PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Plant Immunity”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed2003

Echinacea powder: treatment for canine chronic and seasonal upper respiratory tract infections.

An open multi-centered veterinary clinical trial, comparing conditions before and after treatment with a herbal preparation, containing the powdered root of Echinacea purpurea, was conducted by 6 practicing veterinarians in Switzerland. The plant-based immune stimulant was administered to 41 dogs with manifestations of chronic and seasonal upper respiratory tract infections, including pharyngitis/tonsillitis, bronchitis and kennel cough. Each animal was at an individual stage of the disease, with various symptoms and different severity scores, at start of treatment. There was no control group. Echinacea powder (1:3) was administered with the food at a dose of 1.0 g/10 kg body weight once daily for 8 weeks. Overall efficacy showed significant improvement for 92% of 39 dogs after 4 weeks of treatment and this was confirmed after 8 weeks. Significant reductions of severity and resolution of typical clinical symptoms, of clear nasal secretions, enlargement of lymph nodes, dry cough, dyspnea and dry lung sounds, were evident after 4 weeks. Only two adverse effects, not suspected to be attributable to the study drug, were recorded. Because quality and stability of the Echinacea powder were defined, using an analytical standard and purity tests, these data suggest, that the Echinacea preparation can be recommended as a well tolerated alternative treatment of canine upper respiratory tract infections.

Animals↗
PubMed1986

[Isolation of antibodies against soy protein from the eggs of immunized laying hens].

The authors report on their experiences with immunization of laying hens with alpha-, alpha'- and beta-conglycinin, and on the isolation of specific antibodies from the yolks. Activity and specificity of the immunoglobulins were tested by an enzyme-linked immuno sorbent assay (ELISA). This method of antibody production proved to be very convenient, especially in regard to the high yield of antibodies and the easy handling of the animals. The necessity of using specific antisera for quantitative immunoassays is pointed out.

Animals↗
PubMed1995

Genetic and physical characterization of the LR1 leaf rust resistance locus in wheat (Triticum aestivum L.).

The objective of this study was to characterize the leaf rust resistance locus Lr1 in wheat. Restriction fragment length polymorphism (RFLP) analysis was performed on the resistant line Lr1/6* Thatcher and the susceptible varieties Thatcher and Frisal, as well as on the segregating F2 populations. Seventeen out of 37 RFLP probes mapping to group 5 chromosomes showed polymorphism between Lr1/6* Thatcher and Frisal, whereas 11 probes were polymorphic between the near-isogenic lines (NILs) Lr1/6* Thatcher and Thatcher. Three of these probes were linked to the resistance gene in the segregating F2 populations. One probe (pTAG621) showed very tight linkage to Lr1 and mapped to a single-copy region on chromosome 5D. The map location of pTAG621 at the end of the long arm of chromosome 5D was confirmed by the absence of the band in the nulli-tetrasomic line N5DT5B of Chinese Spring and a set of deletion lines of Chinese Spring lacking the distal part of 5DL. Twenty-seven breeding lines containing the Lr1 resistance gene in different genetic backgrounds showed the same band as Lr1/6* Thatcher when hybridized with pTAG621. The RFLP marker was converted to a sequence-tagged-site marker using polymerase chain reaction (PCR) amplification. Sequencing of the specific fragment amplified from both NILs revealed point mutations as well as small insertion/deletion events. These were used to design primers that allowed amplification of a specific product only from the resistant line Lr1/6* Thatcher. This STS, specific for the Lr1 resistance gene, will allow efficient selection for the disease resistance gene in wheat breeding programmes. In addition, the identification of a D-genome-specific probe tightly linked to Lr1 should ultimately provide the basis for positional cloning of the gene.

Alleles↗
PubMed2004

Full-genome analysis of resistance gene homologues in rice.

The availability of the rice genome sequence enabled the global characterization of nucleotide-binding site (NBS)-leucine-rich repeat (LRR) genes, the largest class of plant disease resistance genes. The rice genome carries approximately 500 NBS-LRR genes that are very similar to the non-Toll/interleukin-1 receptor homology region (TIR) class (class 2) genes of Arabidopsis but none that are homologous to the TIR class genes. Over 100 of these genes were predicted to be pseudogenes in the rice cultivar Nipponbare, but some of these are functional in other rice lines. Over 80 other NBS-encoding genes were identified that belonged to four different classes, only two of which are present in dicotyledonous plant sequences present in databases. Map positions of the identified genes show that these genes occur in clusters, many of which included members from distantly related groups. Members of phylogenetic subgroups of the class 2 NBS-LRR genes mapped to as many as ten different chromosomes. The patterns of duplication of the NBS-LRR genes indicate that they were duplicated by many independent genetic events that have occurred continuously through the expansion of the NBS-LRR superfamily and the evolution of the modern rice genome. Genetic events, such as inversions, that inhibit the ability of recently duplicated genes to recombine promote the divergence of their sequences by inhibiting concerted evolution.

Amino Acid Sequence↗
PubMed2006

Development of simple sequence repeat markers specific for the Lr34 resistance region of wheat using sequence information from rice and Aegilops tauschii.

Hexaploid wheat (Triticum aestivum L.) originated about 8,000 years ago from the hybridization of tetraploid wheat with diploid Aegilops tauschii Coss. containing the D-genome. Thus, the bread wheat D-genome is evolutionary young and shows a low degree of polymorphism in the bread wheat gene pool. To increase marker density around the durable leaf rust resistance gene Lr34 located on chromosome 7DS, we used molecular information from the orthologous region in rice. Wheat expressed sequence tags (wESTs) were identified by homology with the rice genes in the interval of interest, but were monomorphic in the 'Arina' x 'Forno' mapping population. To derive new polymorphic markers, bacterial artificial chromosome (BAC) clones representing a total physical size of approximately 1 Mb and belonging to four contigs were isolated from Ae. tauschii by hybridization screening with wheat ESTs. Several BAC clones were low-pass sequenced, resulting in a total of approximately 560 kb of sequence. Ten microsatellite sequences were found, and three of them were polymorphic in our population and were genetically mapped close to Lr34. Comparative analysis of marker order revealed a large inversion between the rice genome and the wheat D-genome. The SWM10 microsatellite is closely linked to Lr34 and has the same allele in the three independent sources of Lr34: 'Frontana', 'Chinese Spring', and 'Forno', as well in most of the genotypes containing Lr34. Therefore, SWM10 is a highly useful marker to assist selection for Lr34 in breeding programs worldwide.

Alleles↗
PubMed2006

Genetic mapping of two powdery mildew resistance genes in einkorn (Triticum monococcum L.) accessions.

Powdery mildew is a severe foliar disease for wheat and could cause great yield loss in epidemic years. To explore new powdery mildew resistance genes, two einkorn accessions including TA2033 and M80, both resistant to this disease, were studied for the inheritance of resistance. Each accession possessed a single but different dominant resistance gene that was designated as Mlm2033 and Mlm80, respectively. Marker mapping indicated that they are both linked to Xgwm344 on the long arm of chromosome 7A. To establish their genetic relationship with Pm1 on 7AL, five RFLP markers previously reported to co-segregate with Pm1a were converted to STS markers. Three of them detected polymorphism between the mapping parents and were mapped close to Mlm2033 or Mlm80 or both. Xmag2185, the locus determined by the STS marker derived from PSR680, one of the RFLP markers, was placed less than 2 cM away from them. The allelism test indicated that Mlm2033 and Mlm80 are likely allelic to each other. In addition, through comparative and EST mapping, more markers linked to these two genes were identified. The high density mapping of Mlm2033 and Mlm80 will contribute to map-based cloning of the Pm1 locus. The markers for both genes will also facilitate their transfer to wheat.

Ascomycota↗
PubMed2003

Concomitant reiterative BAC walking and fine genetic mapping enable physical map development for the broad-spectrum late blight resistance region, RB.

The wild potato species Solanum bulbocastanum is a source of genes for potent late blight resistance. We previously mapped resistance to a single region of the S. bulbocastanum chromosome 8 and named the region RB (for "Resistance from S. Bulbocastanum"). We now report physical mapping and contig construction for the RB region via a novel reiterative method of BAC walking and concomitant fine genetic mapping. BAC walking was initiated using RFLP markers previously shown to be associated with late blight resistance. Subcontig extension was accomplished using new probes developed from BAC ends. Significantly, BAC end and partial BAC sequences were also used to develop PCR-based markers to enhance map resolution in the RB region. As they were developed from BAC clones of known position relative to RB, our PCR-based markers are known a priori to be physically closer to the resistance region. These markers allowed the efficient screening of large numbers of segregating progeny at the cotyledon stage, and permitted us to assign the resistance phenotype to a region of approximately 55 kb. Our markers also directed BAC walking efforts away from regions distantly related to RB in favor of the 55-kb region. Because the S. bulbocastanum genotype used in BAC library construction is heterozygous for RB (RB/rb), codominant PCR-based markers, originally developed for fine-scale mapping, were also used to determine homolog origins for individual BAC clones. Ultimately, BAC contigs were constructed for the RB region from both resistant (RB) and susceptible (rb) homologs.

Chromosome Walking↗
PubMed2005

Survey of resistance gene analogs in Solanum caripense, a relative of potato and tomato, and update on R gene genealogy.

The resistance (R) proteins of the TIR- and non-TIR (or CC-) superfamilies possess a nucleotide binding site (NBS) domain. Within an R gene, the NBS is the region of highest conservation, suggesting an essential role in triggering R protein activity. We compared the NBS domain of functional R genes and resistance gene analogs (RGA) amplified from S. caripense genomic DNA via PCR using specific and degenerate primers with its counterpart from other plants. An overall high degree of sequence conservation was apparent throughout the P-loop, kinase-2 and kinase-3a motifs of NBS fragments from all plants. Within the non-TIR class of R genes a prominent sub-class similar to the potato R1 gene conferring resistance to late blight, was detected. All non-TIR-R1-like R gene fragments that were sequenced possessed an intact open reading frame, whereas 22% of all non-TIR-non-R1-like fragments and 59% of all TIR-NBS RGA fragments had an interrupted reading frame or contained transposon-specific sequence. The non-TIR-R1-like fragments had high similarity to Solanaceae R genes and low similarity to RGAs of other plant species including A. thaliana and the cereals. It is concluded that appearance of the non-TIR-R1-like NBS domain represents a relatively recent evolutionary development.

Amino Acid Motifs↗
PubMed1997

Map-based cloning of the tomato genomic region that spans the Sw-5 tospovirus resistance gene in tomato.

Two yeast artificial chromosomes (YACs) containing genomic DNA from tomato have been isolated using CT220, an RFLP marker which is tightly linked to the tomato spotted wilt virus resistance gene, Sw-5. High-resolution mapping of the YAC ends and internal YAC probes demonstrated that one of the YAC clones, TY257 (400 kb), spans Sw-5. By chromosome walking in a cosmid library, the position of Sw-5 has been delimited within the YAC to a maximal chromosomal segment of 100 kb, spanned by nine overlapping cosmid clones.

Chromosome Mapping↗
PubMed2006

Phospholipase C/diacylglycerol kinase-mediated signalling is required for benzothiadiazole-induced oxidative burst and hypersensitive cell death in rice suspension-cultured cells.

The involvement of phospholipase C/diacylglycerol kinase (PLC/DGK)-mediated signalling in oxidative burst and hypersensitive cell death was studied in rice suspension-cultured cells treated with benzothiadiazole (BTH) and infected by Xanthomonas oryza pv. oryza (Xoo), the causal agent of rice leaf blight disease. Treatment of rice suspension cells with BTH resulted in a significant oxidative burst, as indicated by accumulation of superoxide anion and H(2)O(2), and hypersensitive cell death, as determined by Evans blue staining. A peak in oxidative burst was detected 3-4 h after BTH treatment and hypersensitive cell death was observed 8 h after treatment. In addition, significant oxidative burst and hypersensitive cell death were detected in BTH-treated suspension cells, but not in untreated control cells, after Xoo infection. Scavengers and antioxidants of active oxygen species, e.g., superoxide dismutase, catalase, N-acetylcysteine, and flavone, reduced significantly the BTH-induced oxidative burst and hypersensitive cell death, indicating that oxidative burst is required for BTH-induced hypersensitive cell death. Expression of the PLC/DGK pathway genes, a diacylglycerol kinase gene, OsDAGK1, and a phosphoinositide-specific phospholipase C gene, OsPI-PLC1, and a defence-related EREBP transcriptional factor gene, OsBIERF3, was activated in rice cells after BTH treatment and in the BTH-treated cells after Xoo infection. Treatment of rice cells with phosphatidic acid, a phospholipid signalling molecule, resulted in the production of oxidative burst and hypersensitive cell death. However, neomycin, a PLC inhibitor, inhibited partially but not completely the production of oxidative burst, hypersensitive cell death, and expression of OsBIERF3 and OsDAGK1 induced by BTH in rice cells. These results suggest that PLC/DGK-mediated signalling plays an important role in BTH-induced oxidative burst, hypersensitive response, and activation of defence response in rice.

Cell Culture Techniques↗
PubMed1981

Enhancement of the immunogenicity of the maize rough dwarf virus outer shell with the cross-linking reagent dithiobis(succinimidyl)propionate.

Injection into rabbits of native or glutaraldehyde (GA)-treated intact particles of the fijivirus maize rough dwarf virus (MRDV) failed to yield antibodies to the outer shell of the virus. After fixation of the particles with the cross-linking reagent dithiobis(succinimidyl)propionate (DSP), antisera were obtained reacting with the outer shell of MRDV (both DSP-fixed and unfixed) to a titre of 1/1024 in immunoelectron microscopic decoration tests, but giving no reaction with another fijivirus, oat sterile dwarf virus, whose subviral particles are known to be unrelated to those of MRDV. Further fixation of the DSP-fixed particles with GA did not appear to enhance immunogenicity. Stabilization with DSP could have further application with viruses the instability of which renders them poor immunogens.

Animals↗
PubMed2004

Defensins: antimicrobial peptides of vertebrates.

This review, based on my presentation at the French Academy of Sciences on May 19, 2003, describes recent progress in the study of antimicrobial peptides, mediators of innate immunity in plants and animals. The main focus is on vertebrate defensins, a family of cysteine-rich antimicrobial peptides abundantly represented in human cells and tissues.

Amino Acid Sequence↗
PubMed2004

NPR1, all things considered.

Recent work has shown that the Arabidopsis NPR1 protein not only plays an essential role in salicylic acid (SA)-mediated systemic acquired resistance and rhizobacterium-triggered induced systemic resistance, but also is involved in crosstalk inhibition of jasmonic acid (JA)-mediated defense responses. Molecular characterization has revealed that activation of NPR1 and certain TGA transcription factors occurs under the reducing conditions that follow an initial oxidative burst after the induction of defense responses. In addition to NPR1 and TGA, the single-stranded DNA-binding transcription factor AtWhy1 and the WRKY70 transcription factor were recently found to be involved in SA-mediated defense and SA-JA crosstalk, respectively.

Arabidopsis↗
PubMed2003

Closing another gap in the plant SAR puzzle.

NPR1 is a key regulator of the salicylic acid (SA) dependent pathogen resistance pathway in plants. In this issue of Cell, Mou and Dong demonstrate that Arabidopsis NPR1 undergoes activation from an inactive oligomer to the active monomer as a result of cellular redox changes induced by SA during systemic acquired resistance.

Arabidopsis↗
PubMed2003

Production of recombinant Potato mop-top virus coat protein in Escherichia coli and generation of antisera recognising native virus protein.

Potato mop-top virus (PMTV, Pomovirus) is difficult to detect because it is unevenly distributed and present at low concentration in infected tissues. The production of PMTV-free seed relies on sensitive and specific detection methods of virus detection, including serological methods. The possibility of using a PMTV recombinant coat protein (CP) as an antigen for antiserum production was investigated. The region encoding the PMTV CP was inserted into pET3A, expressed in Escherichia coli, and the recombinant PMTV CP produced was used to raise antibodies in rabbits. Three antisera were produced. All recognised efficiently the recombinant CP in Western blot analysis and the most sensitive antiserum (H5003) detected native CP on Western blots and in ELISA. Thus, recombinant CP can be used as an alternative to purified virus for the production of specific antibodies against PMTV.

Animals↗