Arabidopsis P4-ATPases ALA1 and ALA7 Enhance Resistance to Verticillium dahliae via Detoxifying Vd-Toxins.

BACKGROUND: Verticillium wilt, which is a soil-borne vascular disease, causes serious economic losses worldwide. Various toxins secreted by V. dahliae are key factors that lead to wilt symptoms. METHODS: The Vd-toxins CIA, indazole, and 3ICD were labeled with fluorescence groups, respectively, to observe the transport pathway. Transcriptome sequencing and qRT-PCR were employed to assess the expression patterns under Vd-toxin treatment. RESULTS: AtALA1 and AtALA7 were up-regulated by V. dahliae and LC-toxins, and overexpression of either AtALA1 or AtALA7 increased Arabidopsis resistance against LC-toxins. Overexpression of AtALA1 improved the resistance of Arabidopsis to 4MBA, 3ICD, and indazole, while AtALA7 enhanced resistance to 4MBA, 3ICD, and CIA. AtALA7-overexpressing plants showed a stronger capability to transport CIA(FITC) and 3ICD(5-FAM) into vacuoles, while AtALA1-overexpressing plants accumulated indazole(5-FAM) and 3ICD(5-FAM). Aggregation of AtALA1 and AtALA7 enhances the resistance of plants to V. dahliae. CONCLUSIONS: Arabidopsis P4-ATPase genes AtALA1 and AtALA7 mediated cell detoxification by transporting different Vd-toxins to vacuoles for degradation, thereby increasing resistance to Verticillium wilt.