Optimization of the TRV-based Gene Silencing Efficiency and Growth Condition on Solanum lycopersicum var. ‘Hawaii7996’ Resistant to Bacterial Wilt Disease

Abstract

Ralstonia solanacearum (R. sol), a pathogen that causes wilt symptoms, is widely distributed in many regions. Breeding plants resistant against this pathogen is well known as the most effective control method. To this end, it is necessary to reveal the function of resistance genes, and virus- induced gene-silencing (VIGS) technology is one of the most widely used methods for analyzing gene functions. However, the problem with functional analysis of bacterial wilt resistance genes based on VIGS is the conflicting temperature environments of inoculated strains. Therefore, the objective of this study is to identify optimal plant size and temperature conditions for experiments using two srains considering a less complicated functional analysis of R. sol resistant candidate genes. We applied five different temperatures and then assessed the disease progress of R. sol inoculated tomatoes. The plants with the highest VIGS efficiency were those treated at 22°C for four weeks (4L), three weeks at a low temperature and one week at 30°C (3L1H), and two weeks at 22°C and two weeks at 30°C (2L2H). Also, we confirmed the most suitable temperature for identifying candidate genes against R. sol was found to be 22°C for plants grown for three weeks, followed by 30°C for one week. The results of this study can provide useful data to those seeking to establish a foundation for functional analysis research focusing on genes related to tomato bacterial wilt resistance.