Zero effect of Bt rice on expression of genes coding for digestion,detoxification and immune responses and developmental performances of Brown Planthopper Nilaparvata lugens (Stål)

Transgenic Cry1Ac, Cry2Aa and Cry1Ca (Bt toxins) rice lines are well developed to manage lepidopteron pests in China. The impact of transgenic Bt rice on the non-target Brown Planthopper (BPH) has become an essential part of environmental risk assessment, however, scanty evidence is found addressing on developmental and molecular responses of BPH to the ingestion of Bt protein from transgenic rice. The focus of the current study is to examine the developmental characteristics and the expression profiles of gene in relation to digestion, detoxification and immune responses were examined. Our study strongly revealed that the tested Bt rice strains have no unfavorable effect on fecundity, survival and growth of BPH. Furthermore, each of the tested genes did not exhibit distinct expression pattern responding to non Bt parental cultivar, thus, it could be concluded that Bt rice have no detrimental effects on the physiological processes of digestion, detoxification and immune responses of BPH.     

Climatic limits of pink bollworm in Arizona and California: effects of climate warming

The distribution and abundance of pink bollworm (Pectinophora gossypiella Saunders (PBW)) in cotton in Arizona and California was examined using a validated weather-driven, physiologically based demographic model of cotton and PBW integrated into a geographic information system (GIS). Survival of diapause larvae during winter as affected by low temperatures is a key factor determining the range of PBW. Winter survival was estimated using data from Gutierrez et al. (Can. Entomol. 109 (1977) 1457) and Venette et al. (Environ. Entomol. 29 (5) (2000) 1018). The model was run continuously over the period 1 January 1995 to 31 December 2003 using observed weather data from 121 locations. Three output variables were mapped as measures of PBW persistence: over-winter survival of diapause PBW larvae, cumulative daily PBW larval densities over the season, and the number of diapause larvae produced during the season. The distribution of pink bollworm is predicted to be restricted to the relatively frost-free cotton growing areas of Arizona and Southern California where it currently reaches pest status. The model predicts that extension of PBW's range into the Central Valley of California is unlikely. The analysis questions the efficacy of an ongoing area-wide effort to prevent the establishment of PBW in the Central Valley of California. Four global warming scenarios were examined to estimate the effects on the potential geographic range of PBW. Average observed daily temperatures were increased 1.0, 1.5, 2.0 or 2.5 °C, respectively, in the four scenarios. Scenarios with average increases of 1.5–2.5 °C predicted that the range of PBW would expand into the Central Valley of California and the severity of the pest would greatly increase in areas of current infestation.     

华恢1号稻谷的大鼠慢性毒性试验研究

为了解长期喂养接触华恢1号稻谷是否会导致慢性毒性作用,尤其是进行性或不可逆的毒性作用以及致癌作用,本研究以SD大鼠为实验动物,进行了为期106周的慢性毒性试验.与普通稻谷对照组和基础饲料对照组比较,喂饲华恢1号稻谷106周的低、中、高剂量组SD大鼠,在一般临床症状、体重和食物利用率、血液学和血液生物化学指标、脏器重量和脏器系数、大体解剖学和病理组织学检查等各项观察指标上,均未见统计学意义和毒理学意义的差异.各组间,老年大鼠的肿瘤发生率为8.3%~10%,没有剂量反应关系,其发生部位主要在皮下,符合美国NIH Rodent 1980 catalogur SD大鼠乳腺肿瘤自然发病的正常范围.故认为华恢1号稻谷对SD大鼠没有明显的慢性毒性和致癌性.     

转基因棉花的遗传研究

选用不同来源的转Ｂｔ基因抗虫棉中棉所３０号和新棉３３Ｂ、转ｔｆｄＡ基因抗除草剂棉花材料ＴＦＤ,通过与不同主栽推广品种正反交和回交研究外源Ｂｔ基因和ｔｆｄＡ基因在棉花体内的遗传和分离行为。结果表明,由外源基因提供给转基因的抗虫和抗除草剂性状均是由一对基因控制的显性性状,且该性状不受细胞质效应的影响,符合孟德尔遗传规律。     

Effects of Elevated Carbon Dioxide on the Growth and Foliar Chemistry of Transgenic Bt Cotton

A field study was carried out to quantify plant growth and the foliar chemistry of transgenic Bacillus thuringiensis （Bt） cotton （cv. GK-12） exposed to ambient CO2 and elevated （double-ambient） CO2 for different lengths of time （1, 2 and 3 months） in 2004 and 2005. The results indicated that CO2 levels significantly affected plant height, leaf area per plant and leaf chemistry of transgenic Bt cotton. Significantly, higher plant height and leaf area per plant were observed after cotton plants that were grown in elevated CO2 were compared with plants grown in ambient CO2 for 1, 2 and 3 months in the investigation. Simultaneously, significant interaction between CO2 level x investigating year was observed in leaf area per plant. Moreover, foliar total amino acids were increased by 14%, 13%, 11% and 12%, 14%, 10% in transgenic Bt cotton after exposed to elevated CO2 for 1, 2 or 3 months compared with ambient CO2 in 2004 and 2005, respectively. Condensed tannin occurrence increased by 17%, 11%, 9% in 2004 and 12%, 11%, 9% in 2005 in transgenic Bt cotton after being exposed to elevated CO2 for 1, 2 or 3 months compared with ambient CO2 for the same time. However, Bt toxin decreased by 3.0%, 2.9%, 3.1% and 2.4%, 2.5%, 2.9% in transgenic Bt cotton after exposed to elevated CO2 for 1, 2 or 3months compared with ambient CO2 for same time in 2004 and 2005, respectively. Furthermore, there was prominent interaction on the foliar total amino acids between the CO2 level and the time of cotton plant being exposed to elevated CO2. It is presumed that elevated CO2 can alter the plant growth and hence ultimately the phenotype allocation to foliar chemistical components of transgenic Bt cotton, which may in turn, affect the plant-herbivore interactions.     

MALDI-TOF-MS and 16S rRNA characterization of lead tolerant metallophile bacteria isolated from saffron soils of Kashmir for their sequestration potential

Toxic metal contamination in soils due industrialization is nowadays a concern to the scientists worldwide. The current study deals with the evaluation of response and tolerance by isolated metallophilic bacteria in different lead concentrations (100 ppm to 1000 ppm). By taking optical densities of the isolates, the minimum inhibitory concentration (MIC) of Pb²⁺ were determined.16S rRNA and MALDI-TOF MS were used for the identification of the bacteria. Total of 37 isolates were observed, among them 04 (Staphylococcus equorum, Staphylococcus warneri, Bacillus safensis and Bacillus thuringiensis), isolated were detected having efficacy of Pb²⁺tolerance and sequestration at varying MIC. Furthermore, B. thuringiensis was observed to have highest (900 ppm) tolerance for lead and lowest (500 ppm) for Staphylococcus warneri. Moreover, the highest (65.3%) sequestration potential has been observed for B. thuringiensis and least (52.8%) for S. warneri. The tolerance and sequestration potential properties of these isolated species can be utilised to exterminate heavy metals and reduce their toxicity from the contaminated environment.     

转cry1Ab/cry1Ac基因籼稻对稻田节肢动物群落影响

将稻田节肢动物群落按营养关系划分为5个功能团,即植食类、寄生类、捕食类、腐食类和其它类,从功能团优势度、功能团内科组成及其优势度、群落主要参数及群落相异性等方面,经两年四点的调查就2个转cry1Ab/cry1Ac基因籼稻（Bt水稻）品系TT9.3和TT9.4对稻田节肢动物群落的影响作了较系统评价。植食类、寄生类和腐食类功能团内某些优势科的优势度在Bt水稻田与对照（IR72）田之间有时呈显著或极显著差异,如Bt水稻田中茧蜂或姬蜂科的优势度有时明显低于对照。但是,在大多情况下Bt水稻田与对照田之间功能团优势度、功能团内科组成及其优势度、群落主要参数（物种丰富度、Shannon-Wiener多样性指数、均匀性指数、优势集中性指数）及其时间动态基本无明显差异;Bt水稻田与对照田间植食类、寄生类、捕食类亚群落和整个节肢动物群落的相异性大多较低。可见,Bt水稻对稻田节肢动物群落基本无明显的负面影响。     

Inheritance and expression of the cry1Ab gene in Bt ( Bacillus thuringiensis) transgenic rice

The inheritance and expression patterns of the cry1Ab gene were studied in the progenies derived from different Bt (Bacillus thuringiensis) transgenic japonica rice lines under field conditions. Both Mendelian and distorted segregation ratios were observed in some selfed and crossed F₂ populations. Crosses between japonica intra-subspecies had no significant effect on the segregation ratios of the cry1Ab gene, but crossing between japonica and indica inter-subspecies led to distorted segregation of the cry1Ab gene in the F₂ population. Field-release experiments indicated that the cry1Ab gene was stably transmitted in an intact manner via successive sexual generations, and the concentration of the Cry1Ab protein was kept quantitatively stable up to the R₆ generation. The cry1Ab gene, driven by the maize ubiquitin promoter, displayed certain kinds of spatial and temporal expression patterns under field conditions. The content of the Cry1Ab protein varied in different tissues of the main stems, the primary tillers and the secondary tillers. Higher levels of the Cry1Ab protein were found in the stems, leaves and leaf sheaths than in the roots, while the lowest level was detected in grains at the maturation stage. The content of the Cry1Ab protein in the leaves peaked at the booting stage and was lowest at the heading stage. Furthermore, the Cry1Ab content of cry1Ab expression in different tissues of transgenic rice varied individually with temperature. Received: 17 April 2001 / Accepted: 7 May 2001     

Gene cloning and expression of cadherin in midgut of Helicoverpa armigera and its Cry1A binding region

Bacillus thuringiensis (Bt), a Gram-positive bacte-rium, produces insecticidal crystal proteins during sporulation. Bt has been used as biopesticides to con-trol a number of insect pests from Lepidoptera, Dip-tera and Hymenoptera and also has become so far the leading gene sources of transgenic plants resistant toinsect pests[1,2]. In China, the use of Bt cotton began in 1997 in Hebei, Shandong and Henan provinces, etc. and rapidly increased to more than 2 million ha in 2002, which is effe…