Trees最新文献

{"title":"Silver birch (Betula pendula Roth) response to polycyclic aromatic hydrocarbons: implications for growth patterns and secondary metabolite production","authors":"Greta Striganavičiūtė,&nbsp;Thomas Hoffmann,&nbsp;Wilfried Schwab,&nbsp;Vaida Sirgedaitė-Šėžienė","doi":"10.1007/s00468-025-02622-0","DOIUrl":"10.1007/s00468-025-02622-0","url":null,"abstract":"<div><p>Birches (<i>Betula</i>) are crucial trees in Northern Europe, enhancing forest resilience and biodiversity, and aiding in pollutant removal through phytoremediation. Industrialization and urbanization introduce polycyclic aromatic hydrocarbons (PAHs), threatening birch ecosystems and human health. This study investigated the impact of PAHs on the growth and secondary metabolite levels of silver birch (<i>Betula pendula</i> Roth) seedlings from four half-sib families (genetic groups). Seedlings were exposed to phenanthrene, pyrene, naphthalene, and fluoranthene at varying concentrations. Thirty-six compounds from birch leaf extracts were identified using LC–MS analysis, including catechin, quercitrin, caffeoylquinic acid. Significant findings included a reduction in shoot and root lengths, with phenanthrene at 200 µg L⁻¹ reducing shoot growth by up to 85% and root length by 69% in some families. Total phenol content increased in most families at higher pollutant concentrations, whereas total flavonoid content generally decreased. Notably, (epi)gallocatechin levels increased by up to 200% with naphthalene exposure, and catechin levels increased tenfold in some cases. The results underscore the differential responses among half-sib families to PAH exposure, with higher concentrations generally causing more pronounced negative effects on both growth and secondary metabolism. These findings emphasize the significance of secondary metabolites in plant–environment interactions, where alterations due to PAH exposure could affect birch resilience, and, consequently, the broader ecosystem functions they support.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The dynamic regulation response to salt stress in poplar","authors":"Wenfang Dong,&nbsp;Xinyu Wang,&nbsp;Kaiye Yang,&nbsp;Hao Zhang,&nbsp;Yuting Ding,&nbsp;Wenshuo Gao,&nbsp;Xiaojin Lei,&nbsp;Caiqiu Gao","doi":"10.1007/s00468-025-02619-9","DOIUrl":"10.1007/s00468-025-02619-9","url":null,"abstract":"<div><h3>Key message</h3><p>This study focuses on poplar root's dynamic salt stress responses, finding that Hsp20s may play an important role and screening its upstream regulators.</p><h3>Abstract</h3><p><i>Populus davidiana</i> × <i>P. alba</i>, an excellent tree species, which is widely planted in China, has been seriously affected by salt stress. In this study, the response of poplar roots to salt stress was deeply studied by time-course transcriptome, and a large number of differentially expressed genes (DEGs) were identified at different times. Through weighted gene co-expression network analysis (WGCNA), it was discovered that oxidative and osmotic stress regulation played a crucial role in resisting salt stress in the early salt stress response (3–6 h), and nitrogen metabolize and transport genes were identified as hub genes. At the middle stage of salt stress (12–24 h), the plants initiated extensive reprogramming to adapt to stress, and the transcription factors (TFs), WRKY53, MYB13 and NFXL1, were identified as hub genes. After 48 h of salt stress, seven <i>PdaHsp20</i> genes were identified as hub genes, which may alleviate the damage of salt stress. The genome-wide analysis of Hsp20s showed that the Hsp20 proteins were divided into 11 groups. A three-layer gene regulatory network with <i>PdaHsp20s</i> as the underlying gene was constructed and the unique <i>PdaERF72</i> was found by association analysis with the co-expression network, which may have important functions in regulating <i>PdaHsp20s</i> under salt stress. The expression level analysis of <i>PdaERF72</i> and <i>PdaHsp20s</i>, which have a direct connection with it, also indicated that some of them may have a negative regulation relationship after salt stress. In a word, poplar dynamically responds to salt stress, and different hub genes play a role in different stress stages, which provided a new perspective to reveal the response mechanism of poplar to salt stress.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Cercis siliquastrum seedling quality to meet ecological challenges in afforestation: influence of the combined effects of light, water stress, and zeolite amendment","authors":"Mehdi Heydari,&nbsp;Mehdi Anbari,&nbsp;Abdolali Karamshahi,&nbsp;Somayeh Hajinia,&nbsp;Orsolya Valkó,&nbsp;Bernard Prévosto","doi":"10.1007/s00468-025-02621-1","DOIUrl":"10.1007/s00468-025-02621-1","url":null,"abstract":"<div><p>The production of high-quality seedlings is crucial for successful afforestation efforts, particularly in arid and semi-arid regions where drought stress is a major ecological challenge. Light and water stress are interrelated and have a major impact on seedling growth and development. The combined effects of light (25, 50, 75, and 100% of full sunlight) and water stress (field capacity of 100, 75, and 50%) on the morpho-physiological characteristics of <i>Cercis siliquatrum</i> seedlings were investigated in a controlled nursery experiment. Additionally, the effect of zeolite on seedling quality was evaluated. The amount of proline greatly increased with water stress, whereas light had no effect. The highest values of morphological traits were obtained in conditions without water stress and light intensity of 50% and above, whereas water deficit had the most negative effect on seedling quality in low light (L25). The use of zeolite reduced the negative effects of drought stress on seedlings and increased the seedling quality index by 15%. Additionally, zeolite increased the number of leaves (+ 13.5%), leaf dry matter (+ 7.9%), leaf area (12.1%), stem diameter (13.4%), stem length (+ 12.6%), stem dry matter (+ %), root length (+ 21.7%), and root dry matter (+ 12.3%). The results support the interplay hypothesis, which predicts stronger drought effects under both full light and heavy shade conditions compared to moderate shade. Our results also suggest that <i>Cercis siliquastrum</i> is a heliophyte species that thrives in moderate to high light conditions. We also recommended the application of zeolite amendment to reduce the negative effects of drought stress and promote seedling growth and quality.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Windthrow mortality influenced by natural root grafting in boreal jack pine forests","authors":"Martín Alcalá-Pajares,&nbsp;Miguel Montoro Girona,&nbsp;Annie DesRochers","doi":"10.1007/s00468-025-02624-y","DOIUrl":"10.1007/s00468-025-02624-y","url":null,"abstract":"<div><h3>Key message</h3><p>Natural root grafting reduces tree uprooting likelihood and promotes stem breakage during windthrow events.</p><h3>Abstract</h3><p>Windthrow is a natural disturbance affecting forest dynamics, characterized by tree uprooting or stem breakage when wind forces surpass tree anchorage strength or stem resistance. Windthrow mortality has been related to several ecological biotic and abiotic factors. However, the influence of natural root grafting on windthrow mortality remains unknown. This research evaluated the influence of root grafting on windthrow mortality by excavating root systems of jack pine (<i>Pinus banksiana</i>) in four windthrow-affected riparian buffers and analyzing root grafts using a dendrochronological approach. Our results revealed that natural root grafting decreased the uprooting likelihood but increased the propensity for stem breakage. In addition, root grafting occurred more frequently in trees closer to one another. These results suggest that root grafting influences the windthrow mortality type, with tree proximity being a good predictor for root grafting. This study provides valuable insights into windthrow dynamics, particularly relevant for managing windthrow mortality following partial harvesting and riparian buffers, conserving soil, and mitigating the impacts of windthrow events in the face of climate change.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 3","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-025-02624-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of climate at origin on Douglas-fir growth, leaf traits and embolism resistance along a rainfall gradient in Central Europe","authors":"Vincent P. Riedel,&nbsp;Patrick Engel,&nbsp;Pierre-André Waite,&nbsp;Roman M. Link,&nbsp;Randolf Schirmer,&nbsp;Joachim Hamberger,&nbsp;Bernhard Schuldt","doi":"10.1007/s00468-025-02605-1","DOIUrl":"10.1007/s00468-025-02605-1","url":null,"abstract":"<div><h3>Key message</h3><p><b>In Douglas-fir grown in Central Europe, growth and specific leaf area differed between coastal and interior provenances but little intra-specific variability was found for the Huber value and xylem safety.</b></p><h3>Abstract</h3><p>In Central Europe, the economically most important timber species for roundwood production, Norway spruce, has been severely affected by recent global change-type drought events. Due to its large spatial distribution, Douglas-fir (<i>Pseudotsuga menziesii</i>) is considered for conversion to climate-resilient forests. Specifically, provenances from moister coastal and drier and colder interior regions might differ in drought tolerance traits. Here, we characterized aboveground biomass increment as well as leaf morphological and plant hydraulic traits in mature trees of 28 Douglas-fir provenances from three climate-at-origin groups across a climatic gradient in Central Europe, covering a precipitation range of 542 mm yr⁻¹. Irrespective of the gradient, the northern interior provenances had a 5.4 kg yr⁻¹ lower aboveground biomass increment than the two coastal groups, accompanied by a 13% smaller specific leaf area. On the other hand, the Huber value, embolism resistance (<i>P</i>₅₀) and leaf carbon isotope signature (δ¹³C) as proxy for long-term intrinsic water use efficiency did not differ between climate-origin groups. Across the gradient and within a climate-origin-group, no effect of climatic aridity on any of the traits covered was observed. Especially <i>P</i>₅₀ showed very little intra-specific variability, and our observed mean of −3.5 MPa is in the same range as <i>P</i>₅₀-values for Douglas-fir recently reported from Europe. Our results for Douglas-fir support that xylem safety is a rather conservative and evolutionary canalized trait in conifers, while the Huber value revealed less plasticity as expected. Future studies are needed to test whether slower-growing interior provenances with thicker and smaller needles might be more drought tolerant and thus better suited for cultivation in the future climate of Central Europe although xylem safety does not differ.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 2","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-025-02605-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of local climate and large-scale climate drivers on the growth of Gmelina arborea Roxb. in a South Asian moist tropical forest","authors":"Chowdhury Rafatul Kabir,&nbsp;Mahmuda Islam,&nbsp;Md Bayzid Hassan,&nbsp;Mizanur Rahman","doi":"10.1007/s00468-025-02618-w","DOIUrl":"10.1007/s00468-025-02618-w","url":null,"abstract":"<div><h3>Key message</h3><p>Tree growth of <i>Gmelina arborea</i> Roxb is mainly influenced by pre-monsoon temperatures and ENSO in a moist tropical forest of Bangladesh.</p><h3>Abstract</h3><p>The present study was conducted to investigate the impact of climate change on tree radial growth in a moist tropical forest of Bangladesh. A standard ring-width index chronology (RWI) of <i>Gmelina arborea</i> Roxb. was developed spanning the 92-year period from 1929 to 2020 using the standard dendrochronological technique. The association between climate variables and RWI was determined by employing simple Pearson's correlation. Pre- and post-monsoon maximum temperature (Tmax) had a strong negative impact on tree growth. Temperatures during the monsoon period however favored tree growth. Tree growth was also influenced by previous years’ temperature providing evidence of a lag effect on radial growth. On a spatial scale, tree growth was influenced by regional climate and sea surface temperatures of Ninö 3.4 region, indicating teleconnection between tree growth and large-scale climate phenomenon. If the negative relationship between temperatures and tree growth continues in future, it will have important implications for tropical forest tree biomass, since temperature is predicted to increase in the tropics. Future global warming is thus very likely to affect the carbon sequestration potential of tropical forests in the face of climate change.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 2","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-025-02618-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning methods for basal area prediction of Fagus orientalis Lipsky stands based on national forest inventory","authors":"Seyedeh Fatemeh Hosseini,&nbsp;Hamid Jalilvand,&nbsp;Asghar Fallah,&nbsp;Hamed Asadi,&nbsp;Mahya Tafazoli","doi":"10.1007/s00468-025-02616-y","DOIUrl":"10.1007/s00468-025-02616-y","url":null,"abstract":"<div><h3>Key Message</h3><p>Machine learning models accurately predict <i>F. orientalis</i> stand basal area in the Hyrcanian forest using environmental variables, with the RF model performing best. Elevation is the most important predictor.</p><h3>Abstract</h3><p>Accurate prediction of tree basal area (BA) as an important forest stand structural characteristic is essential for sustainable forest management. The aim of this study was to use four machine learning methods, including generalized linear model (GLM), k-nearest neighbors (KNN), support vector machine (SVM), and random forest (RF), to predict and assess the stand BA of <i>Fagus orientalis</i> Lipsky using national forest inventory data and a comprehensive set environmental variables. Modeling was performed using a 10-fold spatial cross-validation technique to counteract the effect of spatial auto-correlation in predictor and response data, as well as to reduce the dependency between training and test data. The RF model outperformed the others by having the best match between measured and predicted stand BA values, with the highest squared correlation coefficient (<span>({R}_{text{Train}}^{2})</span> = 0.77; <span>({R}_{text{Test}}^{2})</span>= 0.76) and the lowest root mean square error (<span>({text{RMSE}}_{text{Train}})</span>= 2.70; <span>({text{RMSE}}_{text{Test}})</span>= 2.90) and mean absolute error (<span>({text{MAE}}_{text{Train}})</span>= 1.74; <span>({text{MAE}}_{text{Test}})</span>=1.76). Among all investigated variables, elevation showed the highest correlation with stand BA of <i>F. orientalis</i> in the Hyrcanian forest. The relation was positive and restricted to the range of approximately 700 to 1200 m. The RF and GLM models indicated the bulk density as the second-most important variable, whereas the SVM and kNN models indicated the air temperature as the second important variable. In general, this research identifies key variables influencing the stand BA of <i>F. orientalis</i>, providing valuable insights for forest management and conservation efforts. These findings contribute to a better understanding of forest dynamics in the Hyrcanian region and can inform targeted management strategies.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 2","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does atmospheric nitrogen deposition cause critical nutrient imbalances in temperate tree regeneration?","authors":"Viktoria Dietrich,&nbsp;Jörg Niederberger,&nbsp;Jana Frank,&nbsp;Markus Hauck","doi":"10.1007/s00468-025-02615-z","DOIUrl":"10.1007/s00468-025-02615-z","url":null,"abstract":"<div><h3>Key message</h3><p>Nitrogen deposition and precipitation analyzed along independent gradients did not cause major foliar nutrient imbalances that affected tree health in temperate tree regeneration of <i>Fagus sylvatica</i>, <i>Pseudotsuga menziesii</i> and <i>Abies alba</i>.</p><h3>Abstract</h3><p>While drought tolerance receives great attention in the scope of climate change research, the response of trees to high N deposition, which is also part of global change, has remained less studied. We investigated 45 temperate forest stands across Germany along a gradient of atmospheric N deposition of 22 kg N ha⁻¹ a⁻¹ (range 10–32 kg N ha⁻¹ a⁻¹) and analyzed foliar nutrient concentrations and ratios in saplings of European beech, Douglas fir, and silver fir. We also measured relative shoot length increment and (as a proxy for intrinsic water use efficiency, WUEi, and stomatal conductance, <i>g</i>_s) foliar δ¹³C signatures to detect potential effects of nutrient imbalances on productivity and plant water relations. Although all species responded on deposition with increased foliar N concentrations, reduced foliar nutrient concentrations were only observed for P, but not K, Ca, Mg, and Fe. The effect on foliar P concentrations was only observed at sites with low mean annual precipitation (range 565–1690 mm). Reduced growth was not observed. Low foliar P concentrations were associated with high <i>g</i>_s in Douglas fir, which poses a potential risk under dry conditions and is consistent with the literature, but lacks a mechanistic explanation. The lack of nutrient imbalance at high N supply can at least partly be explained by the relatively low absolute amounts of nutrients needed by the small-sized tree regeneration.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 2","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-025-02615-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic insights of Dalbergia latifolia (Indian rosewood): applications in conservation and beyond","authors":"T. N. Manohara,&nbsp;S. M. Balakrishna,&nbsp;H. S. Suresh","doi":"10.1007/s00468-025-02617-x","DOIUrl":"10.1007/s00468-025-02617-x","url":null,"abstract":"<div><h3>Key Message</h3><p>The de novo genome sequencing of <i>Dalbergia latifolia</i> (Indian rosewood) reveals crucial genetic insights, aiding conservation, sustainable timber production, and scientific research. The high-quality draft genome identifies key pathways and markers for improving disease resistance and timber quality, supporting the protection and sustainable use of this important species.</p><h3>Abstract</h3><p>Wood, as a natural and sustainable energy source, serves as an eco-efficient alternative to fossil fuels, and is playing a vital role in stabilizing woody plants and transporting water to all plant parts. Over the last few decades, our knowledge of cellular wood formation (xylogenesis) has significantly increased. <i>Dalbergia latifolia,</i> commonly known as ‘Indian rosewood’, emerges as a premier timber species from the Indo-Malaysian region. This slow-growing tree is prized for its durable timber, which is stronger and harder than teak, and for its natural resistance to pests and fungal attacks. However, escalating demand for rosewood, particularly from China, has led to increased illegal exploitation and listing under CITES Appendix 2. By the end of 2020, <i>D. latifolia</i> was assessed as globally vulnerable by the IUCN Red List of Threatened Species under criteria A1cd. Key threats in India include inadequate regeneration and slow growth rates due to rising commercial demand. In response, India has banned the export of logs and sawn wood from this species. Despite its ecological and economic significance, genome-level information for <i>D. latifolia</i> has been lacking, hindering scientific research and conservation efforts. This study presents a comprehensive de novo genome sequencing and assembly of <i>D. latifolia</i>, providing valuable insights into its genetic makeup and potential applications. We generated 22,319 contigs totaling 613.95 Mb with high completeness (95%) and an identification rate of 92% for single-copy BUSCO genes.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 2","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developmental study of thorns in tissue culture clone of Lycium ruthenicum","authors":"Haifeng Ke,&nbsp;Yuliang Zhou,&nbsp;Jianguo Cui,&nbsp;Lijie Zhang,&nbsp;Yucheng Wang,&nbsp;Qin-Mei Wang","doi":"10.1007/s00468-025-02610-4","DOIUrl":"10.1007/s00468-025-02610-4","url":null,"abstract":"<div><p><i>Lycium ruthenicum</i> is a thorny shrub species that possesses both economic and ecological benefits; however, the processes and mechanisms underlying its thorn development remain inadequately understood. This study found that clonal line 11 of <i>L. ruthenicum</i> exhibited no thorns prior to transplantation. However, 40 days after transplantation, two distinct phenotypes emerged: thorny and thornless. Thorny plants exhibited significantly higher thorn frequency, larger stem diameters (both at the apex and base), increased leaf density, greater leaf width, and elevated photosynthetic rates in the apical buds and leaves compared to thornless plants. Histological analysis of paraffin sections demonstrated that the meristem tissues located at the axils of thornless stems progressively differentiated into axillary buds, without giving rise to thorn primordia. In contrast, the meristem tissues at the axils of thorny stems developed into thorn primordia, which subsequently matured into branch-thorns, while the tissues beneath the thorn primordia differentiated into axillary buds. The developmental stages of the apical bud and the upper four stem nodes were identified as critical periods determining the presence of thorns on the branch. RNA fluorescence in situ hybridization analysis demonstrated that a <i>L. ruthenicum</i> sucrose synthase gene (<i>LrSUS</i>) was highly expressed in leaflets and leaf primordia, as well as in glandular hairs, but not in thorn structures. Additionally, real-time quantitative PCR analysis revealed that the expression level of <i>LrSUS</i> in the leaves of thorny plants was significantly higher than that observed in the leaves of thornless plants. These suggest that the <i>LrSUS</i> gene does not directly promote thorn formation through high expression in thorn primordia; instead, it may indirectly promote thorn development by its elevated expression in leaves and enhancing overall photosynthesis. This study elucidates the developmental process of thorn in <i>L. ruthenicum</i> line 11, emphasizes the role of <i>LrSUS</i> in thorn development, and lays a foundation for future gene screening and mechanistic investigations.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 2","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}