摘要:

The concept and practice of “molecular farming” that is the production of specialty protein products in plants is critically reviewed. The major questions pertaining to such applications were identified as being: 1. Which kinds of proteins lend themselves readily to plant-based expression systems? 2. Which plants are most amenable at this time? 3. In which tissues or organs would expression be most efficient? 4. What approaches are available to purify the recombinant proteins? Each of these questions is addressed by means of several examples and some tentative conclusions are drawn. I appears likely that the first products that will emerge from this work will be seed-borne traits which require little or no purification. As purification systems are developed or improved, this will open up the possibility of a wide variety of uses for this technology which should be competitive with traditional fermentation methods. The most sensitive areas for discovery and innovation are delineated and discussed.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818814

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

A comparative examination in vitro of the morphogenetic characteristics of two cultivars and one candidate-cultivar of white clover (Trifolium repens L.) was carried out. Callus cultures were initiated from hypocotyl and cotyledon's tissues on five nutrient culture media. Embryo-like structures were generated in callus cultures only induced on MS nutrient medium containing 2 mg/l 2,4-D, 0.2 mg/l kinetin and 1 mg/l adenine. This medium turned out expediently balanced as for callus tissue initiation as well as for somatic embryoide induction. The complete development of differentiated structures to a plant was effectuated on MS culture medium with addition of 0.2 mg/l 2,4-D and 1 mg/l kinetin. In some of the obtained regenerants morphological deviations were established.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818815

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

The soft rot bacterium Erwinia carotovora subspecies carotovora strain EC14 contains multiple pectate lyase genes. Genes pel9.5 and pel10.5, coding for pectate lyases (pI 9.5 and 10.5), were cloned on a plasmid, transformed into Escherichia coli, and expressed catalytically active products. The isoenzymes were subcloned separately and sequenced. Along most of their lengths, the genes are homologous to each other and to the pelBC family of Erwinia extracellular pectate lyase genes. However, the amino acid sequence of the Pel10.5 carboxy-terminus diverges markedly from the PelBC consensus. We constructed hybrid genes and their products were found to be pectolytic. The pel9.5 and pel10.5 genes were mutagenized by marker exchange mutagenesis. A double mutant, pel9.5−pel10.5−, was obtained by mobilization of pLA115 into the pel10.5::kan mutant and exchange recombination by the above method. Hybridization of EcoRI digests of the mutant chromosomal DNAs with pel9.5-, pel10.5-, kan-, and tet-specific probes gave profiles consistent with single-site insertions of the kan and tet genes in the corresponding pel genes. In planta accumulation of Pel9.5 and Pel10.5 mRNAs way induced within 3 to 4 hr after inoculation, reaching maxima between 6 and 12 hr with Pel10.5 peaking at 6 hr and Pel9.5 at 9 hr. The induction of the two genes was regulated differentially and the level of their mRNAs was higher during compatible than during incompatible conditions. The three mutants, obtained here, especially the double mutant, have diminished virulence compared to the wild type.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818816

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

Transformation of three potato cultivars (Desiree, Isola and Anaç) was achieved using tuber discs and callus tissue derived from cultured stems via co-cultivation with Agrobacterium tumafaciens Ti plasmid based vectors. Neomycin phosphotransferase (NPT II) marker andβ-glucuronidase (GUS) reporter genes were used in transfer-optimization studies. First selection of transgenics was done on selective Murashige and Skoog (MS) media containing 100 mg/l kanamycin and 500 mg/l cefotaxime. Histochemical assays were done for GUS activity using X-Gluc substrat. In addition polymerase chain reaction based Southern blot analyses revealed the existence of the transferred genes. The highest transformation frequency (10%) was obtained with cultivar Desiree in MS media supplied with 5 mg/l zeatin riboside and 1.5 mg/l indolacetic acid. However, Anaç gave the lowest frequency using tuber discs (3%) and stem explants (2%). This protocol could be useful for the improvement of potato through gene manipulation.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818817

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

The polymorphism of seven enzyme systems in plum (Prunus domestica) was analyzed by vertical polyacrilamide gel electrophoresis in two different somatic tissues, bark and leaves. Variation among the studied plum cultivars was observed in Peroxidase. Interspecific hybrids between plum and apricot exhibited Aspartate aminotranspherase pattern with bands from both parents. This enzyme system my be used for plum x apricot interspecific hybrid identification.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818818

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

This paper describes the results of trials carried out with a selected isolate of Bacillus cereus which was applied to tobacco seedlings (treatment of roots) in order to assess its effect as a potential tool for black-shank disease control in artificially infected soil. The roots of tobacco plants from several cultivars known to possess different levels of resistance to Phytophthora parasitica var.nicotianae, race O, were pretreated with either bacterial suspension or culture filtrate of B. cereus and then transplanted into soil infected by zoospores and mycelium from the fungus. The experiments were conducted under controlled conditions favouring the induction of disease symptoms. The data were expressed in terms of percentage of surviving tobacco plants. The isolate of B. cereus provided significant and durable protection against black shank disease. The data suggest the potential of B. cereus as an efficient agent in the biological control of black shack disease.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818819

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

T0and T1transgenic tobacco and alfalfa plants expressing the gene coding for β-interferon driven by 1′ - 2′ promoter are assayed for resistance respectively to TMV and AIMV. Marked delay of symptoms development of virus infection is detected in both transgenic tobacco and alfalfa plants These studies indicate that interferon accumulation in transgenic plants alters their reaction to virus infection. The influence of environmental conditions on transgene expression (transgenic plants tolerance to virus infection) is discussed in connection with the bidirectional 1′ - 2′ promoter.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818820

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

Fertile kanamycin resistant plants of Medicago sativa L. were obtained by genetic transformation with binary vector of Agrobacterium tumefaciens and were used as a fertilizer of Lethionine (ETH) resistant alfalfa variants. The dominant nature of both kanamycin and Lethionine resistant traits was demonstrated by the double resistant phenotype of obtained hybrid plants. Southern blot analysis showed that transgenic plants and self-pollinated progeny harbored the kanamycin gene, and expressed the neomycin phosphotransferase (npt) activity in vitro. The inheritance of both single (kanamycin) and double (kanamycin and Lethionine) resistance traits was analyzed and the way in which marker characters are segregated is discussed.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818821

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

Twelve bovine embryos flushed from cows of the endangered native Bulgarian breed Rhodope's Short-Horn Cattle were frozen and stored in a cryobank at -196°C. The methods for production, recovery and deep-freezing of the embryos are described. The potential applications of embryo freezing biotechnology in animal science and stock-breeding as well as the possibility for a long-term storage are discussed.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818822

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor

摘要:

Two steps of enhancement of phenol detoxification by Bacillus laterosporus BT-271 by means of increasing of the rate of aeration and adding in an apropriate moment a carrier (penopolystyrol pellets, covered with active carbon) were studied. The effectiveness of phenol biodegradation was enhanced with 42 %. Comparative study of the oxygenase activities of the freely suspended cells at the two steps of speeding up of the phenol elimination to elucidate the mechanisms of the processes was carried out.

ISSN:1310-2818    

DOI:10.1080/13102818.1995.10818823

出版商:Taylor & Francis    

年代:1995

数据来源: Taylor