Methyl jasmonate (MJ) is an important plant growth regulator that plays a key role in tolerance to biotic and abiotic stresses. In this research, the effects of exogenous MJ on cold tolerance, photosynthesis, activity and gene expression of antioxidant enzymes, proline accumulation, and expression of cold-regulated (COR) genes in wheat seedlings under low temperature (4 °C) were investigated. Exogenous MJ treatment (1 µM) promoted wheat cold tolerance before and during cold exposure. Low temperature significantly decreased photosynthetic parameters, whereas MJ application led to their partial recovery under cold exposure. Hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) levels increased in response to low temperature, and this was counteracted by MJ application. Exogenous MJ significantly enhanced the activities of antioxidant enzymes and upregulated the expression of MnSOD and CAT during cold exposure. MJ application also led to enhanced proline content before 4 °C exposure, whereas the P5CS gene expression was upregulated by MJ’s presence at both normal (22 °C) and low (4 °C) temperatures. It was also shown that MJ tended to upregulate the expression of the COR genes WCS19 and WCS120 genes. We conclude that exogenous MJ can alleviate the negative effect of cold stress thus increasing wheat cold tolerance.

The aim of this study was to investigate the effects of low temperature (4 °C), cadmium sulphate (100 μM), or their combination on content of free proline (Pro), glutathione (GSH), and phytochelatins (PCs) in wheat (Triticum aestivum L.) leaves. Results revealed an increase in proline and phytochelatins accumulation in leaves of wheat seedlings along with enhanced cold tolerance at the low temperature, CdSO4, and their combination. Moreover, there were increases in mRNA content of TaP5CS and TaPCS1 genes, encoding ∆1-pyrroline-5-carboxylate synthase (P5CS) and phytochelatin synthases (PCS), respectively. A rapid increase in glutathione content was found within 1 h of exposure to the low temperature and its combination with CdSO4, followed by a drop. However, upregulation of the TaGS1 gene, encoding glutathione synthetase (GS), was maintained during 7 d. A significant decrease in glutathione content on the seventh day of exposure to the low temperature, CdSO4, and their combination was most probably due to its involvement in cadmium detoxification and/or in phytochelatin synthesis. Our data suggest that proline, glutathione, and phytochelatins may be important for plant tolerance to low temperature and cadmium stress in wheat.

The effect of methyl jasmonate (MJ) (1 µM) on wheat (Triticum aestivum L. cv. Moskovskaya 39), seedlings and the fatty acid (FA) content of leaves under optimal and cadmium (Cd) (100 µM) stress conditions wasinvestigated. Height and biomass accumulation was studied traditionally; the netphotosynthesis rate (P_n) was studied using a photosynthesis system, FAs’profile—GS-MS. No effect on the height and P_n rate of the MJ pre-treatment wheat at optimum growth conditions was found. MJ pre-treatment led to a decrease in the total amount of saturated (about 11%) and unsaturated (about 17%) identified FAs, except α-linoleic FA (ALA), which is probably associated with its involvement in energy-dependent processes. Under Cd impact, the MJ-treated plants had a higher biomass accumulation and P_n rate compared to untreated seedlings. Both MJ and Cd caused stress-induced elevation of palmitic acid (PA) versus an absence of myristic acid (MA), which is used for elongation. It is suggested that PA participates in alternative adaptation mechanisms (not only as a constituent of the lipid bilayer of biomembrane) of plants under stress. Overall, the dynamics of FAs showed an increase in the saturated FA that is important in the packing of the biomembrane. It is supposed that the positive effect of MJ is associated with lower Cd content in plants and a higher ALA content in leaves.

Zinc (Zn) is a fundamental micronutrient for plants’ metabolism, but in high concentrations, it is toxic. In this study, we investigated the physiological response of white mustard (Sinapis alba L. cv. Belgia) plants to the Zn excess concentrations (50, 100, and 150 mg kg⁻¹) in the substrate. The results showed that sand Zn concentration of 50 mg kg⁻¹ did not affect the physiological parameters of plants, despite to the high Zn accumulation in shoots. The growth, biomass accumulation, photosynthesis rate, and pigment amount were inhibited at Zn concentrations of 100 and 150 mg kg⁻¹ in substrate. A slight increase in malondialdehyde (MDA) was also observed at zinc concentrations (100 and 150 mg kg⁻¹) without changes in membrane permeability, which is partly connectedtoan increase in the proline content. The results suggested that white mustard tolerates Zn excess impact. S. alba is able to grow on Zn-contaminated substrates along with significant Zn accumulation in shoots, which supports its high potential for phytoremediation of Zn-polluted agricultural soils. It is also possible to propose the following recycling of white mustard plants for Zn fortification feedstuff.

The aim of this study was to investigate the effect of zinc (Zn) deficiency on the growth and grain yield of wheat with different allele statuses of the Gpc-B1 gene. For this research, common wild emmer wheat (Triticum turgidum ssp. dicoccoides (Koern. ex Asch. &Graebn.) Schweinf.), bread wheat (Triticum aestivum L. cv. Festivalnaya), and two intogressive lines were used. T. dicoccoides and introgressive line 15-7-1 carry a functional allele of the Gpc-B1 gene, while the T. aestivum cv. Festivalnaya and introgressive line 15-7-2 carry the non-functional Gpc-B1 allele. Zn deficiency did not affect the shoot height or fresh weight of any of the studied plants. The only exception was T. dicoccoides, where a small decrease in shoot height was registered. Additionally, under Zn deficiency T. dicoccoides had an increase in flag leaf area, spike length, and dry weight, as well as in grain number and grain yield per spike. The other variants did not experience changes in the above-described parameters under Zn deficiency. Under Zn deficiency, the Zn concentration in the grains was higher in the plants with a functional allele of the Gpc-B1 gene compared to the plants with a non-functional allele. These results show that wheat with a functional allele of the Gpc-B1 gene growing under Zn deficiency is capable of grain production with a sufficient Zn concentration without a decrease in yield.

Zinc (Zn) is a vital micronutrient for all living organisms, but in high concentrations, it is a major anthropogenic pollutant. In this study, it was investigated the effect of zinc excess concentrations (50, 100, and 150 mg kg⁻¹) in the substrate on some physiological parameters and the dynamics of fatty acid (FA) content in yellow mustard (Sinapis alba L. cv. Belgia) and oriental mustard (Brassica juncea L. (Czern) cv. Slavanka). The Zn concentration of 50 mg kg⁻¹ did not affect the physiological parameters of yellow mustard, whereas some physiological parameters slightly decreased in oriental mustard. Moreover, this concentration stimulated an increase in total and unsaturated FAs content in leaves of both species, along with high Zn accumulation by both species. The Zn concentrations of 100 and 150 mg kg⁻¹ in substrate had a negative effect on the state of plants as measured by the studied physiological parameters and caused different changes in FAs content in yellow and oriental mustard. Particularly, the total amount of FA increased in comparison to the control, but this increase was due to an elevation in saturated FA (SFA) content. At the same time, the total FA content in oriental mustard slightly decreased while the proportion of unsaturated FAs to SFA kept rising. According to the present data and analysis of the available literature, two strategies of adaptation to heavy metals were suggested through the changes in FAs: height-resistant horticultural plant species on the one side and sensitive species on the other.