The role of auxin-signaling gene axr1 in salt stress and jasmonic acid inducible gene expression in Arabidopsis thaliana

Response of auxin resistant mutant, axr1-24, on salt stress in primary root growth was tested over a range of NaCl concentrations and results were compared with wild type. The axr1-24 was more resistant to the inhibitory effect of any salt concentrations tested than wild type, except 128 mM NaCl. Total inhibition of root elongation was 62% and 70% for axr1-24 and wild type, respectively, at 64 mM NaCl. Exogenous application of salicylic acid (SA) or 1-aminocyclopropane-1-carboxylic acid resulted in a significant increase in jasmonic acid (JA)-inducible allene oxide synthase (AOS) gene expression, while induction was severely reduced on axr1-24 seedlings treated with SA after 24 h. The results of this study provided a link between auxin and salt stress as well as SA and JA signaling through AXR1.