水稻耐1,2,4-三氯苯胁迫的生理生化响应与分子机理

On view of the more and more serious rice paddy pollution caused by chlorobenzene ( CBs ) in the Yangtze River Delta region, investigation is to be conducted on the biological mechanisms of rice responding to TCB stress with the major CBs pollution component 1,2,4-trichlorobenzene ( TCB ) and the potential victim rice plants to be the research objects. Based on previous preparative experiments, focusing on representative rice cultivars respectively sensitivity and accumulation to TCB stress,and by the means of potted-soil cultivation and sand-bed hydroponic culture, the following issues are to be studied. The morphological and structural characteristics of rice major organs including roots, leaves and grains, as well as the characteristics of plant growth and development, C/N metabolism, yield formation and TCB accumulation under the stress of TCB, are to be clarified. The activity and differential response of key enzymes in the lipid peroxidation and antioxidant system such as superoxide dismutase (SOD), cytochrome oxidase ( COD ), catalase ( CAT ), and malondialdehyde ( MDA ) are to be revealed.The differential expressing protein profiles of TCB responseare to be established, and the critical responding proteins and the expression and regulation patterns of the relating genes will be obtained.Furthermore, based on the above morphology, physiology, enzymology and proteomics results, the morphological,physiological and biochemical mechanisms, the metabolic regulating networks and the molecular mechanism attributing to rice TCB tolerance will be systematically elucidated,the understanding of biological mechanism in the rice response to TCB stress will be deepened, and advices and suggestions for safer rice productioncan be proposed.

针对长江三角洲等地区稻田氯苯类（CBs）有机物污染日趋严重的实际，以CBs有机污染物主要成分-1,2,4-三氯苯（TCB）和潜在受害作物-水稻为研究对象，开展水稻对TCB胁迫响应的生物学机制研究。在预备试验基础上，以对TCB胁迫耐敏性和积累显著差异的典型水稻品种为材料，通过土培、沙（水）培，研明在TCB胁迫下根、叶、籽粒等主要器官的形态结构以及生长发育、C/N代谢、产量形成、TCB积累等特性及其差异；揭示超氧化物歧化酶(SOD)、细胞色素氧化酶(COD)、丙二醛(MDA)等膜脂过氧化和抗氧化关键酶活性特点及其差异；建立并获取TCB胁迫响应的蛋白质差异表达图谱、关键响应蛋白质及其相关基因表达与遗传信息。进而从上述的形态生理、酶学和蛋白质组学等方面，系统阐明水稻耐TCB胁迫响应的形态生理生化机制、代谢调节网络与分子机理，加深对水稻耐TCB胁迫响应的生物学机制的新认识，为水稻安全生产提供依据。

针对稻田氯苯类（CBs）污染趋重的实际，以1,2,4-三氯苯（TCB）为对象，从形态结构、生理生化、酶学和蛋白质组学等方面研究了水稻耐1,2,4-三氯苯胁迫的生理生化响应与分子机理，获得如下重要结果。. 1、明确水稻品种对TCB响应存在显著的基因型差异，提出根长，根尖数作为耐TCB敏感性指标，获得敏感性品种为宁粳1号、南粳5055等，耐性品种为扬辐粳8号、武运23号等。. 2、水稻植株各器官TCB含量为：根＞茎＞叶＞籽粒（3.4:1.96:1.60:1），敏感性品种各器官TCB含量高于耐性品种。.3、敏感性品种在TCB处理下的株高、分蘖、生物量、根系、穗粒数、产量等均随TCB浓度增加极显著降低。耐性品种在20mg/kg TCB低浓度影响较小或略有升高，在40-60mg/kg TCB中高浓度时均极显著下降。敏感性品种受TCB影响的降幅显著大于耐性品种。. 4、敏感性品种在TCB处理下可溶性蛋白质含量、SOD、POD、CAT活性明显降低, O2–和MDA含量显著增高。耐性品种在低浓度TCB下与敏感性品种呈现出相反趋势，耐在高浓度TCB下一致。. 5、在TCB 处理下敏感品种的净光合速率、胞间CO2 浓度、蒸腾速率、气孔导度、Fv/Fm、Fv/Fo、qp显著降低，光合受抑制。耐性品种低浓度TCB 处理有一定的促进作用, 在中高浓度TCB时表现出较强的耐性。. 6、灌浆期剑叶、籽粒蛋白质表达差异位点宁粳1号分别24个、15个，扬辐粳8号分别37个、19个。其中宁粳1号灌浆期剑叶蛋白质差异位点中有6个参与光合作用，4个参与能量代谢，6个逆境胁迫应答，3个参与蛋白质氨基酸合成代谢；逆境胁迫应答相关蛋白大量表达，叶片光合速率降低，能量代谢减缓，蛋白质及氨基酸合成代谢受阻。. 7、硅能缓解TCB对水稻胁迫，在低浓度TCB效果更明显。. 上述结果加深了对水稻耐TCB胁迫响应机制的认识，为水稻安全生产提供依据。