Externí autoři: Jiří Malbeck

Carotenoids and phenolic acids during ripening, harvest and storage in selected scab-resistent and mildew-tolerant apple cultivars

Submitted by Kateřina Eliášová on Fri, 03/05/2021 - 14:15

The aim of this study was to characterise the changes in concentration and composition of antioxidants during ripening, harvest and after 3 and 6 months of storage in three commercially successful scab-resistant and powdery mildew-tolerant apple cultivars selected in the Institute of Experimental Botany. The detailed description of free and glycosylated phenolic acid profiles and content of 6 selected carotenoids - neoxanthin, violaxanthin, antheraxanthin, lutein, zeaxanthin and ß-carotene will serve for outcomes of major characteristics of these apple cultivars.

The effect of storage conditions on the carotenoid and phenolic acid contents of selected apple cultivars

Submitted by Kateřina Eliášová on Mon, 07/20/2020 - 15:53

The present study investigated how different storage conditions affect antioxidant levels in three scab-resistant and powdery mildew-tolerant apple cultivars. The contents of carotenoids, along with free and glycosylated phenolic acids, were quantified in harvested apples and apples stored in boxes with controlled atmospheric conditions (1.2% O2 and 2.2% CO2) and temperature (1 °C), boxes with regulated temperature (1 °C) and storage rooms with a temperature between 1 and 4 °C.

Is phenolic acid content in apples influenced by environmental factors?

Submitted by Kateřina Eliášová on Tue, 04/21/2020 - 14:13

Phenolic compounds (phenylpropanoids with an aromatic ring bearing one or more hydroxyl groups and various other substituents) are produced by plants as secondary metabolites, ranging from simple monomers to very large polymers. Due to their antioxidant activity they play crucial roles in plant defences against both biotic and abiotic stressors, moreover they are an important component of animal diet and they are highly beneficial for human health.

Phenolic acids in selected scab‑resistant and mildew‑tolerant apple cultivars

Submitted by Kateřina Eliášová on Thu, 04/16/2020 - 13:33

Phenolic compounds play important roles in plant defences against both biotic and abiotic stressors, and many in crop plants are highly beneficial for human health, but their quantities and profiles are influenced by numerous factors. Thus, the purpose of this study was to quantify free and glycosylated phenolic acids in apples (important sources of beneficial phenolics) in the course of fruit development, at harvest and during 5 months of storage.

Dormancy breaking in Fagus sylvatica seeds is linked to formation of abscisic acid-glucosyl ester

Submitted by Kateřina Eliášová on Thu, 09/26/2019 - 13:20

Seed dormancy is an adaptive mechanism that allows seed germination under suitable environmental conditions. Germination of stored dormant seeds proceeds after dormancy breaking induced by stratification. To improve understanding of dormancy breaking in beechnuts, we: investigated effects of moisture content and temperature during storage; analysed contents of abscisic acid, abscisic acid metabolites and indole-3-acetic acid in embryonic axes during storage and stratification; and histochemically localized storage proteins.

Profiles of phenolic acids in apples during ripening and storage

Submitted by Kateřina Eliášová on Wed, 07/03/2019 - 10:49

Phenolic compounds constitute a substantial group of phenylpropanoids which are produced by plants as secondary metabolites with antioxidant properties. The spectrum and concentrations of phenolic acids serve as a convenient marker of plant resistance to biotic stresses. Phenolics form also an important component of animal diet. Apples are a widely available fruit exhibiting significant concentrations of antioxidants, especially phenolics and carotenoids. Generally, the concentrations and composition of antioxidants vary during ripening and subsequent handling of harvested fruits.

Cytological, Biochemical and Molecular Events of the Embryogenic State in Douglas-fir (Pseudotsuga menziesii [Mirb.])

Submitted by Kateřina Eliášová on Wed, 02/27/2019 - 17:19

Somatic embryogenesis techniques have been developed for most coniferous species, but only using very juvenile material. To extend the techniques’ scope, better integrated understanding of the key biological, physiological and molecular characteristics of embryogenic state is required. Therefore, embryonal masses (EMs) and non-embryogenic calli (NECs) have been compared during proliferation at multiple levels.

The response of Picea abies somatic embryos to UV-B radiation depends on the phase of maturation

Submitted by Kateřina Eliášová on Tue, 11/27/2018 - 11:17

In summary, the exposure of Norway spruce EC to UV-B radiation at different stages of maturation had the strongest effect on cell viability of embryos at early stages of development and resulted in the inhibition of somatic embryo development and/or the substantial decrease in the number of embryos. The extent of cell damage was dependent on the UV-B dose applied, as well as the embryo developmental stage, and might be related to differentiation of the outermost cell layers and formation of protoderm.

Antioxidants (phenolic acids and carotenoids) in selected apple varieties - harvested and stored

Submitted by Kateřina Eliášová on Wed, 02/27/2019 - 16:26

The aim of this work was to determine the concentration of selected carotenoids (neoxanthin, violaxanthin, antheraxanthin, lutein, zeaxanthin and ß-carotene) and phenolic acids in selected scab resistant and powdery mildew tolerant apple varieties originating from the Station of apple breeding of the IEB. We investigated three different apple varieties - Luna (yellow), Red Topaz (red) and Karneval (streaked) for their antioxidant contents in peel and flesh immediately after the harvest and after 7 months of storage.

The effect of different air humidity during desiccation on the development of Norway spruce somatic embryos

Submitted by Lucie Fischerová on Fri, 09/21/2018 - 12:38

The objective of the study was to follow morphological, selected biochemical and transcriptional characteristics induced by various air humidity during desiccation of Norway spruce somatic embryos. The level of free polyamines lowered, higher forms of polyamines were favoured. Expression profiles of monitored genes were variously influenced by different relative air humidity. Our data proved, that desiccation of somatic embryos is metabolically active process highly affected by relative air humidity.