【作者】 张建萍；

【导师】 赵志模； 王进军；

【作者基本信息】 西南农业大学 ， 农业昆虫与害虫防治， 2004， 博士

【摘要】 酸雨是指pH值小于5.6的雨、雪、雹、雾等酸性沉降的总称。随着现代工业的迅速发展，人口剧增和城市化趋向，硫化物、氮氧化物等被排放的愈来愈多，这些气态化合物在大气中形成的酸雨越来越严重，酸沉降现己成为重大的全球环境问题，它不仅损害人体健康，侵蚀建筑物，而且影响生物生长。酸雨除了直接影响植物外，还会诱发和加剧森林和农业病虫害的发生和危害，由此造成的经济损失可能比污染物本身的直接危害还要大，其对林业和农业生态系统的潜在危害更不容忽视。鉴于此，有关酸雨胁迫对昆虫(螨)的作用已逐渐成为国内外研究的热点之一。 朱砂叶螨Tetranychus cinnabarinus(Boisduval)为多食性重要害螨，分布范围广，危害棉花、烟草、果树等100多种经济、粮食作物及观赏植物。在酸雨严重污染地区，朱砂叶螨的危害逐年加重，对农业生产尤其是市郊蔬菜生产构成了严重威胁。系统研究酸雨胁迫对害螨的直接影响和酸雨通过改变寄主作物的生理代谢对害螨的间接作用，弄清朱砂叶螨适应酸雨胁迫的行为机制及生理生化机理，评估其生态适合度，系统分析酸雨对寄主植物与害螨的综合作用，不仅将深化对环境胁迫下植物与昆虫(螨)生命活动规律的认识，为今后进一步探讨酸雨胁迫下昆虫(螨)——植物的协同进化机制奠定基础，而且对于提高害螨发生预测的质量和害螨综合治理的水平也具有重要意义。本项研究得到了国家自然科学基金(30170617)资助。通过近3年的工作，获得了以下主要研究结果。 1．酸雨对朱砂叶螨主要酶系及能源物质的影响 人工配制不同梯度的模拟酸雨(pH 5.6、pH 4.0、pH 3.0和pH 2.5)，并设置去离子水 西南农业大学博士学位论文为对照，喷洒朱砂叶瞒与寄主植物，每两天喷洒一次，分别在巧天、30天和45天后测定朱砂叶蜗几种主要保护酶、水解酶、基团转移酶的活性、同工酶谱及能源物质的含量，通过比较不同酸雨和处理时间朱砂叶瞒酶活性和能源物质含量的变化，探讨朱砂叶瞒适应酸雨胁迫的生理生化机制。1.1酸雨对朱砂叶蜻三种保护酶的影响 保护酶(超氧化物歧化酶SOD、过氧化物酶POD和过氧化氢酶CAT)活性增强被认为是生物体抵抗不利环境的一个重要的生理生化机制。本研究表明，朱砂叶蜗在酸雨胁迫下，其体内的三种保护酶活性与对照相比均有显著增强。其中SOD和POD活性随酸雨的酸度增加呈现先上升后下降的趋势，其最高值出现在pH3.o或pH4.0;CAT在酸雨胁迫下其活性随酸度增强而一直上升;随着酸雨作用时间的增加，三种保护酶活性增长率均有所下降，说明酸雨胁迫对朱砂叶蜻保护酶活性的应激反应十分明显。1.2酸雨对朱砂叶蜻三种水解酶的影晌 梭酸酷酶(CarE)、酸性磷酸酷酶(ACP)及碱性磷酸酷酶(ALP)是昆虫体内极为重要的三种水解酶，在对外源化合物的解毒代谢中起着重要的作用。结果表明，在酸雨作用下，AcP活性随酸度增强先升高后降低，pH4.0处理达最高值，较对照增强29%:ALP活性随酸度增强而逐渐降低;CarE活性除了在30天后，pH4.o和pH3.0有所降低外，其它时期无显著变化.由此看出，在水解酶系中ACP活性增强是朱砂叶蜻适应和防御酸雨的生化机制之一。1 .3酸雨对朱砂叶蜻谷肤甘肚一S一转移酶的影响 谷肤甘肤一S一转移酶(GSTs)在外源化合物生物转化、药物代谢和保护过氧化作用损害中具有重要作用。据报道，截形叶蜗对三氯杀蜗醇的抗性、橘全爪蜻对甲氢菊酷的抗性都与GSTS活性增高有关。但本研究结果表明，不同酸度酸雨和作用时间对朱砂叶蜿GSTS活性没有显著影响，只有当PH值降低至2.5，且处理30天后GSTs活性才有所增加。1.4酸雨对朱砂叶蜻过氧化物酶同工酶、醋酶同工酶和蛋白质酶谱的影响 环境条件引起生物的酶活性变化，可以是量的差异也可以是质(酶发生变构)的差异或两者兼有。同工酶的变化，能够反应出生物体内的代谢变化。通过对不同酸雨作用下朱砂叶蜻的过氧化物酶同工酶、酷酶同工酶和蛋白质酶谱的电泳分析比较，结果表明，酸雨可明显影响酶的活性或含量，但没有引起酶结构的变异。1.5酸雨对朱砂叶蟒能源物质的影响 昆虫生命活动需要的能量除少部分来白勿理能(光和热等)外.人部分来白贮存于体内的糖类、脂肪和蛋白质等能源物质中的化学能。本实验结果表明，酸雨胁迫可增加朱砂叶鳞可溶性糖和甘油三脂的含量，但对可溶性蛋白含量的影响不大。由此可见可溶性塘和甘油二 中文摘要醋是补偿酸雨胁迫所需的主要能源物质，这也是朱砂叶瞒适应酸雨胁迫的重要生理机制之一。 本章研究表明，酸雨胁迫引起朱砂叶蟒主要酶系及能源物质的活性或含量发生变化，其中三种保护酶、ACP酶活性增强，可溶性糖和甘油三酷含量增加是朱砂叶瞒适应酸雨胁迫的重要生理生化机制。2.酸雨对朱砂叶蜗寄主植物的作用 植物是酸雨的主要受体，也是昆虫生存最重要的因子。昆虫除了受酸雨的直接作用外，还通过寄主植物受到间接影响。本章系统研究了不同酸度酸雨和不同胁迫时间对朱砂叶蜗寄主更多还原

【Abstract】 Acid rain is a natural precipitation con+taining some acidic substances such as rain, snow, hail, fog and so on, and its pH values are often below 5.6. With the rapid development of modern industry, intensely increased population and tendency of urbanization, more and more exhaust gas, sulfide and oxynitrogen, are emitted and acid rain resulted from the exhaust gas are much more serious than ever. The threat of acid rain to the global biosphere has become an environmental problem of worldwide importance. It not only harms to people’s health and erodes buildings, but also influences organism growth. Except for exerting direct effects on plants, acid rain induces and sharpens the occurrence and damages of plant diseases and insect pests in forestry and agriculture ecosystems as well. The subsequent economic loss is even greater than the direct loss of pollutants. Furthermore, its potential harm to the ecosystem of forestry and agriculture is well worth attention. Due to its economic importance, the effects of acid rain on insects (mites) have become one of focus studies in this field.The carmine spider mite, Tetranychus cinnabarinus (Boisduval), a serious mite pest of over 100 species of economical crops and ornamental plants, for example cotton, tobacco, and fruit trees, is widely distributed. In areas seriously polluted by acid rain, the damage of this mite is more and more serious and it does great harm to the agricultural production especially to suburb vegetables. In this study, the direct effects of acid rain on the mite and the indirect effects of acid rain through altering the physiological metabolism of host plants were investigated systematically. Meanwhile, the ethological, physiological and biochemical mechanisms of the mites adaptable to acid rain and its ecological fitness were also studied, respectively. We analyzed the comprehensive effects of acid rain on the mite and its host plant, which not only deepens the acquaintance of life phenomena of plants and insects (mites) under environmental impact establishing the basis of convergent evolutionbetween insects (mites) and plants, but also helps occurrence forecast and integrated management of the mite. This study was supported in part by National Natural Science Foundation of China (30170617), and lasted about 3 years, the main results are as follows: 1. Eeffects of acid rain on major enzymes and energy sources of T. cinnabarinusThe simulated acid rain treatments were pH5.6, 4.0, 3.0 and 2.5, and the deionized water was used as the control. In all experiments, simulated acid rain of different pHs were sprayed to the mite and its host plants at the same time. The plants were sprayed every two days. The activities of major protective, hydrolytic and group- transferring enzymes, isozyme zymogramsand energy source contents of mites from each treatment were measured, respectively, after 15, 30 and 45 d treatments. Through" the comparison of enzyme activities and energy source contents of mites under different acid rain and impact periods, the physiological and biochemical mechanisms of this mite adaptable to acid rain were clarified.1.1 Effects of simulated acid rain on three protective enzyme activities of T. cinnabarinusThe elevated activity of the protective enzymes (superoxide dismutase: SOD, peroxidase: POD, catalase: CAT) is considered to be an important physiological and biochemical mechanism of organisms against adverse environment. The results indicated that compared to the control, the protective enzyme activities of the mites under acid rain impact were increased significantly. With the increasing of acidity, SOD and POD activities ascended at the beginning and then declined, The highest activity was recorded at pH3.0 or 4.0 treatment, respectively. In contrast. CAT activity ascended throughout the experiment. As impact period prolonged, the activity ascending ratio values of three protective enzymes all decreased. This suggested the corresponding stress reaction of acid rain on the carmine spider mite was quite significant.更多还原