Maize (Zea mays L.) is a globally significant crop that plays a crucial role in feeding the growing global population.  Among its various traits, plant height is particularly important as it affects yield, lodging resistance, ecological adaptability, and other important factors.  Traditional methods for measuring plant height often lack cost-efficiency and accuracy.  In this study, we employed a light detection and ranging (LiDAR) sensor mounted on an unmanned aerial vehicle (UAV) to collect point cloud data from 270 doubled haploid (DH) lines.  This innovative application of UAV-based LiDAR technology was explored for high-throughput phenotyping in maize breeding.  We constructed high-density genetic maps and assessed plant height at both single-plant and row scales across multiple developmental stages and genetic backgrounds.  Our findings revealed that for many varieties and small areas, single-plant-scale estimation accuracy was superior to row-scale estimation, with an R² of 0.67 versus 0.56 and an RMSE of 0.12 m vs. 0.17 m, respectively.  Two high-density genetic maps were constructed based on SNP markers.  In Sanya and Xinxiang, the F₁DH and F₂DH populations identified 12 and 20 QTLs (quantitative trait loci) for plant height, respectively.  The study successfully identified and validated QTLs associated with plant height, revealing novel genetic loci and candidate genes.  This research highlights the potential of UAV-based remote sensing to advance precision agriculture by enabling efficient, large-scale phenotyping and gene discovery in maize breeding programs.

Avian pathogenic Escherichia coli (APEC) could cause colibacillosis, which is economically devastating to poultry industries worldwide. The bacterial membrane is critical to its environment adaptability and virulence. The inner membrane protein TolA maintains membrane integrity, but the roles of which in fitness and pathogenesis of APEC are not completely understood. Thus, the tolA gene mutant and complemented strains of APEC were constructed and characterized. We found that mutant strain ΔtolA was damaged in inner and outer membranes, and showed altered morphology, impaired flagella production, reduced motility, increased outer membrane vesicles (OMVs) production, decreased resistance to antibiotics and environmental stress. Deletion of tolA gene resulted in a significant decrease in biofilm formation and interbacterial competition, due to the downregulated expression of biofilm-associated genes and type VI secretion system (T6SS) genes, respectively. In addition, the mutant strain exhibited diminished serum bactericidal resistance, reduced cell infection capacity, decreased intracellular survival, consequently, leading to attenuated bacterial survival and virulence in mice. Compared with the wild-type and complemented strains, mutant strain induced less expression of inflammatory cytokine interleukin 1 beta (IL-1β) in HD-11 macrophages, consistent with the pathological damage in mice. In conclusion, inner membrane protein TolA contributed to the antibiotic resistance, environment adaptability, biofilm formation and virulence of APEC.

Green manuring is essential for improving soil quality and nutrient uptake. With the gradual depletion of phosphorus (P) resources, more attention is being paid to the role of green manures in cultivation systems, such as maize-green manure intercropping, to find possible pathways for enhancing soil P utilization. A maize-green manure intercropping experiment was started in 2009 to investigate the effects and mechanisms for enhancing P uptake and yield in maize. Three species of green manures (HV: hairy vetch; NP: needle leaf pea; SP: sweet pea) and a sole maize treatment (CK) were used, resulting in four treatments (CK, HVT, NPT, and SPT) in the experiment. During 2020-2023, the intercropping treatments enhanced maize yields in 2020 and 2021, particularly in the HVT treatment with increases of 13.7% (1.96 t ha^-1) and 13.0% (2.13 t ha^-1) compared with CK, respectively. Grain P accumulation of maize was significantly higher in the intercropping treatments than CK in 2020, 2021, and 2023, and with an average increase of 10.6% over the four years (5.2% for NPT, 10.8% for SPT and 15.9% for HVT) compared with CK. Intercropping promoted maize growth with a greater root length density and a higher organic acid release rate. HVT changed the soil properties more dramatically than the other treatments, with increases in the acid phosphatase and alkaline phosphatase activities of 29.8 and 38.5%, respectively, in the topsoil (0-15 cm), while the soil pH was reduced by 0.37 units compared to CK (pH=8.44). Intercropping treatments facilitated the conversion of non-labile P to mod-labile P and stimulated the growth of soil bacteria in the topsoil. Compared with CK, the relative abundance of Gemmatimonadota, known for accumulating polyphosphate, and Actinobacteriota, a prominent source of bioactive compounds, increased significantly in the intercropping treatments, especially in HVT and SPT. A PLS-PM analysis showed that intercropping promoted soil P mobilization and the enrichment of beneficial bacteria by regulating maize root morphology and physiology. Our results highlight that maize-green manure intercropping optimizes root traits, soil properties and bacterial composition, which contribute to greater maize P uptake and yield, providing an effective strategy for sustainable crop production.