H. pluvialis is a unicellular freshwater alga containing many bioactive compounds, especially carotenoids, which are the strongest antioxidants among the pigments. This study evaluates the composition and content of carotenoids and other pigments in both stages of algae life cycle, especially in the green vegetative stage, less studied in comparison to the red stage. To determine the composition and content of carotenoids, a combination of HPLC-DAD and LC-QTOF-MS was used. The content of carotenoids in the green vegetative stage was significantly lower than in the red vegetative stage. In the green vegetative stage, 16 different carotenoids and other pigments were identified. Among the total 8.86 mg g⁻¹ DW of pigments, 5.24 mg g⁻¹ DW or 59% of them were chlorophyll a with its derivatives, and 3.62 mg g⁻¹ DW or 41% of them were free carotenoids. After the transition from the green to the red stage, the carotenoid composition was replaced by secondary carotenoids, astaxanthin and its esters, which predominated in the whole carotenoid composition. In addition to free astaxanthin, 12 astaxanthin monoesters, 6 diesters and 13 other carotenoids were determined. The majority of 37.86 mg g⁻¹ DW pigments were monoesters. They represented 82% of all pigments, and their content was about 5 times higher than both, diesters (5.91 mg g⁻¹ DW or 12% of all) and free carotenoids (2.4 mg g⁻¹ DW or 6% of all). The results of the study contribute to the data on the overall pigment composition and content of H. pluvialis algae and provide the basis for further improvement of cultivation of the H. pluvialis algae.

Chlorogenic acid is one of the most prominent bioactive phenolic acids with great pharmacological, cosmetic and nutritional value. The potential of Berula erecta in tissue culture was investigated for the production of chlorogenic acid and its elicitation combined with light of different wavelengths and low temperature. The content of chlorogenic acid in the samples was determined by HPLC-UV, while the content of total phenolic compounds and the antioxidant activity of their ethanol extracts were evaluated spectrophotometrically. The highest fresh and dry biomasses were obtained in plants grown at 23 °C. This is the first study in which chlorogenic acid has been identified and quantified in Berula erecta. The highest chlorogenic acid content was 4.049 mg/g DW. It was determined in a culture grown for 28 days after the beginning of the experiment at 12 °C and under blue light. The latter also contained the highest content of total phenolic compounds, and its extracts showed the highest antioxidant activity. Berula erecta could, potentially, be suitable for the in vitro production of chlorogenic acid, although many other studies should be conducted before implementation on an industrial scale.

Plants Physiology: Exercise Instructions Manual. The manual is prepared for students in undergraduate courses in biology, ecology with nature conservation, and prospective biology teachers who wish to become familiar with experimental work in plant physiology. It consists of eight sections dealing with plant pigments, plant respiration and photosynthesis, plant enzyme activity, plant water regulation, plasmolysis, plant mineral nutrition by recognizing symptoms of nutrient deficiency, methods for determining sugar content, and bioassays for plant hormones. Each of the exercises begins with a content introduction and continues with the objectives, tasks, materials, and procedure for the exercise. The exercises are supported by pictures of the individual experiments, tables, chemical formulas for calculating individual physiological parameters, and instructions for using chemicals and equipment. Priročnik je namenjen študentom na študijskih programih s področja biologije, ekologije z naravovarstvom in bodočim učiteljem biologije, ki bi se radi spoznali z eksperimentalnim delom s področja fiziologiji rastlin. Sestavlja ga osem vsebinskih sklopov, ki obravnavajo rastlinske pigmente, dihanje rastlin in fotosintezo, encimsko aktivnost rastlin, uravnavanje vodnih razmer v rastlinah, plazmolizo, mineralno prehrano rastlin s prepoznavanjem simptomov pomanjkanja posameznih hranil, metode določanja vsebnosti sladkorjev in bioteste za rastlinske hormone. Vsaka od vaj se začne z vsebinskim uvodom ter nadaljuje s cilji, nalogami, materiali in potekom izvedbe vaje. Vaje so podprte s slikami posameznih poskusov, preglednicami, kemijskimi formulami za preračune posameznih fizioloških parametrov in navodili za delo s kemikalijami in opremo.

Corn cockle (Agrostemma githago L. (Lychnis githago (L.) Scop.)) is the main ingredient in some plant preparations for biostimulation in agriculture, and it elicits many positive responses. In our study, we attempted to determine if the fresh and dry plant material of A. githago contained auxin-like and cytokinin-like growth regulators (PGRs). Cucumis and mung bean bioassays were used to determine the presence of auxin-like PGRs and Cucumis and Triticum bioassays were used to determine the presence of cytokinin-like PGRs. A water solution derived from the crushed, homogenized and extracted seeds, fresh and dry seedlings, and fresh and dry young plants showed auxin-like activity in both bioassays. The activity in the Cucumis bioassay corresponded to 0.5 to 2 mg L⁻¹ of Indole-3-butyric acid (IBA), and in the mung bean bioassay, the activity corresponded to 0.5 to 4 mg L⁻¹ of IBA. While the same water solutions showed weak or no cytokinin-like activity in the Cucumis cotyledon expansion bioassay, and they showed an activity of approximately 0.5 to 1 mg L⁻¹ of 6-Benzylaminopurine (BAP) in the Triticum bioassay. An LC-MS analysis confirmed the presence of free auxins, low levels of or no auxin analogues, a small amount of free cytokinins and a higher level of their cytokinin analogues in the samples, seeds, dry seedlings and young plants of A. githago, which was likely related to the fine-tuning between the free and analogue forms of the PGRs in the water solutions used in the experiments.