ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Hits per page

hits 1 - 5 | 5 hits

Sorting

Electronic Resource

‘Plantibodies’: a flexible approach to design resistance against pathogens (1992)

Schots, A. ; Boer, J. ; Schouten, A. ; [et al.]

Springer

European journal of plant pathology 98 (1992), S. 183-191

add to mindlist on the mindlist

Details

ISSN: 1573-8469

Keywords: Monoclonal antibodies ; single chain antibodies ; scFv ; potato cyst nematodes

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Engineering resistance against various diseases and pests is hampered by the lack of suitable genes. To overcome this problem we started a research program aimed at obtaining resistance by transfecting plants with genes encoding monoclonal antibodies against pathogen specific proteins. The idea is that monoclonal antibodies will inhibit the biological activity of molecules that are essential for the pathogenesis. Potato cyst nematodes are chosen as a model and it is thought that monoclonal antibodies are able to block the function of the saliva proteins of this parasite. These proteins are, among others, responsible for the induction of multinucleate transfer cells upon which the nematode feeds. It is well documented that the ability of antibodies to bind molecules is sufficient to inactivate the function of an antigen and in view of the potential of animals to synthesize antibodies to almost any molecular structure, this strategy should be feasible for a wide range of diseases and pests. Antibodies have several desirable features with regard to protein engineering. The antibody (IgG) is a Y-shaped molecule, in which the domains forming the tips of the arms bind to antigen and those forming the stem are responsible for triggering effector functions (Fc fragments) that eliminate the antigen from the animal. Domains carrying the antigen-binding loops (Fv and Fab fragments) can be used separately from the Fc fragments without loss of affinity. The antigen-binding domains can also be endowed with new properties by fusing them to toxins or enzymes. Antibody engineering is also facilitated by the Polymerase Chain Reaction (PCR). A systematic comparison of the nucleotide sequence of more than 100 antibodies revealed that not only the 3′-ends, but also the 5′-ends of the antibody genes are relatively conserved. We were able to design a small set of primers with restriction sites for forced cloning, which allowed the amplification of genes encoding antibodies specific for the saliva proteins ofGlobodera rostochiensis. Complete heavy and light chain genes as well as single chain Fv fragments (scFv), in which the variable parts of the light (VL) and heavy chain (VH) are linked by a peptide, will be transferred to potato plants. A major challenge will be to establish a correct expression of the antibody genes with regard to three dimensional folding, assembly and intracellular location.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01974485

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Identification and management of virulence genes in potato cyst nematodes (1992)

Gommers, F. J. ; Roosien, J. ; Schouten, A. ; [et al.]

Springer

European journal of plant pathology 98 (1992), S. 157-163

add to mindlist on the mindlist

Details

ISSN: 1573-8469

Keywords: Globodera rostochiensis ; G. pallida ; hybridoma ; PCR ; pathotypes ; RAPD ; 2D-gel electrophoresis ; virulence genes

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Efficient and accurate diagnostic assays are essential for the design and evaluation of control measures of the potato cyst nematodesGlobodera rostochiensis andG. pallida by means of resistance. The hybridoma technology and the polymerase chain reaction (PCR) offer in potential various possibilities to design such diagnostic tests for routine purposes. We set out to devise a refined advisory system based on biochemical assays by using the following stepwise approach. In the early 80's a research program was started to develop an immunoassay to differentiate the two sibling species of potato cyst nematodes. Species specific monoclonal antibodies were raised against nematode proteins which are thermostable, abundant and homologous, and which enable reliable species identification using single eggs. The second step to improve the management of virulence genes is aimed at discriminating groups of populations within a species (‘virulence groups’ or ‘pathotypes’). The concept is that the number of initial populations introduced from South America is limited and that numerous Dutch populations (‘secondary founders’) are closely related by descent. Biochemical characters revealed by two-dimensional gel electrophoresis (2-DGE) of polypeptides, PCR in combination with restriction enzyme digests and RAPD (Random amplified polymorphic DNA) will be used to delineate groups of populations. The final diagnostic assay will be based on PCR. One of the challenges will be to devise a manageable number of primers to recognize all distinct groups. The third research line is aimed at developing a PCR assay based on the virulence genes themselves. Genetic studies showed that virulence inG. rostochiensis towards the H1 resistance gene is inherited at a single locus and is recessive to avirulence. To identify molecular markers linked to the virulence gene, 300 virulent lines were selected via backcrossing the F1 (Aa) with the virulent (aa) parent line. Molecular differences between the parent lines were obtained by 2-DGE, RFLP's (restriction fragment length polymorphisms) and RAPD. Especially RAPD proved to be a valuable technique to construct a linkage map. Screening 80 primers (10-mer) resolved more than 120 markers. RAPD will eventually lead to flanking DNA sequences, which will be used to isolate and characterize the virulence gene. Sequence information of the virulence gene inG. rostochiensis for the H1 resistance gene can be used to devise primers for a PCR assay and may also provide a starting point to isolate other virulence genes.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01974482

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Specificity of polycllonal and monoclonal antibodies for the identification of Xanthomonas campestris pv. campestris (1992)

Franken, A. A. J. M. ; Zilverentant, J. F. ; Boonekamp, P. M. ; [et al.]

Springer

European journal of plant pathology 98 (1992), S. 81-94

add to mindlist on the mindlist

Details

ISSN: 1573-8469

Keywords: black rot ; serology ; sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) ; proteinase K

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Polyclonal and monoclonal antibodies (PCAs and MCAs), produced to whole cells and flagellar extracts ofXanthomonas campestris pv.campestris (Xcc), respectively, were tested for specificity. In immunofluorescence microscopy (IF) the three PCAs tested, reacted at low dilutions with all Xcc strains, some other xanthomonads and non-xanthomonads. At higher dilutions most cross-reactivity with non-xanthomonad strains disappeared. However, the cross-reactivity with strains ofX. c. pv.vesicatoria (Xcv),X. c. pv.amoraciae (Xca) andX. c. pv.phaseoli var. fuscans (Xcpf) remained. Six MCA-producing cell clones viz. 20H6, 2F4, 18G12, 10C5, 17C12 and 16B5 were selected for specificity tests with an enzyme immunoassay (EIA), IF and a dot-blot immunoassay (DBI). None of the MCAs reacted with all Xcc strains in IF and EIA. In DBI, only MCAs 17C12 and 16B5 reacted with all Xcc strains. All six MCAs tested, cross-reacted in one of either tests with other pathovars ofX. campestris, such as Xcv or Xca. The MCAs were also tested in immunoblotting experiments using total bacterial extracts, cell envelope and flagellar extracts. MCAs 20H6, 2F4, 18G12 and 10C5 reacted with the lipopolysaccharide (LPS) of Xcc. MCAs 16B5 and 17C12 reacted with a 39 kilodalton and a 29 kilodalton protein, respectively. It is concluded that the PCAs and MCAs discussed in this study may be used for routine identification and differentiation of (a group of) Xcc strains. The significance of the cross-reactions with other pathovars ofX. campestris needs to be determined by testing seed lots.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01996321

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Coordinate expression of antibody subunit genes yields high levels of functional antibodies in roots of transgenic tobacco (1994)

Engelen, Fred A. ; Schouten, Alexander ; Molthoff, Jos W. ; [et al.]

Springer

Plant molecular biology 26 (1994), S. 1701-1710

add to mindlist on the mindlist

Details

ISSN: 1573-5028

Keywords: Antibody ; coordinated expression ; genetic engineering ; protein assembly ; root ; secretion

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract To explore the feasibility of employing antibodies to obtain disease resistance against plant root pathogens, we have studied the expression of genes encoding antibodies in roots of transgenic plants. A model monoclonal antibody was used that binds to a fungal cutinase. Heavy and light chain cDNAs were amplified by PCR, fused to a signal sequence for secretion and cloned behind CaMV 35S and TR2′ promoters in a single T-DNA. The chimeric genes were cloned both in tandem and in a divergent orientation. The roots of tobacco plants transformed with these constructs produced antibodies that were able to bind antigen in an ELISA. Immunoblotting showed assembly to a full-size antibody. In addition, a F(ab′)2-like fragment was observed, which is probably formed by proteolytic processing. Both antibody species were properly targeted to the apoplast, but the full-size antibody was partially retained by the wall of suspension cells. The construct with divergent promoters showed a better performance than the construct with promoters in tandem. It directed the accumulation of functional antibodies to a maximum of 1.1% of total soluble protein, with half of the plants having levels higher than 0.35%. The high efficiency of this construct probably results from coordinated and balanced expression of light and heavy chain genes, as evidenced by RNA blot hybridization.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00019485

Permalink