Jia Xiaochen, Meng Qingshan, Zeng Haihong, Wang Wenxia, Yin Heng
Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Sci Rep. 2016 May 18;6:26144. doi: 10.1038/srep26144.
Chitosan is one of the most abundant carbohydrate biopolymers in the world, and chitosan oligosaccharide (COS), which is prepared from chitosan, is a plant immunity regulator. The present study aimed to validate the effect of COS on inducing resistance to tobacco mosaic virus (TMV) in Arabidopsis and to investigate the potential defence-related signalling pathways involved. Optimal conditions for the induction of TMV resistance in Arabidopsis were COS pretreatment at 50 mg/L for 1 day prior to inoculation with TMV. Multilevel indices, including phenotype data, and TMV coat protein expression, revealed that COS induced TMV resistance in wild-type and jasmonic acid pathway- deficient (jar1) Arabidopsis plants, but not in salicylic acid pathway deficient (NahG) Arabidopsis plants. Quantitative-PCR and analysis of phytohormone levels confirmed that COS pretreatment enhanced the expression of the defence-related gene PR1, which is a marker of salicylic acid signalling pathway, and increased the amount of salicylic acid in WT and jar1, but not in NahG plants. Taken together, these results confirm that COS induces TMV resistance in Arabidopsis via activation of the salicylic acid signalling pathway.
壳聚糖是世界上最丰富的碳水化合物生物聚合物之一，由壳聚糖制备的壳寡糖（COS）是一种植物免疫调节剂。本研究旨在验证COS诱导拟南芥对烟草花叶病毒（TMV）抗性的效果，并探究其潜在的防御相关信号通路。在接种TMV前1天，用50mg/L的COS预处理是诱导拟南芥对TMV产生抗性的最佳条件。包括表型数据和TMV外壳蛋白表达在内的多水平指标显示，COS能诱导野生型和茉莉酸途径缺陷型（jar1）拟南芥植株对TMV产生抗性，但不能诱导水杨酸途径缺陷型（NahG）拟南芥植株产生抗性。定量PCR和植物激素水平分析证实，COS预处理增强了防御相关基因PR1的表达，PR1是水杨酸信号通路的标志物，并且增加了野生型和jar1植株中的水杨酸含量，但NahG植株中未增加。综上所述，这些结果证实COS通过激活水杨酸信号通路诱导拟南芥对TMV产生抗性。
