Zinc (Zn) is a nutrient that regulates many vital functions of the human body, hence the demand for Zn in the balanced daily nutrition has to be covered. Priming of seeds with Zn for Zn-enriched sprout production can be considered a good alternative to artificial supplementation in a modern diet. Hence, the aim of our study was to determine the exposure level of Zn bringing neither risk for humans nor growth inhibition of enriched broccoli, pea and sunflower sprouts. Seeds treated with 0, 10, 20 and 30 μg mL−1 ZnSO4 responded in a differentiated way to Zn. Pea seed germination and sprout growth was diminished by 30 μg mL−1 ZnSO4, but for sunflower sprouts this Zn level resulted in the highest fresh mass and largest hypocotyls. Zn content in sprouts greatly increased in a dose-dependent manner, mostly in broccoli (up to 25 times) and peas (up to 4 times), and to a lesser extent (up to 120%) for sunflowers. Free radical scavenging activity was usually decreased. Considering the potential non-carcinogenic risk of sprouts consumption estimated by the hazard analysis, the safest exposure level for seed priming will be 10 μg mL−1 ZnSO4. It was confirmed by random amplification of polymorphic DNA analyses indicating no DNA variations in sprouts treated with 10 μg mL−1 ZnSO4 compared to the control.

Chlamydomonas reinhardtii (WT 2137) P. A. Dang. (Volvocales, Chlorophyceae) is a green microalgae serving as a suitable model in scientific research and a promising industrial biotechnology platform for production of biofuel, hydrogen and recombinant proteins. Fullerenes (C60) are allotropic carbon nanoparticles discovered in 1985 and used in biomedical studies since the early 1990s, when water solubilization methodologies were developed. Recently, surface-modified hydroxylated derivatives of fullerenes were proven to enhance algal growth and drought tolerance in plants. Here, a novel type of water-soluble [60]fullerene derivative with 12 glycine residues (GF) has been synthesized and tested for acute toxicity (up to 50 µg/ml) and as a potential biostimulant of algal growth. The effects of GF on pigment composition and growth rate of Chlamydomonas reinhardtii were systematically investigated. Our results suggest that GF was not toxic, and no negative change in the pigment content and no stress symptoms were observed. No changes in the photosynthetic parameters based on the fluorescence of chlorophyll a in Photosystem II (NPQ, Fv/Fm, Fv/F0, PI and RC/ABS) were observed. The GF had no effect on cell size and growth rate. At a concentration of 20 µg/ml, GF stimulated chlorophyll accumulation in 3-day-old cultures.

Callus from Nicotiana tabacum is used as a model in plant developmental research. We tested several phytohormone (Indoleacetic acid – IAA; 2,4-Dichlorophenoxyacetic acid – 2,4-D; kinetin – KIN; 6-Benzylaminopurine – BAP) combinations to compare different approaches to callus induction directly from the seeds of Nicotiana tabacum. Callus formation was observed up to 4 weeks after sowing and the most effective were 0.5 mg/L of 2,4-D with 0.25 mg/L of BAP and 2 mg/L 2,4-D with 1 mg/L of BAP. The calli were green, photosynthetically active and after 6 weeks of growth, no stress symptoms (estimated on the basis of fluorescence of chlorophyll a in photosystem II) were noticed.