Hydrogen sulfide (H2S) has traditionally been thought of as a phytotoxin, having deleterious effects on the plant growth and survival. It is now recognized that plants have enzymes which generate H2S, cysteine desulfhydrase, and remove it, O-acetylserine lyase. Therefore, it has been suggested that H2S is considered as a signalling molecule, alongside small reactive compounds such as hydrogen peroxide (H2O2) and nitric oxide (NO). Exposure of plants to low of H2S, for example from H2S donors, is revealing that many physiological effects are seen. H2S seems to have effects on stomatal apertures. Intracellular effects include increases in glutathione levels, alterations of enzyme activities and influences on NO and H2O2 metabolism. Work in animals has shown that H2S may have direct effects on thiol modifications of cysteine groups, work that will no doubt inform future studies in plants. It appears therefore, that instead of thinking of H2S as a phytotoxin, it needs to be considered as a signalling molecule that interacts with reactive oxygen species and NO metabolism, as well as having direct effects on the activity of proteins. The future may see H2S being used to modulate plant physiology in the field or to protect crops from postharvest spoilage.

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Different substances from the natural origin which have beneficial effects on plant growth and development, stress resistance, and crop yield and quality can be called biostimulants or biostimulators. Their physiological effects depend on their composition as they contain various organic and mineral compounds which plants can use as metabolites, growth regulators, and nutrients; however, biostimulants cannot be considered biofertilizers. Biostimulants applied in plant production have been widely considered as an environment‐friendly agricultural practice—and so are now among tools used in sustainable agriculture. Here, we discuss the results of the biostimulants’ effect investigations performed in Croatia, focused on horticultural crops, with edible plant species, such as tomato, garlic, bell pepper, lettuce, strawberry, garden cress, and basil, as well as ornamentals, such as wild rose, wax begonia, Mexican and French marigold, moss rose, everlasting flower, common zinnia, English primrose, and scarlet sage. The investigated biostimulants were applied at all plant growth stages, from germination to full plant and fruit or flower commercial maturity, using the seed treatment, foliar application, or irrigation. To evaluate biostimulant effectiveness, various morphological, physiological, and quality traits were analyzed. In this wide array of studies, the evaluated biostimulants mostly enhanced seed and transplant vigor, stimulated vegetative growth, improved nutrient acquisition and distribution within the plant, increased antioxidative capacity of plant tissues, contributing to higher stress tolerance, and improved plant yield and fruit/flower quality. In general, the research reviewed here implies possible benefits of biostimulant application in horticultural production, especially in stressful growth conditions, such as the transplant stage, reduced fertilization, or incidence of other abiotic stress. Considering possible interactions among the contained physiologically active compounds, the effects on plants may depend on dose, time of treatment, growth conditions, and plant species. Therefore, further research of biostimulant applications in horticultural production is suggested.

Hydrogen sulfide (H(2)S) has recently been reported to be a signaling molecule in plants. It has been well established that is has such roles in animals and it has been suggested that it is included into the group of gasotransmitters. We have recently shown that hydrogen sulfide causes stomatal opening in the model plant Arabidopsis thaliana. H(2)S can be supplied to the plant tissues from donors such as sodium hydrosulfide (NaSH) or more recently from slow release H(2)S donor molecules such as GYY4137. Both give similar effects, that is, they cause stomatal opening. Furthermore both H(2)S donors reduced the accumulation of nitric oxide (NO) induced by abscisic acid (ABA) treatment of leaf tissues. Here similar work has been repeated in a crop plant, Capsium anuum, and similar data has been obtained, suggesting that such effects of hydrogen sulfide on plants is not confined to model species.

Plants must cope with different environmental stresses during their whole lifetime. Abiotic stresses like drought, salt, mineral nutrition disturbances and temperature stress are commonly interconnected through some physiological events in stressed plants, such as the synthesis of protective plant compounds as a response to stress. Many of these, produced within plant primary or secondary metabolism, act as functional compounds not exclusively in plants but in other organisms as well. Concurrently, many of the active compounds in biostimulants which can support plant stress tolerance and productivity in adverse growth conditions are the metabolites or intermediates that may influence the plant's edible parts nutritional quality. Such effects of biostimulants application are not elucidated enough, therefore, we aimed to give an overview of recent advances in the research related to the interplay among abiotic stress, plant response, biostimulants effects and plant‐derived functional food, focusing on plant metabolites as the link which connects the environment with the food chain.

Plants are the first step of a metal's pathway from the soil to heterotrophic organisms such as animals and humans, so the content of metallic trace elements in edible parts of a plant represent available load of these metals that may enter the food chain through plants. Among metal elements, Cu, Fe, Mn, and Zn are micronutrients as they are essential in trace amounts for physiological processes in living organisms and therefore are a significant component of the soil-plant-food continuum. Billions of people around the world suffer from micronutrient malnutrition. This review is aimed at giving an overview of the data pertaining to the Fe, Mn, Zn, and Cu content of the grains of the globally most important cereals -wheat, rice, and maize, reported mostly during the last two decades. The prevailing opinions on their importance in the food chain, and current strategies for enrichment of cereal grains with those essential microelements are briefly summarized.

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