相关防御酶对人参锈腐病诱导抗性的响应

 为明确水杨酸(SA)对人参抗人参锈腐病的诱导作用，本研究首先采用琼脂平板法测定了SA对人参锈腐病菌(Cylindrocarpon destructans)生长的影响。然后用SA溶液处理二年生人参移栽苗，温室接种人参锈腐病菌，测定了人参根内防御酶系活性（PAL，CAT，PPO，POD）、β-1,3-葡聚糖酶和几丁质酶活性的动态变化。结果表明:浓度为0~200 mg·L^-1 的SA溶液对人参锈腐病菌无直接抑制作用。但SA溶液处理后，人参锈腐病发病率较直接接种处理的下降30%，人参根系PAL、CAT、PPO、POD活性较对照均表现上升趋势，β-1,3-葡聚糖酶和几丁质酶活性也较对照增强，并且经SA诱导后接种锈腐菌的人参体内上述酶活性比只诱导不接种处理上升速度快。这表明SA处理可以改变人参根部相关防御酶的活性，从而提高人参对人参锈腐病的抗性。

Response of the defense enzymes to induced resistance of ginseng rusty root rot

In order to study the effect of salicylic acid (SA) on the induced resistance of ginseng to ginseng rusty root rot, the inhibition effect of SA to Cylindrocarpon destructans（Zinns.）Scholten was analyzed by using the agar plate method. In greenhouse, the ginseng plants were treated with the solution of salicylic acid, and then inoculated with Cylindrocarpon destructans. The activities of some plant defense enzymes including phenylalanine ammonia-lyase (PAL), catalase (CAT), polyphenoloxidase (PPO) and peroxidase (POD), along with β-1, 3-glucanase and chitinase were analyzed. The results showed that no inhibition effect to the growth of the pathogen occured at the SA concentration of 0-200 mg·L^-1. However, the disease incidence rate in SA-treated ginseng plants was reduced by 30%. The activities of PAL, CAT, PPO, POD, β-1, 3-glucanase and chitinase increased significantly in ginseng roots treated by SA than those in control. The increase of enzymes activities were faster in ginseng treated with SA and Cylindrocarpon destructans than that only treated with SA. This demonstrated that the activities of these resistance-related defense enzymes could be firstly increased by SA treatment, thus to improve the ginseng resistance to ginseng rusty root rot.