水杨酸诱导辣椒抗疫病生化机制的研究

Study on the Relative Biochemical Mechanism Induced by Salicylic Acid Against Phytophthora capsici in Pepper (Capsicum annuum)

对水杨酸(SA)处理及其挑战接种辣椒疫霉菌的4个抗性不同的辣椒品系体内木质素含量和多酚氧化酶(PPO)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)活性的测定结果表明:SA诱导的供试品系与未经诱导的相同品系相比,木质素含量增高,PPO、POD、PAL活性增强,其中木质素的含量与抗病性呈显著正相关;挑战接种后两者相比,SA处理的供试材料的木质素含量和PPO、POD、PAL活性的增强幅度更大,其中抗、耐病品系的增加早且增加幅度高于感病、高感品系。值得注意的是,经SA诱导的各供试品系接种后木质素含量与抗病性也呈显著相关。木质素含量与相关酶活性的上述变化趋势与SA对各品系的诱抗效果完全吻合。

The variation in the relative enzymes activities and lignin content in leaves and stems/roots of four hot pepper seedlings induced by SA and after challenge inoculation with Phytophthora capsici were studied. The results shows that the lignin content and activities of PPO, POD and PAL in four hot pepper lines treated with 0.225g/L SA were increased compared with untreated plants, and the lignin content had a significant positive correlation with varietal resistance of pepper to P capsici. The lignin content and activities of PPO, POD and PAL in pepper seedlings by SA-treatment were much higher than that in untreated control after challenge inoculation with P capsici, and this kind of increment came more rapid and earlier in the resistant and tolerant pepper lines than in susceptible and high susceptible ones. After challenge inoculation, the lignin content was also significantly positively correlated with the disease resistance in SA-treated pepper plants, which suggested that the variation of lignin level, PPO, POD and PAL activities corresponded well with the induced resistance against P capsici in pepper plants by SA-treatment.