Does plant genetics shape the protective efficacy of biocontrol against diseases?

Abstract: Over the last few decades, research on biocontrol, and particularly on natural
substances that induce plant defense mechanisms, known as Plant Resistance Inducers (PRIs), has considerably expanded. These studies have primarily focused on elucidating their modes of action and identifying factors that influence their efficacy under controlled and field conditions. Several investigations have demonstrated variations in PRI efficacy depending on plant genotypes. However, few studies have explored the genetic basis of plant responses to PRIs. In our research, we investigated the role of genetic diversity in determining the protective efficacy of PRIs against plant pathogens. To achieve this, we focused on two major pathogens of tomato plants: Oidium neolycopersici and Phytophthora infestans. First, we conducted a transcriptomic analysis to study the genetic variation in the induction of defense-related genes by four natural substances across five tomato accessions with similar susceptibility levels. Next, we examined the impact of tomato genetic diversity on PRI efficacy. This effect was quantified using heritability estimates for both pathogens. Our findings reveal that, for both pathogens, over 50% of the phenotypic variation in PRI efficacy can be attributed to the genetic effect of the tested accessions. Future research will aim to identify the genomic regions involved in the observed variation in plant responses to PRIs for each pathogen. These insights will provide valuable tools for breeders, enabling the selection of new tomato varieties that respond favorably to PRIs. This approach will contribute to the sustainable improvement of biological and integrated pest management strategies in protected crop systems.