【作者】 张雯；

【导师】 沈应柏； 沈昕；

【作者基本信息】 北京林业大学 ， 植物学， 2006， 硕士

【摘要】 本研究以合作杨(P.simonii×P.pyramidalis‘Opera 8277’)为实验材料,采用杨扇舟蛾幼虫取食、茉莉酸甲酯熏蒸以及用抑制剂处理昆虫取食叶片三种方式,检测了受伤植株及受伤邻近健康植株中过氧化氢含量、相关防御性酶活性及基因的变化情况,主要分析了在虫害诱导的抗性防御反应中,过氧化氢作为植株间伤信号分子在信息传导中的作用。结果表明:昆虫取食后,虫咬叶、虫咬植株上的完整叶、邻近健康植株上的熏蒸叶中过氧化氢的含量均有明显的升高,相应的酶活性也可被系统性的诱导,说明在植株内部及植株间存在传递抗性信息的信号转导途径;用质膜NADPH氧化酶抑制剂DPI处理虫咬叶片后,可以显著抑制虫咬诱导的过氧化氢迸发,与之相关的抗氧化酶类活性也随之下降,说明过氧化氢作为第二信使在植株间的伤信息传递中起着作用。茉莉酸信号传导途径在植物防御反应中有着重要的作用,对植株用茉莉酸甲酯熏蒸后,可诱导植株产生与昆虫取食类似的反应--叶片过氧化氢含量有明显的提高,同时对POD、PPO、PAL等直接防御物质有显著的诱导作用,进而证明了茉莉酸甲酯是伤信息在植株间传递的报警信号分子之一。本研究首次运用含有杨树全基因组序列探针的Affymetrix GeneChip? Poplar Array芯片,检测合作杨叶片在杨扇舟蛾幼虫取食1h前后的基因表达变化。昆虫取食后,共有334个基因诱导上调,569个基因诱导下调,根据功能注释结果对诱导表达的基因进行分类,主要包括新陈代谢相关基因、光合电子传递相关基因、转运调控基因、信号传导相关基因、氧化胁迫相关基因、次生代谢相关基因及大量的功能未知基因。它们通过复杂的相互作用激发植物的防御反应,从而表现为抗性。本研究从全基因组的角度去研究虫害诱导的杨树抗性反应,为我们下一步探讨植物抗虫机制以及植物-昆虫相互作用提供了理论基础。更多还原

【Abstract】 We used P.simonii×P.pyramidalis‘Opera 8277’as experiment materials. In order to discuss the role of hydrogen peroxide as the wounding signal transduction mediated by herbivory injuried among poplar, three treaments including Clostera anachoreta feeding, exposure to Methyl Jasmonic acid and feeding with inhibitor were applied to the poplar. At different times after treatments, measured the contents of hydrogen peroxide, the activities of antioxidant enzymes , the expression of genes between the wounded plant and the neibouring intact plant.The results showed that: The contents of hydrogen peroxide were appeared to rapidly increase in the herbivore-infested leaves and undamaged parts of herbivore-infested leaves, also increased in the neighbour health plants. And the antioxidant enzymes were also activated. We found that there was some signaling pathway within the damaged plant and interplant. Diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, could significantly inhibit H2O2 burst and enzymes activities that mediated by herbivore-infested. H2O2 has also been proved to play the signal role in defensive response. Jasmonate-signal transduction pathway is involved in the induction of plant defense in response to herbivore and pathogen attack. Treatment of poplar trees with gaseous methyl jasmonate (MeJA) induced the similar response with the caterpillars feeding, It could effectively induce plant defense response.It increased the contents of hydrogen peroxide, enhanced the levels and activities of defense-related protein Peroxidase (POD), Polyphenol oxidase (PPO) and Phenylalanine ammonia lyase (PAL).It can be concluded that methyl jasmonate is an important alarm signaling between plants.We used the Affymetrix Genechip microarray technique for analysis of gene expression profiles, it is a powerful strategy to identify gene expression in poplar leaves in response to herbivory by caterpillars (Clostera anachoreta). After 1 h of feeding, 334genes were classified as up-regulated, compared to 569 down-regulated. Functional classification of this induced gene set revealed genes with roles in general metabolism, photosynthesis, transport, transcriptional regulation and signalling, jasmonic acid signalling, response to stress, secondary metabolism, detoxification and redox processes. This study provides the first genome-scale approach to characterize insect-induced defences in a woody perennial providing large-scale transcriptional changes in solid platform for functional investigation of plant–insect interactions in poplar.更多还原