This study aimed to investigate the impact of straw returning (SR) combined with appropriate N application rates on soil properties and maize yield for a double cropping maize system in South China. From 2021 to 2022, a two-year field experiment was conducted (the perennial orientation study began in 2018) with two nitrogen application rates, 0 kg ha⁻¹ (N0) and 250 kg ha⁻¹ (N250), under various straw treatments (SR and traditional planting). The findings revealed that SR, along with the nitrogen application of 250 kg ha⁻¹ (N250), increased soil total nitrogen (TN), soil total phosphorous (STP), and the soil total potassium (STK) content besides soil organic carbon (SOC) and labile organic carbon (LOC); similarly, their interaction improved SOC and LOC in the 0–20 cm soil layer. In addition, within the 20–40 cm soil layer, SR and N250 also increased the soil TN, SOC, LOC, STP, and STK content. Notably, these soil properties exhibited a decrease with increasing soil depth. Furthermore, SR and N250 led to improvements in the grain yield and yield component of maize. Combining SR with N250 led to a significant 101.53% increase in SOC content from 2018 to 2022. Our research indicates that implementing N rates of 250 kg ha⁻¹ under SR is an effective method to boost maize grain yield, enhance soil chemical characteristics, and ensure safe and productive maize cultivation.

Insect odorant receptors (ORs) are pivotal molecular interfaces that translate environmental chemical cues into neuronal electrical impulses, thereby governing essential behaviors such as foraging, mating, oviposition, and predator avoidance. The past three years have witnessed a paradigm shift driven by high-resolution cryo-electron microscopy (cryo–EM) structures of OR-odorant receptor co-receptor (Orco) heterocomplexes, which definitively established the 1:3 stoichiometry (one odorant-specific OR subunit and three Orco subunits) of the functional ion channel. These structures have revealed the architecture of the ligand-binding pocket and the conformational dynamics underlying channel gating. This structural framework has illuminated long-standing questions regarding the evolution of ORs from ancestral gustatory receptors and their lineage-specific expansion via a “birth-and-death” model, enabling adaptation to diverse ecological niches. Concurrently, the long-debated signal transduction mechanism has been reconciled by evidence of a unified bimodal system, where OR–Orco complexes function as both direct ligand-gated ion channels and activators of an IP3-dependent metabotropic cascade. Here, we integrate these recent breakthroughs—from atomic-level structures and evolutionary genomics to in vivo functional validation—with classical knowledge of OR expression, localization, and diversity. We further synthesize the emerging field of structure-guided applications, including virtual screening for novel semiochemicals and the development of RNAi- and CRISPR-based strategies for pest management. This comprehensive review provides a framework for understanding the molecular logic of insect olfaction and its exploitation for biotechnological innovation.

Aim and methods Staged water shortages and excessive nitrogen application lead to a decline in crop yield, and nitrogen loss, waste of resources and environmental pollution. In order to explore the appropriate water management in humid areas and to determine an efficient nitrogen rates for maize, we conducted a field experiment (2020-2021), with five nitrogen rates N0, N150, N200, N250, N300 (0, 150, 200, 250, 300 kg ha^-1) under different water conditions (rainfed and irrigated). Conclusion Consequently, under the irrigated conditions, the soil organic matter (SOM), microbial biomass carbon (MBC), dry matter accumulation and grain yield were significantly (P < 0.05) increased by 8.06%, 15.50%, 11.43% and 13.86%, respectively, compared with the rainfed conditions. And the total nitrogen (TN), nitrate nitrogen (NO₃^--N), ammonia nitrogen (NH₄⁺-N) decreased significantly by 4.38%, 8.28%, 13.21%, respectively. Furthermore, compared with other nitrogen rates, N250 and N300 combined with irrigated significantly (P < 0.05) increased soil carbon and nitrogen content, dry matter accumulation and grain yield. However, N250 and N300 displayed no significant difference (P > 0.05) in TN, NO₃^--N, NH₄⁺-N, SOM, MBC, dry matter accumulation and grain yield. Moreover, under the irrigated conditions, when the nitrogen rates increased more than 250 kg ha^-1, the nitrogen use efficiency decreased. Hence, application of nitrogen rates of 250 kg ha^-1 under irrigated conditions is the best choice to increase grain yield, improve nitrogen use efficiency, and ensuring safe and efficient production in maize.

Selenium is a beneficial trace element for humans, animals, and plants, and adequate intake contributes to health, growth, and development. Selenium accumulation in sweet potato varies among genotypes. In this study, 77 sweet potato germplasm resources were planted in the Wuming natural selenium‑rich soil region and the Mingyang low‑selenium soil region. The differences and correlations in major agronomic traits, quality traits, and tuber selenium content between the two regions were analyzed, and natural selenium‑enriched germplasm were screened. The results showed that yield, vine length, branch number, and fresh vine and leaf weight per plant in the Mingyang low‑selenium region were higher than those in the Wuming selenium‑rich region, while storage root number per plant was similar between the two sites. Dry matter rate and total flavonoid content in Wuming were higher than those in Mingyang. Tuber selenium content in Wuming ranged from 0.034 to 0.319 mg/kg DW, with a mean of 0.070 mg/kg; in Mingyang, it ranged from 0.025 to 0.068 mg/kg DW, with a mean of 0.040 mg/kg. Zhenghong 163, Longzi 9, and Guangzishu 9 exhibited the highest selenium enrichment multiples and were identified as the optimal selenium‑enriched candidate varieties. Principal component analysis and cluster analysis further revealed the structural differences in trait variation between the two regions and the significant influence of soil selenium level on germplasm classification. This study provides core germplasm resources for selenium‑enriched sweet potato breeding and industrial development.