CO2倍增和转Bt水稻对二化螟幼虫的生理影响
Impacts of elevated CO2 on the larvae of stem borer Chilo suppressalis fed on transgenic Bt rice
常晓娜1， 韩 超1，肖能文2，李俊生2，陈法军1**
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DOI：
作者单位：1.南京农业大学植物保护学院 南京 210095； 2.中国环境科学研究院环境科学研究所 北京 100012
中文关键词： CO2倍增, 二化螟, 转Bt水稻, 代谢酶, 保护酶
英文关键词：double CO2 level, Chilo suppressalis, transgenic Bt rice, metabolism enzymes, protective enzyme
中文摘要：
通过开顶式气室研究了CO2浓度倍增（750 vs. 375 μL/L）对取食转Bt水稻及其对照亲本秀水11的二化螟Chilo suppressalis (Walker)幼虫体内代谢酶乙酰胆碱酯酶（AChE）和保护酶（超氧化物歧化酶SOD、过氧化物酶POD和过氧化氢酶CAT）活力的影响，以期明确该类害虫对大气CO2浓度升高及转Bt水稻的生理响应。研究结果表明：（1）AChE受CO2浓度水平影响显著，与对照CO2处理相比，高CO2条件下该酶活力显著降低；（2）高CO2水平及水稻中Bt毒素蛋白的存在均会导致二化螟幼虫体内POD活力显著降低，SOD初期活力显著升高，但不能维持较长时间，CAT活力表现为先升后降的特点；（3）当受到水稻品种、CO2浓度水平和取食时间的综合影响时，以上代谢酶和保护酶活力会发生显著变化。短时间内二化螟幼虫可通过体内以上生理代谢调节减缓受CO2浓度升高和水稻中Bt毒素蛋白的不利影响，但长时间环境胁迫下这种应对不利环境的响应机制将会失去作用，最终导致种群适合度的降低。
英文摘要： The effects of double-atmospheric CO2 (750 vs. 375 μL/L) on the metabolic enzyme acetylcholinesterase (AChE) and the three protective enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), were investigated on stem borer Chilo suppressalis (Walker) larvae as these fed on transgenic Bt rice (cv. KMD expressing pure Cry1Ab) and nontransgenic rice (cv. XSD; i.e., the parental line) in open-top chambers. The results indicate that: (1) Increased CO2 levels significantly reduced AChE activity in larvae feeding on both transgenic Bt rice or nontransgenic rice. (2) Elevated CO2 and Bt rice both markedly enhanced the activities of POD and SOD. POD activity decreased sharply but SOD activity increased only initially. An obvious increase in CAT activity was observed initially but this declined after a period. (3) There were significant interactive effects between CO2 level, rice variety and sampling time. It appears that C. suppreddalis can alleviate some short-term adverse effects of elevated CO2 and transgenic Bt rice through physiological regulation using metabolic and protective enzymes. However, this regulatory mechanism can be suppressed by environmental factors, which can thereby reduce population performance.