%0 Journal Article %A GE Xiu-chun %A SONG Feng-ming %A CHEN Yong-ye %A ZHENG Zhong %T Changes in Activities of Defense-Related Enzymes in Rice Resistance Induced by Benzothiadiazole to Blast Fungus(Magnaporthe grisea) %D 2002 %R %J Chinese Journal OF Rice Science %P 171-175 %V 16 %N 2 %X The changes in activities of phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), peroxidase (POD), lipoxygenase (LOX), β-1,3-glucanase and chitinase in rice seedlings of susceptible variety pretreated with benzothiadiazole(BTH) and infected by M. grisea were analyzed to explore the physiological and biochemical mechanisms of the BTH induced systemic acquired resistance (SAR). Treatment of the third leaves of rice seedlings with BTH increased the activities of CAD, LOX and β-1,3-glucanase both in the third leaves and the upper untreated fourth leaves, showing systemic induction on the enzyme activity. After inoculation with M. grisea, the activities of CAD, POD, LOX and β-1,3-glucanase in the BTH treated third leaves and the upper untreated fourth leaves showed a more rapid and significant increase than those in the controls. No significant difference in the chitinase activity was observed between BTH treated and untreated seedlings after inoculation with the fungus, although pathogen infection increased markedly the enzyme activity. However, the PAL activity in the leaves did not show any remarkable changes upon BTH treatment and/or pathogen infection. The results suggested that the increased activities of CAD, POD, LOX and β 1,3 glucanase induced by BTH is most likely to be associated with the development of SAR in rice. %U http://www.ricesci.cn/EN/abstract/article_992.shtml