Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme III: PATHOGENS AND NUISANCES, FOOD AND MEDICINE Posters
852 - Inhibition of microconidia of F. oxysporum var.
vasinfectum with antibiotic substances from Bacillus
subtilis strains
R.N. Mannanov * & R.K. Sattarova
Department of Phytopathology and Plant Physiology,
Tashkent State Agrarian University, Tashkent 700140,
Uzbekistan. - E-mail: abdukahar.kadyrov@syngenta.com
Previously obtained results from comparative
physiological, biochemical and antimicrobal investigation
of endophyte and soil borne cultures of Bacillus subtilis N
and 23 had allowed to suggest that both strains produce the
same antibiotic substances active against cotton
phytopathogens. To additionally prove the hypothesis, we
carried out phase-contrast microscopy of phytopathogens'
cells in the inhibition zone. The use of phase-contrast
microscopy had shown inhibitory effect of antibiotic
substances from 23 and N strains of B. subtilis on growth
of microconidia which was different depending on the
diffusion of antibiotic substances from the 0.5 cm well on
agar in the centre with antibiotic filtrates from cultural
liquids of B. subtilis strains towards edges of Petri dishes.
Basing on the analysis of comparative influence of filtrates
of 23 and N strains in the following dilutions: 1:1, 1:2, 1:4,
1:9 and 1:99, we had systemized investigated microconidia
of F. vasifectum by the character of inhibition to four
conventional groups. Obtained results allowed to determine
the unit of biological activity of filtrates of 23 and N strains
which was equal to 85 mg of extracted antibiotic
substances, whereas 1 ml of filtrates of each strain
contained 11.8 units of antibiotic activity. Further
experiments will be directed on studies of mechanisms of
biological action of antibiotics produced by 23 and N
strains on cells of different groups of fungal and bacterial
microorganisms.
853 - Bee pollen as a substrate for fungal development
and mycotoxin production
R. Mateo 1* , G. González 2 , J.M. Sáez 2 , A. Medina 2 , A.
Llorens 2 & M. Jiménez 2
1
Unidad de Analisis de Sanidad Animal (Conselleria de
Agricultura, Pesca y Alimentación), Av. Manuel Soto 18,
2
E-46024, Valencia, Spain. - Departamento de
Microbiologia y Ecología (Univ. de Valencia, Dr. Moliner
50, E-46100, Burjasot, Valencia, Spain. - E-mail:
rufino.mateo@uv.es
Pollen is a basic food for bee larvae development due to its
high content of proteins, which contain all the amino acids.
Pollen also contains minerals, vitamins, enzymes, growth
regulators, fatty and organic acids and flavonoids. It is
considered by the FAO a source of essential nutrients for
the daily intake. Pollen consumption has increased in the
last years as a diet complement in cases of fatigue,
undernourishment and in vegetarian diets. Bees gather
pollen in flowers, mix it with honey and nectar to make
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Book of Abstracts
pellets and carry it to the beehive to serve as a food for
larvae. Beekeepers catch pollen in traps put at the hive
entry. Pollen remains in traps for some time, then it is taken
and carried to stores where it is cleaned, fumigated, stored
and marketed. During this stage pollen can be
contaminated by several fungal species, among them those
that are mycotoxin producers. We have evaluated for the
first time the capacity of bee pollen to serve as a substrate
for the development of Fusarium and Aspergillus species
that are potential producers of zearalenone,
deoxynivalenol, fumonisins and aflatoxins. The levels of
the mycotoxins produced in pollen have been determined
and a comparative study between pollen and other
especially susceptible substrates, like cereal grains has
been made. The results obtained point out that the toxin
levels found in pollen are significantly higher than those
produced by the same isolates in cereal grains under the
same incubation conditions.
854 - Analysis of gene expression in targeted infection
structures of obligate parasites, Blumeria graminis f. sp.
hordai by intracellular RT-PCR
Y. Matsuda * , T. Nonomura & H. Toyoda
Laboratory of Plant Pathology and Biotechnology, Faculty
of Agriculture, Kinki University, 3327-204 Nakamachi
Nara 631-8505, Japan. - E-mail:
ymatsuda@nara.kindai.ac.jp
To detect specific mRNAs in postinfectional differentiation
of obligate fungal parasites Blumeria graminis f. sp.
hordai, we applied an intracellular RT-PCR to conidia
inoculated onto barley coleoptile epidermis. The RT-PCR
primers for target genes were constructed using a EST
library of powdery-mildewed Italian ryeglass leaves. In the
present study, the chitin synthase gene (chs1) was used as a
target gene expressed specifically during the differentiation
of fungal infection structures. The primers were
constructed on the base of nucleotide sequences between
translation and 3'-untranslation regions. The first strand
cDNA was conducted in the fungal structures (conidia,
appressoria and secondary hyphae) by microinjecting the
reaction mixture (primers, reverse transcriptase, rTaq
polymerase and dNTPs) and subsequently amplified by
PCR using the primers amplifying the internal region of the
chs1. The nucleotide sequence of the amplified DNA was
determined and confirmed to be consistent with the chs1
gene of B. graminis f. sp. hordai. Thus, the present work
provides a new molecular tool for analyzing gene
expression during the differentiation process of infection
structures of obligate fungal pathogens, especially
emphasizing that cell-specific gene expression in
individual infection structures of the pathogen can be
monitored with respect to host and parasite interactions.