An open-field 3-year-long microplot experiment was set up with three micropropagated lines (SC Blossom, BFT Indiana, and STM Hajdúsági) of giant reed (Arundo donax L.). Plants were grown on a soil cover of a former sewage settling pond located in Debrecen Lovász-Zug, Hungary. Soil cover of the sewage sediment was moderately contaminated with various toxic elements (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, and Zn). The highest total concentration of examined toxic elements in leaves was found in the BFT Indiana line (∑326 mg/kg), while in the SC Blossom and STM Hajdúsági lines, ∑210 mg/kg and ∑182 mg/kg were measured, respectively. The highest Zn concentration (117 mg/kg) was found in the leaves of in BFT Indiana line and was 67% higher than that in SC Blossom and 95% more than in the STM Hajdúsági line. The BFT Indiana leaves showed typical signs of adaptation to heavy metal stress in the case of numerous micromorphometric characteristics. The extent of leaf mesophylls decreased, and the number of bulliform cells and phytoliths, as well as the sclerenchymatous stock, increased. The size of the vascular bundles was reduced. The size of the stomata decreased while the stomatal density increased. It can be concluded that the BFT Indiana line had the best adaptational response to heavy metal stress.

High temperatures have adverse impacts on the photosynthetic efficiency and yield of many crop plants. This study investigated how high temperatures affect the photosynthetic efficiency parameters and chloroplast ultrastructure of three edamame cultivars (AGS354, UVE17, and UVE14) at the reproductive stages (flowering and pod-filling). Heat stress (HS) treatments were performed under controlled conditions in climate chambers set at 25/18 °C (control), 30/23 °C (HS-I), and 35/28 °C (HS-II). The AGS354 cultivar exhibited the greatest susceptibility under HS-II treatment, characterised by a reduction in the photochemical reactions, decreased chlorophyll-a (chl-a) and carotenoid accumulation, the highest increase in the starch grain traits, and reduced plastoglobule and grana area traits. In UVE 14 and UVE17, the HS-II treatment enhanced chl-a and chl-b accumulation. Elevated carotenoid levels in UVE14 and UVE17 likely protected chlorophyll from degradation and mitigated photooxidative damage. The HS-II treatment also enhanced the grana traits, supporting improved light-harvesting capacity during heat stress in UVE14 and 17. However, heat stress disrupted the photochemical reactions (quantum efficiency of photosystem II, performance index absorbance, and performance index), indicating that elevated carotenoids alone do not exhibit complete tolerance to heat stress. Since plastoglobules play an essential in carotenoid biosynthesis, increased or stabilised plastoglobule traits in UVE14 and UVE17 under HS-II treatment strongly indicate improved heat stress tolerance. Overall, UVE14 and UVE17 emerged as the most heat-tolerant cultivars, with AGS354 being the most susceptible. These findings provide valuable insights into heat stress adaptation mechanisms and suggest the UVE14 and UVE17 cultivars as potential candidates for breeding heat-tolerant edamame cultivars.

This open-field small-plot long-term experiment was set up between 2011 and 2021 with willow (Salix triandra × S. viminalis ‘Inger’), grown as a short rotation coppice energy crop in Nyíregyháza, Hungary. The sandy loam Cambisol was treated with wastewater solids (WS) in the form of municipal sewage sludge compost (MSSC, 2011, 2013, and 2016), municipal sewage sediment (MSS, 2018), and with willow ash (WA, 2011, 2013, 2016, and 2018). Control plots remained untreated since 2011. All soil treatments significantly enhanced the uptake or accumulation of potentially toxic elements (PTEs) in the leaves of willows. During June 2019, 53 weeks after the last soil treatments, MSSC + MSS-, WA-, and MSSC + MSS + WA-treated willows leaves had 14–68% more As, 17–48% more Ba, 31–104% more Cr, 4–12% more Cu, 6–15% more Mn, 18–218% more Pb, and 11–35% more Zn compared to the untreated control. Significantly higher Mn and Zn concentrations were measured in the MSSC + MSS + WA treatments than in the MSSC + MSS treatments. The assumption that WA reduces the accumulation of PTEs in willow leaves when applied together with MSSC and MSS was therefore only partially confirmed. The hypothesis of this study was that PTEs accumulated in the leaves would affect the microanatomical parameters of the leaves. Numerous positive changes were observed with the combined application of WS and WA. MSSC + MSS + WA treatment reduced the thickness of the mesophyll less than MSSC + MSS or WA treatments alone; the size of the cells building the palisade and spongy parenchyma and the extent of the main vein significantly increased. In the case of the combined treatment, the extent of the sclerenchymatous stock was smaller than in the control but larger than in WS- or WA-treated willow. The extent of the collenchymatous stock significantly increased compared to the control. Increases in the thickness of the adaxial epidermis and the number of stomata were statistically significant. However, the extent of the increases did not reach the extent of the increase experienced in the case of WS treatment, as the size of the stomata did not significantly decrease.

Postharvest water loss critically determines the shelf life and quality of pepper fruits. This study investigated how three alternative soil amendments—rhyolite tuff (RT), composted and pelletized poultry litter (CPPL), and clarifying agent (CA)—affect water loss, structural traits, and their interrelationships across three ripening stages (immature, mature, and overripe) in the Hungarian wax pepper cultivar ‘Tizenegyes’. A completely randomized design (CRD) was applied in a small-plot field experiment. Macro- and micromorphometrical analyses included pericarp, cuticle, epidermis, collenchyma, hypodermis, parenchyma, and endocarp thickness; fruit fresh weight; surface area; and the surface area-to-weight ratio (SA/W). Daily weight measurements were used to quantify water loss, while cuticle function was assessed by comparing wax-removed and intact fruits. The water loss rate (WLR) was strongly influenced by pericarp tissue structure—particularly cuticle thickness, hypodermal cell layer number and thickness, and collenchyma cell wall thickness—as well as fruit size at ripening stage. Among treatments, RT was the most effective in reducing postharvest water loss and extending fruit shelf life. Fruits from the control plots lost 26% more water than RT samples, 12.8% more than CPPL, and 14.2% more than CA. Although RT-treated fruits were smaller, they had thicker pericarp and hypodermis layers, more collenchymatous cell rows, and thicker cell walls, all of which contributed to lower water loss and prolonged freshness. These findings highlight RT as a promising alternative nutrient source for sustainable pepper production, with significant potential to improve postharvest quality.

The effects of progressive drought stress were examined in four economically important plant species belonging to the Lamiaceae family: catnip (Nepeta cataria L.), lavender (Lavandula angustifolia Mill.), holy basil (Ocimum tenuiflorum L.), and perilla mint (Perilla frutescens (L.) Britton). Plants were grown in a controlled pot experiment under three soil water capacity levels: 70% (control), 50% (moderate stress), and 30% (severe stress), and the drought stress lasted for 30 days. The study evaluated a comprehensive set of leaf micromorphological parameters, including the density and diameter of glandular trichomes, stomatal density and size, and the thickness of the lamina, mesophyll, epidermis, cuticle, and parenchymal layers. In addition, essential oil (EO) content, total flavonoid content (TFC), and elemental composition were analyzed. Drought responses were strongly species-specific. O. tenuiflorum, P. frutescens, and N. cataria showed high sensitivity characterized by reduced biomass and thinning of leaf tissues. These changes were accompanied by typical xeromorphic adaptations, such as increased stomatal and glandular trichome density, and reduced stomatal size. L. angustifolia exhibited pronounced cuticle thickening, suggesting an effective structural mechanism to minimize water loss. Secondary metabolism also responded differently among species. In some cases, drought shifted metabolic allocation toward flavonoid accumulation at the expense of essential oils, whereas in others, moderate stress promoted the co-accumulation of both compounds. These patterns indicate distinct adaptive strategies linking anatomical plasticity with metabolic regulation. Overall, moderate drought supported adaptive responses, while severe water limitation impaired growth and metabolic production. From a practical perspective, maintaining moderate soil water availability appears critical to optimize both plant performance and the accumulation of valuable secondary metabolites in Lamiaceae species.

The effects of a heavy metal containing wastewater sediment on two cultivars of white willow were investigated in a pot experiment. Our aim was to examine the effect of toxic elements on the microanatomical parameters of the leaves of the tested plant. We examined the following parameters: stomatic density, stoma width and length, lamina thickness, adaxial and abaxial epidermis thickness, mesophyll thickness, palisad and spongy parenchyma thickness, main vein width and length. The experiment had the following results: with the presence of toxic elements, the thickness of the lamina increased, within this, there was a significant growth in the thickness of the spongy parenchyma. The width and the length of the main vein decreased, so did the extent of the xylem cavities. The extent of the collenchymal stock of the leaf venation increased. The number of stomas increased, but the size of the stomas decreased. As a result of toxic element contamination, the number of Ca-oxalate crystals increased within the leaf mesophyll.