绿色杜氏藻DvGGPS生物信息学及转录差异研究

香叶酰香叶酰焦磷酸合成酶(GGPS)能够催化焦磷酸异戊烯酯(IPP)与二甲基丙烯焦磷酸(DMAPP)反应形成二萜化合物通用前体香叶酰基香叶酰焦磷酸(GGPP)。为深入了解GGPS蛋白在类胡萝卜素合成途径中的作用,通过Illumina Hi Seq TM 2000高通量测序获得Dv GGPS基因c DNA全长序列,对GGPS基因序列进行生物信息学分析,并研究花生四烯酸(AA)、乙酰水杨酸(ASA)和硫酸铈铵(ACS)对Dv GGPS基因转录水平的影响及绿色杜氏藻类胡萝卜素含量变化。生物信息学分析结果表明,Dv GGPS基因c DNA全长2 229 bp,含1 041 bp开放阅读框,编码346个氨基酸。GGPS蛋白质序列理论等电点(p I)为5.82,相对分子质量为37.66 k Da,该蛋白为疏水性蛋白,无信号肽和跨膜区域。二级结构预测显示该蛋白分子中α-螺旋结构最多,占57.23%。同源比对结果表明,绿色杜氏藻GGPS蛋白与雨生红球藻亲缘关系最近。qRT-PCR结果表明,62.5 mg·L~(-1)AA、50 mg·L~(-1)ASA和0.8 mg·L~(-1)ACS处理的Dv GGPS基因转录水平达到最高,此时类胡萝卜素含量也均有提高,说明绿色杜氏藻类胡萝卜素的生物学合成可能是通过诱导Dv GGPS基因表达实现的,Dv GGPS基因在类胡萝卜素生物合成中起关键作用。Dv GGPS基因的克隆及表达调控研究为今后探明类胡萝卜素积累的分子机理提供了重要参考,也为进一步通过代谢工程手段提高绿色杜氏藻类胡萝卜素含量奠定了理论基础。     

普洱市小粒咖啡绿蚧田间药效试验研究

进行小粒咖啡绿蚧的田间药效试验,结果表明:5%吡虫啉乳油、25%噻虫嗪可湿性粉剂、5%啶虫脒乳油、40%杀扑磷乳油平均防效均在91%以上,说明它们具有很好的速效性和持效性。在7中药剂中药效最好的是5%啶虫脒乳油,平均防效为94.10%,其次是40%杀扑磷乳油,平均防效为92.95%,药效最差的是2%阿维菌素乳油,平均防效仅为54.23%。     

大青叶蝉的有效积温

为适时防治大青叶蝉,预测其各虫期的发育进度,在自然变温条件下,根据有效积温法则,对该虫的卵、若虫及成虫的有效积温和发育起点温度进行了研究.卵的有效积温和发育起点温度为196.25±10.67日度、8.84±0.94℃;若虫的有效积温和发育起点温度为244.67±28.61日度、14.23±0.80℃;成虫的有效积温和发育起点温度为87.40±14.58日度、19.67±1.19℃.     

0#柴油水溶液对翡翠贻贝CYP4基因表达的影响研究

在室内半静水的试验条件下,应用实时荧光定量PCR技术研究了不同质量浓度（0 gL-1、5 gL-1、10 gL-1、50 gL-1和100 gL-1）的0#柴油水溶液（WSF）胁迫15 d和清洁海水恢复7 d中翡翠贻贝（Perna viridis）外套膜与内脏团组织中CYP4基因的相对表达水平变化。2-△△Ct法分析结果表明,CYP4基因在翡翠贻贝外套膜和内脏团中均有表达,WSF胁迫对其表达水平有明显的诱导作用,且表达水平具有组织差异性;内脏团表达水平明显高于外膜套,两组织CYP4基因相对表达水平随着WSF胁迫时间的延长,整体呈现出先诱导后抑制再诱导的波动变化趋势,其中50gL-1浓度组表现最为显著（P0.01）。WSF胁迫解除后外套膜与内脏团CYP4基因相对表达水平迅速下降,部分浓度组逐渐恢复到正常水平。     

A Field Bioassay Approach to Assess the Toxicity of Insecticide Residues on Soil to Collembola

Field bioassays were conducted to assess the toxicity of three insecticides, chlorpyrifos, cypermethrin and pirimicarb, to four species of springtails, Isotoma viridis, Isotomurus palustris, Folsomia candida (Collembola: Isotomidae) and Sminthurus viridis (Collembola: Sminthuridae). Spray residues on two soil types (a sandy clay loam and a sandy soil) were obtained in the field, in the presence and absence of a wheat crop canopy, after spray application by a commercial tractor-mounted sprayer. Collembola were then confined for 24-h periods on the sprayed soils in a constant laboratory environment at 1, 2, 3, 8 and 15 days after treatment. Residual insecticide toxicity was compared between species, insecticides, soils and exposure conditions (crop or no crop) using the age of residue at which median mortality occurred (DAT₅₀). Cypermethrin and pirimicarb residues were of low toxicity, causing less than 10% mortality, whereas residues of chloryprifos were toxic to all four species of Collembola on both soil types and in both exposure treatments. Interspecific differences in collembolan susceptibility to chlorpyrifos residues gave the ranking (from most to least susceptible) S. viridis>F. candida>Isotomurus palustris>Isotoma viridis. Residues on the sandy soil were more toxic than those on the sandy clay loam. These results are discussed in terms of how field bioassay approaches may be used to determine pesticide residual toxicity to microarthropods. We conclude that field bioassays offer a feasible method for evaluating the toxicity of pesticides and the persistence of toxic effects on Collembola. Advantages and disadvantages of this method are considered.