低浓度呕吐毒素作为激发子对马铃薯抗干腐病的诱导及其作用机制

Low concentration of vomitoxin as elicitor induced resistance of dry rot disease of potato and its mechanism

Dry rot disease is a fungal disease caused by Fusarium sp. infection in the process of potato cellar storage, which seriously affects the commercial value. Vomitoxin (DON), also known as deoxynivalenol, is a secondary metabolite produced by fusarium sp. in the process of infecting potato lump. Biological control is an effective method of disease control. Using biological factors as elicitors to induce plant system produce disease resistance has become a hot research topic. In this study, in order to provide theoretical basis for biological control of dry rot disease, potato tubers were treated with low concentration of DON as elicitor to determine its role in the resistance to dry rot disease and the mechanism of inducing systemic acquired resistance (SAR) of potato. DON treatment had a certain effect on the development of dry rot disease, and affected by the concentration. The treatment of potato tubers with 5 ng mL^-1 DON for four hours could effectively reduce the diameter expansion of dry rot disease lesions induced by Fusarium sambucinum. Low concentration of DON increased the activities of SOD, POD, chitinase and β-1, 3-glucanase in tuber tissue, and decreased the accumulation of MDA. DON treatment increased the activities of PAL and 4CL, the key enzymes of phenylpropane metabolism, and promoted the accumulation of total phenols, flavonoids, lignin and anthocyanins. Meanwhile, the content of endogenous signal molecules SA, JA, and ET in potato tubers could be increased by using DON as elicitor, and the expression of NPR1 (regulatory gene of plant systemic resistance) was increased.