D- and most L-enantiomers of carbohydrates and carbohydrate-containing compounds occur naturally in plants and other organisms. These enantiomers play many important roles in plants including building up biomass, defense against pathogens, herbivory, abiotic stress, and plant nutrition. Carbohydrate enantiomers are also precursors of many plant compounds that significantly contribute to plant aroma. Microorganisms, insects, and other animals utilize both types of carbohydrate enantiomers, but their biomass and excrements are dominated by D-enantiomers. The aim of this work was to review the current knowledge about carbohydrate enantiomers in ecosystems with respect to both their metabolism in plants and occurrence in soils, and to identify critical knowledge gaps and directions for future research. Knowledge about the significance of D- versus L-enantiomers of carbohydrates in soils is rare. Determining the mechanism of genetic regulation of D- and L-carbohydrate metabolism in plants with respect to pathogen and pest control and ecosystem interactions represent the knowledge gaps and a direction for future research.

European sugar production is influenced by the demand for alternative sweeteners, new technologies, and Common Agricultural Policy. Sugar beet is a biological resource with high carbon accumulation; chemically and energy-intensive crop with high rate of assimilation and carbon-dependent microbiome. The structure of associated greenhouse gas emissions is well known. In this review, currently available tools able to reduce environmental burden and the risk of resistance are summarized from the viewpoint of sustainability. In the field of herbicide protection, strip tillage combined with early-sown, fast-growing and freezing out intercrops is discussed, combined with tolerance to acetolactate synthase enzyme inhibitors, herbicide point application techniques, and autonomous inter-row weeding systems. Modern methods of insecticidal protection are based on cultivation of companion crops with camouflage or repellent effects, biological traps used by organic sugar beet growers and plant protection products based on essential oils. Current state of European insecticide scene calls for the utmost need for the integration of signaling methods and techniques of chemical and physical fixation of conventional plant protection products not burdened by resistance. Protection against pathogens is discussed according to the activity of the associated microflora, subsequently categorized into four lines of defense. Biofungicides are widely available, but for now, too technology-demanding and costly. The implementation of new fungicidal biotechnologies based on breeding associated with microbiome is very close, but – for now – still missing proper impulse for their introduction into practice, caused by a fundamental legislative restriction or economic pressure.

Morphological and biochemical responses were assessed in an iceberg (G_IL) and butterhead (G_BL) lettuce (Lactuca sativa var. capitata) treated with commercially available soluble preparation of mycorrhizal fungi and beneficial soil bacteria (MT) grown in three irrigation treatments considered in greenhouse (continental Croatia, 2022): I₁₀₀—control treatment (100% volumetric water content—VWC); I₈₀—80% VWC, moderate drought and I₆₀—60% VWC, severe drought), in two growing cycles. MT was applied during lettuce drought-sensitive stages, i.e., transplanting and heading. Study results show that MT improved lettuce growth-related traits, yet the results are genotype and growing-cycle dependent. The beneficial effect of MT was also noted for root length, weight, and diameter which confirms the mycorrhizal role in improving the plant water uptake. Both lettuce genotypes responded to water deficit by overproduction of MDA and proline content, whereby the response of tested variables was growing cycle and genotype-specific. Both genotypes in severe drought treatment (MT-I₆₀) responded with higher MDA in the first growing cycle and lower MDA content in the second growing cycle. MT-I₆₀ treatment reduced proline accumulation in G_BH in both growing cycles, while increased accumulation in G_IL during the second growing cycle. The responses of lettuce to MT are genotype-specific and shaped by environmental conditions.

The High Voltage Electrical Discharge (HVED) is a physical hydropriming method which alters the physicochemical properties of water, creating the plasma activated water (PAW). The mixture of highly reactive ions and molecules can break down the seed dormancy and speed up the growing process. Previous studies presented the promotional role of HVED technology on the germination, growth and polyphenol content. The aim of this study was to explore the effect of HVED technology on germination ability and vitality of three types of seeds with low germination rate. Selected species included carrot (Daucus carota L.), melilot (Melilotus albus Medik.), and mallow (Malva verticillata L.). In carrot and mallow, HVED (20Hz/30s) significantly promoted germination percentage, whilst in melilot seeds, germination was unchanged. HVED treatment enhanced the growth of shoots and roots in both carrot and mallow. In melilot, shorter treatment time of exposure to high voltage (30Hz/10s) resulted in longer shoots and roots. Perspectives of HVED as a method for improvement of germination exist, especially in mellow and carrot, but it is necessary to optimize the process parameters for each type of seed separately.