【摘要】 以叶子花品种‘大红宝巾’(Bougainvillea glabra‘Mrs Butt’)的2年生扦插苗为试验材料,克隆到了一个9-顺式-环氧类胡萝卜素双氧合酶(NCED)同源基因,并分析了内源脱落酸(ABA)含量及NCED活性等变化与该基因表达之间的内在联系,探讨ABA对促进叶子花开花的作用机理。结果表明:(1)外源50mg·L-1 ABA处理促进了叶子花开花,而与10μmol·L-1的去甲二氢愈创木酸(NDGA,ABA合成抑制剂)共处理可抑制这种效果。(2)外源ABA处理可诱导叶子花叶片中内源ABA含量和NCED含量与活性上升,这种诱导可被NDGA抑制。(3)克隆得到的NCED基因全长为2 380bp,其推定的编码蛋白包含618个氨基酸残基,与草莓中的FvNCED1同源性最高,命名为BgNCED1。(4)Real-time PCR结果显示,外源ABA处理显著诱导BgNCED1基因的表达,而10μmol·L-1的NDGA可显著抑制BgNCED1基因的诱导效果,这种表达模式与内源ABA含量及NCED活性等的变化趋势较为一致。研究认为,外源ABA可能通过诱导BgNCED1的表达,增强内源ABA的生物合成,进而促进叶子花从营养生长到生殖生长的转变,使其提前开花。更多还原

【Abstract】 In this study,Bougainvillea glabra ‘Mrs Butt’was used to analyze the regulation mechanism of ABA in promoting its flowering promotion.The results showed that:(1)50mg·L-1 ABA treatment promotes B.glabraflowering,and 10μmol·L-1 NDGA(Nordihydroguaiaretic acid,one kind of ABA biosynthesis inhibitor)treatment inhibited this effect.(2)Exogenous ABA treatment increased the content of endogenous ABA and the enzyme content and activity of nine-cis-epoxy carotenoid dioxygenase(NCED)in B.glabraleaves,and these inductions could be inhibited by NDGA treatment.(3)The full length of cloned NCED gene was 2 380 bp,and the putative encoding protein is 618 aa,which showed the highest homologywith FvNCED1 in the strawberry,and was named as BgNCED1.(4)Real-time PCR results showed that the expression of BgNCED1 was significantly induced by ABA treatment,and 10μmol·L-1 NDGA could significantly inhibit the induction effect.This expression pattern was similar to the changes of endogenous ABA content and NCED enzyme activity.Therefore,exogenous ABA may enhance endogenous ABA biosynthesis through the induction of BgNCED1 expression,which promoted B.glabra from vegetative growth to reproductive growth,and ultimately make it flowering early.更多还原