Differential responses of bell pepper genotypes to indigenous Pseudomonas putida A32 treatment: implications for drought resilience

Abstract

Aims This study aimed to evaluate the potential of endophytic plant growth-promoting bacteria (PGPB), Pseudomonas putida A32, to mitigate drought stress in two bell pepper genotypes, Amfora 19 and Amfora 26, and to assess the genotype-specific responses to bacterial treatment. Methods and results The isolate P. putida A32 was selected for its remarkable beneficial properties, exhibiting 13 out of 14 traits tested. Under drought conditions, Amfora 26 showed increased relative water content (RWC) and decreased H2O2 and malondialdehyde following bacterial treatment, while Amfora 19 exhibited enhanced growth parameters but responded less to bacterial treatment regarding drought parameters. However, Amfora 19 displayed inherent drought tolerance mechanisms, as indicated by lower stress parameters compared to Amfora 26. Conclusions The study emphasises the importance of genotype-specific responses to PGPB treatment and the mechanisms of drought tolerance in peppers. P. putida A32 effectively mitigated drought stress in both genotypes, with differential responses influenced by plant genotype. Our study confirmed our initial hypothesis that Amfora 19, as a genotype tolerant to biotic stress, is also more tolerant to abiotic stress. Understanding these interactions is crucial for the development of customised strategies to improve plant productivity and tolerance to drought.