Involvement of Rop and Rab GTPases in grape berry development
Résumé
Aim: The aim of this paper was to study the involvement of Rop and Rab GTPases in grape berry development. Methods and results: Phylogenetic analysis, quantitative RT-PCR and Western blot analysis have been performed. Grapevine genome contains seven VvRops and twenty-six VvRabs. VvRop and VvRab transcripts are expressed in almost all the organs investigated. In grape berries, VvRop transcript expression peaks early before véraison, with little or no expression after véraison. A similar expression profile was revealed in the whole berries and in roots for VvRop proteins. For VvRabs, expression of VvRabA5e protein was observed only during the ripening stages whereas transcript expression was observed all along berry development. A closer examination indicated that expression of this VvRab was restricted to the skin of grape berries. Conclusion: Our results are consistent with a regulation of VvRop and VvRab expression by fruit development signals. Significance and impact of the study: The results revealed a crossed regulation of the VvRop and VvRab proteins during grape berry development. They open new perspectives in the understanding of the grape ripening signalling.