三角梅甜菜色素代谢酶4,5-DOPA-dioxygenase基因的分离和表达  

Separation and Expression Analysis of the Betalain Synthase 4,5-DOPA-dioxygenase Gene in Bougainvillea

作　　者：徐夙侠[1] 林春松[1] 黄青云[1] 曾碧玉[1] 林富聪[1] 

机构地区：[1]福建省亚热带植物研究所福建省亚热带植物生理生化重点公共实验室,福建厦门361006

出　　处：《热带作物学报》2013年第11期2214-2221,共8页Chinese Journal of Tropical Crops

基　　金：国家自然科学基金资助(No.31071814、31372093)

摘　　要：甜菜色素在自然界中与花青素排斥分布,主要在石竹目(Caryophyllales)的9个科的植物中合成。虽然甜菜色素的生物合成已经有很多猜测,酶催化的生物合成关键步骤仍然缺少足够的实验数据支持。本研究首先从三角梅属的3个种(B.spectabilis‘Splendens’,B.buttiana‘Mahara’,B.pruviana‘Thimma’)的苞片中分离了甜菜色素合成途径末端的关键酶4,5-DOPA-dioxygenase完整的cDNA,大小分别为902、899、899 bp,分别编码298、297、297个氨基酸,并对这3个同源基因与已经报道的来自B.glabra的该基因进行比较。推测的分子量分别为33 758、33 076、33 233 u,等电点(pI)分别是5.62、5.54和5.94。对分属于4个种(B.spectabilis‘Splendens’,B.buttiana‘Mahara’,B.glabra‘Alba’,B.pruviana‘Thimma’)花的4,5-DOPAdioxygenase的Real-time分析结果表明,该基因在4个种的花中,种间变化较大,总体趋势是开花早期该基因的表达较弱,盛花期表达迅速增强,后期又呈现下降。其中,在红色的B.buttiana‘Mahara’中,该基因的表达最强,在白色的B.glabra‘Alba’中表达最弱。这些结果表明,该基因的表达与花的颜色鲜艳程度直接相关。In the study,three cDNA encoding the dihydroxyphenylalanine （DOPA） dioxygenase were identified from three species of bougainvillea （B.spectabilis ‘Splendens’,B.buttiana ‘Mahara’,B.pruviana ‘Thimma’）.The eDNA was 902 bp （B.spectabilis ‘Splendens’）,899bp （B.buttiana ‘Mahara’） and 899.bp （B.pruviana ‘Thimma’）,similar to the known eDNA of Bougainvillea,respectively.The deduced molecular weight was 33.8 ku （B.spectabilis ‘ Splendens’）,33.1 ku （B.buttiana ‘ Mahara’） and 33.2 ku （B.pruviana ‘ Thimma’）.pI of the three deduced proteins was 5.62,5.54 and 5.94,respectively.The expression of the enzyme was explored from four species of Bougainvillea （B.spectabilis ‘ Splendens’,B.buttiana ‘ Mahara’,B.glabra ‘ Alba’,B.pruviana ‘Thimma’）.The results showed that the gene of 4,5-DOPA-dioxygenase was expressed variably obviously among the flowers of four species.Generally,the expression of the gene was weak in early stage of blooming,was strong in blooming and weak in late stage.The gene was expressed most strongly in scarlet B.buttiana ‘Mahara’ while expressed most weakly in white B.glabra ‘Alba’.Information above indicated that expression strength of 4,5-DOPA-dioxygenase gene in Bougainvilleas is closely related to the color depth.

关 键 词：三角梅 4 5-DOPA-dioxygenase表达 

分 类 号：S723.2[农业科学—林木遗传育种]