Liriodendron Tulipifera Research Articles

Evaluation of the tensile strength of Korean yellow poplar lumber

This study was conducted to confirm the feasibility of using yellow poplar, which is a fast-growing hardwood species in Korea, as a structural material. Lumber was produced, and the mechanical grading and the knot diameter ratio on the wide surface measurement were performed for each grade of lumber. It was confirmed that the majority mechanical grades of yellow poplar were E10, E11, and E12, and the size of knot in the surface increased as the mechanical grades decreased. A fitted distribution of tensile strength of the lumbers was the Weibull distribution. As a result of calculating the tensile allowable stress using the 5th percentile value calculated by the Weibull distribution and the non-parametric method according to the mechanical grade, all the experimental values were higher than the minimum allowable stresses presented in the Korean industrial standards. However, for the low grades, there was no significant difference from the standard values. This was thought to be due to the large size of knots in low-grade lumber. It was expected that the prospect of using yellow poplar structural member will be higher if additional research is conducted on the restriction of knot size according to the mechanical grade.

Dimensional stability and equilibrium moisture content of thermally modified hardwoods

The dimensional stability and equilibrium moisture content (EMC) of thermally modified hardwoods were studied. Lumber of yellow-poplar (Liriodendron tulipifera); red oak (Quercus borealis); white ash (Fraxinus americana), red maple (Acer rubrum); hickory (Carya glabra), and black cherry (Prunus serotina) were modified in industrial thermo-vacuum system. The water absorption rate, EMC, swelling, anti-swelling efficiency, shrinkage, anti-shrinkage efficiency, and anisotropy of the specimens were measured and compared to unmodified wood. The results show that thermal modification significantly decreased water absorption of wood which leads to improved dimensional stability. Specifically, thermally modified wood showed reduced EMC (22% in hickory to 59% in red maple), increased water absorption repellent (14.9% in black cherry to 29.6% in yellow-poplar), increased anti-swelling efficiency (14.2% in hickory to 71.4% in ash), increased anti-shrinkage efficiency (23.5% in red maple to 65.6% in ash), and reduced anisotropy coefficient (4.7% in red oak to 31.9% in black cherry).

Early silvicultural intervention affects species dominance in efforts to restore pine-hardwood mixedwoods following stand-replacing disturbance

Interest in replacing monocultures with species diverse stands has steadily grown. Mixedwoods (stands containing a balance of conifer and hardwood species) represent an alternative to monocultures and occur naturally through forest succession on most sites in eastern North America. In the central and southeastern United States, mixedwoods were generally dominated by pine and upland oak species. However, a combination of anthropogenic land use legacies has allowed fire-sensitive species to establish creating an opportunity for different mixedwood types to develop (e.g., pine-oak, pine-poplar, pine-gum). While any mixedwoods combination would increase tree species diversity relative to a monoculture, interest exists in whether silvicultural intervention can improve the performance of individual species to promote the development of different mixture types based on specific management objectives (e.g., wildlife habitat, timber quality, drought resistance). To address this question, we established an experiment examining the response of juvenile volunteer loblolly pine and six planted hardwood species (northern red oak, white oak, sweetgum, blackgum, yellow-poplar, and mockernut hickory to four silvicultural treatments (controlled release hardwood fertilization, coppicing, coppicing + broadcast fertilization, and planted control) in northern Mississippi, USA.Four-years post-planting, our results demonstrate that all treatments produced loblolly pine-hardwood co-dominance; however, hardwood dominance varied among treatments. In the planted control, loblolly pine and sweetgum were the co-dominant species, and statistically outgrew all species except yellow-poplar. Mockernut hickory (+ 40%), yellow-poplar (+ 23%), and blackgum (+ 15%) seedling height increased in controlled release fertilization compared to the planted control; however, apart from northern red oak, seedling survival of all hardwood species was less than 50%. The controlled release hardwood fertilization treatment was co-dominated by loblolly pine, yellow-poplar, and sweetgum. Sprouting in the coppiced treatment (89%) statistically exceeded that in the coppiced + broadcast fertilization treatment (73%), but did not vary among species. In general, coppicing reduced sprout height and survival relative to seedlings in the planted control, and promoted loblolly pine, yellow poplar, and sweetgum co-dominance. Coppicing + broadcast fertilization consistently reduced sprout survival compared to the planted control. However, trends in seedling height were mixed, with northern red oak (+ 14%) showing the largest improvement, and volunteer loblolly pine the largest decline (- 34%). Moreover, coppicing + broadcast fertilization produced the most species diverse outcome featuring yellow-poplar, loblolly pine, sweetgum, and northern red oak in co-dominant growing positions. Collectively, these results indicate that sweetgum and loblolly pine are likely to be prominent species in contemporary mixedwoods regardless of treatment. However, more species-diverse mixtures may be promoted by coppicing and broadcast fertilizing early in stand development.

Phylogenetics Study to Compare Chloroplast Genomes in Four Magnoliaceae Species.

Magnoliaceae, a family of perennial woody plants, contains several endangered species whose taxonomic status remains ambiguous. The study of chloroplast genome information can help in the protection of Magnoliaceae plants and confirmation of their phylogenetic relationships. In this study, the chloroplast genomes were sequenced, assembled, and annotated in Woonyoungia septentrionalis and three Michelia species (Michelia champaca, Michelia figo, and Michelia macclurei). Comparative analyses of genomic characteristics, repetitive sequences, and sequence differences were performed among the four Magnoliaceae plants, and phylogenetic relationships were constructed with twenty different magnolia species. The length of the chloroplast genomes varied among the four studied species ranging from 159,838 bp (Woonyoungia septentrionalis) to 160,127 bp (Michelia macclurei). Four distinct hotspot regions were identified based on nucleotide polymorphism analysis. They were petA-psbJ, psbJ-psbE, ndhD-ndhE, and rps15-ycf1. These gene fragments may be developed and utilized as new molecular marker primers. By using Liriodendron tulipifera and Liriodendron chinense as outgroups reference, a phylogenetic tree of the four Magnoliaceae species and eighteen other Magnoliaceae species was constructed with the method of Shared Coding Sequences (CDS). Results showed that the endangered species, W. septentrionalis, is relatively genetically distinct from the other three species, indicating the different phylogenetic processes among Magnoliaceae plants. Therefore, further genetic information is required to determine the relationships within Magnoliaceae. Overall, complete chloroplast genome sequences for four Magnoliaceae species reported in this paper have shed more light on phylogenetic relationships within the botanical group.

Surface Roughness of Wood Substrates after Grinding and Its Influence on the Modification Effect of Structural Color Layers

For a comprehensive understanding of the surface roughness of wood substrates after grinding and its influence on the construction of surface structural color layers (SCLs) and the effect of color production, four typical diffuse-porous wood species were investigated by grinding with abrasive belts of different grits. The results indicated that an abrasive belt of suitable grit was required to form the flattest surface for different wood species. Notably, 400-grit abrasive belts can be used for quaking aspen (QA) and yellow poplar (YP) wood, while 320-grit abrasive belts can be used for kang duan (KD) and hard maple (HM) wood for the grinding process. When the grit of the belt was 80–240, the surface roughness of the wood was high, and the gully contour was mainly determined by the machining marks created by the grits during the cutting process. When the SCLs were constructed on these wood samples, the grooves formed by grit grinding caused the emulsion to overflow on the surface of the wood, thus preventing the formation of well-ordered SCLs with excellent color production. In contrast, when the grit of the abrasive belts was increased to the range of 320–800, the main factors affecting the roughness of the wood surface led to the anatomical structural features. Vessels, in particular, not only affected the surface roughness of the wood but also served as a major path for emulsion flow. The number, diameter, and patency of vessels per unit area were the main factors affecting the SCL’s construction and decoration effect on wood surfaces. This study clarifies that the roughness of the wood surface after the grinding process is jointly influenced by the grit of the abrasive belt and the wood’s anatomical structure. Roughness is an essential factor that affects the modification effect of the SCLs on the surface of wood.

Invasion by Callery pear (Pyrus calleryana) does not affect understory abundance or diversity in early-successional meadows

AbstractTrait differences between invasive plants and the plants in their recipient communities moderate the impact of invaders on community composition. Callery pear (Pyrus calleryana Decne.) is a fast-growing, stress-tolerant tree native to China that has been widely planted for its ornamental value. In recent decades, P. calleryana has naturalized throughout the eastern United States, where it spreads rapidly and achieves high abundance in early-successional environments. Here we compare the impacts of low-density, establishment-phase P. calleryana to those of functionally similar native trees on the understory community diversity and total cover of three early-successional meadows in Indiana’s Eastern Corn Belt Plains. In contrast to our prediction that P. calleryana would have greater negative effects on the total abundance and diversity of the understory plant community compared with native tuliptree (Liriodendron tulipifera L.), American sycamore (Platanus occidentalis L.), or non-tree control plots, we found that these low-density populations of P. calleryana had no significant impact on total cover, species richness, or diversity indices for the understory community compared with the native trees and non-tree control plots. Likewise, the studied populations of P. calleryana had no significant impact on the native, introduced, woody, or native tree subsets of the understory community. These results indicate that in young, low-density populations situated in early-successional meadows, the trait differences between P. calleryana and functionally similar native trees are not of a great enough magnitude to produce changes in community composition. Going forward, complementary research on the impacts of P. calleryana on community composition and ecosystem processes in areas with long-established, dense invasions or invasions in more sensitive ecosystems would allow us to more fully understand how this widespread invader disrupts its host ecosystems.

Decay resistance and dimensional stability of wood impregnated with castor oil using a pressure treatment

Abstract This study was conducted to investigate the uptake of castor oil (CAO) in some wood specimens and the effect of CAO on the leaching ability, dimensional stability and fungal-decay resistance of the wood specimens. CAO was infused into the specimens using a pressure treatment. Uptakes of CAO penetrated in yellow poplar (YEP), Japanese cedar (JAC) and Douglas fir (DOF) blocks were higher than 100 %. The leaching ability of the CAO-based suspensions against saline water was the lowest in YEP, followed by Japanese larch (LAR), JAC and DOF. The retention values were 90 % or higher in most of the specimens. Radial and tangential swellings of CAO-treated strips submerged in saline water for 2 weeks were restrained compared to control specimens. No significant differences were found between bending strength and Janka hardness of CAO-treated and control strips. CAO treatment provided acceptable decay resistance to most wood specimens against Fomitopsis palustris and Trametes versicolor. Retention of CAO in the leached strips were identified through X-ray microscopic observation. Based on the results, CAO was determined to be an effective agent for improving the dimensional stability of wood. These results demonstrate the great potential of CAO as an environmentally friendly wood preservative and dimensional stabilizer, allowing CAO-permeated wood as raw materials for both indoor and outdoor use.

Adhesive bonding performance of thermally modified yellow poplar

Thermal modification of wood changes its chemical, physical, and structural properties, which may affect adhesive bondline quality and bonding performance. This research compared the effect of thermal modification on the adhesive bonding performance of poplar (Liriodendron tulipifera) wood. Samples were prepared from thermally modified and unmodified yellow poplar using one-component polyurethane (PUR) and polyvinyl acetate (PVA), as they are adhesives used in wood products. Microscopic properties of the bondlines were investigated to understand shear performance and durability. Adhesive line thickness, penetration, shear strength, and moisture durability were measured, and failure modes were recorded. Thermal modification negatively affected the wood and adhesive interaction by reducing penetration (31.2% in PUR and 29% in PVA), therefore creating a thicker adhesive line (70% in PUR and 2% in PVA) and consequently causing a significant reduction in the shear strength of both adhesive types (27% in PUR and 36% in PVA) compared with non-modified specimens. The PUR adhesive had higher shear strength than PVA by 2.7% in non-modified and 14% in thermally modified wood.

Environmental Factors Affecting Volume Growth of Yellow Poplar Plantations in South Korea

South Korean forests need hardwood tree species that can produce timber, as global warming progresses and the habitats of conifers dwindle. For the past 30 years, exotic yellow poplar (Liriodendron tulipifera) has been planted to replace some of the pine-dominated forests, as there is a lack of native hardwood tree species that produce large and good quality timber. However, yellow poplar growth has varied among planting sites across the country. We studied how environmental factors affect the growth of 49 stands of yellow poplar trees, with 945 dominant trees across 129 plots. To identify the optimal conditions for yellow poplar growth, we assessed 28 environmental variables, including geographic, climatic, topographic, and soil properties, for their correlation with volume growth. We estimated the optimal conditions for yellow poplar growth by averaging the values of the variables for the top five performing stands. To calculate the relative distance of any stand from the optimal conditions, we divided the difference between the stand’s values for the environmental variables and the optimal conditions by the standard deviation of those variables. We then calculated Spearman rank correlation coefficients between these distances and volume growth rankings. Wind exposure (WE), growing season temperature (GT), Latitude (LN), soil phosphorus pentoxide (P2O5) content, low extreme temperature during January and February (LT), and spring humidity (SH) were the most important environmental factors governing growing sites for yellow poplar in Korea, with WE being the most critical. Some variables showed synergistic effects and correlated slightly more strongly with volume growth when combined with the WE variable. Our study provides crucial insights for optimizing plantation management and site selection in non-native ranges, enhancing overall success in establishing yellow poplar plantations in South Korea.

Study on the Combustion Characteristics of Tulip Tree (Liriodendron tulipifera) for Use as Interior Building Materials

Study on the Combustion Characteristics of Tulip Tree (Liriodendron tulipifera) for Use as Interior Building Materials

Dendrochronology reveals different effects among host tree species from feeding by Lycorma delicatula (White).

The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), was first detected in the United States in Berks County, Pennsylvania, in 2014. Native to China, this phloem-feeding planthopper threatens agricultural, ornamental, nursery, and timber industries in its invaded range through quarantine restrictions on shipments, as well as impacts on plants themselves. The long-term impacts of L. delicatula feeding on tree species have not been well studied in North America. Using standard dendrochronological methods on cores taken from trees with differing levels of L. delicatula infestation and systemic insecticidal control, we quantified the impact of L. delicatula feeding on the annual growth of four tree species in Pennsylvania: Ailanthus altissima, Juglans nigra, Liriodendron tulipifera, and Acer rubrum. The results suggest that L. delicatula feeding is associated with the diminished growth of A. altissima, but no change was observed in any other tree species tested. The results also suggest that systemic insecticides mitigate the impact of L. delicatula feeding on A. altissima growth.

Forest mycorrhizal dominance depends on historical land use and nitrogen‐fixing trees

Abstract Most forests are recovering from human land use, making it critical to understand the effect of disturbance on forest recovery. Forests of the eastern United States have a long history of land use, but it is unknown whether historical disturbances have contributed to their transition from ectomycorrhizal (ECM) to arbuscular mycorrhizal (AM) tree dominance. Disturbance may promote nitrogen (N)‐fixing trees in early succession, which can elevate soil N availability even after they die. Higher soil N availability may facilitate the competitive success of AM trees over ECM trees, but such ‘N fixer founder effects’ have not been empirically tested. Here, we analysed data from three land‐use disturbances in a temperate forest historically dominated by ECM trees: selective‐cutting (ranging from 0 to 52 m2 ha−1), clear‐cutting and agricultural abandonment. These disturbances occurred at different times, but long‐term data capture 3–7 decades of forest recovery. We found that the AM tree fraction in contemporary forests was 2, 4, and 6‐fold higher following selective‐cutting, clear‐cutting and agricultural abandonment, respectively, compared to forest composition in 1934. Across these disturbances we also observed an increasing abundance of the N fixer black locust immediately following disturbance. Using a simulation model parameterized by data from black locust, we estimated historical rates of symbiotic N fixation to understand the relationship between N fixation and AM dominance in individual plots. We found that N fixation was positively associated with the growth of ECM trees generally, and oak and hickory specifically, only following light selective‐cutting (<12 or <18 m2 ha−1 basal area extraction, respectively). Following higher levels of selective‐cutting and clear‐cutting, N fixation was positively associated with the growth of AM trees, particularly red maple and tulip poplar. Agricultural abandonment led to AM dominance regardless of N fixation rates. Synthesis and applications. Our findings suggest that common land use practices and black locust, a native N fixer, can reduce the dominance of ECM trees. If N fixers are likely to proliferate following disturbance, we might maintain ECM dominance by cutting trees at low densities and by applying prescribed fire to remove N.

Evaluation of the Optimal Conditions for Oxygen-Rich and Oxygen-Lean Torrefaction of Forestry Byproduct as a Fuel

Wood biomass is an alternative to fossil fuels. However, biomass use has several limitations. Torrefaction, in which reduction conditions prevail to overcome these limitations, has been suggested. Here, torrefaction using different wood chips (Liriodendron tulipifera, Populus canadensis, Pinus rigida, and Pinus koraiensis) was conducted under oxygen-rich and oxygen-lean conditions to determine the effects of oxygen. Torrefaction was conducted at 230–310 °C for 1 h. A mass yield difference of 3.53–20.02% p (percentage point) was observed between oxygen-lean and oxygen-rich conditions. The calorific value increased by a maximum of 50.95% and 48.48% under oxygen-rich and oxygen-lean conditions, respectively. Decarbonization (DC), dehydrogenation (DH), and deoxygenation (DO) occurred in the following order because of dehydration and devolatilization during biomass torrefaction: DO > DH > DC. The calorific value of the torrefied biomass increased linearly with the extent of all three processes. The combustibility index and volatile ignitability were calculated based on proximate composition to suggest the optimal conditions for replacing anthracite and bituminous coal. This study provides suggestions for stable operation in a standard boiler design.

Effect of 16 different (N, P combination) fertilizer treatments on the growth of Liriodendron tulipifera seedlings and soil chemical properties in the Nursery Station

Effect of 16 different (N, P combination) fertilizer treatments on the growth of Liriodendron tulipifera seedlings and soil chemical properties in the Nursery Station

Differences in leaf gas exchange strategies explain Quercus rubra and Liriodendron tulipifera intrinsic water use efficiency responses to air pollution and climate change.

Trees continuously regulate leaf physiology to acquire CO2 while simultaneously avoiding excessive water loss. The balance between these two processes, or water use efficiency (WUE), is fundamentally important to understanding changes in carbon uptake and transpiration from the leaf to the globe under environmental change. While increasing atmospheric CO2 (iCO2 ) is known to increase tree intrinsic water use efficiency (iWUE), less clear are the additional impacts of climate and acidic air pollution and how they vary by tree species. Here, we couple annually resolved long-term records of tree-ring carbon isotope signatures with leaf physiological measurements of Quercus rubra (Quru) and Liriodendron tulipifera (Litu) at four study locations spanning nearly 100 km in the eastern United States to reconstruct historical iWUE, net photosynthesis (Anet ), and stomatal conductance to water (gs ) since 1940. We first show 16%-25% increases in tree iWUE since the mid-20th century, primarily driven by iCO2 , but also document the individual and interactive effects of nitrogen (NOx ) and sulfur (SO2 ) air pollution overwhelming climate. We find evidence for Quru leaf gas exchange being less tightly regulated than Litu through an analysis of isotope-derived leaf internal CO2 (Ci ), particularly in wetter, recent years. Modeled estimates of seasonally integrated Anet and gs revealed a 43%-50% stimulation of Anet was responsible for increasing iWUE in both tree species throughout 79%-86% of the chronologies with reductions in gs attributable to the remaining 14%-21%, building upon a growing body of literature documenting stimulated Anet overwhelming reductions in gs as a primary mechanism of increasing iWUE of trees. Finally, our results underscore the importance of considering air pollution, which remains a major environmental issue in many areas of the world, alongside climate in the interpretation of leaf physiology derived from tree rings.

De novo Assembly and Comparative Analyses of Mitochondrial Genomes in Piperales.

The mitochondrial genome of Liriodendron tulipifera exhibits many ancestral angiosperm features and a remarkably slow evolutionary rate, while mitochondrial genomes of other magnoliids remain yet to be characterized. We assembled nine new mitochondrial genomes, representing all genera of perianth-bearing Piperales, as well as for a member of the sister clade: three complete or nearly complete mitochondrial genomes from Aristolochiaceae and six additional draft assemblies including Thottea, Asaraceae, Lactoridaceae, and Hydnoraceae. For comparative purpose, a complete mitochondrial genome was assembled for Saururus, a member of the perianth-less Piperales. The average number of short repeats (50-99 bp) was much larger in genus Aristolochia than in other angiosperm mitochondrial genomes, and approximately 30% of repeats (<350 bp) were found to have the capacity to mediate recombination. We found mitochondrial genomes in perianth-bearing Piperales comprising conserved repertories of protein-coding genes and rRNAs but variable copy numbers of tRNA genes. We identified several shifts from cis- to trans-splicing of the Group II introns of nad1i728, cox2i373, and nad7i209. Two short regions of the cox1 and atp8 genes were likely derived from independent horizontal gene transfer events in perianth-bearing Piperales. We found biased enrichment of specific substitution types in different lineages of magnoliids and the Aristolochiaceae family showed the highest ratio of A:T > T:A substitutions of all other investigated angiosperm groups. Our study reports the first mitochondrial genomes for Piperales and uses this new information for a better understanding of the evolutionary patterns of magnoliids and angiosperms in general.

Cross-Laminated Timber Panels Produced from Low-Grade Yellow-Poplar Sorted by Structural Visual Grade

Abstract Low-grade yellow-poplar (Liriodendron tulipifera) graded No. 2 Common, and No. 3 Common (National Hardwood Lumber Association - NHLA rules) is mainly used by the industry to produce wood pallets. Cross-laminated timber (CLT) panels are options to diversify the usage and increase the value of this material. Therefore, the objective of this study was to produce CLT panels from a population of NHLA graded No. 2A, No. 2B, No. 3A, and No. 3B lumber and to evaluate whether the panel properties meet the bending criteria (major strength direction) and adhesive bond requirements listed for “V” type CLT in ANSI/APA PRG 320-2019 (2020) using Northeastern Lumber Association Manufacturers No. 2 and No. 3 in longitudinal and transverse layers, respectively. Ten panels were produced to evaluate the bond quality and mechanical properties. The bond test results showed average delamination under 5 percent and were more frequent in the central areas of the panel than in the outer panel areas. The results from testing showed that the calculated allowable stress-design bending-strength (major direction) value for the yellow-poplar CLT panels was 1,718 psi (11.84 MPa), which corresponds to a value 90 percent higher than V1 (900 psi, 6.20 MPa) layups. Modulus of elasticity (MOE; major direction) was comparable to V2 and V3, with an average MOE of 1.39 by 106 psi (9,584 MPa). Based on these findings, the study indicated the potential for using low-grade yellow-poplar lumber to produce CLT panels. However, more research is needed to evaluate other mechanical properties in both the major and minor axis.

Lianas (Vitis spp.) reduce growth and carbon sequestration of light‐demanding tree species in a temperate forest

Governments worldwide are seeking natural climate solutions that can provide economic stimulus while meeting climate goals. Forests provide essential carbon dioxide (CO2) sequestration services, but their potential may be limited by elevated liana densities often resulting from human disturbance. Here we report the first estimate of liana (Vitis spp.) impacts on CO2 removal rates by trees in temperate Appalachian forests and suggest liana removal with biodiversity safeguards as a potential strategy for improved forest management. Shade‐intolerant tree species without lianas removed CO2 20% faster than conspecifics with lianas (p = 0.025). We did not detect significant impacts of liana presence on the CO2 removal rates for shade‐tolerant species (p = 0.838). Additionally, the merchantable boles of trees without lianas increased in volume 9% faster annually compared to trees with lianas, for all species (p = 0.003). Our findings indicate that thinning lianas—particularly from light‐loving species such as Liriodendron tulipifera—may improve sustainability of forest management and increase carbon storage while mitigating climate change.

Coefficient of Acceptability for Joints on Furniture Frame Analysis under Cyclic Loads

In this study, it was aimed to determine the coefficient of acceptability for furniture joints on chair frames. In doing so, three chair configurations made of soft maple and yellow poplar were defined. Chairs were subjected to a front-to-back cyclic load test until non-recoverable failure occurred. Ultimate failure loads for each chair frame were used to determine the moment capacity of critical joints. Likewise, according to American Library Association, acceptable light, medium and heavy-duty service loads were subjected to chairs in the structural analysis to obtain acceptable moment capacities of critical joints using the stiffness method. Then, lines were drawn from an initial strength of the joint to the moment capacities of the joint at the load level imposed on the chair. Differentiating the slopes between lifeline and acceptable levels gives a coefficient of acceptability. This coefficient would provide insight into the serviceability and durability of joints and chair frames.

Overexpression of the Liriodendron tulipifera BOP2 Gene (LtuBOP2) Affects Leaf Margin Development in Transgenic Arabidopsis thaliana

BLADE-ON-PETIOLE 2 (BOP2) plays a pivotal role in leaf morphogenesis. Liriodendron tulipifera is a suitable model for exploring the molecular mechanisms underlying leaf serration formation, which are largely unknown. Here, we isolated the full-length LtuBOP2 gene and its promoter from L. tulipifera and characterized its function in leaf morphogenesis through multidimensional approaches. The spatiotemporal expression pattern of LtuBOP2 indicated the high expression of LtuBOP2 in stems and leaf buds. We constructed LtuBOP2 promoter, fused the promoter sequences to the β-glucuronidase (GUS) gene, and then transformed them into Arabidopsis thaliana. Histochemical GUS staining results indicated that GUS activity was higher in petioles and the main vein. LtuBOP2 overexpression in A. thaliana caused moderate serration in the leaf tip, owing to the increased number of abnormal lamina epidermal cells and defective vascular tissue, thus indicating a novel role of BOP2. The ectopic expression of LtuBOP2 in A. thaliana promoted the expression of the lateral organ boundary gene ASYMMETRIC LEAVES2 (AS2) and inhibited JAGGED (JAG) and CUP-SHAPED COTYLEDON2 (CUC2) expression to establish leaf proximal-distal polarity. Moreover, LtuBOP2 participated in leaf serration formation by promoting the antagonistic relationship between KNOX I and hormones during leaf margin development. Our findings revealed the role of LtuBOP2 in the proximal-distal polarity formation and development of leaf margin morphology, providing new insights into the regulatory mechanisms of the leaf formation development of L. tulipifera.