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At least 217 records · Page 12Linked to original sources
PubMed2002

Putative resistance genes of cereals: structure and expected function.

Sequences of two recently cloned genes playing a role in resistance against wheat pathogens (receptor-like kinase Lrk10 and Cre3 genes) were used to search for similarity of cereal clones included in the NCBI database. We found 23 clones with similarity to the Cre3 gene with predicted NBS and LRR domains, and 50 clones with serine/threonine kinase function and similarity to the new receptor-like kinase gene Lrk10 from wheat. In those two groups of clones some conservative nucleotide sequences were identified. Two sequences are identical between the majority of resistance gene candidate clones with a high similarity to Lrk10, and two sequences are identical between the majority of resistance gene candidate clones with similarity to the Cre3 gene.

Databases, Factual↗
PubMed2004

Enhancing the resistance of triticale by using genes from wheat and rye.

At present two separate nomenclature systems exist for wheat and rye. This paper provides a proposed common catalogue of wheat, rye and triticale resistance gene symbols. More than 130 postulated wheat resistance genes are listed. Over 39 rye and 6 triticale resistance (R) genes have been identified and named. Genes responsible for reaction to powdery mildew and to leaf, stem and yellow rusts are the best-represented group of resistance genes. From the common catalogue it can be concluded that there exists a potential for further transfer of rye resistance genes to wheat and triticale. Many molecular markers can be applied for marker-assisted gene transfer, but the expression of the R genes in the new genetic background of triticale remains to be investigated.

Edible Grain↗
PubMed2006

[Identification of efficient leaf-rust resistance genes in wheat (Triticum aestivum) using STS markers].

Molecular STS markers J13, Gb, and J09 were used for screening wheat (Triticum aestivum L.) accessions previously found to possess leaf-rust resistance genes according to test crosses or phytopathological tests. Specific amplicons were detected in all accessions assumed to possess the Lr9 gene, in nine of ten accessions with the conjectured Lr19 gene, and in 13 of 29 accessions with the conjectured Lr24 gene. Application of STS markers to identification of accessions possessing efficient leaf-rust resistance genes is discussed.

Basidiomycota↗
PubMedDate not supplied

[The use of plant heteropolysaccharides for correcting the immune response to the action on the body of vibration].

It was established that intragastric administration of heteropolysaccharides to rats under vibration enhanced the development of the humoral immune response to ram erythrocytes without influencing its development induced by bacterial lipopolysaccharides. The immunostimulating effect of heteropolysaccharides is mediated by the humoral factors produced by the splenocytes not adhering to the plastic. These factors stimulate the development of the immune response after short-term vibration but exert no enhancing influence on this process after long-term vibration.

Animals↗
PubMed1996

Humoral and cellular immunity rates in chemical plant workers employed in the production of liquid pesticides.

In order to assess the immunological system of the chemical plant workers certain rates of cellular and humoral immunity were estimated. The study group was composed of 19 males employed in the production of liquid pesticides, and 18 females performing ancillary jobs and handling closed containers. They were alternatively exposed to phosphoroorganic compounds and pyrethroides, and to chlorinated hydrocarbons, carbamates, nitrophenols and organic solvents, however exposure to the latter was lower. Chronic bronchitis was observed in 7 (37%) males and 4 (22%) females. Serum concentrations of immunoglobulins G, A and M, complement protein Cs, and circulating immune complexes were estimated. The peripheral blood leukocyte count and percentage, the granulocyte adherence and phagocytic activity, spontaneous NBT-dye reduction as well as cytochemical reactions to alkaline and acid phosphatase, beta-glucuronidase, myeloperoxidase and catalase of neutrophils were evaluated; the lymphocyte subpopulations CD3, CD4, CD8, CD16 were also estimated. As compared to controls, a significantly increased serum IgG concentration was found, together with elevated IgM in males and IgA in females. The leukocyte count in males was significantly higher. A considerable decrease in the percentage of neutrophils was accompanied by a significantly greater spontaneous NBT-dye reduction in both groups. Neutrophil adherence impairment was observed in males. Cytochemical reactions to beta-glucuronidase and catalase in both sexes, to alkaline and acid phosphatase in females, and to myeloperoxidases in males were significantly lowered, whereas the reaction to acid phosphatase in males was significantly enhanced. The percentages of lymphocytes CD3, CD4 and the CD4/CD8 ratio were significantly decreased.

Adult↗
PubMed2026

CBL1/9-CIPK6 complex negatively regulates Respiratory burst oxidase homolog D in Arabidopsis thaliana.

Plant innate immune response is a well-balanced process with positive and negative regulations for the plants to survive. Calcium signaling is essential for pathogen-associated molecular pattern (PAMP)-driven respiratory burst oxidase homolog D (RBOHD)-mediated reactive oxygen species (ROS) burst. We show that calcium sensors calcineurin B like protein 1 (CBL1) and CBL9 and their interacting protein kinase CIPK6 negatively regulate RBOHD activity and immune response in Arabidopsis thaliana. Arabidopsis mutant cbl1cbl9, like cipk6, exhibited enhanced resistance and ROS production when infected with the bacterial pathogen Pseudomonas syringae pv. tomato (Pst). CBL1 and CBL9 enhanced kinase activity of CIPK6. CBL1/9-CIPK6 module interacts with RBOHD at the plasma membrane. CIPK6 along with CBL1 reduces RBOHD activity in planta. CIPK6 phosphorylates the N-terminal cytoplasmic domain of RBOHD at a non-conserved (S33) and a conserved (S39) serine residue. While S39 phosphorylation increased RBOHD activity, S33 phosphorylation drastically reduced it and superseded the effect of S39 phosphorylation. We propose a model that CIPK6 phosphorylates RBOHD at S33 to suppress its activity to balance ROS generation in post-PTI situation in Arabidopsis. Our study reports a direct mechanism of negative regulation of ROS production and plant immune response by a calcium-signaling module in Arabidopsis thaliana.

Arabidopsis↗
PubMed2003

Immunization with a plant-produced colorectal cancer antigen.

Cancer vaccination has become an important focus of oncology in recent years. Active immunization with tumor-associated antigens such as colorectal cancer antigen GA733-2 is thought to potentially overcome the reoccurrence of metastasis. As recombinant protein production in bioreactors is costly and subject to growing safety concerns, we tested plants as an alternative for the expression of a potential colorectal cancer vaccine. Comparing colorectal cancer antigen GA733-2 produced in tobacco plants with the same antigen produced in insect cell culture, we found a similar humoral immune response to injection of either of the two antigen preparations into mice. Some minor differences were observed in the cellular response that might be due to impurities. Our studies compare for the first time, immunization with the same antigen expressed in either plants or insect cell culture. This will provide important data for use of plants as production systems of therapeutics.

Animals↗
PubMed2004

A family of conserved bacterial effectors inhibits salicylic acid-mediated basal immunity and promotes disease necrosis in plants.

Salicylic acid (SA)-mediated host immunity plays a central role in combating microbial pathogens in plants. Inactivation of SA-mediated immunity, therefore, would be a critical step in the evolution of a successful plant pathogen. It is known that mutations in conserved effector loci (CEL) in the plant pathogens Pseudomonas syringae (the Delta CEL mutation), Erwinia amylovora (the dspA/E mutation), and Pantoea stewartii subsp. stewartii (the wtsE mutation) exert particularly strong negative effects on bacterial virulence in their host plants by unknown mechanisms. We found that the loss of virulence in Delta CEL and dspA/E mutants was linked to their inability to suppress cell wall-based defenses and to cause normal disease necrosis in Arabidopsis and apple host plants. The Delta CEL mutant activated SA-dependent callose deposition in wild-type Arabidopsis but failed to elicit high levels of callose-associated defense in Arabidopsis plants blocked in SA accumulation or synthesis. This mutant also multiplied more aggressively in SA-deficient plants than in wild-type plants. The hopPtoM and avrE genes in the CEL of P. syringae were found to encode suppressors of this SA-dependent basal defense. The widespread conservation of the HopPtoM and AvrE families of effectors in various bacteria suggests that suppression of SA-dependent basal immunity and promotion of host cell death are important virulence strategies for bacterial infection of plants.

Arabidopsis↗
PubMed2002

NPK1, an MEKK1-like mitogen-activated protein kinase kinase kinase, regulates innate immunity and development in plants.

Mitogen-activated protein kinase (MAPK) cascades are rapidly activated upon plant recognition of invading pathogens. Here, we describe the use of virus-induced gene silencing (VIGS) to study the role of candidate plant MAP kinase kinase kinase (MAPKKK) homologs of human MEKK1 in pathogen-resistance pathways. We demonstrate that silencing expression of a tobacco MAPKKK, Nicotiana Protein Kinase 1 (NPK1), interferes with the function of the disease-resistance genes N, Bs2, and Rx, but does not affect Pto- and Cf4-mediated resistance. Further, NPK1-silenced plants also exhibit reduced cell size, defective cytokinesis, and an overall dwarf phenotype. Our results provide evidence that NPK1 functions in the regulation of N-, Bs2-, and Rx-mediated resistance responses and may play a role in one or more MAPK cascades, regulating multiple cellular processes.

Cell Size↗
PubMed2001

Wheat puroindolines enhance fungal disease resistance in transgenic rice.

Antimicrobial peptides play a role in the immune systems of animals and plants by limiting pathogen infection and growth. The puroindolines, endosperm-specific proteins involved in wheat seed hardness, are small proteins reported to have in vitro antimicrobial properties. Rice, the most widely used cereal crop worldwide, normally does not contain puroindolines. Transgenic rice plants that constitutively express the puroindoline genes pinA and/or pinB throughout the plants were produced. PIN extracts of leaves from the transgenic plants reduced in vitro growth of Magnaporthe grisea and Rhizoctonia solani, two major fungal pathogens of rice, by 35 to 50%. Transgenic rice expressing pinA and/or pinB showed significantly increased tolerance to M. grisea (rice blast), with a 29 to 54% reduction in symptoms, and R. solani (sheath blight), with an 11 to 22% reduction in symptoms. Puroindolines are effective in vivo in antifungal proteins and could be valuable new tools in the control of a wide range of fungal pathogens of crop plants.

Gene Expression Regulation, Plant↗
PubMed2006

Oral immunization of mice with plant-derived fimbrial adhesin FaeG induces systemic and mucosal K88ad enterotoxigenic Escherichia coli-specific immune responses.

The importance of adhesins in pathogenicity has resulted in them being useful targets in the defense against bacterial infections. To produce edible vaccines against piglet diarrhea caused by enterotoxigenic Escherichia coli (ETEC), plants were genetically engineered to produce recombinant fimbrial adhesin FaeG. To evaluate the efficacy of the edible vaccine FaeG in mice, the soluble protein extracts were examined by about 15 microg recombinant FaeG for each oral immunization dose per mouse. After four doses of vaccination, both IgG and IgA antibodies specific to K88ad fimbriae were elicited in serum, and specific IgA antibodies were also evoked in feces of the immunized mice. Moreover, visible K88ad ETEC agglutination by the specific serum from the immunized mice was observed, implying the antibody was highly specific and effective. Results from an in vitro villous-adhesion assay further confirmed that serum antibodies of the immunized mice could inhibit K88ad ETEC from adhering to pig intestinal receptors, further demonstrating the oral immune efficacy of the plant-derived FaeG. This study provides a promising, noninvasive method for vaccinating swine by feeding supplements of transgenic plant. Moreover, the low cost and ease of delivery of this edible ETEC vaccine will facilitate its application in economically disadvantaged regions.

Adhesins, Escherichia coli↗
PubMedDate not supplied

Humoral and cellular immunity rates in chemical plant workers producing dust pesticides.

BACKGROUND: Exposure to pesticides may affect humoral and cell-mediated immunity. MATERIAL AND METHODS: The study group was composed of 24 men employed in the production of dust pesticides and 23 females performing ancillary jobs under conditions of lower pesticide exposure. Chronic bronchitis was diagnosed in 10 males (41.7%) and 13 females (56.5%). The workers were exposed to: triazines, carbamates and dithiocarbamates, carbendazim, captan, dodine, dichlorophenoxy acetic acid (2,4-D), and cupric oxychloride. Silica, kaolin, chalk, and talc were used as carriers. The average workplace air concentrations of pesticides did not exceed the MAC. The serum concentrations of immunoglobulins G, A and M, complement component C3, and circulating immune complexes (CIC) were estimated. The peripheral blood leukocyte count and percentage of CD3, CD4, CD8, CD19 lymphocytes were evaluated. RESULTS: IgA and CIC concentrations in the female group were higher as compared to controls, whereas the percentage of CD3, CD4, CD8 cells was significantly lower, as opposed to an increased percentage of CD19 cells. The male group showed lower CIC concentrations, and the C3 complement component level was significantly higher. The decreased percentage of CD3 cells was accompanied by a higher CD19 cells ratio. The white blood cell count was higher in the males. No significant changes were found in other immunity parameters. CONCLUSIONS: The results of the study showed changes in some components of humoral and cellular immunity, which may influence damage to the respiratory system.

Adult↗
PubMed1988

[Evaluation of various indicators of cellular immunity in persons exposed to work environment in the Masovian Refinery and Petrochemical Plants in Plock].

In 137 workers of the Mazovian Refining Petrochemical Plant cellular immunity parameters were examined. The following tests were performed: number of E rosette forming cells (T lymphocytes), TG and TM lymphocytes, EAC rosette forming cells (B lymphocytes), MIF generation and suppressor and cytotoxic activity of T lymphocytes. Workers of Asphalt Oxidation Division exhibited most pronounced deviations of the test parameters, as compared to controls.

Adult↗
PubMed2006

Identification of QTLs associated with citrus resistance to Phytophthora gummosis.

Citrus gummosis, caused by Phytophthora spp., is an important citrus disease in Brazil. Almost all citrus rootstock varieties are susceptible to it to some degree, whereas resistance is present in Poncirus trifoliata, a closely related species. The objective of this study was to detect QTLs linked to citrus Phytophthora gummosis resistance. Eighty individuals of the F1 progeny, obtained by controlled crosses between Sunki mandarin Citrus sunki (susceptible) and Poncirus trifoliata cv. Rubidoux (resistant), were evaluated. Resistance to Phytophthora parasitica was evaluated by inoculating stems of young plants with a disc of fungal mycelia and measuring lesion lengths a month later. Two QTLs linked to gummosis resistance were detected in linkage groups 1 and 5 of the P. trifoliata map, and one QTL in linkage group 2 of the C. sunki map. The phenotypic variation explained by individual QTLs was 14% for C. sunki and ranged from 16 to 24% for P. trifoliata. The low character heritability (h2 = 18.7%) and the detection of more than one QTL associated with citrus Phytophthora gummosis resistance showed that inheritance of the resistance is quantitative.

Chromosome Mapping↗
PubMed2004

Identification and genetic characterization of an Aegilops tauschii ortholog of the wheat leaf rust disease resistance gene Lr1.

Aegilops tauschii (goat grass) is the progenitor of the D genome in hexaploid bread wheat. We have screened more than 200 Ae. tauschii accessions for resistance against leaf rust (Puccinia triticina) isolates,which are avirulent on the leaf rust resistance gene Lrl. Approximately 3.5% of the Ae. tauschii accessions displayed the same low infection type as the tester line Thatcher Lrl. The accession Tr.t. 213, which showed resistance after artificial infection with Lrl isolates both in Mexico and in Switzerland, was chosen for further analysis. Genetic analysis showed that the resistance in this accession is controlled by a single dominant gene,which mapped at the same chromosomal position as Lrl in wheat. It was delimited in a 1.3-cM region between the restriction fragment length polymorphism (RFLP) markers ABC718 and PSR567 on chromosome 5DL of Ae.tauschii. The gene was more tightly linked to PSR567(0.47 cM) than to ABC718 (0.79 cM). These results indicate that the resistance gene in Ae. tauschii accession Tr.t. 213 is an ortholog of the leaf rust resistance gene Lrlof bread wheat, suggesting that Lrl originally evolved in diploid goat grass and was introgressed into the wheat D genome during or after domestication of hexaploidwheat. Compared to hexaploid wheat, higher marker polymorphism and recombination frequencies were ob-served in the region of the Lrl ortholog in Ae. tauschii. The identification of LrlAe, the orthologous gene of wheatLrl, in Ae. tauschii will allow map-based cloning of Lrlfrom this genetically simpler, diploid genome.

Basidiomycota↗