顺-冷杉醇诱导烟草抗青枯病的效果及作用机制研究
Effect and Mechanism of cis-Abienol to Induce Tobacco against
Bacterial Wilt
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摘要: 为探究顺-冷杉醇诱导烟草抗青枯病的适宜处理条件和作用机制,采用盆栽接种方法,研究了顺-冷杉醇灌根施用的适宜浓度、时间间隔和次数,测定了顺-冷杉醇处理后烟草根部主要防御酶活性、植保素和植物激素含量的变化,利用高通量测序技术测定了顺-冷杉醇对烟草根系转录水平的影响。结果表明,顺-冷杉醇施用浓度60~80 mg/L对烟草青枯病的防效为54.50%~57.10%,与阳性对照中生菌素相当,其适宜施用时间间隔为3~6 d,连续施用2~3次;顺-冷杉醇处理后1~6 d烟草根部过氧化氢酶(CAT)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)活性显著提高,1~10 d过氧化物酶(POD)和超氧化物歧化酶(SOD)活性显著提高,处理后3~6 d多酚类物质和木质素含量显著增加,1~3 d茉莉酸(JA)和水杨酸(SA)含量显著增加,引起烟草根部抗性基因NtSIPK、NtMEK2、NtMAPK、NtPAL和NtC4H上调表达,提高烟株对青枯病的抗性。由此可知,顺-冷杉醇可作为诱抗剂有效防控烟草青枯病的发生。Abstract: In order to explore the appropriate treatment conditions and the mechanism of cis-abienol to induce tobacco against bacterial wilt, the suitable root application concentration, time interval and frequency were investigated by pot inoculation, combined with determination of the changes of major defense enzyme activities, phytoalexin and phytohormone contents in tobacco roots after cis-abienol treatment. Additionally, the effect of cis-abienol on the transcript level of tobacco roots was evaluated using high-throughput sequencing technology. The results showed that the control efficiency of cis-abisol at 60-80 mg/L against tobacco bacterial wilt was 54.50%-57.10%, which was comparable to that of bacteriocin in positive control. The suitable application interval was 3-6 days and 2-3 times. The activities of catalase (CAT), polyphenol oxidase (PPO) and phenylalanine aminolyase (PAL) were significantly increased at 1-6 d after cis-abienol treatment, and the activities of peroxidase (POD) and superoxide dismutase (SOD) were significantly increased at 1-10 d, while the contents of polyphenols and lignin were significantly increased at 3-6 d after cis-abienol treatment. The contents of jasmonic acid (JA) and salicylic acid (SA) were significantly increased at 1-3 d, which cause the up-regulated expression of NtSIPK, NtMEK2, NtMAPK, NtPAL and NtC4H, thereby improving the resistance of tobacco plants against bacterial wilt. Therefore, cis-abienol could be used as bacterial wilt inducers to effectively control the occurrence of tobacco bacterial wilt.