Reactive oxygen species (ROS) play dual roles in plants as signaling molecules and cytotoxic agents, making ROS homeostasis critical for abiotic stress adaptation. Numerous studies have shown that central carbon metabolism (CCM) provides the energy required for plant growth and maintains ROS homeostasis by coordinating energy distribution and reconfiguring metabolic streams under abiotic stress, providing energy and metabolites for plants to resist adverse conditions. As a crucial mechanism by which cells respond to short-term stress, post-translational modifications (PTMs) influence CCM by targeting and modifying its enzymes. This enables both energy and metabolic flow redistribution, enabling plants to balance growth and defense under stress conditions. In this review, we discuss the ROS–PTM–CCM interaction and how it improves plant adaptation to abiotic stress. We propose that ROS coordinate ROS homeostasis by mediating the feedback regulation of CCM through PTMs under abiotic stress. This review provides a theoretical basis for improving crop stress tolerance through PTM-targeted metabolic engineering.

Primary mechanism through which nanomaterials enhance plant photosynthesis.

Nitrogen fertilizer setback and planting density both affect wheat yield. However, the differences in winter wheat yield and its components, canopy structure, and microenvironment caused by N fertilizer setback at different planting densities are not clear. A two-year field experiment was conducted to investigate the most suitable planting density and N fertilizer setback combinations for winter wheat. Three planting densities of 3.3, 2.36, and 1.77 million plants·hm⁻², and two basal fertilizer/nodulation and fertilizer/spike fertilizer ratios of 6:4:0 and 4:3:3, respectively, were used in the experiment. The results of the two-year experiment showed that, under the same planting density, the yields of wheat with nitrogen fertilizer setback increased by 8.2%, 2.7%, and 2.8%, respectively; the total leaf area of the upper trifoliate leaves increased by 10.7–17.4%; and the leaf area index (LAI) increased by 5.4% and 5.3%, respectively. The results showed that the yield, the effective number of spikes, leaf area index, and vertical light interception of wheat at a density of 3.30 million plants·hm⁻² were higher than those of the other treatments. In both years of the experiment, the planting density of 3.30 million plants·hm⁻² with nitrogen fertilizer setback (basal fertilizer/nodulation fertilizer/spike fertilizer = 4:3:3) was the best. Therefore, a nitrogen application of 240 kg·hm⁻² and a planting density of 3.30 million hm⁻² with nitrogen fertilizer setback was found to be the best combination.

Soybean, an important cash crop, is often affected by soil salinity, which is one of the important types of abiotic stress that affects its growth. Poly (acrylic) acid coated Mn₃O₄ (PMO) has been reported to play a vital role in defending against a variety of abiotic stresses in plants. To date, the effects of PMOs on soybean have not been reported; this study explored the mechanism of PMO-enhanced soybean germination under salt stress. In this experiment, 100 mg/L PMO was used as an immersion agent with a salt treatment of 150 mM NaCl. The results showed that when compared with the PMO treatment, salt stress significantly decreased the germination rate, fresh weight, carbohydrate content, and antioxidant enzyme activity of soybean and significantly increased the contents of reactive oxygen species, malondialdehyde, and osmoregulatory substances. However, PMO treatment enhanced the antioxidant defense system and significantly reduced the malondialdehyde content of soybean. Moreover, the activities of H⁺-ATPase and Ca²⁺-ATPase were significantly higher in treated soybean than in the control, and the content of ATP was also higher in treated soybean than in the control. Generally, PMO regulates the homeostasis of reactive oxygen species and reduces ATP consumption, thereby improving the ability of soybeans to germinate under salt stress. This study provides new insights into how nanomaterials improve plant salt tolerance.

Southern Xinjiang is an important soybean production region in China. However, the short growing season and the cultivation of winter crops (such as wheat) in the region limit the expansion of soybean planting areas. An increased planting density can compensate for the loss in yield due to delayed sowing. To identify the quantitative relationship between increased density and delayed days, a two-year field experiment was conducted at the Tarim University Agronomy Experiment Station. Two sowing dates (April 7 (S1) and May 7 (S2)) and three planting densities of 206,800 plants·ha⁻¹ (D1), 308,600 plants·ha⁻¹ (D2), and 510,200 plants·ha⁻¹ (D3) were used to compare various plant growth parameters and canopy characteristics. Late sowing and a high planting density significantly increased the plant height (S2 was 37.3% higher than S1, and D3 was 17.6% and 8.8% higher than D1 and D2), main stem internode, petiole length, and the mean tilt angle of the leaves (S2 was 22.5% higher than S1, and D3 was 11.7% higher than D2) but reduced the stem diameter (D3 was 28.6% and 12.5% lower than D1 and D2), branch number (S2 was 26.7% lower than S1, and D2 was 75% lower than D1), canopy light transmittance (S2 was 49.2% lower than S1, and D3 was 36.7% and 20.8% lower than D1 and D2), photosynthetic rate, and dry matter. The highest yield was achieved at S1D1, but the lowest yield was found for S2D1. Overall, the results suggest that earlier sowing and a lower planting density contribute to achieving an optimum canopy structure and higher yield. Our conclusions provide a reference for soybean production in southern Xinjiang.

Salinity is a major factor limiting the increase in crop yield around the world. Wheat starch and straw are important raw materials for producing bioethanol, and their productivity is adversely affected by salinity. Polyacrylic acid-modified Mn₃O₄ nanoparticles (PMO) have been reported to improve crop tolerance to stressors, including salt stress. Therefore, this study aimed to elucidate the mechanism by which seed soaking with PMOs enhances wheat salt tolerance. PMO seed soaking promoted wheat germination (increase of 30.9%) under salt stress, and seedlings treated with PMO seed soaking had a higher fresh weight (increase of 31.4%). PMO seed soaking increased the POD activity (by 31.9%) but decreased superoxide dismutase and catalase activities of wheat seeds and the O₂⁻ and H₂O₂ contents (by 25.0 and 71.4%, respectively). Furthermore, PMO soaking increased the ATP, NADPH, and NADH contents (by 367.6, 212.0, and 283.2%, respectively) by regulating sugar metabolism and enhanced the ascorbic acid–glutathione cycle. Additionally, the PMO soaking treatment optimized energy allocation in wheat under salt stress and increased yield (by 9.7%). PMO modulated sugar metabolism, thereby optimizing energy allocation to plant growth and the antioxidant system, which enhanced wheat germination and yield formation under salt stress.