下增加，但是並不受到低溫處理的影響。我們推測GAMYB-binding protein可能利用SKIP/SNW domain與GAMYB發生結合，進而抑制GAMYB所活化的下游基因，透過GAMYB-binding protein的調控，使這些下游基因只在有適當的GA訊息時表現。

An EST encoding the GAMYB binding protein (GAMYBBP) of Phalaenopsis amabilis subsp. formosa was isolated from a cDNA library constructed using the PCR-select cDNA subtraction method. Gibberellin (GA) signaling plays important roles in plant growth and development. The full length cDNA was 2552 bp obtained with RT-PCR and 5’RACE and designated PaGAMYBBP. The predicted coding region of PaGAMYBBP contains 1899 nucleotides. The deduced peptide sequence of GAMYBBP has a conserved SKIP/SNW domain from residues 205 to 368. The SKIP (Ski interacting protein) is a nuclear protein exists in chromatin and functions as a transcriptional regulator in Drosophilia. The expression of PaGAMYBBP in leaf was similar to that in floral bud. The expression of PaGAMYBBP was inhibited by GA at concentration of 10-4 M. Abnormal temperature that caused heat stress increased the expression of PaGAMYBBP but cold stress did not affect the expression. We hypothesize that the PaGAMYBBP binds to GAMYB with the SKIP/SNW and thus regulate the expression of GA-responsive genes to prevent the precocious expression of downstream hydrolase gene under insufficient GA signal.

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