Background: Soil salinity restricts plant growth and productivity. 2-(3,4-dichlorophenoxy) triethylamine (DCPTA) can alleviate salinity stress in plants. However, the mechanism of DCPTA-mediated salinity tolerance has not been fully clarified. We aimed to investigate its role in enhancing photosynthetic capacity, improving water status, maintaining K⁺/Na⁺ homeostasis and alleviating salinity stress in maize (Zea mays L.). Results: In present study, maize seedlings were grown in nutrient solutions with a combination of NaCl (0, 150 mM) and DCPTA (0, 20, 100, and 400 μM). And photosynthesis, water status, ion homeostasis and the expression of genes involved in ion uptake and transport were evaluated in the maize seedlings. The results demonstrated that DCPTA alleviated the growth inhibition of maize seedlings exposed to salinity stress by increasing the net photosynthetic rate (P_n) and the quantum efficiency of photosystem II (PSII) photochemistry. DCPTA improved the root hydraulic conductivity, which help maintained the water status. A relatively high K⁺ concentration but a relatively low Na⁺ concentration and the Na⁺/K⁺ ratio were observed in the presence of DCPTA under salinity stress. Additionally, DCPTA altered the expression of four genes (ZmSOS1, ZmHKT1, ZmNHX1 and ZmSKOR) that encode membrane transport proteins responsible for K⁺/Na⁺ homeostasis. Conclusions: DCPTA improved the salinity tolerance of maize may be associated with enhanced photosynthetic capacity, maintenance of water status and altered expression of genes involved in ion uptake and transport.

In response to the production crisis caused by a winter feed shortage due to the rapid development of the animal husbandry industry, winter rye 001 was selected to study differences in stalk and senescence characteristics in yield formation in cold regions. Five density treatments were established in a randomized design as 225 × 10⁴ plant·hm⁻² (D₁), 275 × 10⁴ plant·hm⁻² (D₂), 325 × 10⁴ plant·hm⁻² (D₃), 375 × 10⁴ plant·hm⁻² (D₄), and 425 × 10⁴ plant·hm⁻² (D₅). Stem characteristics, SOD activity, POD activity, MDA content, and differences in yield and feeding quality under different population densities were analyzed. The plant height, center of gravity, and stem basal internode length showed an increasing trend with an increase in planting density. The stem wall thickness, diameter, strength, and lodging resistance indices decreased. At 275 × 10⁴ plants·hm⁻², the rye crude protein content was the highest while neutral washing fiber and acid washing fiber were the lowest, and feed quality was the best. With an increase in density, spike number, grain number per spike, and thousand-grain weight first increased and then decreased. We concluded that the yield and feeding quality were best when the basic seedling was at 275 × 10⁴ plants hm⁻².

Maize (Zea mays L.) is a global staple crop for food, feed and industrial use in China. As a thermophilic crop, its seedlings suffer from cold stress. Heilongjiang, China’s major maize producer, faces worsening early cold that impedes germination and seedling growth, causing heavy yield losses. Improving germination cold tolerance stabilizes yields. Ubiquitous proline (Pro) works as a key osmoprotectant and core stress-resistance regulator in plants. In this field experiment, the maize cultivar Damin 3307 was used to explore the effects and regulatory mechanisms of Pro seed soaking on low-temperature-stressed maize. We analyzed seedling emergence, plant growth, photosynthetic performance, nitrogen metabolism, dry matter accumulation, ear traits and grain yield of treated maize under low temperature. The results showed that seed soaking with 15 mmol·L⁻¹ Pro effectively improved the seedling emergence rate of early-sown maize under low temperature and compensated for cold-induced population decline. It significantly increased plant height at the seedling and jointing stages, which enhanced vegetative growth. Exogenous Pro regulated the activities of key nitrogen metabolism enzymes, including NR, GS, GOGAT, GDH, GOT and GPT, alleviating low-temperature-induced nitrogen metabolism inhibition and accelerating ammonia assimilation as well as protein and amino acid synthesis to promote maize growth. Additionally, Pro soaking mitigated the cold-induced suppression of leaf photosynthetic indices (Pn, Gs, Tr, Ci) and key photosynthetic enzymes (RuBPCase, PEPCase). It maintained higher leaf chlorophyll content and green leaf area, delayed leaf senescence, and sustained stable carbon and energy supply for nitrogen metabolism. These improvements strengthened maize cold resistance, promoted dry matter accumulation, optimized ear and kernel traits by increasing ear number and kernels per ear and reducing empty kernels, and ultimately improved the grain yield of early-sown maize under low-temperature stress.

Background: Sainfoin (Onobrychis viciifolia) is a nutritious perennial leguminous herb with strong resistance to stress and is a valuable livestock forage and ecologically beneficial crop. It grows in many Chinese provinces, where its stress resistance varies due to different ecological environments. This study aimed to evaluate drought resistance during germination of sainfoin from different regions. Methods: The registered sainfoin variety Onobrychis viciifolia cv. Mengnong was used as a control andaqueous solutions of PEG-6000 (0-20%) were used to simulate drought stress in wild varieties collected from seven regions of China. Seed germination characteristics were determined andthe drought resistance of each variety was comprehensively evaluated using membership function analysis. Result: As PEG-6000 concentration increased, germination indices initially increased then decreased, showing that mild drought stress was conducive to the germination of sainfoin. Calculation of comprehensive drought resistance coefficients revealed that sainfoin from Shizuishan City exhibited strong drought resistance, those from Hami City and Jiuquan City showed medium resistance, the registered cultivar Mengnong and varieties from Ejin Banner and Yulin City were weakly resistant, while samples from Kunming City were non-resistant.