水稻细菌性条斑病菌侵染后抗、感近等基因系酶活性的变化

Changes of Enzyme Activities in Resistant and Susceptible Near-isogenic Lines of Rice after Infection with Xanthomonas oryzae pv.oryzicola

【目的】研究水稻抗、感近等基因系受细菌性条斑病(简称细条病)病菌侵染后酶活性的变化,为研究水稻细条病的抗性机制提供理论依据。【方法】以水稻抗、感近等基因系LR19和LS19为材料,用针刺法接种细条病菌(处理),对照则用无菌水模拟接菌。在接菌后0、24、48、96 h 取水稻分蘖期叶片为样品,分析丙二醛(MDA)含量、过氧化氢酶(CAT)、苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)活性变化。【结果】接种后,LR19处理CAT、PAL、POD、PPO、SOD活性分别为269.36、39.61、31 677.75、106.4、2 035.44 U/g,对照分别为195.16、33.23、21 449.75、85.67、1 139.38 U/g。LS19处理CAT、PAL、POD、PPO、SOD活性分别为149.13、34.3、26 635.25、87.6、1 354.82 U/g,对照分别为73.95、30.45、10 506.43、62.3、779.5 U/g。细条病菌侵染后,LR19和LS19的CAT、PAL、POD、PPO和SOD活性均增加,且都高于LS19;而细条病菌侵染导致LR19和LS19的MDA含量降低,且LR19总体低于LS19。【结论】CAT、PAL、POD、PPO、SOD活性的增强有助于提高细条病抗性,而MDA含量积累与细条病抗性呈负相关。这些酶活性可作为水稻细条病抗性鉴定的辅助评价指标。

【Objective】The study was conducted to explore the changes of enzyme activity in rice resistant and susceptible near-isogenic lines infected with Xanthomonas oryzae pv.oryzicola(Xooc),which provided a theoretical basis for studying the resistance mechanism of rice bacterial leaf streak(BLS).【Method】With the rice BLS resistant near-isogenic line LR19 and susceptible near-isogenic line LS19 as materials,the treatment group was inoculated with pathogenic bacteria of Xooc by needling method,while the control group was inoculated with sterile water.The leaves at tillering stage of rice were taken as samples at 0,24,48 and 96 h after inoculation,and the changes of enzyme activities of malondialdehyde(MDA),catalase(CAT),phenylalanine ammonia-lyase(PAL),and peroxide enzyme(POD),polyphenol oxidase(PPO)and superoxide dismutase(SOD)were analyzed.【Result】After inoculation,the average activities of CAT,PAL,POD,PPO and SOD in the LR19 treatment group were 269.36,39.61,31 677.75,106.4 and 2 035.44 U/g,respectively,and those in the control group were 195.16,33.23,21 449.75,85.67 and 1 139.38 U/g.The average activities of CAT,PAL,POD,PPO and SOD in the LS19 treatment group were 149.13,34.3,26 635.25,87.6 and 1 354.82 U/g,respectively,and those in the control group were 73.95,30.45,10 506.43,62.3 and 779.5 U/g,respectively.After being infected with Xooc,the activities of CAT,PAL,POD,PPO and SOD in both near-isogenic lines increased,and the activities of these five enzymes in LR19 were higher than those in LS19.However,the infection of Xooc reduced the MDA content in LR19 and LS19,and the MDA content of LR19 was generally lower than that of LS19.【Conclusion】The enhanced activity of CAT,PAL,POD,PPO and SOD is conducive to improving the resistance to BLS,while the accumulation of MDA content is negatively correlated to the BLS resistance.The activities of these enzymes can be used as supplementary evaluation indexes for identification of resistance to rice BLS.