These authors contributed equally to this work.
Arabidopsis thaliana plants differentially modulate auxin biosynthesis and transport during defense responses to the necrotrophic pathogen Alternaria brassicicola
Article first published online: 25 JUN 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 195, Issue 4, pages 872–882, September 2012
How to Cite
Qi, L., Yan, J., Li, Y., Jiang, H., Sun, J., Chen, Q., Li, H., Chu, J., Yan, C., Sun, X., Yu, Y., Li, C. and Li, C. (2012), Arabidopsis thaliana plants differentially modulate auxin biosynthesis and transport during defense responses to the necrotrophic pathogen Alternaria brassicicola. New Phytologist, 195: 872–882. doi: 10.1111/j.1469-8137.2012.04208.x
- Issue published online: 2 AUG 2012
- Article first published online: 25 JUN 2012
- Received: 20 April 2012, Accepted: 14 May 2012
- Alternaria brassicicola;
- Arabidopsis thaliana;
- necrotrophic pathogen
- •Although the role of auxin in biotrophic pathogenesis has been extensively studied, relatively little is known about its role in plant resistance to necrotrophs.
- •Arabidopsis thaliana mutants defective in different aspects of the auxin pathway are generally more susceptible than wild-type plants to the necrotrophic pathogen Alternaria brassicicola. We show that A. brassicicola infection up-regulates auxin biosynthesis and down-regulates the auxin transport capacities of infected plants, these effects being partially dependent on JA signaling. We also show that these effects of A. brassicicola infection together lead to an enhanced auxin response in host plants.
- •Application of IAA and MeJA together synergistically induces the expression of defense marker genes PDF1.2 (PLANT DEFENSIN 1.2) and HEL (HEVEIN-LIKE), suggesting that enhancement of JA-dependent defense signaling may be part of the auxin-mediated defense mechanism involved in resistance to necrotrophic pathogens.
- •Our results provide molecular evidence supporting the hypothesis that JA and auxin interact positively in regulating plant resistance to necrotrophic pathogens and that activation of auxin signaling by JA may contribute to plant resistance to necrotrophic pathogens.