The role of WRKY transcription factors, FaWRKY29 and FaWRKY64, for regulating Botrytis fruit rot resistance in strawberry (Fragaria × ananassa Duch.)

• Published in: BMC plant biology Vol. 23; no. 1; pp. 1 - 420
• Main Authors: Lee, Man Bo, Han, Hyeondae, Lee, Seonghee
• Format: Journal Article
• Language: English
• Published: London BioMed Central Ltd 11.09.2023; BioMed Central; BMC
• Subjects: Abscisic acid; Agricultural research; Analysis; Arabidopsis; Arabidopsis thaliana; Berries; Biosynthesis; Botrytis; Botrytis cinerea; Botrytis fruit rot; Cell walls; Control; CRISPR; Cultivars; Cultivation; Data analysis; Disease resistance; Disease susceptibility; Diseases and pests; DNA binding proteins; Fragaria ananassa; Fruit rot; Fruits; Fungal diseases of plants; Fungicides; Gene expression; Gene regulation; Genes; Genetic aspects; Genetic modification; Genetic research; Genetic resources; Genome editing; Genomes; Homeostasis; Hormones; Infections; Metabolism; Metabolites; Mutants; Octoploid strawberry; Oxidation; Pathogens; Pesticides; Physiological aspects; Plant breeding; Plant diseases; Plant immunology; Plant resistance; RNA-mediated interference; Roles; Signs and symptoms; Strawberries; T-DNA; Transcription factors; Transcriptomics; WRKY transcription factor; Florida; South Korea
• ISSN: 1471-2229; 1471-2229
• DOI: 10.1186/s12870-023-04426-1

The cultivated strawberry (Fragaria x ananassa Duch.) is one of the most economically important horticultural crops worldwide. Botrytis fruit rot (BFR) caused by the necrotrophic fungal pathogen Botrytis cinerea is the most devasting disease of cultivated strawberries. Most commercially grown strawberry varieties are susceptible to BFR, and controlling BFR relies on repeated applications of various fungicides. Despite extensive efforts, breeding for BFR resistance has been unsuccessful, primarily due to lack of information regarding the mechanisms of disease resistance and genetic resources available in strawberry. Using a reverse genetics approach, we identified candidate genes associated with BFR resistance and screened Arabidopsis mutants using strawberry isolates of B. cinerea. Among the five Arabidopsis T-DNA knockout lines tested, the mutant line with AtWRKY53 showed the greatest reduction in disease symptoms of BFR against the pathogen. Two genes, FaWRKY29 and FaWRKY64, were identified as orthologs in the latest octoploid strawberry genome, 'Florida Brilliance'. We performed RNAi-mediated transient assay and found that the disease frequencies were significantly decreased in both FaWRKY29- and FaWRKY64-RNAi fruits of the strawberry cultivar, 'Florida Brilliance'. Furthermore, our transcriptomic data analysis revealed significant regulation of genes associated with ABA and JA signaling, plant cell wall composition, and ROS in FaWRKY29 or FaWRKY64 knockdown strawberry fruits in response to the pathogen. Our study uncovered the foundational role of WRKY transcription factor genes, FaWRKY29 and FaWRKY64, in conferring resistance against B. cinerea. The discovery of susceptibility genes involved in BFR presents significant potential for developing resistance breeding strategies in cultivated strawberries, potentially leveraging CRISPR-based gene editing techniques.