In addition to the structural and storage functions of the (1,3; 1,4)-β-d-glucans (β-d-glucan), the possible protective role of this polymer under biotic stresses is still debated. The aim of this study was to contribute to this hypothesis by analyzing the β-d-glucans content, expression of related cellulose synthase-like (Csl) Cs1F6, CslF9, CslF3 genes, content of chlorophylls, and β-1,3-glucanase content in oat (Avena sativa L.) leaves infected with the commonly occurring oat fungal pathogen, Blumeria graminis f. sp. avenae (B. graminis). Its presence influenced all measured parameters. The content of β-d-glucans in infected leaves decreased in all used varieties, compared to the non-infected plants, but not significantly. Oats reacted differently, with Aragon and Vaclav responding with overexpression, and Bay Yan 2, Ivory, and Racoon responding with the underexpression of these genes. Pathogens changed the relative ratios regarding the expression of CslF6, CslF9, and CslF3 genes from neutral to negative correlations. However, changes in the expression of these genes did not statistically significantly affect the content of β-d-glucans. A very slight indication of positive correlation, but statistically insignificant, was observed between the contents of β-d-glucans and chlorophylls. Some isoforms of β-1,3-glucanases accumulated to a several-times higher level in the infected leaves of all varieties. New isoforms of β-1,3-glucanases were also detected in infected leaves after fungal infection.

No abstract

Although growth stimulation at low arsenic doses was observed in several plants, few studies have focused on this phenomenon in more detail. The effects of different concentrations of arsenic (0–50 mg kg−1 of soil: As0–As50) on the growth and selected physiological parameters of two maize cultivars (Zea mays L. cvs. Chapalu and MvNK 333) were tested. Cultivar MvNK 333 manifested a generally higher tolerance to As than cv. Chapalu, which may be related to the lower content of As in the tissues. The highest stimulatory effect of As was recorded at doses of As1 and As2 (cv. Chapalu), and at the As5 dose (MvNK 333), there was an increase in shoot elongation, biomass, and relative water content (RWC), as well as the content of photosynthetic pigments. The stimulatory effect of lower doses of As apparently represents an adaptation mechanism that is associated with water content regulation in the given conditions. The stomata of the studied cultivars were involved in this regulation in different ways. While cv. Chapalu exhibited increased numbers of stomata on both sides of leaves, cv. MvNK 333 instead responded to the given conditions with decreased stomata size. Although hormetic manifestations closely related to changes in stomatal number and size were observed, a typical stomatal hormetic response was not observed in the given range of As doses.

No abstract

The autochtonous taxa of the genus Prunus L.: Prunus × fruticans, Prunus × fechtneri and Prunus × dominii was chosen for this research: the phenological observations and occurrence pest and diseases. We recorded, that two of the studied taxa P. × fruticans and P. × dominii started growth phases the first and P. × fechtneri the last. The longest vegetation period from first phenophase to dormancy (224 days) for P.× fechtneri in 2012 was observed. The shortest vegetation period (209 days) from first phenophases to phenophases flowering for P. × fruticans in 2013 was observed. We recorded the occurrence of insect Cydia funebrana, parasitic lichen Xanthoria parietina and fungal disease Botrytis cinerea. The highest incidence of Cydia funebrana was recorded on taxa P. × fechtneri from the locality Bádice and Prunus × dominii from the locality Dolné Lefantovce. On the shoots of the taxa L2, L3 and P1 the presence of parasitic lichen Xantoria parietina and in the plum P. × fechtneri B fungal disease Botrytis cinerea was observed. Only for the taxa Prunus × fruticans L1 no lichen was recorded. The taxa Prunus × fruticans L1, P1 and Prunus × dominii L2, L3 no fungal disease was show.