Characterization of two PR genes from Fragaria chiloensis in response to Botrytis cinerea infection: A comparison with Fragaria x ananassa

Abstract

Fragaria chiloensis (L.) Mill. is one of the parent of the commercial strawberry, and has emerged as a variety for breeding purposes. Botrytis cinerea infection is one of the most important infectious diseases for cultivated plant species, producing important losses in yield as well as fruit quality. Plants and fruits of Chilean strawberry have showed tolerance to this pathogen. The responses to fungus infection can be diverse, and the mechanisms that take place in strawberry during B. cinerea infection are unknown. The objective of this work was to further characterize two genes isolated from the Chilean strawberry species which were previously reported as over expressed after Botrytis infection. Leaves and ripe fruits of Chilean strawberry were inoculated with this fungus, comparing the biological response with F. x ananassa plants. Fruit and leaf samples were taken in a time course along nine days. The two characterized Protein Related (PR) genes were: pathogen related proteins from group five (FcPR5) and group ten (FcPR10). Comparative analysis indicated significant differences in the expression pattern of both genes. Higher transcript accumulation was recorded in F. chiloensis infected tissues compared to F. x ananassa. In F. chiloensis, FcPR5 showed high transcript level in infected leaves, while FcPR10 transcripts were high in infected fruits, suggesting that these genes could be implicated in the pathogen response in a tissue specific manner. The response in F. chiloensis was fast and consistent, showing high transcript levels until seven days after inoculation.