[A study on the mechanism of copper-induced resistance to potato virus Y-vein necrosis strain (PVY(N)) in tobacco].

In order to reveal the induced resistance mechanism of tobacco treated with copper solution to potato virus Y-vein necrosis strain (PVY(N)), disease indexes, contents of virus and some physiological and biochemical indexes in tobacco were studied. The results showed that when treated at the copper concentration of 0.8 mg x L(-1), the symptom displayed and vein necrosis on tobacco were postponed, the disease index and content of virus sharply decreased , and the content of chlorophyll a, chlorophyll b and phenylalanine ammonia lyase (PAL) activity remarkably increased. Furthermore, vein necrosis closely linked to contents of total phenol and flavonoid. In this study, the contents of total phenol and flavonoid were promoted when treated with a solution at the copper concentration of 0.8 mg x L(-1). But the contents of total phenol and flavonoid reached to the first peak at the 3rd day after inoculation, and then decreased to the lowest levels which even were lower than those of the control after inoculating PVY(N). Then the contents of total phenol and flavonoid increased slowly from the 6td but still lower than those of the control. The result implied that spraying copper solution might play an important role in induced resistance of tobacco to vein necrosis disease and strengthen the antiviral capability to PVY(N).