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Microdochium bolleyi is a fungal endophyte of cereals and grasses proposed as an ideal model organism for studying plant-endophyte interactions. A qPCR-based diagnostic assay was developed to detect M. bolleyi in wheat and Brachypodium distachyon tissues using the species-specific primers MbqITS derived from the ITS of the ribosomal gene. Specificity was tested against 20 fungal organisms associated with barley and wheat. Colonization dynamics, endophyte distribution in the plant, and potential of the seed transmission were analyzed in the wheat and model plant B. distachyon. The colonization of plants by endophyte starts from the germinating seed, where the seed coats are first strongly colonized, then the endophyte spreads to the adjacent parts, crown, roots near the crown, and basal parts of the stem. While in the lower distal parts of roots, the concentration of M. bolleyi DNA did not change significantly in successive samplings (30, 60, 90, 120, and 150 days after inoculation), there was a significant increase over time in the roots 1 cm under crown, crowns and stem bases. The endophyte reaches the higher parts of the base (2-4 cm above the crown) 90 days after sowing in wheat and 150 days in B. distachyon. The endophyte does not reach both host species' leaves, peduncles, and ears. Regarding the potential for seed transmission, endophyte was not detected in harvested grains of plants with heavily colonized roots. Plants grown from seeds derived from parental plants heavily colonized by endophyte did not exhibit any presence of the endophyte, so transmission by seeds was not confirmed. The course of colonization dynamics and distribution in the plant was similar for both hosts tested, with two differences: the base of the wheat stem was colonized earlier, but B. distachyon was occupied more intensively and abundantly than wheat. Thus, the designed species-specific primers could detect and quantify the endophyte in planta.

Brachypodium distachyon is a useful model organism for studying interaction of cereals with phytopathogenic fungi. The present study tested the possibility of a compatible interaction of B. distachyon with the endophytic fungus Microdochium bolleyi originated from wheat roots. There was evaluated the effect of this endophytic fungus on the intensity of the attack by pathogen Fusarium culmorum in B. distachyon and wheat, and also changes in expression of genes (in B. distachyon: BdChitinase1, BdPR1-5, BdLOX3, BdPAL, BdEIN3, and BdAOS; and in wheat: TaB2H2(chitinase), TaPR1.1, TaLOX, TaPAL, TaEIN2, and TaAOS) involved in defence against pathogens. Using light microscopy and newly developed specific primers was found to be root colonization of B. distachyon by the endophyte M. bolleyi. B. distachyon plants, as well as wheat inoculated with M. bolleyi showed significantly weaker symptoms on leaves from infection by fungus F. culmorum than did plants without the endophyte. Expression of genes BdPR1-5, BdChitinase1, and BdLOX3 in B. distachyon and of TaPR1.1 and TaB2H2 in wheat was upregulated after infection with F. culmorum. M. bolleyi-mediated resistance in B. distachyon was independent of the expression of the most tested genes. Taken together, the results of the present study show that B. distachyon can be used as a model host system for endophytic fungus M. bolleyi.

Brachypodium distachyon is a useful model organism for studying interaction of cereals with phytopathogenic fungi. The present study tested the possibility of a compatible interaction of B. distachyon with the endophytic fungus Microdochium bolleyi originated from wheat roots. There was evaluated the effect of this endophytic fungus on the intensity of the attack by pathogen Fusarium culmorum in B. distachyon and wheat, and also changes in expression of genes (in B. distachyon: BdChitinase1, BdPR1-5, BdLOX3, BdPAL, BdEIN3, and BdAOS; and in wheat: TaB2H2(chitinase), TaPR1.1, TaLOX, TaPAL, TaEIN2, and TaAOS) involved in defence against pathogens. Using light microscopy and newly developed specific primers was found to be root colonization of B. distachyon by the endophyte M. bolleyi. B. distachyon plants, as well as wheat inoculated with M. bolleyi showed significantly weaker symptoms on leaves from infection by fungus F. culmorum than did plants without the endophyte. Expression of genes BdPR1-5, BdChitinase1, and BdLOX3 in B. distachyon and of TaPR1.1 and TaB2H2 in wheat was upregulated after infection with F. culmorum. M. bolleyi-mediated resistance in B. distachyon was independent of the expression of the most tested genes. Taken together, the results of the present study show that B. distachyon can be used as a model host system for endophytic fungus M. bolleyi.

Two ectoparasite powdery mildew species Golovinomyces cichoracearum (Gc) and Podosphaera xanthii (Px) occurring on cucurbits differ, besides other characteristics, by specific ecologic requirements. While Px is common in subtropical and tropical areas and greenhouse crops, Gc occurs more frequently in temperate and cooler areas under field conditions. Their presence on cucurbit field crops (Cucurbita pepo, C. maxima, Cucumis sativus) was monitored in the Czechoslovakia (1979-1980) and in the Czech Republic (1995-2007). Their identification was carried out by microscopic observation of the morphological characteristics of the dry conidia on 1527 leaf samples. Data on air temperature in 1979-2007 were provided by the Czech Hydrometeorological Institute. In 1979-1980 Gc was identified in 86.0% of samples, Px in 14.0% samples, there was no mixed infection; prevalence of Px was recorded in South Slovakia and South Moravia, and on crops under cover. Since 1995 species Px was recorded each year on field crops in different locations of Bohemia and Moravia, usually in mixed infection with Gc. The average year temperature of 8.1°C for period 1992-2007 was higher than corresponding value of 7.4°C in 1979-1983. Similarly, average temperature in vegetation season of 16.2°C in 1992-2007 was higher than corresponding value of 15.7°C in 1979-1983. The higher air temperature can positively influence spreading of Px in the Czech Republic. Climate variability and effect of their changes are discussed in relationship to the geographic distribution and geographic patterns of cucurbit powdery mildews.