Fusarium sp. Strain K-23 Alleviates Salt Stress in Arabidopsis Thaliana Through Its Root Hair Growth-Promoting Effect

The study investigates how Fusarium sp. strain K23 enhances salt stress tolerance in Arabidopsis thaliana by promoting root hair growth. Soil salinity affects 8.7% of global soils, threatening food security for over 1.5 billion people. The research utilized transcriptomics, phenomics, reverse genetics, and live cell imaging to explore the molecular mechanisms involved. The fungus significantly improved Arabidopsis growth under salt stress by increasing root hair density and elongation, counteracting the inhibition of root hair development. Transcriptome analysis revealed that over 50% of differentially expressed genes in K23-infected samples were affected by salt stress, with a focus on cell wall organization and root hair development. Functional network analysis identified RAP2.11 and RSL2 as key nodes, and the transcription factor JUNGBRUNNEN 1 (JUB1) was crucial for maintaining enhanced root hair length. The study provides evidence of a novel molecular mechanism by which Fusarium sp. strain K23 improves salt stress tolerance in Arabidopsis.