葡萄成熟过程中生理特征与β-葡萄糖苷酶基因的表达分析

为了解β-葡萄糖苷酶基因是否与葡萄果实成熟有关,从基因库中分离出了3个β-葡萄糖苷酶基因,分别命名为VυBG1,VυBG2和VυBG3,并对其表达进行了分析.结果显示:所获得的3个基因在葡萄浆果成熟过程中均有表达.果皮中,随着果实的成熟,VυBG1变化较平稳；VυBG2在转色期时略有降低,之后不断升高,在完熟期时达到最大值；VυBG3在成熟过程中先升高后降低,在转色期时达到高峰.果肉中,VυBG1和VBG2分别与果皮VυBG2和VυBG3变化趋势相似；VυBG3在转色前期和成熟期时表达较低,在完熟期达到最大值.种子中,VυBG1在转色前期出现最大值,之后迅速降低；随着果实的成熟,VυBG2不断上升；VυBG3在转色期时有个小峰,之后不断降低,在完熟期时表达量最低.综上,3个β-葡萄糖苷酶基因在葡萄成熟过程中的表达量和表达模式均不相同.其中果皮VυBG3和果肉VυBG2的变化趋势与ABA一致,可能在果实成熟过程中对ABA水平调节起作用.

Expression of beta-glucosidase genes VvBGs and physiological feature in the berry of Muscat Hamburg during grape maturation

In order to investigate the relationship between beta-glucosidase genes and grape berry maturation,we identified three beta-glucosidase genes from NCBI named as VvBG1,VvBG2 and VvBG3 and then analyzed their expression.The results showed that three genes were all expressed during grape berry ripening.In peel,the expression of VvBG1 changed smoothly along with berry ripening,while the expression of VvBG2 was slightly low at véraison,then increased gradually and reached the maximum at full ripening stage.However,the expression of VvBG3 increased at first,then decreased and had a transient expression peak at véraison.In pulp,expression patterns of VvBG1 and VvBG2 displayed similar trends with VvBG2 and VvBG3 in peel.The VvBG3 expressed relatively low at véraison,with the expression peak at full ripening stage.In seed,the expression of VvBG1 was highest at pre-véraison,then decreased rapidly.The expression of VvBG2 rose continuously during grape maturation,while the VvBG3 gene had a small expression peak at véraison,then reduced to the lowest at the stage of full ripening.In summary,the expression patterns and levels of the three beta-glucosidase genes performed differently during grape maturation.Among them,the trends of VvBG3 in peel and VvBG2 in pulp were in consistent with the change of ABA,which might indicate that the two genes played a role in regulating ABA content during grape berry ripening.