The use of vegetation as a diagnostic tool for environmental contamination has evolved from descriptive practices. Plants have long been used as bioindicators of environmental contamination，particularly heavy metals. While analytical advances have greatly improved our ability to quantify trace elements in plant tissues，interpreting these data remains a critical challenge. This viewpoint argued that plants should not be considered as passive recorders of environmental pollution，but as dynamic systems that integrate，transform，and redistribute metals according to species-specific physiology and environmental conditions.

Temperature stress is a key factor limiting the distribution and growth of Cinnamomum camphora，with fundamentally distinct response mechanisms to high and low temperatures. This review systematically compared the core strategies employed by C. camphora under the two stresses. Under high-temperature stress，the photosynthetic system undergoes metabolic dissipation via enhanced photorespiration；redox regulation is driven by a monoterpene-mediated WRKY-HSF signaling network；and proline exhibits the most rapid response in osmotic adjustment. In contrast，under low-temperature stress，the photosynthetic system depends on non-photochemical quenching and cyclic electron flow for physical protection；molecular regulation is centered on the Ca²⁺-ethylene-ERF/CBF cascade；and soluble sugar accumulation dominates osmotic adjustment. Based on these mechanisms，this review evaluated the effectiveness of current regulatory strategies from three dimensions（physical，chemical，and biotechnological approaches） and identified existing bottlenecks in elucidating monoterpene signaling pathways，deciphering combined stress mechanisms，and development of precise regulation technologies. Future research should focus on integration of multi-omics data to resolve molecular networks，construction of predictive models for combined stresses，breakthroughs in genetic transformation systems，and assessment of the ecological and economic feasibility of regulatory strategies. These advances will facilitate the shift of stress-resilient cultivation of C. camphora from passive protection to active，mechanism-driven precise regulation.

When confronted with complex soil environments such as drought，salinity，and nutrient imbalance，terrestrial plant roots have to achieve a dynamic trade-off between efficient acquisition of water and nutrients，effective blockage of solute leakage，and selective exclusion of harmful ions. The endodermis，a key structural layer in the roots of vascular plants，forms a continuous apoplastic barrier through the Casparian strip and suberin lamellae，thereby maintaining ionic and water homeostasis at the physiological level by regulating radial transport pathways. This review synthesized current knowledge on the biosynthesis，deposition，and structural characteristics of the Casparian strip and suberin lamellae. It further discussed their plasticity under the coordinated regulation of the MYB36 pathway and the Schengen surveillance pathway. Recent advances in understanding the roles of these barrier structures in maintaining mineral nutrient homeostasis，enhancing stress resistance，and mediating rhizosphere interactions were examined. Finally，future research directions were proposed from the perspectives of evolutionary adaptation and crop improvement. This review provided novel insights for a deeper understanding of the adaptive evolution of plant roots and stress-resistant breeding.

The increasing frequency of drought and heatwaves due to global climate change poses a severe threat to desert vegetation. However，the mechanisms by which desert shrubs coordinate hydraulic safety and thermal-tolerance to cope with compound drought-heat stress remain unclear. Five sympatric Tamarix species in the arid region of Northwest China were investigated in this study. By combining 24 h field measurements of gas exchange parameters and leaf water potential with the determinations of physiological traits（xylem embolism vulnerability（P₅₀），turgor loss point（Ψ_tlp），and semi-lethal high temperature（LT₅₀）），we systematically evaluated their adaptive strategies. The results showed that：（1）There was significant interspecific differentiation in drought and heat resistance among the five species. Tamarix hispida exhibited the strongest embolism resistance（P₅₀=-2.20 MPa） and thermal tolerance（LT₅₀=66.5 ℃），while T. hohenackeri showed the highest gas exchange rates but the weakest resistance. （2）Thermal tolerance（LT₅₀） was significantly negatively correlated with embolism resistance（P₅₀） and significantly positively correlated hydraulic safety margins（H_SM），confirming a high degree of coordinated adaptation rather than a trade-off between hydraulic safety and thermal tolerance in desert plants. （3）Principal Component Analysis（PC1 explained 92.4%） revealed a continuous spectrum of adaptive strategies：ranging from an “Acquisitive-Cooling” strategy represented by T.hohenackeri，to a “Conservative-Tolerance” strategy represented by T.hispida. This study reveals niche differentiation mechanisms based on hydraulic-thermal coupling and highlights the importance of prioritizing species with “Conservative-Tolerance” strategies for vegetation restoration under future hotter and drier climate scenarios.

To clarify stage-specific differences in the functional status of a typical sand-fixing shrub following stubble treatment in an ecologically fragile zone，we investigated approximately 50-year-old Haloxylon ammodendron individuals in the Minqin desert-oasis ecotone，Gansu Province，China. Four treatments were compared：no stubble，half stubble by branch number（50%），half stubble by height（50%），and complete stubble. Approximately two years after treatment，architectural traits，water-related functional traits，carbon acquisition traits，non-structural carbohydrate（NSC） contents during the peak growing season，and fine-root segment traits from the 80-90 cm soil layer were measured. Correlation analysis，principal component analysis，and the entropy-weighted TOPSIS method were used to evaluate trait associations and overall functional performance among treatments. The results showed that the multidimensional functional trait configuration of H. ammodendron varied among stubble treatments. Compared with no stubble and complete stubble，the two half-stubble treatments generally showed better aboveground architectural status and functional maintenance characteristics. Half stubble by height（50%） demonstrated relatively better performances in mean crown width，number of living branches，native water transport capacity，hydraulic safety margin，and organ NSC contents. In contrast，half stubble by branch number（50%） showed certain advantages in net photosynthetic rate，fine-root segment length，and specific root length. Correlation and principal component analyses revealed associations among native water transport capacity，hydraulic impairment，stomatal regulation，chlorophyll content，NSC accumulation，and fine-root segment traits，suggesting linked variation among multiple functional traits following stubble treatment. The entropy-weighted TOPSIS evaluation indicated that half stubble by height（50%） had the highest comprehensive score，followed by half stubble by branch number（50%），whereas no stubble and complete stubble exhibited lower overall functional performance. These results indicated that，for approximately 50-year-old H. ammodendron individuals observed two years post-treatment，half stubble by height（50%） showed relatively better performance in aboveground architecture，maintenance of native water transport capacity，and growing-season non-structural carbohydrate accumulation. This study provides a stage-specific reference for stubble management of aging H. ammodendron plantations in desert-oasis ecotones.

Light is an indispensable environmental factor for plant growth and development. However，UV-B radiation interferes with normal growth processes，causing oxidative damage and inhibiting photosynthesis. To explore the morphological and physiological characteristics and underlying mechanisms of poplars to UV-B stress，dioecious Populus cathayana were used as materials. The cuttings were subjected to UV-B stress alone or combined with exogenous applications of exogenous phytohormones（indole-3-acetic acid（IAA），1-aminocyclo-propanecarboxylic acid（ACC），methyl jasmonate（MeJA），salicylic acid（SA） and melatonin（MT））. A series of indictors were conducted，including leaf photosynthetic parameters，antioxidant activities，hormone contents，relative expression levels of related genes，anthocyanin contents in stems and leaves，as well as principal component analysis（PCA）. Results showed that under UV-B stress，the net photosynthetic efficiency decreased，and the reactive oxygen species（ROS） molality increased in P.cathayana leaves，with male exhibiting stronger tolerance to UV-B than female P.cathayana. Exogenous hormone applications alleviated UV-B stress-induced damage by improving leaf photosynthetic performance and regulating ROS homeostasis. Specifically，IAA，ACC，and MT treatments exerted more pronounced alleviating effects on female than that on male P.cathayana under UV-B stress. SA application significantly reduced the H₂O₂ content in leaves. MeJA application promoted organ anthocyanin accumulation，decreased leaf H₂O₂ content，and enhanced net photosynthetic efficiency and UV-B tolerance on P. cathayana. In addition，the relative expression levels of PtrJAZ1/2/3/5/9 genes were significantly upregulated under both UV-B stress and MeJA treatment，suggesting that these genes may act as key regulators in the JA signaling pathway，mediating anthocyanin synthesis and stress responses. In conclusion，males displayed greater physiological plasticity and stress resistance potential than female P. cathayana under UV-B radiation stress. This study provides practical insights for stress-resistant plant cultivation and hormone regulation in practices.

To investigate the function of PsnSWEET7 in nitrogen response and regulation of carbon and nitrogen metabolism，the transgenic lines overexpressing PsnSWEET7 were generated in Populus simonii × P. nigra via Agrobacterium-mediated transformation. The effects of this gene on plant growth and carbon-nitrogen metabolism were investigated by subcellular localization and phenotype analysis，as well as determinations of physiological indices and gene expression under treatments with different concentrations of ammonium nitrate （NH₄NO₃）. The PsnSWEET7 protein was localized to the plasma membrane. Under NH₄NO₃ treatments，compared with the wild type，the plant height and ground diameter of PsnSWEET7 overexpressing plants increased by 17.3% and 17.8%，respectively（P<0.05）；the mass fractions of sucrose，glucose，soluble protein and free amino acids in stems increased by 20.1%，25.4%，9.3% and 7.5%，respectively（P<0.05）；the cellulose mass fraction increased by 10.5%（P<0.05），while the lignin mass fraction decreased by 12.2%（P<0.05）. Under normal and high nitrogen conditions，the activities of vacuolar invertase and cell wall invertase were significantly elevated in transgenic plants. This study indicates that PsnSWEET7 can remodel the carbon and nitrogen metabolism of P.simonii×P. nigra by regulating sugar transport，thereby promoting plant growth，and provides new genetic resources and theoretical basis for the molecular breeding of high-yield and high-quality poplars.

Tonoplast intrinsic proteins（TIPs），as important members of the aquaporin family，play crucial roles in plant water balance and stress responses. In this study，the function and molecular mechanism of the PagTIP1；3 gene in response to salt stress were investigated in the leaves of wild-type 84K poplar（Populus alba×P.glandulosa） and PagTIP1；3 knockout lines. The results showed that under normal conditions，knockout of the PagTIP1；3 gene led to decreases in chlorophyll content，net photosynthetic rate，and plant height. Under salt stress，the knockout lines exhibited aggravated wilting and yellowing，significantly reduced plant height，and marked decreases in photosynthetic physiological parameters，including maximum photochemical efficiency，electron transport rate，and relative chlorophyll content，compared with the wild type. Transcriptome analysis revealed that the expression patterns of key genes involved in the photosynthetic pathway（including PagLHCB7，PagGAPCP-2，PagPSY，and PagRCA） were significantly altered in the PagTIP1；3 knockout lines in response to salt stress. In summary，it is speculated that PagTIP1；3 deficiency disrupted the transcriptional response of photosynthesis-related genes in poplar under salt stress，thereby impairing photosynthetic electron transport and photoprotection capacity，disturbing growth and photosynthetic physiological homeostasis，and ultimately significantly reducing salt tolerance in poplar.

This study aimed to investigate the molecular function of the C2H2-type zinc finger transcription factor PtrZAT11 in the process of wood formation in poplar. The expression pattern of PtrZAT11 in the xylem at different stem internodes of Populus trichocarpa was analyzed by RT-qPCR. The subcellular localization of the PtrZAT11-GFP fusion protein was observed using a PEG-mediated protoplast transient transformation system. A double mutant of PtrZAT11 and its homologous gene PtrZAT11h was generated using CRISPR-Cas9 technology. Growth parameters and stem anatomical structures of the mutant were subsequently analyzed. The results indicated that PtrZAT11 was significantly highly expressed in stem internodes during the secondary growth stage，and its protein was localized in the nucleus. Compared with the wild type，the ptrzat11 ptrzat11h double mutant exhibited an approximately 31.5% increase in plant height and a significant increase in the number of stem internodes，while no significant differences were observed in ground diameter or internode length. In the 12th internode of the mutant，the width of xylem ring and proportion of xylem cell area were significantly reduced. Additionally，the number of fiber cells per unit area decreased，whereas the number of vessel cells increased. As a nuclear-localized transcription factor，PtrZAT11 participates in wood formation in poplar by influencing the differentiation quantity of xylem cells to regulate xylem tissue organization. It may also coordinate the balance between primary and secondary growth in poplar.

To systematically reveal the synergistic regulatory mechanisms of thinning intensity and water-nitrogen addition on leaf functional traits in plantations，this study conducted a split-plot experiment with Populus tomentosa plantations in the Yellow River Flood Plain. Two thinning intensities（50% and 75%） and three water-nitrogen treatments（water-nitrogen addition，single water addition，and control） were established. The response characteristics and coupling relationships were analyzed from three dimensions：leaf water status，structural construction，and nutrient stoichiometry. The results indicate that：（1）Leaf relative water content remained generally stable，whereas leaf dry mass water content exhibited high sensitivity to thinning and its interaction with water-nitrogen treatments，showing a significant increase of 43.05% under 75% thinning with water-nitrogen addition. （2）Structural traits showed no significant overall changes，with low variation in leaf dry matter content and high variation in specific leaf mass，demonstrating potential plasticity. （3）Among nutrient traits，leaf carbon content remained relatively stable，whereas leaf nitrogen and phosphorus contents as well as their stoichiometric ratios responded significantly to the treatments. The leaf N∶P ratio（mass ratio）ranged from 11.06 to 18.46，with an average value of 13.94，indicating that the P.tomentosa plantations in the study area were generally under nitrogen limitation. （4）Multivariate analysis revealed significant coupling relationships among leaf water content，structural traits，and nutrient allocation，with leaf dry mass water content and specific leaf mass identified as key traits driving nutrient partitioning. （5）Principal component analysis revealed that the first two principal components cumulatively explained 66.4% of the variation. Thinning at 75% promoted leaf adjustment towards high resource-use efficiency，while 50% thinning maintained a conservative strategy. Different water and nitrogen treatments primarily diverged along the nutrient structure dimension，with the single water addition treatment showing strong association with nutrient ratio traits. Overall，thinning and water-nitrogen regulation drive coordinated changes in leaf functional traits by altering resource availability，thereby influencing plant resource utilization strategies.