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Purification and characterization of an extracellular levansucrase from Pseudomonas syringae pv. phaseolicola
The rheological behavior of the product levan prompted a new assessment of the enzyme's role in pathogenesis and supports the presumption that the levansucrase is important in the early phase of infection by creating a separating layer between bacteria and plant cell wall to prevent the pathogen from recognition.
Adaptation of Fusarium graminearum to tebuconazole yielded descendants diverging for levels of fitness, fungicide resistance, virulence, and mycotoxin production.
Assessment of individual infected spikelets for mycotoxin contents by high-performance liquid chromatography mass spectrometry and for Fusarium DNA by quantitative polymerase chain reaction indicated that some of the adapted isolates produced significantly higher levels of nivalenol per fungal biomass than the NRRL 13383 strain.
Survey of maize from south-western Nigeria for zearalenone, α - and β -zearalenols, fumonisin B1 and enniatins produced by Fusarium species
- T. O. Adejumo, U. Hettwer, P. Karlovsky
- Biology, MedicineFood additives and contaminants
- 8 August 2007
A survey for the natural occurrence of Fusarium mycotoxins in maize for human consumption in four south-western states of Nigeria showed that 93.4% of the samples were contaminated with zearalenone (ZON), α- and β-zearAlenols (α- and α-ZOL), fumonisin B1 (FB1) or enniatins (ENNs).
Occurrence of Fusarium species and trichothecenes in Nigerian maize.
Citramalic acid and salicylic acid in sugar beet root exudates solubilize soil phosphorus
- R. Khorassani, U. Hettwer, A. Ratzinger, B. Steingrobe, P. Karlovsky, N. Claassen
- Biology, MedicineBMC Plant Biology
- 26 August 2011
Root exudates of sugar beet contain salicylic acid and citramalic acid, the latter of which has rarely been detected in plants so far, and these results provide the first assignment of a biological function to citramAlic acid of plant origin.
Cloning, Nucleotide Sequence, and Expression in Escherichia coli of Levansucrase Genes from the Plant PathogensPseudomonas syringae pv. glycinea and P. syringaepv. phaseolicola
- U. Hettwer, F. Jaeckel, J. Boch, M. Meyer, K. Rudolph, M. Ullrich
- Biology, EngineeringApplied and Environmental Microbiology
- 1 September 1998
Levansucrase was not secreted into the supernatant but was located in the periplasmic fraction of E. coli harboring the lsc gene, indicating that the native promoter of lsc was not functional in E.ccoli.
An investigation of genetic variation in Cirsium arvense field patches
Three years sampling within a patch showed that the patch mainly ‘grew’ via the establishment of new clones rather than by clonal growth of one genotype, indicating that root fragment dispersal via soil cultivation was of minor importance.
The tryptophan aminotransferase Tam1 catalyses the single biosynthetic step for tryptophan‐dependent pigment synthesis in Ustilago maydis
It is provided the first direct evidence that these indole pigments form spontaneously from indolepyruvate and tryptophan without any enzymatic activity, which suggests that compounds with a proposed function in M. furfur‐associated disease consist of indolespyruVate‐derived spontaneously generated metabolic by‐products.
Real-time PCR and agar plating method to predict Fusarium verticillioides and fumonisin B1 content in Nigerian maize.
Despite the high consumption of maize in Nigeria, the amount of FB 1 ingested by consumers appears to be low and the estimated daily intake of fumonisins was 0.21 µg/kg body weight per day.
The role of extracellular polysaccharides as virulence factors for phytopathogenic pseudomonads and xanthomonads
It is suggested that alginate which is very similar to plant pectate is required for establishing bacterial infections in later disease stages, and this concept was confirmed by evaluating transposon mutants with EPS deficiencies.