Wx蛋白缺失对水稻颖果和剑叶生理活性的影响

以转反义Wx基因粳稻和籼稻为材料的研究结果表明，直链淀粉含量降低后的转基因水稻颖果的光合和呼吸活性在发育前期显著高于亲本，但下降较快，到了发育中期(花后15~18 d)以后，就低于同期的亲本。但其SOD和CAT活性比其亲本下降得慢，从花后9 d开始一直保持着比亲本高的水平。花后转基因水稻剑叶的叶绿素含量、光合速率和SOD     

Generation of White Flowers by Transgenic Approach

Flower color is one of the most attractive characteristics in ornamental plants, contributing to the major value in the floricultural market. Anthocyanins are a major colored class of flavonoids that are responsible for the pink, red, violet and blue colors of flowers and other tissues. Chalcone synthase （CHS; EC 2.3.1.74） is a key enzyme in anthocyanin biosynthesis. We have cloned a full-length cDNA （1 170 bp） encoding CHS from a Petunia cDNA library of violet flower. DNA sequence analysis showed 85%-92% identity with other chs sequences from higher plants including tobacco （91%）. Accumulation of the chs mRNA was found in flowers but not in leaves or roots of Petunia plants. As a first step in engineering of flower color, the gus reporter gene in the binary vector pBI121 was replaced by the Petunia chs cDNA, and a sense chs construct （pCHS） was obtained. The expression vector pCHS containing Petunia chs cDNA under the control of CaMV 35S promoter was then transformed into tobacco via Agrobacterium-mediated method. Southern blot analysis and T1 progeny assay suggested the presence of one or two copies of transgene in seven transgenic tobacco plants we obtained.     

转基因小麦目标基因通过花粉漂流的可能性研究

以去雄小麦为受体，在10m范围内小麦花粉可在任何方向发生有效漂移（使受体结实），花粉的最远有效漂移距离可达80m，以不去雄的小麦、柱穗山羊草和卵穗山羊草为受体时，在距花粉源1m的范围内，小麦间的异交率最高为0.24%、小麦与柱穗山羊草和卵穗山羊草间的异交率分别为0.25%和0，花粉的最远有效漂移距离可达20m。依照欧盟的标准，非转基因小麦即使与转基因品种相邻种植，其产品中的转基因成分也不会超标，在麦类近缘野生植物的起源中心及主要分布区，释放转基因小麦要特别慎重。     

转基因番茄有效铁及Vc含量的研究

培育高铁和高VC品种对减少人类贫血,提高人体免疫力有重要意义。试验测定了7种转基因番茄有效铁和VC含量变化。结果显示,转铁还原酶FRO2基因番茄(TFRO2)叶片有效铁含量是对照的1.44倍,是转反义ACS基因番茄F1-3的2倍。TFRO2果实有效铁含量是对照的1.5～1.6倍。青果中TFRO2番茄VC含量最高,是对照的1.3倍。其次是F1、F2、F3基因型。红果中TFRO2和F3VC含量最高、是对照的1.5倍,其次是F1-3、F2、F1′-28、NR。叶片中TFRO2和F2番茄的VC含量最高,是对照的1.4倍。     

Binding of an insecticidal transgene product to soil: Biological activity of soil-bound avidin and the effects of time and microbial activity

The insecticidal effects of avidin fed in artificial diet either unbound or bound to one of two New Zealand soils (a sandy loam and a clay soil), on a lepidopteran pest insect, Epiphyas postvittana were investigated. Immediately after binding of avidin to soil, 70-75% of the avidin retained the ability to bind biotin. Both soil-type and duration of incubation after binding of avidin to the soil markedly affected its insecticidal activity. After 6 months incubation, residual activity of avidin in the sandy loam sample had been almost completely lost, whereas some insecticidal activity was still present in the clay sample. Loss of activity of avidin did not correlate with the numbers of culturable bacteria in the two soil types nor did the presence of avidin affect the number or type of culturable bacteria present in soil. The concentration of avidin at which insecticidal effects were observed was conservatively estimated at approximately 100-fold higher than that expected in the field, based on known expression levels in insecticidal plants.     

脉冲场凝胶电泳技术及应用

脉冲场凝胶电泳(PFGE)是一种重要的用于分离大分子量线状DNA的电泳技术。介绍了PFGE的基本原理、方法、影响因素,并对其在微生物分子分型、DNA辐射损伤修复、细胞凋亡和转基因技术等研究方面的应用作了简要的综述。     

抗纹枯病、赤霉病的转TaPIEP1基因小麦的分子鉴定与选育

小麦纹枯病(主要病原为禾谷丝核菌)和赤霉病(主要病原为禾谷镰刀菌)已成为我国小麦生产的重要病害。TaPIEP1是从小麦中分离到的1个病原诱导的基因,其编码蛋白是可与GCC-box顺式元件结合、转录激活型的ERF转录因子。本研究以8个转TaPIEP1基因小麦株系的T₄和T₅代植株为试材,进行了外源转TaPIEP1基因的PCR检测、Southern杂交、RT-PCR与Q-RT-PCR的分析以及纹枯病菌、赤霉病菌接种与抗性鉴定。结果表明,外源TaPIEP1基因在转基因小麦中能够稳定遗传,以单拷贝或双拷贝整合到7个转基因小麦株系基因组的不同位点;外源TaPIEP1基因在转基因小麦中能超量表达;与受体扬麦12相比,TaPIEP1表达水平高的8个转基因小麦株系对纹枯病抗性显著提高,4个株系中一些材料对赤霉病抗性显著提高,3个株系中一些材料兼抗纹枯病和赤霉病,说明TaPIEP1正向参与了小麦对纹枯病和赤霉病抗性反应,利用该基因通过基因工程可创制抗纹枯病、赤霉病的小麦新种质。     

植物核糖核酸酶与转基因工程雄性不育系研究进展

核糖核酸酶(Ribonuclease,RNase)的全名为聚核苷-#-寡核苷酸转移酶,它在植物体内分布广泛,是降解RNA的一类酶的总称。它与植物的衰老、抗逆、自交不亲和、植物雄性不育有密切关系。另一方面,当将从烟草、水稻中分离出的TA29和OsgB6等花药绒毡层及花粉特异启动子与核糖核酸酶基因(barnase)构建成嵌合基因,转移给正常油菜、烟草、番茄、小麦、水稻等植株时,又会产生雄性不育。因此,植物核糖核酸酶的研究日益受到人们的广泛关注。     

转DREB基因小麦新品系抗旱生理指标测定

脱水应答元件结合蛋白(DREB)基因的应用,为培育抗旱转基因小麦新品种奠定了重要基础。本试验对在旱地和水地上种植的6个转GmDREB1和GhDREB基因的转基因小麦新品系旗叶中可溶性糖和脯氨酸进行了提取与测定,结果显示转基因小麦新品系旗叶中的可溶性糖及脯氨酸含量较其受体品种有所提高,证明抗旱转录因子基因的导入可提高受体小麦品种的抗旱性。     

正义、反义、干涉调控肉桂酰辅酶A脱氢酶基因对烟草的影响

肉桂酰辅酶A还原酶(Cinnamoyl-CoA reductase,CCR)是在木质素合成途径中起到关键作用的酶,负责催化肉桂酰辅酶A类物质的还原反应生成相应的醛类化合物.分离得到毛白杨CCR基因的cDNA.将CCR基因以正义、反义和干涉的形式,通过农杆菌介导的方法转入烟草中,Southem杂交以确定转基因成功.在获得的转基因植株中,所有下调基因的植株都表现出可溶性酚酸含量下降,木质素含量也有明显的下降趋势,纤维素含量则有上升,可能是对木质素含量下降的一种代偿性增长.植物细胞壁组分的含量变化表明CCR基因可能是一个控制木质素代谢途径的一个很好的调控点.