Abstract

This study explored the nematicidal activity of silver nanoparticles (AgNPs), ascorbic (AA) and salicylic acid (SA) compared with Mycorrihizin (Myco) against Meloidogyne javanica infecting eggplants. The characterization and size confirmation of the AgNPs was done by ultraviolet–visual (UV–vis) spectrophotometry, surface zeta-potential and transmission electron microscopy. The results illustrated that 150 μg/mL AgNPs had nematicidal activity against the second-stage juvenile and egg hatching of M. javanica in vitro, and caused 100% mortality in juveniles after 48 h of exposure. In open-field conditions, the treatment with 100 µg and 150 µg AgNPs 24 h before transplanting killed almost all of the nematode eggs and galls per root system compared with the control. All treatments improved the eggplant growth in terms of plant height, root weight, number and weight of fruits, shoot and root length and fresh weight of shoot and root with various degrees as compared to control. The activities of oxidative enzymes, peroxidase (POX), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL), during the flowering stage, increased with all treatments comparing to healthy and infected plants. To assess the defense response of infected eggpant, the gene expression levels (PAL, POX and PPO) were monitored using quantitative reverse transcription polymerase chain reaction (qRT-PCR). The PPO enzyme showed the highest rate on day 60 after infection when 50 µg AgNPs were used during transplanting. The POX enzyme activity showed the highest increase in all treatments during all stages of growth, on day 30, 45 and 60.

摘要

本研究探讨了银纳米粒子 (AgNPs)、抗坏血酸 (AA) 和水杨酸 (SA) 与菌根霉 (Myco) 相比对感染茄子的根结线虫的杀线虫活性。AgNPs 的表征和尺寸确认是通过紫外-可见（UV-vis）分光光度法、表面 zeta 电位和透射电子显微镜完成的。结果表明，150 μg/mL AgNPs 对爪哇二期幼虫和卵孵化具有体外杀线虫活性，并在暴露 48 小时后导致幼鱼 100% 死亡率。在露天条件下，与对照相比，在移植前 24 小时用 100 µg 和 150 µg AgNPs 处理几乎杀死了每个根系的所有线虫卵和虫瘿。与对照相比，所有处理在株高、根重、果实数量和重量、枝条和根长、枝条和根鲜重方面均有不同程度的改善。氧化酶、过氧化物酶 (POX)、多酚氧化酶 (PPO) 和苯丙氨酸解氨酶 (PAL) 的活性，在开花阶段，与健康和受感染植物相比，随着所有处理而增加。为了评估受感染茄子的防御反应，基因表达水平（PAL，POX 和 PPO) 使用定量逆转录聚合酶链反应 (qRT-PCR) 进行监测。当移植期间使用 50 µg AgNPs 时，PPO 酶在感染后第 60 天显示出最高的比率。在第 30、45 和 60 天的所有生长阶段，POX 酶活性在所有处理中的增幅最大。