THE EXPRESSION OF VVGA20OX1 AND VVGA3OX1 DURING FRUIT SET OF GRAPEVINE
Gibberellin plays an important role in fruit set in grapevine and is often used to improve berry fruit set percent. However, few studies have focused on the molecular mechanism(s) of how gibberellin improves fruit set. This research aims to explore the influence of gibberellin and paclobutrazol (PAC; an inhibitor of gibberellin biosynthesis) on grape berry fruit set. The expression of VvGA20ox1 and VvGA3ox1 were also analyzed. The result showed that application of gibberellin improved fruit set percent, PAC inhibited fruit set, and PAC inhibition was fully reversed with GA3 application. The fruit size of berries treated with gibberellin was smaller than controls. The expression of VvGA20ox1 and VvGA3ox1 showed different patterns; VvGA20ox1 seemed to be ubiquitously expressed, but VvGA3ox1 was expressed less in tendrils and stems. Before anthesis, VvGA20ox1 showed high expression, but it decreased after anthesis. VvGA20ox expression was lower in ovaries treated with gibberellin than PAC. This indicated that VvGA20ox1 may not or may negatively regulate gibberellin biosynthesis during grape berry fruit set. By contrast, the expression of VvGA3ox1 in inflorescence was low before anthesis, but expression increased rapidly after anthesis. Before anthesis, VvGA3ox1s expression in inflorescences treated with gibberellin was higher than controls. After anthesis, there was no significant difference in VvGA3ox1 expression between control and gibberellin-treated berries. However, after using PAC, there was no difference with control before anthesis, but 8 days after anthesis, VvGA3ox1 expression in berries was much lower than control and gibberellin-treated berries, indicating that VvGA3ox1 may be involved in gibberellin biosynthesis during grape berry fruit set. There was no significant difference in tissue microstructure among different applications.
Jingyun Lu, , Long Lu, and Jianfang Hu, (2015). THE EXPRESSION OF VVGA20OX1 AND VVGA3OX1 DURING FRUIT SET OF GRAPEVINE. Acta Hortic. 1082, 367-372
grapevine, fruit set, VvGA20ox, VvGA3ox1, gene expression, gibberellin