Abstract
Trichothecenes are synthesized by phytopathogenic Fusarium species and are likely to be virulence factors in fusarium head blight (FHB). We investigated effects of T-2 toxin, which is highly toxic molecular species among trichothecenes, on growth and morphology in Arabidopsis plants. During T-2 toxin-induced dwarfism, an AtNF-X1 gene, which is homologous to human transcriptional repressor NF-X1 gene, was significantly induced in Arabidopsis plants. Furthermore, we analyzed a T-DNA insertinonal mutant of an AtNF-X1 in Arabidopsis. In contrast to wild type, strong inhibition of growth occurred at 100 nM concentration of T-2 toxin in the atnf-1 mutant. Microarray analysis revealed that mRNAs for many defense-related genes (ex. Receptor protein kinase, NBS-LRR, WRKY) expressed more than 3-fold higher in the atnf-1 mutant than wild type after T-2 toxin treatment. These results suggest that AtNF-X1 play an important role in regulation of these defense-related genes.
