硅对瓠瓜酚类物质代谢的影响及与抗白粉病的关系

研究了硅酸盐和诱导接种白粉菌对瓠瓜叶片苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)活性的动态变化和木质素含量的影响.结果表明,诱导接种提高了瓠瓜叶片的PAL、PPO、POD活性,加硅后接种处理植株叶片酶活性更明显增加;接种后瓠瓜叶片中木质素含量增加,加硅处理植株叶片木质素含量是不加硅处理的1.43倍.说明酚类物质代谢在植物抗病机制中起着重要作用,硅能提高酚类代谢的酶活性.1.7mmol/L的硅能显著降低瓠瓜白粉病的病情指数,提高其对白粉病的抗病能力.

Influences of silicon on phenolic metabolism in Chinese white-flowered gourd and its relation to resistance to powdery mildew

Hydroponic culture experiments were conducted to investigate the effects of solublesilicon and inoculation with Sphaerotheca fuliginea on time-dependent changes in activities ofphenylalanine ammonia-lyase(PAL),polyphenoloxidase(PPO),peroxidase(POD)and lig-nin content in the leaves of Chinese white-flowered gourd(Lagenaria leucantha).The resultsshowed that the activities of PAL,PPO and POD,and lignin content were increased by inocula-tion.Silicon increased the activities of PAL,PPO and POD in the inoculated-leaves.Lignincontent of silicon-supplied plants increased by 1.43 times compared with silicon-deprivedplants.The phenolic metabolism played an important role in disease resistance and silicon in-creased these enzymes activity.Application of the hydroponic culture with 1.7mmol/L siliconsignificantly decreased disease index and improved the ability of resistance to powdery mildew.