伊贝母愈伤组织细胞内微管网络的免疫学观察

通过解聚－聚合循环过程纯化鸡脑蛋白,免疫家兔得到抗血清。采用免疫酶标技术显示出伊贝母愈伤组织细胞内的微管网络。用１％Ｔ ｒｉｔｏｎＸ－１００洗去细胞内其它成分,用８％ＮａＮ３消除内源过氧化物酶活性。实验结果提出了一种显示植物细胞内微管网络的方法。     

白浆土－植物系统营养物质转化机制及其有效性研究——Ⅰ．32P同位素示踪法对白浆土中P肥利用率

利用³²P同位素示踪法对白浆土中P肥利用率进行了研究.结果表明,在岗地白浆土上,表层土壤表现出一定程度的供P不足现象,白浆层土壤有效P含量严重缺乏.表层土壤中当季P肥利用率的变幅范围为6.09～12.35%,白浆层土壤P肥利用率为13%左右.施用有机肥能明显提高白浆土Olsen P的含量,加速土壤本身P的活化,各种有机物中,以猪粪对土壤潜在P的活化效果最好.将Olsen P与X值、A值比较,认为Olsen P是评价白浆上P肥力简便易行的可靠指标.     

Enhanced resistance to stripe rust disease in transgenic wheat expressing the rice chitinase gene RC24

Stripe rust is a devastating fungal disease of wheat worldwide which is primarily caused by Puccinia striiformis f. sp tritici. Transgenic wheat (Triticum aestivum L.) expressing rice class chitinase gene RC24 were developed by particle bombardment of immature embryos and tested for resistance to Puccinia striiformis f.sp tritici. under greenhouse and field conditions. Putative transformants were selected on kanamycin-containing media. Polymease chain reaction indicated that RC24 was transferred into 17 transformants obtained from bombardment of 1,684 immature embryos. Integration of RC24 was confirmed by Southern blot with a RC24-labeled probe and expression of RC24 was verified by RT-PCR. Nine transgenic T₁ lines exhibited enhanced resistance to stripe rust infection with lines XN8 and BF4 showing the highest level of resistance. Southern blot hybridization confirmed the stable inheritance of RC24 in transgenic T₁ plants. Resistance to stripe rust in transgenic T₂ and T₃ XN8 and BF4 plants was confirmed over two consecutive years in the field. Increased yield (27–36 %) was recorded for transgenic T₂ and T₃ XN8 and BF4 plants compared to controls. These results suggest that rice class I chitinase RC24 can be used to engineer stripe rust resistance in wheat.     

Production of biologically active human interleukin-4 in transgenic tobacco and potato

Interleukin-4 (IL-4) is a pleiotropic cytokine that plays a key regulatory role in the immune system. Recombinant human IL-4 (rhIL-4) offers great potential for the treatment of cancer, viral and autoimmune diseases. Unfortunately, the high production cost of IL-4 associated with conventional expression systems has, until now, limited broader clinical testing, particularly with regard to the more convenient and safer oral delivery of IL-4 as opposed to parenteral injection in patients. In this study, we investigated the feasibility of transgenic plants for the cost-effective production of rhIL-4. IL-4 expression vectors with different modifications under the control of a constitutive cauliflower mosaic virus 35S (CaMV 35S) promoter were introduced into tobacco by Agrobacterium-mediated transformation. Transgenic tobaccos expressing various levels of rhIL-4 protein were generated. Higher expression was achieved through IL-4 retention in the endoplasmic reticulum (ER), with the maximal accumulation being approximately 0.1% of total soluble protein (TSP) in the leaves. No improvement in expression was further achieved by replacing the native signal peptide of IL-4 with the plant signal peptide. The best rhIL-4-expressing vector shown in tobacco was selected and further transferred into potato plants. The analysis of transgenic tubers also revealed various levels of rhIL-4, with the highest being 0.08% of TSP. Sensitive in vitro T-cell proliferation assays showed that plant-derived rhIL-4 retained full biological activity. These results suggest that plants can be used to produce biologically active rhIL-4 and probably many other mammalian proteins of medical significance. Moreover, the production of plants expressing rhIL-4 will enable the testing of plant rhIL-4 by oral delivery for the treatment of clinical diseases.     

拟南芥新型脂转移蛋白AtDHyPRP1的亚细胞定位及其对灰霉菌的抗性

通过遗传转化技术研究了拟南芥脂转移蛋白AtDHyPRP1在细胞中的定位及其对真菌病原体的抗性。采用PCR方法从拟南芥Ws生态型克隆了AtDHyPRP1基因,构建产生pRI101-AN-AtDHyPRP1植物双元表达载体和pCAMBIA1302-AtDHyPRP1-GFP融合表达载体,经农杆菌介导的叶盘和浸花法得到烟草和拟南芥转基因植株。AtDHyPRP1基因能够明显增加烟草对灰霉菌的抗性,转AtDHyPRP1烟草叶片的被侵染部位有大量H2O2积累,激光共聚焦显微观察发现AtDHyPRP1蛋白定位于细胞表面。说明AtDHyPRP1蛋白在合成后被分泌到细胞外执行特殊的功能,与植物抗病防御机制有关。     

沙冬青愈伤组织对培养基的特殊要求和球形胚状分化结构的诱导

通过对沙冬青未成熟子叶进行离体培养,获得了愈伤组织。基本培养基采用Ｂ５,再配合ＭＳ培养基的铁盐成分,对沙冬青未成熟子叶愈伤组织的诱导和生长效果最佳。愈伤组织的诱导和生长对培养基的附加成分要求十分严格,２,４－Ｄ浓度为０．５ｍｇ／Ｌ,６－ＢＡ浓度为０．５ｍｇ／Ｌ,蔗粮不宜超过２％。愈伤组织最初为乳白色透明松散状态,生长比较缓慢,极易褐化死亡。如果培养基中的蔗糖浓度低于２％,两周后未成熟子叶愈伤组织逐     

Preparation and characterization of surface crosslinked TPS/PVA blend films

Surface crosslinked thermoplastic starch (TPS)/PVA blend films were prepared by applying ultra violet (UV) irradiation. Sodium benzoate was used as photosensitizer and induced onto film surface layer by soaking the TPS/PVA films in the photosensitizer aqueous solution. The effects of concentration of photosensitizer aqueous solution, soaking time and UV irradiation dose on the surface photocrosslinking reaction were investigated. Physical properties, such as water contact angle, moisture absorption, swelling degree and solubility in water as well as mechanical properties of the films were measured to characterize the influence of the surface photocrosslinking modification. The obtained results showed that the surface modification considerably reduced the surface hydrophilic character of the TPS/PVA films, enhanced the film’s water resistance and also increased tensile strength and Young’s modulus but decreased elongation at break of the films.     

白浆土植物系统营养物质转化机制及其有效性研究Ⅴ.有机物对磷根际有效性的影响

采用根盒试验研究了施用紫花苜蓿腐解物对白浆土小麦根际Ｐ 素形态转化、有效性及小麦植株Ｐ 素吸收的影响．结果表明,施用有机物料使土壤有效磷显著上升,铝磷、铁磷含量也显著升高,且培养时间越长,效果越明显．小麦植株含Ｐ 量明显上升,且与非根际土壤铝磷、铁磷的变化显著相关