As a natural active substance, dihydromyricetin (DHM) has been proven to have good hepatoprotective activity. However, the therapeutic effect of DHM on liver fibrosis, which has become a liver disease threatening the health of people around the world, has not been studied to date. The purpose of this study was to investigate the effect of DHM as a new nutritional supplement on thioacetamide (TAA)-induced liver fibrosis. The liver fibrosis model was established by intraperitoneal injection of TAA (200 mg/kg, every 3 days) for 8 weeks, and oral administration of DHM (20 mg/kg and 40 mg/kg, daily) after 4 weeks of TAA-induced liver fibrosis. The results showed that DHM treatment significantly inhibited the activities of alanine aminotransferase (ALT) (37.81 ± 7.62 U/L) and aspartate aminotransferase (AST) (55.18 ± 10.94 U/L) in serum of liver fibrosis mice, and increased the levels of superoxide dismutase (SOD) and glutathione (GSH) while reversed the level of malondialdehyde (MDA). In addition, histopathological examination illustrated that TAA induced the inflammatory infiltration, apoptosis and fibroatherosclerotic deposition in liver, which was further confirmed by western-blot and immunofluorescence staining. Moreover, DHM inhibited hepatocyte apoptosis by regulating the phosphorylation level of phosphatidylinositol 3-kinase (PI3K), protein kinase-B (AKT) and its downstream apoptotic protein family. Interestingly, immunofluorescence staining showed that DHM treatment significantly inhibited alpha smooth muscle actin (α-SMA), which was a marker of hepatic stellate cell activation, and regulated the expression of transforming growth factor (TGF-β1). Importantly, supplementation with DHM significantly inhibited the release of nuclear factor kappa-B (NF-κB) signaling pathway and pro-inflammatory factors in liver tissue induced by TAA, and improved liver fiber diseases, such as tumor necrosis factor alpha (TNF-α) and recombinant rat IL-1β (IL-1β). In conclusion, the evidence of this study revealed that DHM is a potential hepatoprotective and health factor, and which also provides the possibility for the treatment of liver fibrosis.

Lodging resistance is a critical trait in modern maize breeding. This study aimed to examine maize stalk lodging and its related characteristics in response to increasing planting densities in modern hybrids. A two-year field trial was conducted from 2018 to 2019 with two widely grown commercial hybrids (‘Xy335’ and ‘Fm985’) and three planting density treatments of 4.5 × 10⁴ (low density, LD), 6.5 × 10⁴ (medium density, MD), and 8.5 × 10⁴ plants/ha (high density, HD). New hybrid Fm985 had a significantly higher grain yield and lower lodging rate at HD, while there was no significance at LD and MD. Compared to Fm985, old hybrid Xy335 had a significantly high plant height, ear and gravity height, and culm length (CL) across the three planting densities, while opposite stalk bending strength (SBS), dry weight per unit length (DWPU), cross-sectional area, and the cellulose and lignin content in the basal internode were low. Correlation and path analysis revealed that kernel number per ear and lodging rate directly contributed to maize grain yield, while lodging-related traits of SBS, stem lignin, and DWPU had an indirect effect on maize grain yield, suggesting that modern hybrid maize yield enhancement is associated with greater stalk lodging resistance at a high planting density in northeast China.

With the continuous improvement of the mechanization level and the development of new crop varieties, the optimal strip width for intercropping crops is important. In this study, field experiments were conducted to analyze the effects of different row spacings and planting patterns on photosynthesis, chlorophyll fluorescence, and the related enzyme activities of maize ear leaves in a maize–soybean intercropping system using two planting patterns (wide–narrow rows of 80–50 cm and uniform ridges of 65 cm) and two intercropping ratios (four rows of maize and four rows of soybean; six rows of maize and six rows of soybean). The results showed that the pattern of wide–narrow-row spacing significantly improved the photosynthetic capacity of maize compared with the uniform-ridge planting pattern, along with marked elevation in the values of stomatal conductance (Gs), the transpiration rate (Tr), and the photosynthetic rate (Pn). On the other hand, the values of photochemical quenching (qP), actual photochemical efficiency (φPSII), and maximum photochemical efficiency (Fv/Fm) also significantly increased, and the effect of D-M6S6 treatment was the most significant on these parameters. Similarly, the activities of phosphoenolpyruvate carboxylase and ribulose-1,5-bisphosphate carboxylase/oxygenase also increased significantly. Among different treatments, the yield under the D-M6S6 treatment was the highest. Therefore, based on the planting pattern of the wide–narrow-row spacing, the intercropping of six rows of maize and six rows of soybean is the better design in the semi-arid regions of western China.

Maize lodging is a major factor limiting maize grain yield. Potassium (K) fertilization is known to reduce lodging, but the potential impact of straw return on lodging resistance remains unclear. A two-year field experiment was conducted with five K levels (0, 30, 60, 90, and 120 kg ha⁻¹) under straw return (S1) and no straw return (S0). Maize yield, stem lodging resistance index (SLRI), crushing strength (CS), stem morphological and physicochemical characteristics, and soil nutrient levels were measured. Compared to S0, increased K application with S1 significantly enhanced the SLRI (16.0%) and CS (19.8%) across two years, which was due to the improvement of stem morphological (internode dry weight, length, and plumpness) and physiological characteristics (soluble sugar, cellulose, lignin, phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), and cinnamyl alcohol dehydrogenase (CAD)), especially the third internode. The highest SLRI and CS of each internode of the two straw treatments were obtained in K120, while no significant difference between K90 and K120 was observed for these indicators under the same straw treatment. Grain yield and soil available K content of S1 were higher by an average of 5.0% and 18.0% than S0, respectively. Compared to K0, K120 increased the yield and soil available K content by 17.3% and 18.8%, but there was no significant difference with K90. As a result, S0 and S1 both achieved a soil K balance when the surplus rate was close to zero at a K input of 90 kg ha⁻¹. Fitting analysis indicated that, compared to S0, the K application rate of S1 was reduced by an average of 11.8% while maintaining a K surplus rate of 0, which means S1 could enhance soil potassium cycling and supply capacity but also reduce fertilizer input. In conclusion, straw return combined with K fertilizer (e.g., 90 kg ha⁻¹) is an effective strategy to enhance lodging resistance and maintain maize yield by improving stem morphological and physicochemical characteristics.

Increasing the nitrogen (N) use efficiency (NUE) of modern high-yield maize hybrids is essential for food security and reducing environmental risks. However, the relationship between dry matter (DM), N accumulation, and reallocation among different high-yield maize hybrids and NUE, particularly under various N fertilization levels, is not well understood. The field experiment was conducted in Jilin Province, Northeast China. In this study, two maize hybrids, Zhengdan958 (ZD958) and Tie 391 (T391), were grown under four N fertilizer levels: 0 (NN), 120 (LN), 240 (MN), and 360 (HN) kg ha⁻¹. We examined the effects of N input on grain yield, NUE, DM, and N accumulation, partitioning, and reallocation of these two high-yielding maize hybrids during the 2023–2024 growing season. The results showed that N input significantly increased grain yield but reduced NUE. There was no significant difference in yield and NUE between the two maize hybrids at the HN level. However, under LN conditions, the grain yield and NUE of ZD958 were higher by 16.2% and 15.6%, respectively, compared to T391. Meanwhile, ZD958 exhibited greater per-silking and post-silking DM (5.0% and 7.9%) and N accumulation (11.6% and 32.7%), as well as a higher amount of reallocated DM (45.6%) and N (17.5%) compared to T391. Moreover, 15.5–38.1% of grain N for ZD958 and 17.2–46.7% for T391 still needed to be reallocated from vegetative organs, with a larger fraction coming from the stem rather than the leaves. The middle leaves and lower stems of the canopy tended to reallocate more N to the grain, and lower-layer stem N reallocation was significantly related to grain yield. In conclusion, higher accumulation of DM and N, along with greater N reallocation—especially from the lower-layer stem—could be regarded as important traits in maize breeding to improve the NUE of high-yield maize hybrids under insufficient N supply.

The PP2C gene family plays crucial roles in plant growth, development, and responses to biotic/abiotic stresses. Flax ( Linum usitatissimum L.), as an important oilseed and fiber crop, lacks comprehensive characterization of its PP2C genes. In this study, we conducted a genome-wide bioinformatics analysis of the PP2C gene family in flax using the Telomere to Telomere (T2T) genome assembly, identifying 117 LuPP2C genes. Phylogenetic analysis classified these LuPP2C proteins into 11 distinct subclades. Gene structure and motif analyses revealed conserved exon-intron architectures and motif compositions among members within the same phylogenetic branches. Cis-regulatory element analysis of LuPP2C promoters identified abundant stress-responsive elements, including those associated with plant hormones (MeJA and ABA) and abiotic stresses (anaerobic induction, drought responsiveness, and low-temperature adaptation). Genomic duplication events revealed 104 segmental duplication pairs, suggesting expansion through large-scale duplication. miRNA target prediction identified lus-miR395 as the predominant miRNA targeting LuPP2C family members. Expression profiling demonstrated preferential expression of most LuPP2C members in leaf tissues. Quantitative real-time PCR (qRT-PCR) analysis further revealed that subfamily A genes, particularly LuPP2C26 and LuPP2C99 , were significantly upregulated under cold, drought, and salt stress conditions. Functional validation through heterologous expression confirmed that overexpression of LuPP2C26 and LuPP2C99 enhances salt tolerance in yeast transformants. These findings systematically characterize the flax PP2C family and provide insights into its potential roles in stress adaptation mechanisms.