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The increasing use of nanoparticles is driving the growth of research on their effects on living organisms. However, studies on the effects of nanoparticles on cellular respiration are still limited. The remodeling of cellular-respiration-related indices in plants induced by zinc oxide nanoparticles (nnZnO) and its bulk form (blZnO) was investigated for the first time. For this purpose, barley (Hordeum vulgare L.) seedlings were grown hydroponically for one week with the addition of test compounds at concentrations of 0, 0.3, 2, and 10 mg mL−1. The results showed that a low concentration (0.3 mg mL−1) of blZnO did not cause significant changes in the respiration efficiency, ATP content, and total reactive oxygen species (ROS) content in leaf tissues. Moreover, a dose of 0.3 mg mL−1 nnZnO increased respiration efficiency in both leaves (17 %) and roots (38 %). Under the influence of blZnO and nnZnO at medium (2 mg mL−1) and high (10 mg mL−1) concentrations, a dose-dependent decrease in respiration efficiency from 28 % to 87 % was observed. Moreover, the negative effect was greater under the influence of nnZnO. The gene transcription of the subunits of the mitochondria electron transport chain (ETC) changed mainly only under the influence of nnZnO in high concentration. Expression of the ATPase subunit gene, atp1, increased slightly (by 36 %) in leaf tissue under the influence of medium and high concentrations of test compounds, whereas in the root tissues, the atp1 mRNA level decreased significantly (1.6–2.9 times) in all treatments. A dramatic decrease (1.5–2.4 times) in ATP content was also detected in the roots. Against the background of overexpression of the AOX1d1 gene, an isoform of alternative oxidase (AOX), the total ROS content in leaves decreased (with the exception of 10 mg mL−1 nnZnO). However, in the roots, where the pressure of the stress factor is higher, there was a significant increase in ROS levels, with a maximum six-fold increase under 10 mg mL−1 nnZnO. A significant decrease in transcript levels of the pentose phosphate pathway and glycolytic enzymes was also shown in the root tissues compared to leaves. Thus, the disruption of oxidative phosphorylation leads to a decrease in ATP synthesis and an increase in ROS production; concomitantly reducing the efficiency of cellular respiration.

The objective was investigated the effects of CdO and nano-CdO as potential toxic pollutants on growth and redox response of barley. CdO and nano-CdO have been found to cause significant phytotoxicity in barley seedlings, with nano-CdO increasing plant tissue cadmium accumulation. This accumulation is linked to growth retardation and oxidative stress. Low molecular weight antioxidants like restored glutathione and ascorbate have been found to increase the activity of glutathione peroxidase (GPX), glutathione-S-transferase (GSTs), and ascorbate peroxidase (APX) in green tissues. Catalase (CAT) activity increased from 50 % with 100 mg/l CdO to 70 % with 1000 mg/l and nano-CdO. The observed disturbance in redox balance signals the upregulation of corresponding genes. Antioxidant enzyme isoform gene transcripts increased for SODB, CAT2, and APX. Cadmium buildup in root cells causes oxidative stress, leading to upregulation of SOD, CAT, GR, and GSTs isoform genes as well as protein carbonylation, sulfhydryl group degradation, and MDA accumulation. CdO and nano-CdO have similar phytotoxic effects, but bioavailability affects biochemical and molecular responses.

Field peas are one of the most common crops and are grown in various climatic zones. However, the productivity of this crop can be largely limited by climatic factors. This study investigated the influence of climatic factors on pea grain yield in the semi-arid conditions of the Rostov region of Russia in 2008–2020. To quantify climatic factors, agro-climatic variables were used, such as total temperatures below the minimum temperature, the number of days with temperatures below the minimum temperature, total temperatures above the critical temperature, the number of days with temperatures above the critical temperature, and the Selyaninov hydrothermal coefficient. Agro-climatic variables were calculated using daily climatic variables, such as maximum and minimum temperatures, relative air humidity, and precipitation during pea growing season (April–June). The yield of the pea varied from 90 to 250 kg/ha. In general, the productivity of peas is negatively affected by high temperatures and low humidification level. The yield is negatively correlated with accumulative temperatures above the critical temperature and the number of days with temperatures above the critical temperature and positively correlated with the Selyaninov hydrothermal coefficient and the precipitation in all analyzed areas. The influence of the accumulative temperatures above the critical temperature is the most significant. It explains between 6.6% and 78.9% of the interannual variability of the pea yield. The increase in accumulative temperatures above the critical threshold by every 1 °C will contribute to a decrease in pea grain yield by an average of 0.150 kg/ha. The maximum temperatures in May and June (the period of flowering–grain filling) have the most negative impact on the yield. A 1 °C increase in the average maximum temperature during this period will contribute to a decrease in pea yield by an average of 19.175 kg/ha. The influence of total precipitation during the growing season explains between 12.3% and 50.0% of the variability. The 1 mm decrease in the total precipitation for the growing season will lead to a decrease in pea yields by an average of 0.736 kg/ha. The results of this study can be applied to regional yield forecasting, as well as predicting the impact of climate variability on the grain yield of pea crops in arid areas.