Molecular and phenotypic characterization of transgenic potato events resistant to PLRV and PVY under different environmental conditions.

BARRIOS-BARÓN, P; NAHIRÑAK, V; GONZALEZ DE URRETA, M; HOPP, HE; ALMASIA, NI; DISTÉFANO, AJ; VAZQUEZ ROVERE, C

Foz de Iguazu

Congreso; Congreso International Plant Molecular Biology; 2015

ISPMB

There are more than 40 described viruses capable of infecting potato crops, amongst which potato leafroll virus (PLRV), potato virus Y (PVY) and potato virus X (PVX) are considered the most important ones. They are present in all major production areas; infecting most cultivars and causing significant yield reductions and economical losses. Additionally, it has been shown that PVY is the responsible of the observed synergism when coinfected with other viruses such as PVX or PLRV.Our objective is to characterize under field conditions potato transgenic events exhibiting resistance to PLRV and PVY that may potentially be released into the environment. Therefore, we obtained transgenic lines co-expressing the PLRV replicase and the capsid protein of the lettuce mosaic virus (LMV-CP). The first gene confers resistance to PLRV infection by post-transcriptional gene silencing mechanism, while the LMV-CP confers resistance to PVY and other potyvirus by a yet unknown mechanism.In order to characterize these transgenic potato lines and the resistance mechanisms involved, phenotypic and molecular analysis have been carried out comparing with non-transgenic and single expressing PLRV transgene plants. Transgenes expression has been analyzed during two months in plants growing at optimal conditions and in developed plants growing in low temperatures or under virus challenging assays. Even by RT-PCR, PLRV transgene was undetectable at day 60 but it could be detected in some lines grown at 15ºC or in single PLRV transgenic lines artificially infected with PVY. Events potentially resistant in all tested conditions were selected to be evaluated under combined stresses and field trials to further characterize the mechanism of resistance and to evaluate their agronomic performance.