The 30th International Conference on Arabidopsis Research (ICAR 2019)

708 / 2019-05-04 10:04:25

Isolation and identification of deoxynivalenol (DON) resistant mutant(s) of Arabidopsis

Arabidopsis thaliana,Fusarium Head Blight (FHB),Fusarium graminearum (Fg),deoxynivalenol (DON),UGT74E2

Plenary track > Biotic Stress

Fusarium head blight (FHB) is a global disease caused by Fusarium graminearum (Fg), which can cause a large reduction in the yield of wheat and other cereals. Deoxynivalenol (DON) is produced by Fg as an effector in the process of plant infection. Here, we screened 4 DON-resistant mutants from an Arabidopsis EMS mutagenesis library, and found that these mutants had the ability to resistance to Fg infection. We found the mutation site of one mutant dor1 (DON resistant 1) at AT1G05680 by MutMap. The gene encodes a glucosyltransferase (UGT74E2) which glycosylating IBA, and EMS mutates its position 100 glycine to arginine. The heterologous expression experiment of yeast showed that the enzyme could also glycosylate DON. However, further experiments showed that this mutation did not significantly change the ability of DON glycosylation in Arabidopsis, indicating that this mutation were not the cause of DON resistance of dor1. Through the phenotypic analysis of seedling, we found that dor1 had shorter roots and smaller plants under normal conditions than wild type. Under auxin treatment, the increase of lateral root density of dor1 mutant decreased significantly, suggesting that UGT74E2 mutation affected the sensitivity of Arabidopsis to auxin, which may makes Arabidopsis resistant to DON and Fg. Therefore, the identification of this mutant provides a very good genetic material for clarifying the molecular mechanism of DON/Fg affecting auxin signaling pathway.