is a soil-borne plant pathogen that infects its hosts through roots. It spreads in the plant's xylem and causes wilt disease symptoms by secreting different virulence factors. Hop (
) is a primary ...host of
, so it is used as a model plant for studying this phytopathogenic fungus. Artificial infections of hop plants and disease scoring are prerequisites for studying the pathogen's virulence/pathogenicity and its interaction with hop plants. In this protocol, we describe the root dipping inoculation method for conducting pathogenicity assay of
on hop plants.
Brown rot fungus Monilinia laxa (Aderh. & Ruhl.) Honey is an important plant pathogen in stone and pome fruits in Europe. We applied a proteomic approach in a study of M. laxa isolates obtained from ...apples and apricots in order to show the host specifity of the isolates and to analyse differentially expressed proteins in terms of host specifity, fungal pathogenicity and identification of candidate proteins for diagnostic marker development. Extracted mycelium proteins were separated by 2-D electrophoresis (2-DE) and visualized by Coomassie staining in a non-linear pH range of 3-11 and M.sub.r of 14-116 kDa. We set up a 2-DE reference map of M. laxa, resolving up to 800 protein spots, and used it for image analysis. The average technical coefficient of variance (13%) demonstrated a high reproducibility of protein extraction and 2-D polyacrylamide gel electrophoresis (2-DE PAGE), and the average biological coefficient of variance (23%) enabled differential proteomic analysis of the isolates. Multivariate statistical analysis (principal component analysis) discriminated isolates from two different hosts, providing new data that support the existence of a M. laxa specialized form f. sp. mali, which infects only apples. A total of 50 differentially expressed proteins were further analyzed by LC-MS/MS, yielding 41 positive identifications. The identified mycelial proteins were functionally classified into 6 groups: amino acid and protein metabolism, energy production, carbohydrate metabolism, stress response, fatty acid metabolism and other proteins. Some proteins expressed only in apple isolates have been described as virulence factors in other fungi. The acetolactate synthase was almost 11-fold more abundant in apple-specific isolates than in apricot isolates and it might be implicated in M. laxa host specificity. Ten proteins identified only in apple isolates are potential candidates for the development of M. laxa host-specific diagnostic markers. Key words: proteomics, fungi, two-dimensional electrophoresis
Verticillium albo‐atrum is a vascular wilt pathogen capable of infecting many important dicotyledonous plant species. Fungal isolates from hop differ in aggressiveness, causing either mild or lethal ...symptoms in infected plants. As in other plant pathogenic fungi, extracellular proteins, such as cell wall‐degrading enzymes and effectors, are thought to be crucial in the pathogenesis process. In this study, mild and lethal isolates from three countries were grown in simulated xylem medium and secretome analysis by 2D‐DIGE showed low qualitative and high quantitative variability among the isolates. Functional classification of 194 identified proteins representing 100 unique protein accessions revealed an arsenal of cell wall‐degrading enzymes and potential effectors. The set of proteins that were more abundant in at least two lethal isolates included enzymes acetylcholinesterases, lipases, polygalacturonases, pectate lyase, rhamnogalacturonan acetylesterases, acetylxylan esterase, endoglucanase, xylanases, mannosidases, and a protein similar to alginate lyase and also potential effectors necrosis‐ and ethylene‐inducing protein, small basic 14 kDa hypothetical protein and 79 kDa hypothetical proteins. Other proteins associated with virulence showed different expression profiles between mild and lethal isolates. The results suggest that the increased virulence of lethal isolates has little background shared by all three lethal isolates and that upregulation of isolate specific sets of proteins may be most important.
Microsatellite genotyping of 38 local Slovenian varieties was performed using 11 SSR markers that have been shown to be highly polymorphic in European Vitis resources. Combining those data with ...previous studies, 49 unique genotypes were identified within the varieties currently cultivated in the Slovenian Primorje region. These genotypes were further compared to 161 cultivars from eight European countries to assess their genetic relationships. A high level of genetic diversity among Slovenian grapevines was revealed and some unknown relationships were discovered. Identity analyses revealed 11 groups of synonyms among Slovenian varieties and three matches between a Slovenian variety and a variety from other countries. Several groups of Slovenian varieties with similar names resulted in different SSR profiles. The genetic distances between varieties used in Slovenia and the most popular cultivars used in other European countries revealed the closest relationship with Croatian varieties and the most distant with French varieties.
, a soilborne vascular phytopathogenic fungus, causes wilt disease in several crop species. Of great concern are outbreaks of highly aggressive
strains, which cause a devastating wilt disease in ...European hops. We report here the genome sequence and annotation of
strain T2, providing genomic information that will allow better understanding of the molecular mechanisms underlying the development of highly aggressive strains.
Bee products such as royal jelly, honey and propolis have been reported to possess several biological activities. In order to better understand their mechanism of action and, consequently, their ...efficiency and safety, 'omic' approaches are used. Here cases with proteomic approach are indicated. In addition to studying biological activity at a proteome level, a proteomic approach for investigation of bee products has also been applied in analyzing proteins as their (bioactive) components. Key words: proteomics, bioactive components, propolis, royal jelly, honey, yeast
Humulus lupulus L. is a dioecious perennial plant, cultivated for its female inflorescences. Spontaneously arising monoecious hop plants, carrying male and female flower types on a specific plant, ...occasionally occur in the progeny of certain hop crosses. We assessed the ploidy of 58 monoecious plants, progenies of various crosses of diploid parents, to provide additional data on hop monoeciousy. Flow cytometric analysis revealed that a high percentage (41.4%) were triploid. An inheritance analysis of parental alleles using six codominant SSR markers demonstrated a primarily paternal origin (84.2%) of unreduced gametes as the cause of triploidy in monoecious plants. All triploids had predominantly male flowers with a few female cones; this phenotype was found only within this ploidy group. All other monoecious plants were diploid, except for one genotype with the highest nuclear DNA content, which showed an aneuploidic number of chromosomes (21). Male hops showed the lowest nuclear DNA amount, as measured by DAPI and propidium iodide fluorochromes. The estimated AT frequency placed hop among species with a high AT content, which was slightly higher in male than in female plants (63.0% vs. 62.5%). The results are discussed in relation to the occurance of ploidy and sex expression in monoecious hop.
Celotno besedilo
Dostopno za:
BF, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Verticillium wilt is one of the most important diseases on hop that significantly influence continuation of production on affected areas. It is caused by the soil borne vascular pathogen
, which ...infects plants through the roots and then advances through the vascular (xylem) system. During infection,
secretes many different virulence factors. Xylem sap of infected plants is therefore a rich source for investigating the molecules that are involved in molecular interactions of
- hop plants. This protocol provides instructions on how to infect hop plants with
artificially and how to obtain xylem sap from hop plants.
Hop is a dioecious perennial, the female plants of which are cultivated for production of resin, used mainly in the brewing industry. Sex determination of hop plants is phenotypically determined in ...the second year of growth, so early sex determination at seedling stage, before planting, is important for breeding and cultivation purposes. We analyzed a microsatellite locus to determine sex specific differences in hop. Alleles of the locus showed tight linkage to male character, since no cross-over event was detected in two analyzed families with 181 progenies. The complete heterozygosity in 50 analyzed diverse males indicates a potential use of this marker for any desired parental pair. The marker is amplified in homologous chromosomes, which rules out incorrect determination of non-amplified samples, as can be the case with the dominant (presence/absence) type of markers. The described microsatellite locus is also highly variable, with 35 sized alleles, the distribution of which in different hop germplasms and their sequence variability are discussed. The sex specific marker determined in our study can contribute to studies of sex determination mechanisms and can be readily used in hop breeding and cultivation.
A sample of 94 pear (Pyrus L.) genotypes, traditionally present in the Slovenian landscape, was analyzed by amplified fragment length polymorphism (AFLP) and SSR (SSR), focusing on the assessment of ...genetic relationships. The analyzed samples involved germplasm of Pyrus communis L., P. nivalis Jacq., and P. pyraster L. The AFLP technique, using five EcoRI and MseI primer combinations, revealed molecular polymorphism at a level of 65.95%, representing 93 polymorphic bands among the total of 141 scored. With SSR analysis, 64 polymorphic alleles were found at seven microsatellite loci, with an average of 9.14 alleles per locus. Genetic distances among the individuals being studied were calculated using the Dice coefficient of similarity, and a dendrogram supported by AFLP and SSR data was constructed using the neighbor-joining method. The clustering method grouped the analyzed genotypes into three main clusters. The first cluster included the P. communis germplasm. The genotypes resembling P. nivalis were grouped in the second largest cluster, which could be divided in to four subclusters. The germplasm of P. pyraster, in this cluster, was found to be much less distinct than we had assumed. The most typical cultivar group in the third cluster was 'Vinska Mostnica'. The study indicated that P. nivalis germplasm is frequently present in Slovenia, but not as a pure species.
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