Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 1.12

VIRUS INDUCED GENE SILENCING TO STUDY GENE FUNCTION IN PEACH (PRUNUS PERSICA [L.] BATSCH)

E. CONDELLO, D. GIANNINO, C. NICOLODI, G. TESTONE, A. TARTARINI, D. MARIOTTI

Istituto di Biologia e Biotecnologie Agrarie del Consiglio Nazionale delle Ricerche, Sezione Territoriale di Roma, Via Salaria Km. 29,300, 00016 Monterotondo Scalo (Roma)

gene silencing, tobravirus based vectors, peach

Peach plants are relatively recalcitrant to the standard leaf disk transformation mediated by Agrobacterium tumefaciens, due to the low efficiency of shoot regeneration. Consequently, the study of gene function and manipulation of this species have been hampered and delayed. The virus induced gene silencing (VIGS) is a manifestation of an RNA-mediated defence mechanism that is related to post-transcriptional gene silencing (PTGS) in transgenic plants. The gene silencing vectors based on tobacco rattle virus (TRV) have been excellent tools to study gene function in crops such as tobacco and tomato. In fact, TRV vectors carrying plant host genes are able to induce silencing of the corresponding genes in infected plants. These vectors are engineered in binary vectors and subsequently transferred into host leaves via syringe inoculation of A. tumefaciens strains. They are also able to target host RNAs in plant meristems and the consequent VIGS for a particular gene mimics the phenotype of loss of function mutant. Though the species of Rosaceae family are not usual hosts of tobraviruses, a TRV-VIGS apporach has been applied to peach by infecting plants, at different stages of growth, with control vectors and TRV carrying gene markers, full length or partial cDNAs derived from genes previously cloned in peach. Preliminary molecular analyses indicated that the transgene insertion and expression occurred in all the inoculated plants, that the vector itself was transmitted to the basal and apical parts of infected plants and did not induce visual symptoms. Putative VIGS mutant phenotypes are being under analysis and will be presented in relation to the silenced gene.