硅对秆锈菌侵染燕麦叶片病程相关蛋白活性及酚类物质代谢的影响

Effect of Silicon on the Activity of Pathogenesis-Related Proteins and Phenolic Metabolism in Oat Leaves Infected by Stem Rust

以易感秆锈病的燕麦品种‘坝莜1号’为试验材料,采用盆栽技术,分析施硅对侵染秆锈病菌后燕麦叶片的病程相关蛋白酶活性及酚类物质代谢的影响,以明确硅提高燕麦抗秆锈病的生理机制,为燕麦秆锈病新型病害防治措施提供理论依据。结果表明:(1)接种秆锈病菌后,施硅处理下燕麦秆锈病严重度显著降低,且叶片秆锈病菌孢子量明显减少。(2)在不接种秆锈病菌的情况下,施硅与否对燕麦叶片的病程相关蛋白酶活性无显著影响;在接种秆锈病菌后,施硅与不施硅处理的燕麦叶片几丁质酶活性均快速升高,并且分别在接种第1天和第3天达到峰值后开始降低;在接种情况下,施硅与不施硅处理叶片β-1,3葡聚糖酶活性均先升后降,并均在接种第3天达到峰值;施硅后可显著提高燕麦叶片几丁质酶和β-1,3葡聚糖酶活性。(3)在不接种秆锈病菌的情况下,施硅与否对燕麦叶片酚类物质代谢无显著影响;接种秆锈病菌能使燕麦叶片多酚氧化酶(PPO)活性、苯丙氨酸解氨酶(PAL)活性、总可溶性酚(TSP)含量及木质素含量快速上升,施硅处理和不施硅处理均在接种后第3天达到峰值后开始快速下降,且施硅能显著提高酚类物质中各组分的含量及相关酶活性。研究认为,施硅可通过诱导燕麦叶片中病程相关蛋白酶活性和酚类物质代谢能力的提升来增强燕麦对秆锈病的抗性。

We used oat variety‘Bayou 1’,which is susceptible to stem rust,as the experimental material,to study the effect of silicon application on the activity of proteases and phenolic substances in oat leaves infected with stem rust and to clarify the physiological mechanism of silicon improving resistance to oat stem rust,and provide theoretical basis for new control measures of oat stem rust.The results showed that:(1)after inoculation,the severity of oat stem rust was significantly reduced under silicon application,and the number of spores on leaves was significantly reduced.(2)No inoculation of stem rust,silicon application or not had no significant effect on the protease activity related to the disease course of oat leaves.The chitinase activity in the leaves increased rapidly and then decreased after reaching the peak on the 1st day and the 3rd day of inoculation;Theβ-1,3 glucanase activity of leaves increased first and then decreased in both silicon and non-silicon treatments,and reached the peak on the 3rd day of inoculation.The activities of chitinase andβ-1,3 glucanase in leaves were significantly increased after silicon application.(3)There was no significant effect of silicon application on the metabolism of phenolic substances in oat leaves without inoculation of stem rust,inoculation of stem rust could make oat leaves polyphenol oxidase activity(PPO),phenylalanine ammonia lyase activity(PAL),total soluble phenol content(TSP)and lignin content to increase rapidly.All treatments began to decline rapidly after reaching the peak on the 3rd day after inoculation,and application of silicon could significantly increase the content of each component in phenolic substances and related enzyme activities.In conclusion,silicon application can enhance the resistance of oat to stem rust by inducing the activity of protease related to disease course and the metabolism of phenolic substances in oat leaves.