Isabel Garcia-Luqueg
Centro de Investigaciones Biológicas,Spain
Title: The transient expression of Tetraspanin 8 of Capsicum chinense inhibits both local and systemic movement of the tobamoviruses Pepper mild mottle virus and Tobacco mosaic virus and induces programmed cell death
Biography
Biography: Isabel Garcia-Luqueg
Abstract
We have isolated de cDNA and characterized the Tetraspanin 8 (Tet8) from C. chinense plants whose mRNA its induced in both compatible and incompatible interactions with the Italian and Spanish strains of Pepper mild mottle virus (PMMoV-I and –S) respectively. Its induction it is associated to ethylene induced PR2-gn1 mRNA but not to the salycilic acid-induced PR1 mRNA. It is located at both the plasmodesmata and cellular membranes and its Agrobacterium-mediated overexpression in Nicotiana benthamiana plants inhibits both the local and systemic movement of the tobamoviruses PMMoV-S and Tobacco mosaic virus (TMV) without affecting viral replication. This inhibition is specific for the members of the tobamoviruses group assayed but it doesn’t have any effect on Potato Virus X, Tobacco Rattle Virus nor in Plum Pox Virus. Assay with transgenic N. benthamiana plants in which either the salycilic acid or jasmonic acid production are inhibited revealed that none of this defence responses are involved in the inhibition of viral movement, so implying that is the ethylene-mediated defence response the metabolic route implied. Furthermore, the overexpression of TET-8 in N. benthamiana plants leads to a Programmed cell death (PCD) associated to nuclear death, overproduction of ROS and it is associated to vacuolar programmed cell death, being for the first time that a tetraspanin in plants is associated to cell death.