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).