Plant lateral root damage is an important ecological problem of vegetation degradation in semi-arid mining areas in western China. The damage mechanism and influencing factors of plant lateral roots caused by stress changes in root-soil layer induced by mining urgently need to be explored in depth. Based on the field survey data of plant roots, combined with quasi-cohesion theory and anchoring theory, and through the control variable method, a numerical model considering four key parameters, namely mining height, advancing distance, mining speed and coal seam burial depth, was established by FLAC3D software to analyze the macroscopic mechanical disturbance characteristics of root-soil complex and plant lateral roots. The research results show that: the stress on the bottom of the root-soil layer above the goaf area is higher than that on the surface; During the advancement of the working face from 60 m to 110 m, the failure range of the plastic zone of the root-soil layer and the stress on the lateral roots of plants showed an increasing trend, and the stress on lateral roots increases up to 3.3 MPa when the working face advances from 80 m to 110 m; in the disturbance zone, the maximum stress of the lateral roots and the failure range of the plastic zone of the root-soil layer increase with the increase of mining height, but decrease with the increase of coal seam burial depth; the change of the mining speed has little effect on the stress of the lateral roots and the failure range of the plastic zone of the root-soil layer, the maximum stress difference on the lateral roots between the maximum and minimum mining rates is only about 0.58 MPa. In addition, compared with plant roots with only the main root, plant roots with lateral root structure show better tensile and shear resistance in the root-soil layer, which shows that the presence of lateral roots help to enhance the overall stability and damage resistance of plant roots. FLAC3D was used to construct a three-dimensional visualization numerical simulation model of plant lateral root, which revealed the macroscopic mechanical response mechanism of plant lateral root damage induced by mining, and clarified the influence of various factors on plant lateral root stress damage induced by mining.The research findings enrich the understanding of plant damage mechanisms induced by underground coal mining in semi-arid areas.

Background Salt is an important factor that affects crop productivity. Plant hexokinases (HXKs) are key enzymes in the glycolytic pathway and sugar signaling transduction pathways of plants. In previous studies, we identified and confirmed the roles of GmHXK2 in salt tolerance. Results In this study, we analyzed the tissue-specific expression of GmHXK2 at different growth stages throughout the plant's life cycle. The results showed that GmHXK2 was expressed significantly in all tissues at vegetative stages, including germination and seedling. However, no expression was detected in the pods, and there was little expression in flowers during the later mature period. Arabidopsis plants overexpressing the GmHXK2 (OE) had more lateral roots. The OE seedlings also produced higher levels of auxin and ascorbic acid (AsA). Additionally, the expression levels of genes PMM, YUC4/YUC6/YUC8, and PIN/LAX1,LAX3, which are involved respectively in the synthesis of AsA and auxin, as well as polar auxin transport, were upregulated in OE plants. This upregulation occurred specifically under exogenous glucose treatment. AtHKT1, AtSOS1, and AtNHX1 were up-regulated in OE plants under salt stress, suggesting that GmHXK2 may modulate salt tolerance by maintaining ion balance within the cells and alleviating damage caused by salt stress. Additionally, we further confirmed the interaction between GmHXK2 and the protein GmPMM through yeast two-hybridization and bimolecular fluorescence complementation assays, respectively. Conclusion The expression of GmHXK2 gene in plants is organ-specific and developmental stage specific. GmHXK2 not only regulates the synthesis of AsA and the synthesis and distribution of auxin, but also promotes root elongation and induces lateral root formation, potentially enhancing soil water absorption. This study reveals the crosstalk between sugar signaling and hormone signaling in plants, where GmHXK2 acts as a glucose sensor through its interaction with GmPMM, and sheds light on the molecular mechanism by which GmHXK2 gene is involved in salt tolerance in plants.

Introduction Plant responses to drought stress are influenced by various factors, including the lateral root angle (LRA), stomatal regulation, canopy temperature, transpiration rate and yield. However, there is a lack of research that quantifies their interactions, especially among different cotton varieties.Methods This experiment included two water treatments: well-watered (75 +/- 5% soil relative water content) and drought stress (50 +/- 5% soil relative water content) starting from the three-leaf growth stage.Results The results revealed that different LRA varieties show genetic variation under drought stress. Among them, varieties with smaller root angles show greater drought tolerance. Varieties with smaller LRAs had significantly increased stomatal opening by 15% to 43%, transpiration rate by 61.24% and 62.00%, aboveground biomass by 54% to 64%, and increased seed cotton yield by 76% to 79%, and decreased canopy temperature by 9% to 12% under drought stress compared to the larger LRAs. Varieties with smaller LRAs had less yield loss under drought stress, which may be due to enhanced access to deeper soil water, compensating for heightened stomatal opening and elevated transpiration rates. The increase in transpiration rate promotes heat dissipation from leaves, thereby reducing leaf temperature and protecting leaves from damage.Discussion Demonstrating the advantages conferred by the development of a smaller LRA under drought stress conditions holds value in enhancing cotton's resilience and promoting its sustainable adaptation to abiotic stressors.