Thursday, May 19, 2016
Origins and structure of somatic variation in the grapevine: how these phenotypes help in the study of the regulation of reproductive development
Professor of Biology and Genetics, Montpellier SupAgro
The grapevine develops reproductive organs from proleptic axes in 2 vegetative cycles. Reproductive development starts with the deployment of inflorescences at the base of vegetative axes. From flowering, fruit development lasts 3 months under temperate climate. Despite being one of the first species whose genome has been sequenced, progresses on regulatory mechanisms of the development are slow due to the biological properties of the plant (duration of the reproductive cycle, juvenility period) and its recalcitrance towards biotechnologies (genetic transformation). Due to its heterozysity, the grapevine is vegetatively propagated that leads to the accumulation of somatic variations. If non-lethal and periclinaly stabilized, these variations can provide tools for research and genotypes for gene functional characterisation. During the seminar, the main characteristics of the reproductive development of the grapevine and the consequences of tissue chimerism on the expression and stability of somatic variations will be reminded. Then, 2 types of grapevine phenotypic variations will be presented. The first, which corresponds to a single mutation in VVgai1, results in the Microvine, a model allowing new approaches for the physiology and the genetics. The second variation, named fleshless berry, which corresponds to an insertion of a transposable element in a PI homologue, leads to some understanding about the morphogenesis of the fruit flesh from the ovary mesocarp.
Contact : Przemyslaw Bidzinski