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101.
Coat protein-mediated protection against plum pox virus in herbaceous model plants and transformation of apricot and plum 总被引:6,自引:0,他引:6
Artur da Câmara Machado Hermann Katinger Margit Laimer da Câmara Machado 《Euphytica》1994,77(1-2):129-134
Summary The expression of the viral coat protein gene in transgenic plants has been shown to induce tolerance against virus infection
(Beachy et al., 1990). Transgenic plants ofNicotiana clevelandii andNicotiana benthamiana- herbaceous host plants for PPV - transformed withAgrobacterium strain LBA 4404 containing the plasmid pBinPPVm, regenerated on selection media containing kanamycin were tested for the
expression of the PPV coat protein gene by ELISA and immuno western blot. After rooting and acclimatisation plants were tested
for the protection against PPV Following the inoculation plants were investigated for symptom development and virus accumulation.
Different lines were identified, according to the different reaction to the mechanical inoculation, ranging from a complete
absence to a strong reduction of symptoms. There have not been many reports on transformation of trees in general, and in
fruit trees particularly. It is obvious that the major obstacle is the regeneration of transformed plantlets. Attempts to
improve crop plants by genetic engineering techniques will always depend very strongly on the availability of reliable protocols
for transformation, selection and regeneration (Laimer et al., 1989, 1990). Different systems involving juvenile and adult
plant material have been developed allowing the transfer of foreign genes into apricot and plum cultivars. We report the transformation
and regeneration ofPrunus armeniaca andPrunus domestica plants withAgrobacterium tumefaciens strain LBA 4404 containing various binary plasmids, pBinGUSint, carrying the marker geneβ-glucuronidase (GUS) and pBinPPVm, carrying the coat protein gene of Plum Pox Virus (PPV), the causal agent of Sharka disease.
The marker geneGUS was used for the optical evaluation of the efficiency of different transformation systems involving cotyledons of immature
embryos as well as somatic embryos and leaf discs. The coat protein gene of PPV was used to introduce the coat protein mediated
resistance against one of the most important pathogens of stone fruit trees in Europe and the whole Mediterranean area. 相似文献
102.
Verdi LG Pizzolatti MG Montanher AB Brighente IM Smânia Júnior A Smânia Ed Ede F Simionatto EL Monache FD 《Fitoterapia》2004,75(3-4):360-363
The hydroalcoholic extract of the leaves from Rheedia gardneriana yielded volkensiflavone (1), fukugetin (2), fukugiside (3), GB2a-I-7-O-glucoside (4) and epicatechin (5). Compounds 1-5, and some derivatives of 1 and 2 were evaluated for lethality to brine shrimp larvae and for antibacterial activity. 相似文献
103.
104.
A novel cytometric approach to study intestinal mucosa rebuilding in weaned pigs fed with dietary nucleotides 总被引:2,自引:0,他引:2
Micha M. Godlewski Joanna B. Biera Artur Strzakowski Daniel Martinez-Puig Beata Pajk Anna Kotunia Carles Chetrit Romuald Zabielski 《Livestock Science》2009,123(2-3):215-220
In the weaning period, transition from sow's milk to the post-weaning diet causes the withdrawal of important nutrients as milk nucleotides, which are known to be determinant for the development of the gastrointestinal tract and immune function. The role of dietary nucleotides in the rebuilding of gut epithelium remains unclear. The aim of the study was to evaluate using appropriate markers the rate of mitosis (Ki67) in the crypt epithelial cell, and the rate of apoptosis (active caspase 3), autophagy (MAP I LC3) and DNA damage (p53) in the crypt and villi epithelial cells of the small intestine of weaned pigs fed diets supplemented without/with nucleotides. An in-tissue cytometry method, based on confocal imaging and automated quantitative analysis was implemented. The studies allowed us to understand molecular bases of animal performance which could not be accessed by a routine histometric approach. Namely, the dietary nucleotides provided more uniform small intestine epithelium with considerably less animal-to-animal variation in respect to mitosis (SEM = 1.02 in control vs. 0.62 in supplemented group), autophagy (SEM = 1.22 vs. 0.99) and expression of p53 protein (SEM = 0.72 vs. 0.28). A significant increase in ratio of apoptosis and autophagy, and significantly lower p53 expression was found in the nucleotide-supplemented pigs as compared to control. The mitosis/apoptosis index was lower in the nucleotide-supplemented group suggesting slower rebuilding of gut epithelium in these pigs as compared to the control, respectively 0.454 to 0.191. Finally, in the supplemented group a drop in p53 expression was observed, however, it remains uncertain whether the reduction in DNA damage index is due to the supplementation with nucleotides utilized as a source for repair processes or due to the reduced DNA alterations. 相似文献
105.
Marcelo D. Catarino Catarina Maral Teresa Bonifcio-Lopes Dbora Campos Nuno Mateus Artur M. S. Silva Maria Manuela Pintado Susana M. Cardoso 《Marine drugs》2021,19(7)
Recent studies indicate that plant polyphenols could be pointed as potential prebiotic candidates since they may interact with the gut microbiota, stimulating its growth and the production of metabolites. However, little is known about the fate of brown seaweeds’ phlorotannins during their passage throughout the gastrointestinal tract. This work aimed to evaluate the stability and bioaccessibility of Fucus vesiculosus phlorotannins after being submitted to a simulated digestive process, as well as their possible modulatory effects on gut microbiota and short-chain fatty acids production following a fermentation procedure using fecal inoculates to mimic the conditions of the large intestine. The stability of phlorotannins throughout the gastrointestinal tract was reduced, with a bioaccessibility index between 2 and 14%. Moreover, slight alterations in the growth of certain commensal bacteria were noticed, with Enterococcus spp. being the most enhanced group. Likewise, F. vesiculosus phlorotannins displayed striking capacity to enhance the levels of propionate and butyrate, which are two important short-chain fatty acids known for their role in intestinal homeostasis. In summary, this work provides valuable information regarding the behavior of F. vesiculosus phlorotannins along the gastrointestinal tract, presenting clear evidence that these compounds can positively contribute to the maintenance of a healthy gastrointestinal condition. 相似文献
106.
Tomokazu Tamura Naofumi Nagashima Nicolas Ruggli Artur Summerfield Hiroshi Kida Yoshihiro Sakoda 《Veterinary research》2014,45(1):47
Classical swine fever (CSF) caused by CSF virus (CSFV) is a highly contagious disease of pigs. The viral protein Npro of CSFV interferes with alpha- and beta-interferon (IFN-α/β) induction by promoting the degradation of interferon regulatory factor 3 (IRF3). During the establishment of the live attenuated CSF vaccine strain GPE-, Npro acquired a mutation that abolished its capacity to bind and degrade IRF3, rendering it unable to prevent IFN-α/β induction. In a previous study, we showed that the GPE- vaccine virus became pathogenic after forced serial passages in pigs, which was attributed to the amino acid substitutions T830A in the viral proteins E2 and V2475A and A2563V in NS4B. Interestingly, during the re-adaptation of the GPE- vaccine virus in pigs, the IRF3-degrading function of Npro was not recovered. Therefore, we examined whether restoring the ability of Npro to block IFN-α/β induction of both the avirulent and moderately virulent GPE--derived virus would enhance pathogenicity in pigs. Viruses carrying the N136D substitution in Npro regained the ability to degrade IRF3 and suppress IFN-α/β induction in vitro. In pigs, functional Npro significantly reduced the local IFN-α mRNA expression in lymphoid organs while it increased quantities of IFN-α/β in the circulation, and enhanced pathogenicity of the moderately virulent virus. In conclusion, the present study demonstrates that functional Npro influences the innate immune response at local sites of virus replication in pigs and contributes to pathogenicity of CSFV in synergy with viral replication. 相似文献
107.
Artur Alves Carla Barradas Alan J. L. Phillips António Correia 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(4):791-804
Botryosphaeriaceous fungi were isolated from conifers showing disease symptoms such as diebacks, blights, and cankers. The isolates were grouped based on morphology and ERIC-PCR fingerprinting patterns and representatives of each group were identified by sequencing of the internal transcribed spacer (ITS) region. Nine species from four different genera in Botryosphaeriaceae were identified within the isolates. Many new fungus-host associations were established and several species of Botryosphaeriaceae are reported from conifers for the first time. Most of these species also represent new reports from Portugal. The genus Neofusicoccum that was thought to be mainly restricted to angiosperms was the most frequent within the collection of isolates, followed by Diplodia. Dothiorella and Botryosphaeria represented a minor fraction of the isolates. Interestingly, the most common species was N. luteum, which had never been reported from coniferous hosts. Our results indicate that Neofusicoccum species may be more important as pathogens of conifers than it was previously recognised. 相似文献
108.
109.
Osmotin and thaumatin from grape: a putative general defense mechanism against pathogenic fungi 总被引:1,自引:0,他引:1
Monteiro S Barakat M Piçarra-Pereira MA Teixeira AR Ferreira RB 《Phytopathology》2003,93(12):1505-1512
ABSTRACT Little information is available concerning the expression of pathogenesis-related (PR) proteins in grapevine (Vitis vinifera) and their effect properties on the major fungal pathogens of grape. A systematic study was performed on the effect of total or individual grape proteins on mycelial growth, spore germination, and germ tube growth of Uncinula necator, Phomopsis viticola, and Botrytis cinerea. Two proteins, identified as PR proteins by immunological methods and by N-terminal sequencing as osmotin and thaumatin-like protein, exhibited strong antifungal activities in vitro, blocking the growth of Phomopsis viticola and Botrytis cinerea mycelia. In addition, they inhibited spore germination and germ tube growth of U. necator, Phomopsis viticola, and Botrytis cinerea. The presence of both proteins displayed a synergistic effect. The expression of osmotin and thaumatin-like protein was induced in grapevine leaves and berries infected with U. necator and Phomopsis viticola. Thaumatin previously was thought to occur exclusively in berries. Immunoblot analyses revealed the accumulation of the two PR proteins in infected leaves and berries, supporting a role in vivo in increasing the resistance of grapevine to fungal attack. 相似文献
110.
Im Hof M Williamson L Summerfield A Balmer V Dutoit V Kandimalla ER Yu D Zurbriggen A Doherr MG Peel J Roosje PJ 《Veterinary immunology and immunopathology》2008,124(1-2):120-131
Synthetic agonists of TLR9 containing novel DNA structures and R'pG (wherein R=1-(2'-deoxy-beta-d-ribofuranosyl)-2-oxo-7-deaza-8-methyl-purine) motifs, referred to as immune modulatory oligonucleotides (IMOs), have been shown to stimulate T(H)-1-type-immune responses and potently reverse allergen-induced T(H)-2 responses to T(H)-1 responses in vitro and in vivo in mice. In order to investigate the immunomodulatory potential of IMOs in dogs, canine peripheral blood mononuclear cells (PBMC) from healthy dogs were stimulated with three different IMOs and a control IMO, alone or in combination with concanavalin A (ConA). Lipopolysaccharide (LPS) was used as a positive control for B lymphocyte activation. Carboxyfluorescein diacetate succinimidyl ester and phenotype staining was used to tag proliferating T and B lymphocytes (CD5(+) and CD21(+)) by flow cytometry. Real-time PCR and ELISA were processed to assay cytokine production of IFN-gamma, IL-10, TGF-beta, IL-6 and IL-10. Like LPS, IMOs alone induced neither proliferation of CD5(+) T cells nor CD21(+) B cells, but both LPS and IMO had the capacity to co-stimulate ConA and induced proliferation of B cells. In combination with ConA, one of the IMOs (IMO1) also induced proliferation of T cells. IMO1 also significantly enhanced the expression of IFN-gamma on the mRNA and protein level in canine PBMC, whereas expression of IL-10, TGF-beta and IL-4 mRNAs was not induced by any of the IMOs. These results indicate that in canine PBMC from healthy dogs, IMO1 was able to induce a T(H)-1 immune response including T- and B-cell proliferation. 相似文献