Whole-genome sequencing of Ganoderma boninense, the causal agent of basal stem rot disease in oil palm, via combined short- and long-read sequencing.

The hemibiotrophic Basidiomycete pathogen Ganoderma boninense (Gb) is the dominant causal agent of oil palm basal stem rot disease. Here, we report a complete chromosomal genome map of Gb using a combination of short-read Illumina and long-read Pacific Biosciences (PacBio) sequencing platforms combined with chromatin conformation capture data from the Chicago and Hi-C platforms. The genome was 55.87 Mb in length and assembled to a high contiguity (N50: 304.34 kb) of 12 chromosomes built from 112 scaffolds, with a total of only 4.34 Mb (~ 7.77%) remaining unplaced. The final assemblies were evaluated for completeness of the genome by using Benchmarking Universal Single Copy Orthologs (BUSCO) v4.1.4, and based on 4464 total BUSCO polyporales group searches, the assemblies yielded 4264 (95.52%) of the conserved orthologs as complete and only a few fragmented BUSCO of 42 (0.94%) as well as a missing BUSCO of 158 (3.53%). Genome annotation predicted a total of 21,074 coding genes, with a GC content ratio of 59.2%. The genome features were analyzed with different databases, which revealed 2471 Gene Ontology/GO (11.72%), 5418 KEGG (Kyoto Encyclopedia of Genes and Genomes) Orthologous/KO (25.71%), 13,913 Cluster of Orthologous Groups of proteins/COG (66.02%), 60 ABC transporter (0.28%), 1049 Carbohydrate-Active Enzymes/CAZy (4.98%), 4005 pathogen-host interactions/PHI (19%), and 515 fungal transcription factor/FTFD (2.44%) genes. The results obtained in this study provide deep insight for further studies in the future.

Deorphanizing an odorant receptor tuned to palm tree volatile esters in the Asian palm weevil sheds light on the mechanisms of palm tree selection.

The Asian palm weevil, Rhynchophorus ferrugineus, is a tremendously important agricultural pest primarily adapted to palm trees and causes severe destruction, threatening sustainable palm cultivation worldwide. The host plant selection of this weevil is mainly attributed to the functional specialization of odorant receptors (ORs) that detect palm-derived volatiles. Yet, ligands are known for only two ORs of R. ferrugineus, and we still lack information on the mechanisms of palm tree detection. This study identified a highly expressed antennal R. ferrugineus OR, RferOR2, thanks to newly generated transcriptomic data. The phylogenetic analysis revealed that RferOR2 belongs to the major coleopteran OR group 2A and is closely related to a sister clade containing an R. ferrugineus OR (RferOR41) tuned to the non-host plant volatile and antagonist, α-pinene. Functional characterization of RferOR2 via heterologous expression in Drosophila olfactory neurons revealed that this receptor is tuned to several ecologically relevant palm-emitted odors, most notably ethyl and methyl ester compounds, but not to any of the pheromone compounds tested, including the R. ferrugineus aggregation pheromone. We did not evidence any differential expression of RferOR2 in the antennae of both sexes, suggesting males and females detect these compounds equally. Next, we used the newly identified RferOR2 ligands to demonstrate that including synthetic palm ester volatiles as single compounds and in combinations in pheromone-based mass trapping has a synergistic attractiveness effect to R. ferrugineus aggregation pheromone, resulting in significantly increased weevil catches. Our study identified a key OR from a palm weevil species tuned to several ecologically relevant palm volatiles and represents a significant step forward in understanding the chemosensory mechanisms of host detection in palm weevils. Our study also defines RferOR2 as an essential model for exploring the molecular basis of host detection in other palm weevil species. Finally, our work showed that insect OR deorphanization could aid in identifying novel behaviorally active volatiles that can interfere with weevil host-searching behavior in sustainable pest management applications.

Almond fixed oil from Syagrus coronata (Mart.) Becc. has antinociceptive and anti-inflammatory potential, without showing oral toxicity in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Syagrus coronata, a palm tree found in northeastern Brazil, popularly known as licuri, has socioeconomic importance for the production of vegetable oil rich in fatty acids with nutritional and pharmacological effects. Licuri oil is used in traditional medicine to treat inflammation, wound healing, mycosis, back discomfort, eye irritation, and other conditions. AIM OF THE STUDY: The study aimed to evaluate the antinociceptive, anti-inflammatory, and antipyretic effects of treatment with Syagrus coronata fixed oil (ScFO), as well as to determine the safety of use in mice. MATERIALS AND METHODS: Initially, the chemical characterization was performed by gas chromatography-mass spectrometry. Acute single-dose oral toxicity was evaluated in mice at a dose of 2000 mg/kg. Antinociceptive activity was evaluated through abdominal writhing, formalin, and tail dipping tests, and the anti-inflammatory potential was evaluated through the model of acute inflammation of ear edema, peritonitis, and fever at concentrations of 25, 50, and 100 mg/kg from ScFO. RESULTS: In the chemical analysis of ScFO, lauric (43.64%), caprylic (11.7%), and capric (7.2%) acids were detected as major. No mortality or behavioral abnormalities in the mice were evidenced over the 14 days of observation in the acute toxicity test. ScFO treatment decreased abdominal writhing by 27.07, 28.23, and 51.78% at 25, 50, and 100 mg/kg. ScFO demonstrated central and peripheral action in the formalin test, possibly via opioidergic and muscarinic systems. In the tail dipping test, ScFO showed action from the first hour after treatment at all concentrations. ScFO (100 mg/kg) reduced ear edema by 63.76% and leukocyte and neutrophil migration and IL-1ß and TNF-α production in the peritonitis test. CONCLUSION: Mice treated with ScFO had a reduction in fever after 60 min at all concentrations regardless of dose. Therefore, the fixed oil of S. coronata has the potential for the development of new pharmaceutical formulations for the treatment of pain, inflammation, and fever.

Recent advances in sago (Metroxylon sagu) fibres, biopolymers, biocomposites, and their prospective applications in industry: A comprehensive review.

Escalating petroleum depletion and environmental crises linked to conventional plastics have fueled interest in eco-friendly alternatives. Natural fibres and biopolymers are garnering increasing attention due to their sustainability. The sago palm (Metroxylon sagu), a tropical tree, holds potential for such materials, with cellulose-rich fibres (42.4-44.12 %) showcasing strong mechanics. Extracted sago palm starch can be blended, reinforced, or plasticised for improved traits. However, a comprehensive review of sago palm fibres, starch, and biocomposites is notably absent. This paper fills this void, meticulously assessing recent advancements in sago palm fibre, cellulose and starch properties, and their eco-friendly composite fabrication. Moreover, it uncovers the latent prospects of sago palm fibres and biopolymers across industries like automotive, packaging, and bioenergy. This review presents a crucial resource for envisaging and realising sustainable materials.

Effect of fermented Cassava sievate and tiger nut shaft on growth performance, blood profile and immunological parameters in male rabbits.

This study examined the effects of using mushroom mycelium to ferment tigernut and cassava pulp on the growth performance, haematology and immunology of rabbits. Seventy-five New Zealand Bulk grower rabbits were randomly distributed to four treatment groups and a control group in a completely randomized approach. The treatment groups were fed with formulated experimental diets containing one of fermented tigernut drink by-product (FT), fermented cassava sievate (FC), unfermented tigernut drink by-product (UT), or unfermented cassava sievate (UC). The control group was fed a basal diet with no additives. The proximate composition of the fermented feed was analyzed. The weight gain of the animals was, 834.5, 633, 790, 510, and 706 g for control, FT, FC, UT, and UC respectively. The packed cell volume (PCV) for animals in the control group, FT, and FC are 34.33, 37.26, and 32.29% respectively. The red blood cell (RBC) of the FT was favourably improved (5.53 × 1012/L) compared to those of UT (2.28 × 1012/L), while there was a reduction in the red blood cell count of FC group (1.02 × 1012/L). Conclusively, the inclusion of fermented tiger nut drink by-product in rabbit feed improved the PCV and RBC of the rabbits' understudy but did not affect their growth performance.

Dehydration-induced corrugated folding in Rhapis excelsa plant leaves.

Plant leaves, whose remarkable ability for morphogenesis results in a wide range of petal and leaf shapes in response to environmental cues, have inspired scientific studies as well as the development of engineering structures and devices. Although some typical shape changes in plants and the driving force for such shape evolution have been extensively studied, there remain many poorly understood mechanisms, characteristics, and principles associated with the vast array of shape formation of plant leaves in nature. Here, we present a comprehensive study that combines experiment, theory, and numerical simulations of one such topic-the mechanics and mechanisms of corrugated leaf folding induced by differential shrinking in Rhapis excelsa. Through systematic measurements of the dehydration process in sectioned leaves, we identify a linear correlation between change in the leaf-folding angle and water loss. Building on experimental findings, we develop a generalized model that provides a scaling relationship for water loss in sectioned leaves. Furthermore, our study reveals that corrugated folding induced by dehydration in R. excelsa leaves is achieved by the deformation of a structural architecture-the "hinge" cells. Utilizing such connections among structure, morphology, environmental stimuli, and mechanics, we fabricate several biomimetic machines, including a humidity sensor and morphing devices capable of folding in response to dehydration. The mechanisms of corrugated folding in R. excelsa identified in this work provide a general understanding of the interactions between plant leaves and water. The actuation mechanisms identified in this study also provide insights into the rational design of soft machines.

Balancing economic and ecological functions in smallholder and industrial oil palm plantations.

The expansion of the oil palm industry in Indonesia has improved livelihoods in rural communities, but comes at the cost of biodiversity and ecosystem degradation. Here, we investigated ways to balance ecological and economic outcomes of oil palm cultivation. We compared a wide range of production systems, including smallholder plantations, industrialized company estates, estates with improved agronomic management, and estates with native tree enrichment. Across all management types, we assessed multiple indicators of biodiversity, ecosystem functions, management, and landscape structure to identify factors that facilitate economic-ecological win-wins, using palm yields as measure of economic performance. Although, we found that yields in industrialized estates were, on average, twice as high as those in smallholder plantations, ecological indicators displayed substantial variability across systems, regardless of yield variations, highlighting potential for economic-ecological win-wins. Reducing management intensity (e.g., mechanical weeding instead of herbicide application) did not lower yields but improved ecological outcomes at moderate costs, making it a potential measure for balancing economic and ecological demands. Additionally, maintaining forest cover in the landscape generally enhanced local biodiversity and ecosystem functioning within plantations. Enriching plantations with native trees is also a promising strategy to increase ecological value without reducing productivity. Overall, we recommend closing yield gaps in smallholder cultivation through careful intensification, whereas conventional plantations could reduce management intensity without sacrificing yield. Our study highlights various pathways to reconcile the economics and ecology of palm oil production and identifies management practices for a more sustainable future of oil palm cultivation.

Mannans: Structural carbohydrates produced during seed maturation in Euterpe edulis Martius, an Atlantic Forest species vulnerable to extinction.

Palm seedlings are visually selected from mature fruits in a slow process that leads to nonuniform germination and high embryo mortality. In this study, we determined the levels of monosaccharides, their crystallinity, and their role in the formation of Euterpe edulis endosperm during seed maturation. Seeds harvested from 108 to 262 days after anthesis (DAA) were analyzed morphologically, physiologically, and chemically to measure soluble and insoluble lignins, ashes, structural carbohydrates, degree of crystallinity, and endo-ß-mannanase. The seeds achieved maximum germination and vigor at 164 DAA. During the early stages, only compounds with a low structural order were formed. The contents of soluble and insoluble lignins, ashes, glucans, and galactans decreased during maturation. Those of mannans, the main structural carbohydrate in the endosperm, increased along with the degree of crystallinity, as suggested by a mannan-I-type X-ray diffraction pattern. Similarly, endo-ß-mannanase activity peaked at 262 DAA. The superior physiological outcome of seeds and seedlings at 164 DAA implies a 98-day shorter harvesting time. The state of mannans during seed maturation could be used as a marker to improve seedling production by E. edulis.

GWAS determined genetic loci associated with callus induction in oil palm tissue culture.

KEY MESSAGE: GWAS identified six loci at 25 kb downstream of WAK2, a crucial gene for cell wall and callus formation, enabling development of a SNP marker for enhanced callus induction potential. Efficient callus induction is vital for successful oil palm tissue culture, yet identifying genomic loci and markers for early detection of genotypes with high potential of callus induction remains unclear. In this study, immature male inflorescences from 198 oil palm accessions (dura, tenera and pisifera) were used as explants for tissue culture. Callus induction rates were collected at one-, two- and three-months after inoculation (C1, C2 and C3) as phenotypes. Resequencing generated 11,475,258 high quality single nucleotide polymorphisms (SNPs) as genotypes. GWAS was then performed, and correlation analysis revealed a positive association of C1 with both C2 (R = 0.81) and C3 (R = 0.50), indicating that C1 could be used as the major phenotype for callus induction rate. Therefore, only significant SNPs (P ≤ 0.05) in C1 were identified to develop markers for screening individuals with high potential of callus induction. Among 21 significant SNPs in C1, LD block analysis revealed six SNPs on chromosome 12 (Chr12) potentially linked to callus formation. Subsequently, 13 SNP markers were identified from these loci and electrophoresis results showed that marker C-12 at locus Chr12_12704856 can be used effectively to distinguish the GG allele, which showed the highest probability (69%) of callus induction. Furthermore, a rapid SNP variant detection method without electrophoresis was established via qPCR-based melting curve analysis. Our findings facilitated marker-assisted selection for specific palms with high potential of callus induction using immature male inflorescence as explant, aiding ortet palm selection in oil palm tissue culture.

[Evaluation of chemical constituents of Draconis Sanguis and its protective effect on renal tubular injury in diabetic kidney disease].

The chemical constituents of Draconis Sanguis were preliminarily studied by macroporous resin, silica gel, dextran gel, and high-performance liquid chromatography. One retro-dihydrochalcone, four flavonoids, and one stilbene were isolated. Their chemical structures were identified as 4-hydroxy-2,6-dimethoxy-3-methyldihydrochalcone(1), 4'-hydroxy-5,7-dimethoxy-8-methylflavan(2), 7-hydroxy-4',5-dimethoxyflavan(3),(2S)-7-hydroxy-5-methoxy-6-methylflavan(4),(2S)-7-hydroxy-5-methoxyflavan(5), and pterostilbene(6) by modern spectroscopy, physicochemical properties, and literature comparison. Compound 1 was a new compound. Compounds 2 and 6 were first found in the Arecaceae family. Compound 5 had the potential to prevent and treat diabetic kidney disease.

EgMADS3 directly regulates EgLPAAT to mediate medium-chain fatty acids (MCFA) anabolism in the mesocarp of oil palm.

KEY MESSAGE: EgMADS3, a pivotal transcription factor, positively regulates MCFA accumulation via binding to the EgLPAAT promoter, advancing lipid content in mesocarp of oil palm. Lipids function as the structural components of cell membranes, which serve as permeable barriers to the external environment of cells. The medium-chain fatty acid in the stored lipids of plants is an important renewable energy. Most research on MCFA production in plant lipid synthesis is based on biochemical methods, and the importance of transcriptional regulation in MCFA synthesis and its incorporation into TAGs needs further research. Oil palm is the most productive oil crop in the world and has the highest productivity among the main oil crops. In this study, the MADS transcription factor (EgMADS3) in the mesocarp of oil palm was characterized. Through the VIGS-virus induced gene silencing, it was determined that the potential target gene of EgMADS3 was related to the biosynthesis of medium-chain fatty acid (MCFA). Transient transformation in protoplasts and qRT-PCR analysis showed that EgMADS3 positively regulated the expression of EgLPAAT. The results of the yeast one-hybrid assays and EMSA indicated the interaction between EgMADS3 and EgLPAAT promoter. Through genetic transformation and fatty acid analysis, it is concluded that EgMADS3 directly regulates the mid-chain fatty acid synthesis pathway of the potential target gene EgLPAAT, thus promotes the accumulation of MCFA and improves the total lipid content. This study is innovative in the functional analysis of the MADS family transcription factor in the metabolism of medium-chain fatty acids (MCFA) of oil palm, provides a certain research basis for improving the metabolic pathway of chain fatty acids in oil palm, and improves the synthesis of MCFA in plants. Our results will provide a reference direction for further research on improving the oil quality through biotechnology of oil palm.

Fumaric acid production from fermented oil palm empty fruit bunches using fungal isolate K20: a comparison between free and immobilized cells.

This study investigated the potential of using steam-exploded oil palm empty fruit bunches (EFB) as a renewable feedstock for producing fumaric acid (FA), a food additive widely used for flavor and preservation, through a separate hydrolysis and fermentation process using the fungal isolate K20. The efficiency of FA production by free and immobilized cells was compared. The maximum FA concentration (3.25 g/L), with 0.034 g/L/h productivity, was observed after incubation with the free cells for 96 h. Furthermore, the production was scaled up in a 3-L air-lift fermenter using oil palm EFB-derived glucose as the substrate. The FA concentration, yield, and productivity from 100 g/L initial oil palm EFB-derived glucose were 44 g/L, 0.39 g/g, and 0.41 g/L/h, respectively. The potential for scaling up the fermentation process indicates favorable results, which could have significant implications for industrial applications.

Microbiome sequencing revealed the abundance of uncultured bacteria in the Phatthalung sago palm-growing soil.

Environmental variations have been observed to influence bacterial community composition, thereby impacting biological activities in the soil. Together, the information on bacterial functional groups in Phatthalung sago palm-growing soils remains limited. In this work, the core soil bacterial community in the Phatthalung sago palm-growing areas during both the summer and rainy seasons was examined using V3-V4 amplicon sequencing. Our findings demonstrated that the seasons had no significant effects on the alpha diversity, but the beta diversity of the community was influenced by seasonal variations. The bacteria in the phyla Acidobacteriota, Actinobacteriota, Chloroflexi, Methylomirabilota, Planctomycetota, and Proteobacteria were predominantly identified across the soil samples. Among these, 26 genera were classified as a core microbiome, mostly belonging to uncultured bacteria. Gene functions related to photorespiration and methanogenesis were enriched in both seasons. Genes related to aerobic chemoheterotrophy metabolisms and nitrogen fixation were more abundant in the rainy season soils, while, human pathogen pneumonia-related genes were overrepresented in the summer season. The investigation not only provides into the bacterial composition inherent to the sago palm-cultivated soil but also the gene functions during the shift in seasons.

A new species of planthopper in the genus Paraphenice (Hemiptera: Derbidae: Otiocerinae) from palms in eastern Madagascar.

A survey of planthoppers associated with palms in Madagascar was initiated to assess putative vectors of a phytoplasma causing palm decline. Here a derbid collected from a Chinese fan palm (Livistona chinensis) is described as Paraphenice fluctus sp. n., with supplemental molecular data for the cytochrome c oxidase subunit I (COI) gene, 18S rRNA gene, and D9D10 expansion region of the 28S rRNA gene.

Physicochemical assessment of ammonium adsorption using a palm shell-based adsorbent activated with acetic acid: experimental and theoretical studies.

The adsorption of ammonium from water was studied on an activated carbon obtained using raw oil palm shell and activated with acetic acid. The performance of this adsorbent was tested at different operating conditions including the solution pH, adsorbent dosage, and initial ammonium concentration. Kinetic and equilibrium studies were carried out, and their results were analyzed with different models. For the adsorption kinetics, the pseudo-first order equation was the best model to correlate this system. Calculated adsorption rate constants ranged from 0.071 to 0.074 g/mg min. The ammonium removal was 70-80% at pH 6-8, and it was significantly affected by electrostatic interaction forces. Ammonium removal (%) increased with the adsorbent dosage, and neutral pH condition favored the adsorption of this pollutant. The best ammonium adsorption conditions were identified with a response surface methodology model where the maximum removal was 91.49% with 2.27 g/L of adsorbent at pH 8.11 for an initial ammonium concentration of 36.90 mg/L. The application of a physical monolayer model developed by statistical physics theory indicated that the removal mechanism of ammonium was multi-ionic and involved physical interactions with adsorption energy of 29 kJ/mol. This activated carbon treated with acetic acid is promising to depollute aqueous solutions containing ammonium.

Phytochemical analysis and antibacterial activity of palm waste extract against Vibrio harveyi and Vibrio parahaemolyticus.

Vibrio harveyi and Vibrio parahaemolyticus are species of the Vibrio genus that often cause disease and mass mortality in crustaceans. If not handled quickly and appropriately, these diseases can cause considerable losses to farmers. Therefore, it is necessary to find a solution with safe and environmentally friendly disease prevention technology using natural ingredients, among others from plants, namely oil palm. Some parts of oil palm, namely leaves, fronds, fibres and oil palm pulp, which are palm waste, contain antibacterial compounds. This study aimed to assess the antibacterial activity of palm waste extracts, namely pulp, leaves, fronds and fibres using n-hexane, ethyl acetate, chloroform, ethanol and water maceration solvents against pathogenic bacteria V. harveyi and V. parahaemolyticus, and identify active compounds contained in palm waste. The results of the research are expected to produce innovative and sustainable solutions to control diseases in shrimp farming, contribute to the development of a sustainable fishing industry and open up the potential for utilizing palm waste as a value-added resource in the field of aquatic health. The results of observations on antibacterial activity tests and identifying the content of palm waste extract compounds were analysed descriptively displayed in the form of figures, tables and graphs. The results showed that palm waste extracts (pulp, leaves, fronds and fibres) with ethyl acetate and ethanol maceration solvents had very strong antibacterial potential, namely 20.14 ± 0.31 mm-25.52 ± 1.42 mm on V. harveyi bacteria and 20.41 ± 0.55 mm-25.00 ± 0.51 mm on V. parahaemolyticus bacteria. Palm extracts with n-hexane (>20 mm) and chloroform solvents generally have strong category antibacterial potential (10-20 mm), and palm extracts in water solvents have medium category potential (5-10 mm) against V. harveyi and V. parahemolyticus bacteria. The results of phytochemical tests on palm waste extracts with ethyl acetate and ethanol maceration solvents contain bioactive compounds of flavonoids, saponins, polyphenols and alkaloid tannins, steroids and triterpenoids. Palm extracts with n-hexane and chloroform solvents generally contain saponins, alkaloids, steroids and triterpenoids, while palm waste extracts with water solvents contain saponins.

Resistance of dwarf Cocos nucifera L. (Arecaceae) cultivars to Raoiella indica Hirst (Acari: Tenuipalpidae).

The red palm mite Raoiella indica Hirst, 1924 (Acari: Tenuipalpidae) is an important pest of the coconut palm Cocos nucifera L. (Arecaceae) and has caused problems in coconut production worldwide. Research has been carried out aiming at controlling the mite through chemical, biological, alternative, and host plant resistance methods. Identifying coconut palm cultivars resistant to R. indica is important to reduce the problems caused to plantations. Therefore, the objective of this work was to evaluate the performance of R. indica in six dwarf coconut palm cultivars, to identify sources of resistance. The cultivars of the sub-varieties green, red, and yellow evaluated were Brazilian Green Dwarf-Jiqui (BGDJ), Brazilian Red Dwarf-Gramame (BRDG), Cameroon Red Dwarf (CRD), Malayan Red Dwarf (MRD), Brazilian Yellow Dwarf-Gramame (BYDG), and Malayan Yellow Dwarf (MYD). Confinement and free choice tests of R. indica on the cultivars were performed, in which biological parameters and preference were evaluated. Mite performance was different in the cultivars evaluated. In the confinement bioassay, R. indica had the worst performance in the cultivar BGDJ, the best performance in CRD, MRD, and BRDG, and intermediate performance in BYDG and MYD. In the free choice test, the cultivars MRD and MYD were preferred in relation to BGDJ, and CRD was less preferred in relation to BGDJ. Therefore, we considered that the cultivar BGDJ is the most resistant to R. indica, by antibiosis and antixenosis; CRD has resistance by antixenosis; and MRD, BRDG, BYDG, and MYD are susceptible.

Exploring the functional profiles of odorant binding proteins crucial for sensing key odorants in the new leaves of coconut palms in Rhynchophorus ferrugineus.

The red palm weevil (RPW), Rhynchophorus ferrugineus (Curculionidae: Coleoptera) is a highly destructive global pest of coconut trees, with a preference for laying its eggs on new leaves. Females can identify where to lay eggs by using their sense of smell to detect specific odorants found in new leaves. In this study, we focused on the two odorants commonly found in new leaves by GC-MS: trans, trans-2,4-nonadienal and trans-2-nonenal. Our behavioral assays demonstrated a significant attraction of females to both of these odorants, with their electrophysiological responses being dose-dependent. Furthermore, we examined the expression patterns induced by these odorants in eleven RferOBP genes. Among them, RferOBP3 and RferOBP1768 exhibited the most significant and simultaneous upregulation. To further understand the role of these two genes, we conducted experiments with females injected with OBP-dsRNA. This resulted in a significant decrease in the expression of RferOBP3 and RferOBP1768, as well as impaired the perception of the two odorants. A fluorescence competitive binding assay also showed that both RferOBPs strongly bound to the odorants. Additionally, sequence analysis revealed that these two RferOBPs belong to the Minus-C family and possess four conserved cysteines. Molecular docking simulations showed strong interactions between these two RferOBPs and the odorant molecules. Overall, our findings highlight the crucial role of RferOBP3 and RferOBP1768 in the olfactory perception of the key odorants in coconut palm new leaves. This knowledge significantly improves our understanding of how RPW females locate sites for oviposition and lays the foundation for future research on the development of environmentally friendly pest attractants.

Fractionation of oil palm fronds using ethanol-assisted deep eutectic solvent: Influence of ethanol concentration on enhancing enzymatic saccharification and lignin ß-O-4 content.

Numerous fractionation methods have been developed in recent years for separating components such as cellulose, hemicellulose, and lignin from lignocellulosic biomass wastes. Deep eutectic solvents (DES) have recently been widely investigated as captivating green solvents for biomass fractionation. However, most acidic-based deep eutectic solvent fractionation produces condensed lignin with low ß-O-4 content. Besides, most DESs exhibit high viscosity, which results in poor mass transfer properties. This study aimed to address the challenges above by incorporating ethanol into the deep eutectic solvent at various concentrations (10-50 wt%) to fractionate oil palm fronds at a mild condition, i.e., 80 °C, 1 atm. Cellulose residues fractionated with ethanol-assisted deep eutectic solvent showed a maximum glucose yield of 85.8% when 20 wt% of ethanol was incorporated in the deep eutectic solvent, significantly higher than that achieved by pure DES (44.8%). Lignin extracted with ethanol-assisted deep eutectic solvent is lighter in color and higher in ß-O-4 contents (up to 44 ß-O-4 per 100 aromatic units) than pure DES-extracted lignin. Overall, this study has demonstrated that incorporating ethanol into deep eutectic solvents could enhance the applicability of deep eutectic solvents in the complete valorization of lignocellulosic biomass. Highly enzymatic digestible cellulose-rich solid and ß-O-4-rich lignin attained from the fractionation could serve as sustainable precursors for the production of biofuels.

Catalase (CAT) Gene Family in Oil Palm (Elaeis guineensis Jacq.): Genome-Wide Identification, Analysis, and Expression Profile in Response to Abiotic Stress.

Catalases (CATs) play crucial roles in scavenging H2O2 from reactive oxygen species, controlling the growth and development of plants. So far, genome-wide identification and characterization of CAT genes in oil palm have not been reported. In the present study, five EgCAT genes were obtained through a genome-wide identification approach. Phylogenetic analysis divided them into two subfamilies, with closer genes sharing similar structures. Gene structure and conserved motif analysis demonstrated the conserved nature of intron/exon organization and motifs among the EgCAT genes. Several cis-acting elements related to hormone, stress, and defense responses were identified in the promoter regions of EgCATs. Tissue-specific expression of EgCAT genes in five different tissues of oil palm was also revealed by heatmap analysis using the available transcriptome data. Stress-responsive expression analysis showed that five EgCAT genes were significantly expressed under cold, drought, and salinity stress conditions. Collectively, this study provided valuable information on the oil palm CAT gene family and the validated EgCAT genes can be used as potential candidates for improving abiotic stress tolerance in oil palm and other related crops.