江西农业大学

Red soils in subtropical regions are highly susceptible to structural degradation, resulting in poor water retention and restricted water transport. Although tillage strongly influences soil hydraulic properties, the pore-scale mechanisms governing these responses after long-term management remain poorly understood. Here, we investigated how 11 years of no-tillage (NT), rotary tillage (RT), and deep ploughing (DP) reshaped pore architecture and regulated soil hydraulic behavior across a 0-40 cm red soil profile by integrating soil physical measurements, van Genuchten modeling, X-ray computed tomography (CT), and multivariate analyses. Relative to conventional rotary tillage (RT), DP reduced bulk density by 16.8% and increased saturated hydraulic conductivity (Ks) by 138.9-1248.2% and air permeability (Ka) by 25.9-167.0% within the 0-30 cm cultivated layer through enhanced macroporosity and pore connectivity. In contrast, NT maintained higher Ks and Ka in the 20-40 cm subsoil, reflecting the preservation of continuous biopore networks under long-term minimal disturbance. RT preferentially promoted mesopore (200-500 mu m) development, resulting in the highest saturated water content, field moisture capacity, and plant-available water. Random forest analysis identified global pore connectivity (Gamma), pore anisotropy (An) and pore size distribution, rather than total porosity, as the dominant predictors of hydraulic behavior. Correlation, principal component, and redundancy analyses consistently showed that macropores (>500 mu m) primarily controlled water transmission, whereas meso- and micropores (60-200 and 200-500 mu m) governed water retention. Structural equation modeling demonstrated that tillage regulated hydraulic function indirectly through pore architecture, with pore conductivity promoting hydraulic conductivity (standardized path coefficient: 0.38) and pore storage enhancing hydraulic storage (0.45), while revealing a strong antagonistic trade-off (-0.93) between conductivity and water storage. These findings establish pore architecture as the mechanistic link between long-term tillage and soil hydraulic function, providing a scientific basis for optimizing tillage strategies to improve water use efficiency and drought resilience in red soil agroecosystems.

Kiwifruit (Actinidia chinensis) is highly susceptible to chilling injury (CI) during prolonged cold storage. In this study, the effects of micro-perforated (Mi-P) packaging on postharvest CI of kiwifruit were evaluated, and the underlying molecular responses were explored via transcriptome profiling and expression analysis of key pathway genes. The results showed that Mi-P packaging delayed the increase in CI index, weight loss, color difference, as well as malondialdehyde and lignin accumulation in kiwifruit under cold stress. Transcriptome analysis revealed that Mi-P-fruit separated from the control at both 30 and 60 d and down-regulated genes predominated in both comparisons. KEGG enrichment analysis indicated that Mi-P mainly affected lipid and phenylpropanoid metabolism, MAPK signaling, and plant hormone signal transduction. WGCNA further linked phenotypic traits to these pathways. Consistently, Mi-P suppressed expression of genes involved in membrane lipid degradation and oxidation (PLD1, LOX2.1) and in the α-linolenic acid pathway (AOS1, AOC, OPR3, OPR11), and down-regulated monolignol biosynthesis and polymerization–related genes (PAL1/4, 4CL2, HCT1, CCoAOMT, CSE, CAD6, LiPOD, POD4). Collectively, these results suggest that Mi-P packaging may alleviate CI in kiwifruit by restraining lipid and phenylpropanoid-related transcriptional responses, attenuating cold-induced excessive lignification, lipid peroxidation during cold storage.

The precise identification of safe navigable areas constitutes a foundational requirement for autonomous driving in complex unstructured environments. Existing studies have predominantly concentrated on extracting local or single-scale features, neglecting the substantial complementarity between multi-scale representations in complex natural environments, which constrains semantic understanding. To address this issue, a Semantic-Aware Terrain Segmentation Network (SATSNet) is proposed for navigable area recognition with guidance-entropy, which incorporates global sparse contextual information as prior guidance and progressively explores the latent complementarity among multi-scale features from both semantic hierarchy and spatial structure perspectives, achieving discriminative terrain feature aggregation. SATSNet is built around two essential modules: the Entropy-Guided Global Sparsification Module (EGGSM) and the Semantic-Spatial Fusion Module (SSFM). EGGSM performs selective channel-wise global semantic modeling through entropy-guided sparsification, providing representative long-range dependency semantic cues for guidance. SSFM comprises the Attention-Entropy Fusion Unit and the Dynamic Weight Allocation Unit, which leverage entropy-based attention to explore the semantic-spatial complementarity among adjacent features, facilitating the aggregation of semantic-aware terrain features. Validation on multiple challenging wild datasets, as well as large-scale street-view and real-world application datasets, demonstrates that SATSNet outperforms existing state-of-the-art methods in navigable area segmentation, providing a robust solution for safe autonomous navigation.

During the withering process of white tea, the degradation of astringent flavonol glycosides (FGs) plays a vital role in enhancing quality. However, the molecular mechanism underlying this process remains unclear. This study aimed to clarify the molecular mechanism and physiological significance of the degradation of nine key astringent FGs during white tea withering. Two key genes, CsGH3B (beta-glucosidase) and CsPPO1 (polyphenol oxidase), were identified using FGs quantification, transcriptomics, and weighted gene co-expression network analysis (WGCNA). Prokaryotic expression, protein purification, and in vitro enzyme activity assays confirmed that recombinant CsGH3B hydrolyzed all nine FGs, whereas recombinant CsPPO1 did not. Transient inhibition of CsGH3B expression in tea leaves significantly increased the contents of the nine FGs (P < 0.05). Overexpression of CsGH3B in Nicotiana benthamiana promoted the hydrolysis of FGs, further confirming its in vivo function. Molecular docking revealed that CsGH3B binds to FGs through hydrogen bonds and hydrophobic interactions. Our results indicate that dehydration stress during white tea withering induces the accumulation of reactive oxygen species, which may be associated with the upregulation of CsGH3B, catalyzing the hydrolysis of FGs to generate potent antioxidant flavonol aglycones (quercetin and kaempferol) that potentially contribute to oxidative stress alleviation. This process also reduces the bitterness and astringency of white tea products by lowering FG content, thereby improving taste quality. Together, these findings provide a molecular-level insight into the concept that "adversity yields fine tea" and offer a potential theoretical basis for postharvest flavor regulation and quality improvement of white tea.

Xanthomonas is a genus of plant-pathogenic bacteria traditionally associated with leaf and vascular diseases. However, emerging evidence demonstrates that Xanthomonas can also infect fruits, causing canker, necrotic lesions, and rot symptoms. This review examines host range and geographical distribution; genomic features; virulence factors and dispersal pathways; and fruit defense systems. Xanthomonas pathovars associated with fruit include X. arboricola pv. pruni, corylina, and juglandis, X. citri pv. citri and mangiferaeindicae, X. cucurbitae, X. euvesicatoria pv. euvesicatoria and perforans, and X. vasicola pv. musacearum, among others, which exhibit high host specificity, affecting stone fruits, hazelnut, walnut, citrus, mango, cucurbits, pepper, tomato, and banana, respectively. The infection process involves a sophisticated arsenal of virulence factors, including type III and type II secretion systems, biofilm formation, and the hijacking of host nutrient metabolism. Fruits have complex defense responses that include physical barriers (such as the cuticle and lignin), antimicrobial phenolic compounds, volatile terpenes, and defense enzymes. This review establishes a foundation for understanding the current impact of Xanthomonas in fruits and developing disease management strategies.