The Relationship Between Inducible Expression Of Defense Response Gene And Resistance To Rhizomania In Sugar Beet

The relationship between activities or the induced gene expression of polyphenol oxidase(PPO),phenylalnine ammonialyase(PAL) , lipoxygenase(LOX) , chitinase andβ-1,3-glucanase and resistance to Rhizomania in sugar beet were studied in diseased soil and non-diseased soil cultivation conditions by using a method of comparative physiology. The activities or the induced gene expression in different time of polyphenol oxidase( PPO ) ,phenylalnine ammonialyase(PAL), lipoxygenase(LOX), chitinase andβ-1,3-glucanase in sugar beet with different disease resistance which inoculated beet necrotic yellow vein virus(BNYVV) were studied in greenhouse. The relationship between the changes in the expression quantity and resistance to Rhizomania were studied. The results showed: the activities of PPO,PAL,LOX,chitinase andβ-1,3-glucanase of the resistant varieties were higher than the susceptible ones in either diseased soil or non-diseased soil; the expression of various defense response genes of the resistant varieties were earlier than the susceptible ones, furthermore, the expression quantity of the resistant varieties were more than the susceptible ones; the time arrived the greatest expression of these sugar beet varieties in diseased soil is earlier than these varieties in non-diseased soil. The activities were increasedin different time of PPO,PAL,LOX,chitinase andβ-1,3-glucanase in sugar beet with different disease resistance which inoculated BNYVV were studied in greenhouse, the activities of PPO,PAL,LOX,chitinase andβ-1,3-glucanase of the resistant varieties were higher than the susceptible ones, the highest activity of PPO,PAL,LOX,chitinase andβ-1,3-glucanase of the resistant varieties were earlier than the susceptible ones; a bit expression of defense response gene in sugar beet with different disease resistance before inoculated BNYVV, the induced gene expression on12-120 hours of defense response gene in sugar beet with different disease resistance which inoculated BNYVV, the expression of various defense response genes of the resistant varieties were earlier than the susceptible ones, furthermore, the expression quantity of the resistant varieties were more than the susceptible ones. So we can concluded that the PPO,PAL,LOX,chitinase andβ-1,3-glucanase were related to the resistance to Rhizomania in sugar beet. In addition,the results of all indexes in diseased soil were higher than that in non-diseased soil to some extent. It suggested that pathogen infecting lead to an increase in enzymes activities and content of substance related to resistance to Rhizomania. Beet necrotic yellow vein virus (BNYVV) can activated defense response system by induced defense response gene expression in sugar beet of different resistance to some extent, the induced expression of defense genes were related to the resistance to Rhizomania. This research will not only clarify the physiological and biochemical mechanism of resistance to Rhizomania on activities of defense response enzymes and transcriptional level of defense response genes but also provide a theoretical basis for selecting and breeding physiologically new varieties in sugar beet.