盐胁迫下小麦甜菜碱和脯氨酸含量变化

运用高效液相色谱-质谱(HPLC-MS)联用技术分析了耐盐性强、中、弱3个小麦品种SW12、宁春4号和中国春苗期5个NaCl浓度胁迫下甜菜碱和脯氨酸含量的变化.方差分析表明盐胁迫下3个小麦品种之间甜菜碱的含量差异达到极显著水平(P＜0.01),SW12的含量最高,宁春4号次之,中国春最低,与小麦耐盐性表现相一致;脯氨酸在叶片中的含量差异不显著,在根中宁春4号和中国春的含量有显著差异(P＜0.05).结果表明:小麦叶和根中甘氨酸甜菜碱含量与小麦盐胁迫呈正相关,是小麦体内抵御盐胁迫的渗透调节物质之一,可作为小麦耐盐性鉴定指标.     

Screening proteins interacting with VpPR10.1 of Chinese wild grapevine using the yeast two-hybrid system

Among the 17 plant pathogenesis-related (PR) protein families, only PR10 family is intracellular and cytosolic. PR proteins are expressed in response to pathogen challenge and abiotic stresses in higher plants. However, the molecular mechanisms of their actions remain poorly understood. In a previous work, we isolated a PR10 gene from Erysiphe necator-resistant Chinese wild Vitis sp. (Baihe-35-1) and it was designated as VpPR10.1. In this study, yeast two-hybrid method was used to screen proteins interacting with VpPR10.1 proteins. Twenty-one ESTs were isolated and sequenced. All sequences were compared using BLASTx to identify presumptive orthologs. Several proteins associated with VpPR10.1 protein were screened, including CNR8, UFGT6, HSP, DEAD-box, Trx h2, Grx C9 and GLOX. These proteins are closely related to defensive action of plants against pathogens and abiotic stresses. Our results reveal that VpPR10.1 gene may be involved in hormone signaling, programmed cell death and defense responses of grapevine.     

抑前胸腺肽在家蚕体内的活性作用

家蚕Bombyx mori抑前胸腺肽是昆虫脑神经肽的一种,体外实验表明它能抑制处于活动时期的家蚕前胸腺合成蜕皮激素,因此抑前胸腺肽可能对昆虫的变态起着重要的作用。将抑前胸腺肽以不同的浓度分单一注射和加强注射导入家蚕体内,不同的时间间隔取样,利用蜕皮激素放射免疫分析方法,观察到了抑前胸腺肽在家蚕体内的活性作用以及引起家蚕体内血淋巴中蜕皮激素浓度的动态变化,首次证明了抑前胸腺肽在体内对家蚕前胸腺合成蜕皮激素有强烈的抑制作用。     

转Cry1Ac活性杀虫蛋白及慈菇蛋白酶抑制剂B基因的棉花

根据植物基因的结构特征。合成了Cry1Ac活性杀虫蛋白的编码序列并与内质网定位肽编码序列组成嵌合杀虫蛋白基因Bt29K。构建了含Bt29K基因及慈菇蛋白酶抑制剂B（API-B）基因表达框的双抗虫基因植物表达载体。通过根癌土壤杆菌（Agrobacterium trmefaciens(Smith et TOwnsend)ConnLBA4404)介导转化了棉花（Gossypium hirsu-tunL.)的两个生产品种（系）。根据抗棉铃虫（Heliothis armigera)试验及农艺性状的观察调查结果。经6代筛选,获得了抗棉铃虫90.0%_99.7%且农艺性状优良的9个双价抗虫棉纯合品系。分子生物学分析结果表明,两个抗虫基因在棉花基因组中的插入拷贝数为1个或2个,活性Cry1Ac和API-B蛋白在转基因抗虫棉株系中的表达量分别约占总可溶性蛋白的0.17%和0.09%。对双抗纯合系植株及仅转Bt基因的棉花纯合系抗虫性检测结果表明前者的抗虫性明显高于后者,因此推断本研究采用的双抗虫基因表达载体构建策略是合理的。     

大白菜新型细胞质雄性不育系6w-9605A的育性鉴定和花药败育的细胞学观察

采用石蜡切片技术,研究了大白菜(Brassica campestris L.ssp.pekinensis)细胞质雄性不育系6w-9605A及其保持系6w-9605B的花药发育过程的细胞形态学特征,确定不育系花药败育时期及方式,并对不育系6w-9605A进行花器官观察和育性鉴定.结果表明:保持系6w-9605B花药发育正常;不育系6w-9605A花药发育受阻于孢原分化时期,占总败育花药的66.7％,不形成花粉囊和花粉粒,属于无花粉囊型败育;另外33.3％的败育花药可形成花粉囊,小孢子均受阻于单核靠边期或者二胞期,败育特点为绒毡层细胞异常肥大,挤压小孢子,导致小孢子和绒毡层解体;6w-9605A的不育性稳定、彻底,不育株率和不育度均为100％.     

抑前胸腺肽在家蚕体内的活性作用

家蚕Bombyx mori抑前胸腺肽是昆虫脑神经肽的一种,体外实验表明它能抑制处于活动时期的家蚕前胸腺合成蜕皮激素,因此抑前胸腺肽可能对昆虫的变态起着重要的作用。将抑前胸腺肽以不同的浓度分单一注射和加强注射导入家蚕体内,不同的时间间隔取样,利用蜕皮激素放射免疫分析方法,观察到了抑前胸腺肽在家蚕体内的活性作用以及引起家蚕体内血淋巴中蜕皮激素浓度的动态变化,首次证明了抑前胸腺肽在体内对家蚕前胸腺合成蜕皮激素有强烈的抑制作用。     

AFLP─一种DNA分子标记新技术

AFLP──ANovelTechniqueforDNAMolecularMarkerWengYuejin(InstituteofCropGermplasmResourees,ChineseAcademyofAgriculturalSciences,Beijing100081)公司科学家ZabeauMarc和VosPieter发明创建的一种DNA分子标记新技术,它不仅具备了其它DNA分子标记技术所具有的特点,多态性丰富,共显性表达,不受环境影响,无复等位效应,而且还具有带组丰富,用样量少,灵敏度高,快速高效等特殊优点．一个0．5mgDNA样品,可做4000个反应,获得8万个标记,650万条带纹。美国加利福尼亚大学MackillDavid[7]利用14份水稻为材料,比较AF…     

Preparation and mechanical properties of chitosan/carbon nanotubes composites

Biopolymer chitosan/multiwalled carbon nanotubes (MWNTs) nanocomposites have been successfully prepared by a simple solution-evaporation method. The morphology and mechanical properties of the chitosan/MWNTs nanocomposites have been characterized with field emission scanning electron microscopy (SEM), bright field transmission electron microscopy (TEM), optical microscopy (OM), wide-angle X-ray diffraction (XRD), and tensile as well as nanoindentation tests. The MWNTs were observed to be homogeneously dispersed throughout the chitosan matrix. When compared with neat chitosan, the mechanical properties, including the tensile modulus and strength, of the nanocomposites are greatly improved by about 93% and 99%, respectively, with incorporation of only 0.8 wt % of MWNTs into the chitosan matrix.     

Enhanced enzymatic saccharification of rice straw by microwave pretreatment

In this study, Box-Behnken design and response surface methodology were employed to plan experiments and optimize the microwave pretreatment of rice straw. Experimental results show that microwave intensity (MI), irradiation time (IT) and substrate concentration (SC) were main factors governing the enzymatic saccharification of rice straw. The maximal efficiencies of cellulose, hemicellulose and total saccharification were respectively increased by 30.6%, 43.3% and 30.3% under the optimal conditions of MI 680 W, IT 24 min and SC 75 g/L. The chemical composition analysis of straw further confirmed that microwave pretreatment could disrupt the silicified waxy surface, break down the lignin-hemicellulose complex and partially remove silicon and lignin.     

耐辐射球菌pprI在大肠杆菌中表达增强细胞抗氧化能力的研究

将耐辐射球菌(Deinococcus radiodurans)与DNA修复有关的开关基因—pprI通过穿梭质粒pRADZ3导入大肠杆菌TG1中,使其在正常培养条件下(不需诱导剂)表达PprI蛋白,并通过Western blot证实该基因在TG1中可稳定表达。与转化了空白质粒pRADZ3 TG1对照,观察了改造后的两种大肠杆菌在有H2O2氧化压力下的存活率和大肠杆菌中两种过氧化氢酶（KatE, KatG）的活性表达差异。结果表明,无论在指数生长期还是稳定生长期,能表达PprI蛋白的大肠杆菌比对照的存活率要高出10％左右;非变性电泳结果表明,耐辐射球菌pprI 在大肠杆菌中的表达使得KatE活性在指数生长期与稳定生长期分别增加1.5～2倍和2.5～3倍。证明耐辐射球菌pprI 在大肠杆菌中的表达能够增强细胞抗氧化能力。