bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in Sugar Content During Induction of Systemic Acquired Resistance to Late Blight Caused by Phytophthora infestans (Mont.) de Bary in Potato
Authors: Engstrom K. , Strömberg A. 
Published: May 2008

AbstractResistance of plants to their pathogens may be systemically enhanced by a localized induction treatment, a characteristic named systemic acquired resistance (SAR). Changes in amounts and proportions of sucrose, glucose and fructose were examined in induced and noninduced potato plants (Solarium luberosum L. ev. Matilda) before, and 1–9 days after challenge inoculation. The potato plants were induced and challenged with Phytophthora infesians (Mont.) de Bary. Plants which were non‐induced and non‐challenged were also tested (referred to as non‐treated). The sugars were analysed using high‐performance anion exchange chromatography with pulsed electrochemical detection, HPAE‐PED (Dionex system). The amounts as well as the proportions of sucrose, glucose and fructose were similar throughout the experimental period in the non‐treated plants. In induced plants, before challenge inoculation, the amount of sucrose was 44% lower than in non‐treated plants. One day after challenge inoculation, the amount of sucrose had decreased by 79% in non‐induced plants compared with non‐treated plants, while the induced plants were much less affected. The total amount of all sugars were approximately the same 1 day hefore and 9 days after the challenge inoculation in ail treatments. However, 1 day after challenge inoculation, a 65% decrease in total amount was observed in the non‐induced plants compared with the smaller reduction of 37% in the induced plants. The large differences in sugar amounts and proportions between the different treatments are discussed.
Extraction from Plant Tissue and Germination of Oospores of Peronospora viciae f.sp. pisi
Authors: van der Gaag D. J. , Frinking H. D. 
Published: May 2008

AbstractA protocol was developed to extract oospores of Peronospora viciae f.sp. pisi from plant tissue and control bacterial contamination in a germination assay. Oospores were extracted by comminuting infected leaves and pods in water, sonicating the suspension and sieving it through mesh sizes 53 and 20 pm, respectively. Germination of oospores was negatively influenced by addition of chloramphenicol and penicillin. A combination of ampicillin and rifampicin strongly inhibited bacterial growth at 10 C, and did not negatively affect germination. Washing oospores in water or 0.02% Tween‐80, and sonication did not influence germination. Treating oospore suspensions with cellulase buffered at pH 4.6 for 2 h digested most plant tissue but did not influence germination. Incubation in 0.05 m acetate buffer delayed germination. Germination was unaffected when oospores were incubated in 0.05 m citrate buffer.
Induced Systemic Resistance to Cercospora Leaf Spot of Carrot by Inoculation with Cercospora carotae
Authors: Mercier J. , Kuć J. 
Published: May 2008

AbstractThe possibility of inducing systemic disease resistance in carrot leaves was investigated with the pathogen Cercospora carotae as the agent for both induction and challenge. The inoculation of plants with C. carotae induced resistance in newly emerged leaves challenged 23 days later. There was an optimum inoculum concentration of 3 × 104 conidia ml‐1 for inducing resistance, the response decreasing with higher concentrations. Infection of carrot leaves by C. carotae could thus reduce susceptibility to subsequent infections by foliar pathogens later in the growing season. However, the inoculation of leaves with C. carotae did not increase the resistance of roots after harvest when they were wounded and challenged with Botrytis cinerea.
Constitutive and Inducible Proteins in the Root of Chinese Cabbage Infected with Plasmodiophora brassicae
Authors: Ito S. , Tanaka S. , Miyanaga C. , Takabayashi S. , Yano S. , Kameya‐Iwaki M. 
Published: May 2008

AbstractA plant‐pathogen system consisting of a Chinese cabbage cultivar and two isolates of Plasmodiophora brassicae was developed for analysing root proteins accumulated in susceptible and resistant responses to the fungus. Proteins extracted at pH 2.8 were analysed by two‐dimensional gel electrophoresis. More than 150 protein spots were resolved. Spots indicating changes in the intensity by the infection of P. brassicae were classified into six types: class 1 contains proteins enhanced in susceptible response; class 2, proteins unique to susceptible response; class 3, proteins repressed in susceptible response: class 4, proteins enhanced in resistant response; class 5, proteins unique to resistant response; and class 6, proteins repressed in resistant response. Two proteins from class 1 and one protein from class 4 were subjected to an N‐terminal amino acid sequencing. One of the class 1 protein (25 kDa, pl 7.0) revealed high homology with pathogenesis‐related protein group 5.
The Systemic Infection by Tobacco Mosaic Virus of Tobacco Plants Coutaining the N Gene at Temperatures Below 28°C
Authors: White R. F. , Sugars J. M. 
Published: May 2008

AbstractTobacco plants containing the N‐gene are occasionally systemically infected with tobacco mosaic virus (TMV) at tempreratures below 28°C, but contain low concentrations of virus: they often fail to set seed, and can outlive healthy control plants. Infection is thus similar to that induced when N‐gene tobacco plants are grafted onto systemically infected tobacco lacking the N‐gene. Shoots from systemically infected N‐gene plants can induce systemic infection in other graft‐inoculated N‐gene plants. Stem sections of N‐gene tobacco plants act as good conduits for TMV between plants lacking the N‐gene, and girdling experiments suggest that virus movement probably occurs in the phloern.
Location of Soybean Mosaic Virus in Seed‐Parts of Individual Dormant and Germinating Mottled and Non‐mottled Soybean Seeds
Authors: Bajwa M. A. , Pacumbaba R. P. 
Published: May 2008

AbstractSoybean mosaic virus (SMV) was detected in individual embryos of both dormant mottled (50%) and non‐mottled (50%) seeds of certified soybean cvs Davis. Essex. Hutchinson, Ransom, Stonewall, and Young by using the double antibody sandwich enzyme‐linked immunosorbent assay (DAS‐ELISA). SMV was not detected in individual strained seed coats of mottled or non‐stained seed coats of non‐mottled dormant seeds and endosperms of either type of seed. SMV was not detected m individual stained and nonstained seed coats, epicotyls, and endosperms of mottled and non‐mottled seeds at 72 h post‐germination. However, the virus was detected in individual hypocotyls at an average level of 31% in post‐germinated seeds (mottled and non‐mottled) of all cultivars. Symptomless glasshouse‐grown 6–8‐week‐old seedlings from mottled and non‐mottled seeds of certified soybean cultivars occurred twice as often as those showing early symptoms. However, almost half of these symptomless plants were found to be SMV‐infected by DASELISA. Virus‐free soybean plants grown to maturity from non‐mottled seeds also produced mottled seeds.
Fungicidal Activity of Some Common Weed Extracts Against Different Plant Pathogenic Fungi
Authors: Qasem J. R. , Aau‐Blan H. A. 
Published: May 2008

AbstractAqueous extract effects of 64 weed species on growth and development of Alternaria solani Sorauer. Helminthosporium satirum King & Bakke and Rhizodonia solani Kuhn. plant pathogenic fungi were studied in vitro. Extracts varied in the strength and persistence of their antifungal effects against the three fungi species. Some stimulated, others inhibited or had no effect. Among all species tested, extracts of Chenopodium murale, Falearia vulgaris. Ranunculus asiaticus and Sisymbrium irio were the most toxic to A. solani. Anagallis arlensis. Atriptex leucoclada, Crepis aspera. Notobasis syriaca. R. asiatieus, Rumex crispu. S. irio. Sonehu.s oleraceous and Vieia narhonensis to H. satirum and R. asiatieus. S. oleraceous and Mercurialis annua to R. solani. However. R. asiatieus extract was the most effective and completely inhibited growth and sporulation of the three fungi species at all incubation periods.
Resistance to Tomato Yellow Mosaic Geminivirus and Presence of Viral DNA in Some Species of Solanaceae
Authors: Infante D. , Piven N. , de Uuzcátegui R. 
Published: May 2008

AbstractIn this work we studied tomato yellow mosaic geminivirus (ToYMV) symptoms and DNA presence in several species of Solanaeae: Lycopersivon esculentum, Lycoperstcon peru‐vianum. Lycium barbarum, Nicotiaiiu benthautian, Solunum lycopersioides. Solanum quitoense and Solanum rickli. After mechanical and insect transmission, in both greenhouse and open field, we found plants of Lyiium barbarum and Solanum lycopersicoides to be resistance to ToYMV, Polymerase chain reaction analysis showed that the resistant plants did not contain viral DNA.
Identification des acides caféoylshikimiques des racines du palmier dattier, principaux composés fongitoxiques vis‐à‐vis de Fusarium oxysporum f. sp. albedinis
Authors: Ziouti A. , El Modafar C. , El Mandili A. , El Boustani E. , Macheix J. J. 
Published: May 2008

Abstract5‐caffeoylshikimic acid and its isomeres of position (dactylifric acid) found in the roots of date‐palms (Phoenix daetylijera L.) inhibit the germination of conidia and the growth of the mycelium of Fusarium oxysporum f. sp. albedinis. The acid content accumulated in resistant cultivars are toxic to fungi, whereas that accumulated in sensitive cultivars does not seem to affect growth and development of the parasite. This well demonstrates the implication of caffeoylshikimic acid in the resistance of the date‐palm to this fusarium disease. Moreover, these results will be of great use, especially for screening resistant genotypes obtained from directed crossings or from in vitro cultures.
A Robust DNA Amplification Fingerprinting System Applied to Analysis of Genetic Variation Within Fusarium oxysporum f.sp. cubense
Authors: Bentley S. , Bassam B. J. 
Published: May 2008

AbstractGenetic variation among isolates of F. oxysporum f.sp. cubense (Foc) was analysed using a DNA amplification fingerprinting (DAF) system modified to improve reproducibility and transportability. This analysis was done after determining the widest tolerance range (or ‘window of reproducibility’) for each component in amplification reaction. Reproducible polymerase chain reactions (PCRs) were achieved with between 25 and 250 ng of template DNA, 9–15 μM primer, 4–6 mM MgCl2 and 2–4 units of Stoffel Fragment enzyme. For experimental work we used the middle value of these ranges which allowed at least 20% error tolerance for each component. Similarly, thermocycling and electrophoresis conditions were also improved. Manual scoring of the DNA fingerprints was compared to analysis of scanned gel images using the Gel Compar program (Applied Maths, Kortrijk, Belgium). The data were clustered by unweighted pair group method analysis (UPGMA) based on the Jaccard similarity coefficient. Isolates of Foc representing all known vegetative compatibility groups (VCGs) were examined and the genetic relationships between the VCGs were determined. Isolates of Foc were divided into two major groups with 30% genetic similarity. These optimized DNA amplification, thermocycling, and electrophoresis conditions were suitable for analysis of other organisms and should be applicable to other techniques that use arbitrary primers such as random amplified polymorphic DNA (RAPD) and arbitrarily primed‐PCR (AP‐PCR).
The Effect of Lodging and Time of Harvest on Deoxynivalenol Contamination in Barley and Oats
Authors: Langseth W. , Stabbetorp H. 
Published: May 2008

AbstractA split‐split plot design was used to study the effect of lodging and time of harvest on the formation of the Fusarium toxin deoxynivalenol (DON). Altogether 19 experimental fields were included in the study, which was carried out over the period 1991–1993. There were two cultivars each of barley and oats tested. Half of each field was lodged artificially using a drum roller to flatten the crop about 3 weeks after ear emergence. The grain was harvested at the stage of mealy ripe and about 15 and 30 days after. The DON concentratioti in the grain was in descending order influenced by lodging, cultivar, experimental field, year and time of harvest. When paired plots were compared a distinct increase (more than 65%) in the DON concentration was found in samples from 49% of the plots with lodging compared with their pair plot. Both a decrease and an increase in the DON content were detected in the period from the first time of harvest to the second and third titne of harvest. The overall contamination level of DON was found to be higher in the samples of barley compared to oats.
Functional Studies of Complementary Sense Promoter (Replicase Promoter) from Tomato Yellow Leaf Curl Virus: Evidence for Transcription Capability in Non‐host Plants
Authors: Abdallah N. A. , Abou‐Salha A. , Soliman M. H. 
Published: May 2008

AbstractThe complementary sense promoter C1 that regulates the transcription of replicase gene in geminiviruses was cloned from tomato yellow leaf curl virus. A transcription fusion of β‐glucuronidase gene (GUS) coding sequence to complementary sense promoter, that replaced the viral replicase coding sequence, was constructed. Protoplasts of Nicotiana tabacum were electroporated to introduce the GUS gene controlled by the C1 promoter. The level of GUS transient gene expression was enhanced by the increase of the plasmid DNA concentration. Fluorometric GUS assays showed that the C1 promoter has a lower expression compared to the e35S promoter. Bombardment of the constructed plasmid. containing Cl promoter‐GUS ORF‐NOS terminator (pKSIR‐E), was performed to different plant genetic backgrounds and followed by the histochemical GUS assays. The results showed that there were GUS activities expressed in tomato (Lycopersicon esculentum), tobacco (Nicotiana tabacum) and datura (Datura stramonium), as host plants. While in non‐host plants, the GUS activities were observed in faba bean (Vicia faba) and squash (Cucurbita pepo), as examples of dicot plants, but not in maize (Zea mays) as a representative of monocote.
Subcellular Location and Expression of Tobacco Necrosis Necrovirus p7a Protein
Authors: Drouzas A. D. , Offei S. K. , Coutis R. H. A. 
Published: May 2008

AbstractA putative movement protein (p7a) of tobacco necrosis Necrovirus, strain D (TNV‐D), produced in Escherichia coli using an expression vector, was used to raise an antiserum. Immunoblot analysis using this antiserum showed that the p7a protein was detectable only in the combined cell wall and cell membrane fraction prepared from TNV‐D infected Phaseolus vulgaris leaves. The p7a protein was detectable 1 day after inoculation and reached a maximum 3 days later, before declining, whereas coat protein was not detectable until 3 days after inoculation and continued to increase in concentration for a further 2 days before declining. Differences in the detectable amounts of both proteins may reflect their differential stability in extracts from necrotic tissue and/or the transient expression of the putative movement protein early in the replication cycle of TNV‐D.
A Basic Peroxidase Isoenzyme, Marker of Resistance Against Plasmopara viticola in Grapevines, is Induced by an Elicitor from Trichoderma viride in Susceptible Grapevines
Authors: Barceló A. Ros , Zapata J. M. , Calderón A. A. 
Published: May 2008

AbstractThe constitutive expression of basic peroxidase isoenzymes in the Plasmopara viticola‐resistant (Vitis vinifera × Vitis rupestris) × Vitis riparia crossing and in the P. viticola‐susceptible V. vinifera parent species was studied. The results illustrate that both leaves and stems of the (V. vinifera × V. rupestris) × V. riparia crossing showed the differential expression of a basic peroxidase isoenzyme B3 (pl = 8.9), this being almost completely absent from the P. viticola‐susceptible V. vinifera parent species. To test whether the basic peroxidase isoenzyme B3 may be considered as a molecular marker of disease resistance in Vitis spp., suspension cell cultures derived from the P. viticola‐susceptible V. vinifera parent species were treated with an elicitor (cellulase Onoztika R‐10) from the soil fungus Trichoderma viride, a specific and well‐known elicitor of disease resistance reactions in grapevines. The results showed that treatment with the elicitor induces, simultaneously with the activation of the disease resistance mechanism, the appearance of B3 in the cell cultures. These results suggest that the basic peroxidase isoenzyme B3 may be considered as a marker of disease resistance in Vitis species since it is present in the P. viticola‐resistant (V. vinifera × V. rupestris) × V. riparia hybrid and is induced by the elicitor Onozuka R‐10 in cell cultures of the P. viticola‐susceptible Vitis vinifera parent species. This conclusion is supported by the presence of this isoenzyme in other resistant and its absence in other susceptible Vitis spp.
Production and Characterization of Monoclonal Antibodies to Barley Yellow Mosaic Virus and Their Use in Detection of Four Bymoviruses
Authors: Hariri D. , Lapierre H. , Filleur S. , Plovie C. , Delaunay T. 
Published: May 2008

AbstractSix monoclonal antibodies (MAbs) against a French isolate of barley yellow mosaic virus (BaYMV) pathotype 2 were produced and their isotypes determined. These MAbs were compared in ELISA for their reactivity with different isolates of BaYMV, wheat yellow mosaic virus (WYMV), wheat spindle streak mosaic virus (WSSMV) and oat mosaic virus (OMV).The six MAbs detected BaYMV in TAS ELISA and western blot, whereas in ACP ELISA no reaction was observed with isolates of BaYMV and WYMV. These MAbs could recognize the sequential motifs situated at the surface of viral particles. The six MAbs detected all the European isolates of BaYMV pathotype 1 and 2 and the Japanese isolate of this viral pathotype 1–1. In contrast to other MAbs, MAb IV did not react with the Japanese isolate of BaYMV pathotype II‐l. In TAS ELISA. MAbs I, II, III, and IV detected the Japanese isolate of WYMV and American isolates of WSSMV only when they were captured by anti‐WYMV polyclonal antibodies, A French isolate of OMV was detected only by the MAbs I and II in TAS ELISA with Polyclonal anti‐BaYMV.
The Effects of Light and Photo‐ and Protein‐synthetic Inhibitors on the Sekiguchi Lesion Formation by Magnaporthe grisea in Rice cv. Sekiguchi‐asahi*
Authors: Arase S. , Fukuyama R. , Tokizawa K. , Ikegami S. , Honda Y. , Nozu M. 
Published: May 2008

AbstractThe significance of light irradiation in Sekiguchi lesion (SL) formation by infection with Magnaporthe grisea on rice cv. Sekiguchi‐asahi was investigated. When the leaf blades of cv. Sekiguchi‐asahi inoculated with M. grisea spores were kept under different wavelengths of light. SLs were formed under visible light regardless of the compatibility between fungal race and cv. Sekiguchi‐asahi. On the contrary, typical blast and/or nectrotic spot lesions were formed under near ultraviolet radiation from the black light fluorescent lamps and near infrared radiation from infrared fluorescent lamps. The effective wavelength for light‐dependent SL formation was 400–700 nm. Furthermore, the longer the wavelength of radiation, the bigger were the SLs. Such light‐dependent induction of the SL was suppressed by pretreatment of 3‐(3,4‐dichlorophenyl)‐l,l‐dimethylurea (DCMU) and cycloheximide (CY). These results suggested that photosynthetic and protein synthetic activities were involved in SL formation.
The Symptoms and Cause of Guava Wilt in South Africa
Authors: Schoeman M. H. , Benade E. , Wingfield M. J. 
Published: May 2008

AbstractWilt of guava (Psidium guajava), a serious disease occurring in most guava producing areas of the Northern and Mpumalanga provinces of South Africa, was shown to be induced by a fungus tentatively identified as Penicillium vermoesenii. This fungus is the cause of a blight of ornamental palms in the United States and Belgium and its occurrence on guava is enigmatic. Pathogenicity tests were conducted in the glasshouse and under field conditions. Symptoms on trees include wilting, chlorosis and defoliation.
Cytological and Physiological Reasons for the Latent Type of Infection in Sunflower Caused by Plasmopara halstedii
Authors: Heller A. , Rozynek B. , Spring O. 
Published: May 2008

AbstractLightmicroscopy was used to investigate cytological and physiological reasons for the latent type of infection of sunflowers with Plasmopara halstedii. Sections of the hypocotyl of inoculated, but healthy looking plants of compatible and incompatible host‐pathotype combinations revealed vital hyphae and oospores, thus indicating an uninterrupted life cycle of the pathogen. Plants with latent infections showed enhanced cell division activities which restricted the pathogen to the cortical parenchyma. Additionally, hypersensitive reactions inhibited further growth in the pith parenchyma. In contrast, for systemic infection a successful invasion by the pathogen of the pith parenchyma of the hypocotyl and a growth of the hyphae faster than the hypersensitive reactions of the host tissue are needed.
Bacillus pumilus, the Cause of Bacterial Blotch of Immature Balady Peach in Egypt
Authors: Saleh O. I. , Huang Pi‐Yu , Huang Jeng‐Sheng 
Published: May 2008

AbstractFive pectolytic isolates of Bacillus were isolated from bacterial blotch of immature fruits and leaves of Balady peach (Prunus persica cv. Balady) grown in EI‐Minia Governorate in Egypt. Inoculation of the isolated bacteria into premature peach fruits and leaves resulted in the development of large brown spots. The isolated bacterium was identified as Bacillus pumilus from its physiological and biochemical properties, pathogenicity, electron microscopy and fatty acid composition analysis. B. pumilus also induced soft rot on wounded American stone and pome fruits such as Autumn Large and Southern peach, Large Red plums, Golden Delicious and Gala apple and Bartlet pear. Unwounded Autumn Large peach and Bartlet pear were also affected. Moreover, they degraded the parenchymatous tissues of many tested plant organs under experimental conditions. B. pumilus produced endopolygalacturonase (EC 4.2.2.1) and endopectin lyase (EC4.2.2.3) in vitro and in vivo. This is the first report of the disease occurring in Egypt.
Esterase Activity from Venturia nashicola: Histochemical Detection and Supposed Involvement in the Pathogenesis of Scab on Japanese Pear
Authors: Müller M. W. , Ishir H. 
Published: May 2008

AbstractConidia of Venturia nashicola were collected from naturally scab‐infected leaves of Japanese pear. Conidia‐derived esterase activity was detected histochemically during the course of infection in ungerminated conidia, germ tubes, appressoria and conidia exudates. The esterase activity derived from conidia was partly inhibited in vitro by the specific cutinase inhibitor o‐methyl‐o‐butyl‐o(3,5,6‐trichloro‐2‐pyridyl)phosphate and by the serine hydrolase inhibitor diisopropylfluorophosphate. The specific cutinase inhibitor applied at a concentration of 1.5 ppm did not influence the germination rate of the conidia on pear leaves but reduced the formation of subcuticular fungal structures by 64%, It was concluded that cutinase activity from conidia of V. nashicola probably plays an important role in the pathogenesis of scab during the invasion process.