Abstract：Northern corn leaf blight caused by Exserohilum turcicum was inhibited by spraying leaves with salicylic acid (SA) solution in greenhouse test. The tests indicated that: the lesion amount and lesion area on the leaf could be reduced in the maize seedlings (OH43, OH43Ht1, Huangzao4, Huangzao4Ht1) sprayed continuously for 6 days with 10mM SA, which had the effect of inhibition above56% generally.
The study on physiological mechanism of resistance to Northern Corn Leaf Blight showed the infection speed of E. turcicum was slowed in the maize leaves pretreated by 10mM SA. Haustorium formation from papilla and the growth of haustoriun in the leaf cells were delayed compared with the water-control. The pretreatment of SA also induced and promoted cell death in the infected cell as well as the adjacent. The activities of phenylalanine amonnialyase (PAL), chitinase and β-1,3-glucanase of maize leaves were enhanced significantly with SA treatment or treatment of E. turcicum inoculation after SA pretreatment, the content of lignin and DAMBOA in the maize leaves were also increased. Increasing of H2O2 levels was also observed in the maize leaves with the treatment of E. turcicum inoculation after SA inducing.
