A co-silencing system for functional analysis of genes without visible phenotype in tomato plant development and fruit ripening using tobacco rattle virus

Abstract

Abstract Virus-induced gene silencing (VIGS) is known as a powerful tool for identifying gene functions during plant growth and development. Tobacco rattle virus (TRV) based VIGS has been successfully employed in many plants. However, there have been few reports that VIGS can be used to study the function of gene at fruit level, especially the genes without visible silencing phenotype. Here we used miniature tomato cultivar Micro-Tom (Solanum lycopersicum L.) as material to silence phytoene desaturase (SlPDS) and SlARG2, an important gene encoding arginase in arginine metabolism, separately or simultaneously with TRV agroinoculated by sprout vacuum-infiltration to test the utility of concurrently silencing two genes. When SlPDS and SlARG2 were co-silenced in the same tissue at the same time, there are no compromises in silencing efficiency and silencing efficacy compared with SlPDS or SlARG2 silenced separately. Moreover, the silence of SlPDS and SlARG2 with TRV agroinoculated by sprout vacuum-infiltration occurred at the early stage of tomato plant, and the silence can extend to full red stage of fruit. Therefore, our results provide a means for functional analysis of genes, particularly the genes with no obvious visible phenotype after silencing, involved in all of the metabolic networks during fruit development and ripening.