Decay Resistance Research Articles

Decay resistance and weathering properties of thermally-modified amazon woods – Parkia pendula (Willd.) and Simarouba amara (Aubl.)

ABSTRACT Thermal modification is a technique that can be used to increase the resistance of wood to the biodeterioration processes. In this context, the objective of this study was to evaluate the durability of Parkia pendula (angelim-saia) and Simarouba amara (marupá) woods thermally modified in rotting field tests and by the action of natural weathering. The tests were carried out in the Brazilian Amazon region, in the Mato Grosso State. The thermal modification of the wood was set with four treatments: control (T1); electric-oven treatment, 180°C for 3 h (T2); combination of autoclave and electric-oven, 125°C for 3 h, and 180°C for 3 h respectively (T3), and immersion in vegetable oil, 180°C for 3 h (T4). The samples were partially buried for the field rotting assays, and the mass loss and deterioration index were seasonally evaluated after the experiment was installed. These analyses were performed on the same samples which has been exposed to rotting essays. The action of natural weathering was assessed through the CIELAB* colour system. T4 was the most efficient for increasing the resistance to biological deterioration, under the tested conditions. T2 and T3 treatments conferred higher colorimetric stability for both types of woods after natural weathering, under the tested conditions.

Mechanical properties of structural particleboard and termite and decay resistance

The mechanical properties and termite and decay resistance performance of wood-based panel used in wooden houses were evaluated. The physical and mechanical properties, along with the resistance levels, of commonly used wood-based panels, including oriented strand board, structural particleboard, and particleboard for use in interior, were compared. The structural particleboard complied with the physical, mechanical, and formaldehyde emission standards of the International Organization for Standardization and Japanese Industrial Standard, surpassing the requirements for oriented strand board. The structural particleboard exhibited excellent water resistance and a consistent performance. Decay tests classified the particleboard and structural particleboard as “Resistant,” with mass losses of 7.82 to 12.72% (white rot) and 14.69 to 16.55% (brown rot). Pine (Pinus densiflora) and oriented strand board exhibited no decay resistance, with mass losses exceeding 45%. The particleboard and structural particleboard demonstrated superior termite resistance, resulting in 100% termite mortality in three days without chemical treatment. The structural particleboard exhibited excellent water, decay, and termite resistance, which can be an advantage in wooden-house construction in terms of maintenance.

Effects of guayule resin on structural performance and durability of wood strand-based composites

Effects of guayule resin on mechanical, physical, and biological performance of wood strand-based panels were evaluated. Southern yellow pine (Pinus spp. L) wood strands were mixed with phenol formaldehyde (PF) resin to a target resin content of 5% and hot-pressed to manufacture wood strand-based panels. A guayule resin solution was prepared and sprayed on the wood strands immediately after PF resin to different guayule resin contents of 0.5% and 1.0%. Specimens cut from treated panels and control panels were subjected to tensile, internal bond, water absorption and thickness swelling, and fungi soil block tests. Guayule resin had a positive effect on tensile strength, as specimens showed 8.0% and 9.5% increase compared to control specimens. However, the internal bond strength decreased 5.3% and 6.4%, respectively. Water absorption and thickness swelling for the treated specimens with guayule resin decreased as compared to control specimens. The fungal decay resistance test indicated little differences in the average percent mass loss across the untreated and treated wood strand-based composite materials. Regardless of increase or decrease, the effects of guayule resin on mechanical, physical, and biological performances of wood strand-based panels were not statistically significant.

Swelling behavior of thermally modified timber from a cellular and chemical perspective

Abstract Thermally modified timber (TMT) reduces hygroscopicity, increases dimensional stability, and decay resistance. Although there is a substantial amount of research on heat-treated wood, investigations on the sensitivity of cell wall swelling behavior to water variation are limited. Therefore, this study focused on the swelling behavior of TMT from cellular and chemical perspectives. The effects of heat treatment on the hygroscopicity and swelling behavior of the wood cell walls were studied using dynamic vapor sorption and confocal laser scanning microscopy. Changes in the chemical composition and cellulose crystallinity were studied using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction. The results revealed that the hygroscopic swelling of latewood significantly decreased with increasing treatment temperature, reducing the anisotropy of the wood cell swelling. The hygroscopicity of wood was reduced by heat treatment, and a clear decrease in hysteresis was observed at elevated treatment temperatures. The FTIR spectra indicated that both hemicellulose and lignin were degraded. The crystallinity and lateral size of the cellulose increased after heat treatment. Similar changes in the chemical composition and crystallinity of cellulose were observed in the latewood and earlywood.

Resistance of Chip Block Pallet from Teak Wood Particle against Decay Fungi and Subterranean Termites

Wood biomass such as sawdust, particles, and chip obtained wood industry can be used as raw material for chip block pallets (CBP). This study evaluated the resistance of chip block pallets made from teak-sawn waste and polyurethane adhesive against decay fungi (white-rot and brown-rot fungi) and subterranean termites. The CBPs with dimensions of 9 × 9 × 9 cm and a target density of 0.6 g/cm3 were cold pressed at 9.8 MPa for 4 h using several polyurethane concentrations and composition of particle sizes. The termite and decay resistance tests were conducted following JIS K 1571 2004. The results showed that CBP treated with different polyurethane concentrations and composition of particle sizes was resistant to subterranean termite attacks. However, the CBP manufactured were not resistant to white-rot and brown-rot fungi attacks, showing more than 3% mass loss percentage. Considering the efficiency of polyurethane use, the study suggested the best content for using polyurethane in the manufacture of CBP is 4.5% with a particle size composition of 50 (4-14 mesh): 50 (> 60 mesh). Keywords: Biodeterioration, chip block pallet, polyurethane, teak wood particles

Differences of technological properties on sapwood and heartwood of short rotation teak wood

ABSTRACT Short rotation teak has been developed to overcome the limited supply of long rotation teak. The characteristics and technological properties of sapwood and heartwood of short rotation teak are not well studied. The purpose of this study was to evaluate the effect of sapwood and heartwood differences on technological properties for short rotation teak. The short rotation teak woods used were Plus Perhutani teak of 15 years old with a sapwood proportion of 30% and Biotrop teak of 8 years old with a sapwood proportion of 18%. The following technological properties of sapwood and heartwood were studied: extractive content, chemical composition, volumetric swelling, water-sorption isotherm, modulus of elasticity, modulus of rupture, decay resistance, termite resistance, surface roughness, surface free energy, wettability, and weathering performance. The results showed that the extractive content of heartwood was higher than sapwood. The main compounds in the extractive content of heartwood were lapachol and 9,10-anthracenedione; meanwhile the main compounds of sapwood were mostly single sugars and derivatives. The extractives present could contribute to technological properties of short rotation teak wood, particularly for improved dimensional stability, reduced water-sorption, higher decay and termite resistance, and better photostability. Sapwood presented lower quality especially in dimensional stability and durability, which could restrict its utilization for both indoor and outdoor applications. Therefore, sapwood should require certain treatments, especially for wood exposed to outdoor conditions.

Synergic effect of basalt/wood fiber reinforced polylactic acid hybrid biocomposites against fungal decay

In addition to the traditional fibre-reinforced composites, the investigation of novel composites with significant potential for engineering applications attracts increasing attention. In this study, the decay resistance of basalt and/or wood fibre-reinforced polylactic acid (PLA) biocomposites was evaluated with a soil block test by using white rot fungi, Trametes versicolor (Trv) and Irpex lacteus (Irl), and brown rot fungi, Poria placenta (Pop) and Gloeophyllum trabeum (Glt), and a soft rot fungus, Chaetomium globosum (Chg) after 8 weeks of water submersion. Water absorption rate during the water submission and weight losses after the decay test were determined. Furthermore, decay in biocomposites was characterized by SEM and ATR-FTIR. Results showed that the water absorption increased between 52.4–67.5% for wood fibre composites when compared to basalt fibre-reinforced biocomposites. PLA showed good decay resistance against all fungi attacks. However, as the ratio of basalt and wood fibre in the hybrid biocomposites increased, the fungi resistance decreased. The lowest weight loss, 4.9% was found in the biocomposites containing the highest percentage of basalt fibre. On the other hand, the highest weight loss, 54.2% was observed in the composites containing the highest percentage of wood fibre. The results clearly showed that the hybridization of basalt and wood fibres improves the decay resistance of the biocomposites compared to only wood fibre-reinforced composites. However, as the percentage of wood increased in the composites, the decay resistance decreased. SEM and FTIR analysis confirmed the degradation and revealed the degradation mechanism.

Mechanistic Study of the Synergistic Interaction of Furfuryl Alcohol and Caprolactam in the Modification of Pinus massoniana Earlywood and Latewood

Furfurylated wood has many advantages, such as decay resistance, dimensional stability, hardness, etc. However, furfurylation increases the brittleness and decreases the flexural resistance of wood, which greatly limits its application. Therefore, caprolactam (CPL) is incorporated with furfuryl alcohol (FA) to improve the performance of furfurylated wood. In this study, an FA and CPL combinational modifier was used to treat masson pine (Pinus massoniana Lamb.) earlywood and latewood. The synergistic interaction of both components with the wood cell walls was systematically evaluated via microstructural, chemical, and thermal analysis using scanning electron microscopy (SEM), infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectrometry (XPS), and differential scanning calorimetry (DSC). The SEM images showed that polymerized modifiers were distributed in tracheids, ray cells, and pits, with a higher degree of distribution in latewood tissues. The FA-CPL co-treatment led to the highest degree of distribution in cell cavities as well as of cell wall swelling. The results of the weight percentage gain (WPG) of modified wood agreed with the SEM findings that the FA-CPL co-treatment could more effectively increase the WPG than individual modification. The results of FTIR and XPS revealed that FA and CPL might chemically bind with each other as well as react with lignin and hemicellulose in the cell walls during the curing process. In addition, the interactions between modifiers and cell walls were slightly different for earlywood and latewood. DSC analysis indicated that the wood hygroscopicity decreased and the thermal stability improved after modification.

Termite and decay resistances of Sumatran elephant dung-based particleboard modified with wood shavings and bamboo layering

Elephant dung (ED) particleboard (PB) still has subpar physical and mechanical qualities. In earlier research, adding wood shavings and bamboo layers to ED-derived PB successfully enhanced its physical and mechanical qualities. However, the resistance to termites and decay of this PB is still unknown. Therefore, this study examines the resistances to termites and decay of the PBs from ED fiber-modified with wood shavings and bamboo layering. ED and wood shavings were distributed throughout the PB in ratios of 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 (w/w %). Meanwhile, tali bamboo (Gigantochloa apus), talang bamboo (Schizostachyum brachycladum), kuning bamboo (Bambusa vulgaris), belangke bamboo (Gigantochloa pruriens), and betung bamboo (Dendrocalamus asper) were the materials used in this study. These findings demonstrated that adding wood shavings could improve PB’s resistance to termite and decay attacks. However, in this investigation, the layering of bamboo diminishes the PB’s resistance to termite and decay attack. A 50/50 ratio between ED and wood shavings achieved slightly higher termite mortality and lower weight loss than others. Meanwhile, kuning bamboo had lower termite mortality and higher weight loss than others.

Vanillin/silica microencapsulation for wood preservation

Abstract Vanillin is an antifungal and environmentally friendly compound. In this study, vanillin and silica microcapsules (VSM) were microencapsulated using the sol-gel method and then impregnated into wood. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDXA) and transmission electron microscopy (TEM) were used to characterize the morphological structure and distribution of VSM in wood. Fourier transform infrared spectroscopy (FTIR) was used to study the intermolecular interactions between VSM and wood. The antifungal performance of the VSM-treated wood was evaluated. The study revealed that VSM had good sustained-release performance and decay resistance. Mass losses of VSM-treated wood after leaching and exposure to Trametes versicolor (L.) Quel. and Gloephyllum trabeum (Pers.) Murrill decreased from mass losses of 20.8 % and 15.9 % of the control group to 9.2 % and 6.4 %, respectively. VSM treatment disrupted the mycelium of T. versicolor and G. trabeum, inhibited their respiratory metabolism, and the ligninase-laccase enzyme activity of T. versicolor. Meanwhile, MOR and MOE of VSM-treated wood were 96.7 MPa and 12.3 GPa which were 28.8 % and 11.5 % higher than the control group, respectively.

Monopodial and sympodial bamboos grown in tropic and sub-tropic countries – A Review

Bamboo belongs to the grass family and is an important non-timber forest product in tropic and sub-tropic countries. The global trade of bamboo products is worth billions of dollars and is mainly dominant with monopodial bamboo grown in sub-tropic countries such as China and Japan. Many researchers globally discuss that in addition to species and region, bamboo quality can differ based on its rhizome types because the physiology is different for both monopodial and sympodial bamboo. However, there is a massive competition within the yearly forest products due to the challenges posed by underground root system in agroforestry. This review studied the properties of bamboo with regards to their differences in terms of monopodial and sympodial types of rhizomes. It was found that most of the structural, chemical organic, and mechanical properties are higher in monopodial bamboo, but there is a greater fibre morphology and decay resistance in the sympodial bamboo.

Decay resistance of Oriental beech wood treated with fire retardants and coated with epoxy and polyurea resins

Bu çalışmada, yanmayı geciktirici özellikteki kimyasal maddelerden, borik asit, boraks ve amonyum sülfat ile emprenye işlemi uygulanan ve epoksi (Sika floor 156) ve poliürea (Sikalastic®-851 R) reçineleri ile kaplanan Doğu kayını (Fagus orientalis L.) odununun beyaz ve kahverengi çürüklük mantarlarına karşı direnç özelliklerinin geliştirilmesi amaçlanmıştır. Çalışmada, deney örnekleri borlu bileşikler ve amonyum sülfatın %3’lük sulu çözeltisiyle emprenye edilmiştir. Ardından bu örneklere poliürea ve epoksi reçineleri ile kaplama işlemi uygulanmıştır. Daha sonra örnekler 12 hafta boyunca kahverengi (Postia placenta) ve beyaz çürüklük (Trametes versicolor) mantar saldırılarına maruz bırakılarak, ASTM D 1413–07 (2007) standardına göre toprak blok (soil-block) testi gerçekleştirilmiştir. Elde edilen sonuçlara göre, emprenye ve kaplama işlemi gören tüm deney örnekleri için ağırlık kayıplarının kontrol örneğine göre daha düşük çıktığı belirlenmiştir. Çalışmada kaplama öncesi borlu bileşiklerle emprenye işlemi her iki mantar çürüklüğüne karşı, örneklerin çürüklük direncini istatistiksel anlamda önemli ölçüde artırmıştır.

Organic–inorganic hybrid material containing silica–alumina sol and ether polymer for flame retardant wood with decay resistance and excellent mechanical properties

Poplar wood, which is primarily used to manufacture wood-based panels, furniture, and paper, is a fast-growing plantation wood that is produced with high yields; however, its poor mechanical properties and perishability limit its application. Herein, we propose a method that enables silica–alumina sol to penetrate wood smoothly. In this method, silica–alumina sol is added into an ether polymer by blending, and the mixture is completely stirred until hybridization. The ether polymer introduces the silica–alumina sol into wood via pressure impregnation. Poplar wood treated with this hybrid material has excellent mechanical properties; the maximum bending strength and modulus of elasticity are 112.9 MPa and 16.89 GPa, respectively, and the compressive strength along the grain is 111.5 MPa. Moreover, the treated poplar wood exhibits decay resistance and flame retardancy properties. After 12 weeks of decay resistance testing, the average mass loss is 8.35%–18.52% (that of untreated wood is 32.33%–62.06%). The treated wood exhibits 40.5% and 52.4% smaller total heat release and total smoke production, respectively, than the untreated wood. This method incorporates silica–alumina sol in wood via physical filling and chemical bonding, thereby improving the mechanical and flame retardancy properties of wood as an outdoor building material.

Superhydrophobic Wood Surfaces: Recent Developments and Future Perspectives

Wood is a renewable material that has been widely utilized as indoor and outdoor construction and decoration material in our daily life. Although wood has many advantages (i.e., light weight, high strength, low price and easy machinability), it has some drawbacks that influence dimensional stability, cracking and decay resistance in real practical applications. To mitigate these issues, superhydrophobic surfaces have been introduced to wood substrates, creating superhydrophobic wood surfaces (SHWSs) that can improve stability, water resistance, ultraviolet radiation resistance and flame retardancy. Herein, the recent developments and future perspectives of SHWSs are reviewed. Firstly, the preparation methods of SHWSs are summarized and discussed in terms of immersion, spray-coating, hydrothermal synthesis, dip-coating, deposition, sol-gel process and other methods, respectively. Due to the characteristics of the above preparation methods and the special properties of wood substrates, multiple methods are suggested to be combined to prepare SHWSs rather than each individual method. Secondly, the versatile practical applications of SHWSs are introduced, including anti-fungi/anti-bacteria, oil/water separation, fire-resistance, anti-ultraviolet irradiation, electromagnetic interference shielding, photocatalytic performance, and anti-icing. When discussing these practical applications, the advantages of SHWSs and the reason why SHWSs can be used in such applications are also mentioned. Finally, we provide with perspectives and outlooks for the future developments and applications of SHWSs, expecting to extend the utilization of SHWSs in our daily life and industry.

Decay resistance of Pterocarpus erinaceus Poir. and the antifungal properties of its extract

The processing residue of Pterocarpus erinaceus was used to obtain an ethanol-extract, whose anti-fungal properties and mode of action was investigated using multi-omics principles and gas chromatography-mass spectrometry. The results showed that the decay resistance of the heartwood of Pterocarpus erinaceus was in Grade I; it showed strong decay resistance. The effective concentration of 70% ethanol extract of the heartwood of Pterocarpus erinaceus was 13.8%. It showed high inhibition against Coriolus versicolor and Gloeophyllum trabeum, and the content of the extract was positively correlated with the diameter of the inhibition zone. Transcriptomics analysis showed there were 93 genes differentially expressed in Gloeophyllum trabeum. Among them, 42 genes were up-regulated and 51 genes were down-regulated. These genes were mainly related to oxidoreductase activity, integral components of the membrane, carbohydrate metabolism, lipid metabolism, and other related Gloeophyllum trabeum life activities. In total, 31 substances were separated and observed using GC-MS, and their peak areas accounted for 91.8% of the total peak area. Of these, 16 substances including ketones, esters, amines, alkanes, olefins and aromatic compounds showed a relatively high content. Ketones accounted for the most abundance at 29.1%. These compounds may represent the main active components of antifungal and decay resistance.

A SYNERGIC EFFECT OF WATER-BASED ACRYLIC RESIN WITH BORIC ACID ON LEACHABILITY

In this study, the Scots pine wood samples were impregnated (single treatment) with boric acid combined with two types of water-based acrylic resin (pure acrylic and semi-translucent acrylic emulsion) to limit the boron leaching and improve the decay resistance. The results showed dimensional stability in anti-swelling efficiency and water absorption improved in wood specimens treated with boric acid and acrylic types. While the leachability was over 90% for only 3% boric acid-impregnated wood (control), it was calculated at 36% for acrylic emulsions-impregnated wood. Although there were no weight losses for the unleached woods, it was up to 9% for leached woods impregnated with acrylic resin and emulsion. The 25% acrylic emulsion had no weight losses after the leaching test for Coniophora puteana and Trametes versicolor. The boric acid combined with acrylic resin can improve the leaching resistance with the synergic effect, enhancing resistance against biological threats.

Effect of Furfurylation on Bamboo-Scrimber Composites

Bamboo is a material with excellent development prospects. It is increasingly used in furniture, decoration, building, and bridge construction. In this study, Furfurylated bamboo bundles and phenol-formaldehyde resin were used to make bamboo-scrimber composites (BSCs) via molding-recombination and hot-pressing processes. The effects of the impregnation mode, furfuryl-alcohol concentration, and curing temperature on the various physical-mechanical properties and durability of the composites were evaluated. Scanning-electron microscopy (SEM) was used to observe the microstructural differences. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were employed to investigate changes in the chemical constituents. The heat resistance was also investigated using thermogravimetric analysis. The results showed that the density of the furfurylated BSC increased by up to 22% compared with that of the BSC-C with the same paving mode. The furfurylated BSCs had lower moisture contents: the average moisture content of the furfurylated BSCs was 25~50% lower than that of the BSC-C. In addition, the furfurylated BSCs showed better dimensional stability and durability, since the decay-resistance grade of the BSCs was raised from decay resistance (class II) to strong decay resistance (class I). In terms of the mechanical properties, the furfurylation had a slight negative effect on the mechanical strength of the BSCs, and the modulus of rupture (MOR) and horizontal shear strength (HSS) of the BSCs were increased to a certain extent under most of the treatment conditions. In particular, the highest HSS for indoor use and MOR of the furfurylated BSCs increased by 21% and 9% compared with those of the untreated BSCs, respectively. The SEM results indicated that the FA resin effectively filled in the bamboo-cell cavities and vessels, and the modified bamboo-parenchyma cells were compressed more tightly and evenly. The FTIR and XPS spectroscopy showed that the hydroxyl group of carboxylic acid of the bamboo-cell-wall component reacted with that of the furan ring, and the cellulose and hemicellulose underwent acid hydrolysis to a certain extent after the furfurylation. Overall, the present study highlights the potential of furfurylation as a modification method to enhance BSC products. Further research should focus on improving the ability of furfurylated BSCs to prevent the growth of Botryodiplodia theobromae. Additionally, the influence of furfuryl-alcohol resin on the bonding strengths of PF adhesives should be further clarified.

High hydrophobic silanized paper: Material characterization and its biodegradation through brown rot fungus.

Modifying natural polymers with silicones gives new possibilities for packaging products and waste management. In this study, the innovative papers produced were altered following the reaction of polysaccharides and organosilicon compounds. The susceptibility of the studied material to biodegradation caused by a brown-rot fungus was assessed. Strength properties by tensile strength and dynamic mechanical analysis and hydrophobic properties by water uptake test and water contact angle analysis were evaluated. Moreover, elemental analysis by ICP method was controlled. The durability against fungi and the hydrophobic properties were increased by the modification. The fungal decay resistance of the silanized paper was reduced by water storage, which allows for managing paper waste. Cellulose-based paper treated with starch-modified methyltrimethoxysilane showed potential as a packaging material due to its reduced water uptake. Possible application areas could be corrugated boxes, cellulose thermoformed products for electronics, and food packaging. However, the water-repellent effect is limited to short-term exposure in humid conditions.

Chromatic aberration and decay resistance performance of bamboo and bamboo scrimber decayed by white-rot and brown-rot fungi

ABSTRACT Moso bamboo (MB), carbonized moso bamboo (CMB), natural color bamboo scrimber (NBS), and dark color bamboo scrimber (DBS) were subjected to Poria vaporaria (PP), Gloeophyllum trabeum (GT), Coriolus versicolor (CV) and Trametes versicolor (TV) in laboratory experiments. The differences in surface chromaticity and mass loss of four samples before and after decay were compared. The results showed that the decay resistance of DBS after four wood rot fungal infections reached grade I, and DBS had the best decay resistance among the four samples. MB had the worst decay resistance among the four samples. After being infected by four kinds of wood rot fungi, the color of MB and NBS changed significantly, as the brightness decreased significantly. The red-green axis color index and yellow–blue axis color index of MB and NBS infected by PP, GT, CV, and TV showed significant increases compared to those of untreated samples. The chroma values of MB and NBS increased significantly after the decay test. SEM analysis showed that after the brown-rot test, the hyphae of GT entered the MB vessels and the parenchyma cells through the pits in the vessel, causing the cell structure to be destroyed.

Unique gene duplications and conserved microsynteny potentially associated with resistance to wood decay in the Lauraceae.

Wood decay resistance (WDR) is marking the value of wood utilization. Many trees of the Lauraceae have exceptional WDR, as evidenced by their use in ancient royal palace buildings in China. However, the genetics of WDR remain elusive. Here, through comparative genomics, we revealed the unique characteristics related to the high WDR in Lauraceae trees. We present a 1.27-Gb chromosome-level assembly for Lindera megaphylla (Lauraceae). Comparative genomics integrating major groups of angiosperm revealed Lauraceae species have extensively shared gene microsynteny associated with the biosynthesis of specialized metabolites such as isoquinoline alkaloids, flavonoid, lignins and terpenoid, which play significant roles in WDR. In Lauraceae genomes, tandem and proximal duplications (TD/PD) significantly expanded the coding space of key enzymes of biosynthesis pathways related to WDR, which may enhance the decay resistance of wood by increasing the accumulation of these compounds. Among Lauraceae species, genes of WDR-related biosynthesis pathways showed remarkable expansion by TD/PD and conveyed unique and conserved motifs in their promoter and protein sequences, suggesting conserved gene collinearity, gene expansion and gene regulation supporting the high WDR. Our study thus reveals genomic profiles related to biochemical transitions among major plant groups and the genomic basis of WDR in the Lauraceae.