To address the issues of low added value in traditional pepper processing, poor fluidity of pepper oleoresin, and the incomplete extraction and emulsification techniques for freeze-dried green pepper oleoresin, this study used freeze-dried green pepper as raw material to prepare pepper oleoresin through ultrasonic-microwave assisted extraction. The volatile components were analyzed by gas chromatography-mass spectrometry (with cyclohexanone as the internal standard), and a mixed emulsi-system of Tween 80 and Span 80 was selected to investigate the effects of pH, ionic strength, and water content on the of the emulsion. The results showed that a total of 37 volatile compounds were detected in the pepper oleoresin, mainly monoterpenes and sesquiterpenes, among which β-caryophyllene (210.83 mg/mL) had a relatively high content. The ideal value of the mixed emulsifier was approximately 11. Under the conditions of pH 8.0-9.0, without adding NaCl, and a water content of 95%, the emulsion had a lower particle size and stable physicochemical properties. This study optimized the extraction and emulsification process of freeze-dried green pepper oleoresin, providing technical support for its development and utilization as well as the upgrading of the pepper industry's deep processing.

Camellia oleifera from Hainan possesses unique quality traits. Public attention to both quality of life and nutritional health is increasing, while market oversight of food safety is being continuously strengthened. An in-depth analysis of the soil characteristics in the forestlands of Hainan's main C. oleifera planting regions and the impact on the elemental composition of the seeds can fully reveal the safety attributes of Hainan C. oleifera seeds. In this study, a total of 11 sample plots were selected from the main C. oleifera planting areas of Hainan. Soil pH, nutrient contents (including organic carbon, organic matter, total nitrogen, total phosphorus, total potassium, nitrate nitrogen, ammonium nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, rapidly available potassium, and slowly available potassium), and heavy metal elements (copper, zinc, and lead) were measured. Simultaneously, elemental indicators in C. oleifera seeds, including nitrogen, phosphorus, potassium, total calcium, total magnesium, total copper, total zinc, and lead, were determined. Duncan's multiple range test was employed to analyze the differences among various indicators and translocation factors. Pearson correlation analysis was used to examine the influence of soil properties on seed elements. The results indicated that the soils in the main C. oleifera planting areas of Hainan Island ranged from strongly acidic to weakly acidic (pH 3.83-6.90), with significant spatial variation in nutrient content. The DA-1 plot had the highest organic matter content; BT-1 had the highest total nitrogen; HK-1 had the highest total phosphorus and available potassium; and QH-2 had the highest available phosphorus. Notably high levels of copper and zinc were found in the HK-1 plot, while the DA-2 plot exhibited elevated lead content. The contents of the seven nutrient elements in C. oleifera seeds differed extremely significantly (P<0.01), with total calcium showing the largest coefficient of variation (41.2%). Four sample plots, HK-1 (enriched in macronutrients), QH-2 (advantageous in micronutrients), QH-1 (comprehensively balanced), and DA-1 (exhibiting high protein-micronutrient synergy), were identified as high quality resources. The elemental enrichment factors exhibited pronounced plot-specific characteristics, with WZS-1 (for phosphorus), QH-2 (for potassium), DZ-1 (for copper), and CM-1 (for nitrogen and zinc) showing outstanding performance. Correlation analysis confirmed that soil pH was highly significantly positively correlated with the accumulation of magnesium and potassium in C. oleifera seeds, organic matter was strongly associated with seed copper content, and available phosphorus showed significant positive correlations with calcium and zinc contents. This study reveals that maintaining slightly acidic to neutral soil, increasing organic fertilizer application, and balancing phosphorus fertilization are key measures for enhancing the nutritional quality of C. oleifera seeds in Hainan. It would provide a theoretical basis for the selection of high-quality seed resources, targeted cultivation practices, and the optimization of processed product quality.

The study on the ecological suitability regionalization for Coffea arabica in Guangxi is of great reference significance for accurate and effective utilization of ecological and environmental resources, guiding scientific site selection for planting and rational production layout planning. The MaxEnt model and ArcGIS software were used for the modeling of 58 distribution points of C. arabica in Guangxi and 15 environmental factors, and for the prediction of the ecological suitability regionalization and spatial potential prediction in current and future climate scenario. The model's prediction results had high consistency and reliability, with the AUC of 0.937, the Kappa coefficient of 61.6%, and TSS of 0.738. Climatic limiting factors (coefficient of variation of precipitation seasonality, isothermality, precipitation of coldest quarter, mean temperature of coldest quarter, min temperature of coldest month) played a decisive role in the ecological suitability regionalization of C. arabica in Guangxi. The southwest of Guangxi was the core concentration area for highly suitable area, and important distribution area for moderately and lowly suitable area in current. The top five of total suitable areas, in descending order, were Baise (46.20%), Chongzuo (21.97%), Fangchenggang (8.26%), Nanning (7.33%) and Yulin (6.46%) in the prefecture-level scale. The top five of highly suitable areas, in descending order, were Jingxi (149.58 km²), Xilin (109.77 km²), Napo (62.94 km²), Debao (50.78 km²) and Shangsi (47.31 km²) in the county scale. In the future climate scenario, the total suitable area showed an increasing trend, particularly suitable habitat expanding gradually from the southwest dominant suitable area toward the northeast potential area, with the core distribution areas shifting from the southwest area of Guangxi (Baise, Chongzuo, Fangchenggang and other regions) toward the northeast (Nanning area together with the central and eastern area of Guangxi).

As an important resource plant in tropical regions, Daemonorops jenkinsiana has significant value in the fields of ecology, economy and medicine. This study investigated the community structure of D. jenkinsiana in the secondary forest of Fanjia Provincial Nature Reserve, Hainan. Through sample plot investigation and analysis, the secondary forest in the Fanjia Provincial Nature Reserve of Hainan served as the research object in this study, revealing its community structure characteristics in detail and providing a theoretical foundation for resource protection and artificial cultivation of D. jenkinsiana., providing theoretical insights for the conservation and sustainable utilization of D. jenkinsiana resources. The D. jenkinsiana community was rich in species composition, encompassing a total of 161 plant species belonging to 134 genera and 69 families. In dominant taxa, the dominant families included Fabaceae, Rubiaceae and Arecaceae, accounting for 47.83% of the total species; the dominant genera were Ficus, Ardisia and Calamus, contributing to 13.66% of the total species. Tropical elements dominated both the families and genera of the plants. Among them, there were 47 tropical families, representing 77.05% of the total families, and 108 tropical genera, accounting for 85.71% of the total genera. The dominant species in the arbor layer were Ficus microcarpa, Heptapleurum heptaphyllum, Phoebe sheareri, Cryptocarya concinna, Quercus glauca, Aporosa dioica, Lannea coromandelica, Camphora officinarum, Zanthoxylum nitidum, Engelhardia roxburghiana. The dominant species in the shrub layer included D. jenkinsiana, Rhapis excelsa, Desmos chinensis, Calamus tetradactylus, Maesa japonica, Calamus egregius, Dypsis lutescens, Psychotria rubra, Ancistrocladus tectorius and Dalbergia hupeana. The dominant species in the herb layer were Rhapis excelsa, Alpinia japonica, D. jenkinsiana, Psychotria rubra, Dalbergia hancei, Maesa japonica, Desmos chinensis, Schima superba, Ardisia crenata and Tetracera asiatica. Species diversity was the highest in the shrub layer and lowest in the herb layer. The D. jenkinsiana community not only serves as a valuable natural subject and sample source for regional biodiversity studies but also supports population regeneration and the long-term maintenance of habitats. Furthermore, it represents a vital natural germplasm repository. By establishing sample banks (e.g., seeds, seedlings, tissue samples from mature plants) and digital information databases (documenting provenance, growth environment parameters, morphological traits, and genetic characteristics), the provenance information for D. jenkinsiana across different species and growth stages can be systematically enriched. The effort holds significant importance for the sustainable management of both cultivated D. jenkinsiana plantations and natural liana communities.

Natural rubber is an important industrial raw material and strategic resource. It has excellent properties such as comparable elasticity, flexibility and resistance to high temperature, which cannot be replaced by synthetic rubber. The rubber tree (Hevea brasiliensis) is still the only commercial source of natural rubber. Previous studies have reported the key genes involved in rubber biosynthesis including HbSRPP, HbHRT and HbFDP play crucial roles in increasing rubber yield, while MYB, as a transcription factor, may participate in the synthesis of natural rubber. In the study, a MYB transcription factor HblMYB16 gene was cloned from rubber tree, and bioinformatics and expression analysis were carried out successfully. The results showed that the open reading frame (ORF) of HblMYB16 was 1116 bp, encoding 371 amino acids, and the total average hydrophilicity was -0.498, which was a hydrophilic protein containing the R2R3-MYB domain and belonging to the MYB transcription factor family. HblMYB16 was highest expressed in latex and localized in the nucleus. It was found that jasmonic acid had a promoting effect on the expression of HblMYB16, HbSRPP, HbHRT and HbFDP, while ethylene only had an impact on the expression of HblMYB16 and HbFDP. At the same time, the interactions between HblMYB16 and the rubber biosynthesis key genes HbSRPP, HbHRT and HbFDP were verified by yeast one hybrid. The studies would lay a foundation for further revealing the molecular mechanism of HblMYB16 participating in natural rubber biosynthesis.

Pineapple (Ananas comosus) ranks as the world's third most important tropical fruit and is a significant economic crop in China's tropical regions. To investigate the role of the dihydroflavonol 4-reductase (DFR) gene family in anthocyanin accumulation in pineapple and provide a theoretical foundation for germplasm improvement, this study identified and preliminary functionally analyzed members of the pineapple DFR gene family. A total of 17 dihydroflavonol 4-reductase genes were identified in the whole genome of pineapple, which were named AcDFR1 to AcDFR17 and distributed unevenly on 10 chromosomes. AcDFRs encoded proteins ranging from 313 to 378 amino acids (aa) in length, with molecular weights between 34.73 and 47.74 kDa and isoelectric points (pI) from 5.10 to 8.9. The secondary structure of AcDFR proteins primarily consisted of α-helices and β-sheets, with α-helix content ranging from 38.73% to 43.07% and β-sheet content from 13.24% to 15.64%. Phylogenetic analysis revealed that the 17 AcDFRs formed four subfamilies. The motif arrangement and number of exons were similar among AcDFRs. The AcDFR genes promoter regions contained multiple cis-acting elements responsive to light, hormones, abiotic stress, growth and development. Real-time quantitative PCR analysis revealed significant expression variations of AcDFRs genes across different pineapple tissues (roots, stems, leaves, flowers, pulp, peel), though most genes exhibited high expression in both pulp and peel. Cloning and identification of AcDFRs revealed sequences largely consistent with predicted sequences. Subcellular localization studies of the AcDFR1 in tobacco leaves via transient expression indicated localization to the cytoplasm and cell membrane. The findings would provide theoretical references for further investigation into the functions of the dihydroflavonol-4-reductase gene family in pineapple and for pineapple quality improvement.

S-adenosylmethionine synthase (SAMS) is a key enzyme catalyzing the synthesis of S-adenosylmethionine (SAM, S-adenosylmethionine), widely involved in various biological processes in plants, such as epigenetic regulation, oxidative stress, and growth and development. In this study, the full-length cDNA sequence of CaSAMS3 was successfully cloned from coffee, and the physicochemical properties, protein structure, conserved domains, and evolutionary characteristics of the encoded CaSAMS3 protein were analyzed. Through cis-acting element analysis and protein interaction network prediction, and the metabolic processes involving CaSAMS3 were explored, and its expression pattern was analyzed in combination with qPCR and subcellular localization studies. The results showed that the open reading frame length of CaSAMS3 was 1173 bp, encoding a hydrophilic protein (molecular weight 42.57 kDa, theoretical isoelectric point 6.07), with a secondary structure mainly composed of α- helices and irregular curls, and located on cell membrane and nucleus. The protein contained a typical SAMS conserved domain and had the highest homology with SAMS in kiwifruit. Its promoter contained response elements related to light, hormones, stress, and growth and development, including MYB and MYC binding sites. CaSAMS3 exhibited tissue-specific expression, and its expression trend during developmental stages was consistent with accumulation pattern of caffeine. This study would provide an important theoretical basis for elucidating the biological function of CaSAMS3 in the regulation of caffeine synthesis, and provides a potential target for improving coffee quality and resistance.

This study represents sequencing of the chloroplast genome of the tea plant variety Zhuyeqi, with a focus on analyzing its structural characteristics, codon usage bias, and phylogenetic relationships. The results revealed that its chloroplast genome had 157 072 bp, with 135 functional genes annotated. The GC content in the IR region was found to be the highest (42.96%), and several intron-containing genes, such as clpP and ycf3, were identified. Codon usage bias analysis indicated a relatively weak bias, primarily driven by natural selection (contribution rate of 86.6%). Optimal codons were mostly A/U-ending, deviating from expectations based on mutational pressure. Phylogenetic analysis further confirmed that Zhuyeqi formed a highly supported monophyletic clade with cultivated types such as Pu-erh tea and Baihao tea, demonstrating close maternal genetic relationships. This study would provide important insights into the evolution of Theaceae species and the functional optimization of chloroplast genomes.

Plant annexin is a conserved calcium-dependent phospholipid binding protein involved in plant growth, development and stress resistance. The sequence characteristics and expression patterns of the ANX gene family in C. oleifera remain unclear. For this reason, the present study aims to investigate the expression regulatory mechanisms of this gene family in the stress resistance responses of C. oleifera. Three ANX genes were identified from the whole genome of C. oleifera, and the physical and chemical characteristics, evolutionary relationship, gene structure, conserved sequence, chromosome location, expression level in different tissues and the content of annexin under drought stress were analyzed in the study. Phylogenetic analysis showed that 15 different families were clustered into 5 groups, among which CsANX and CoANX1/2 from Camellia were clustered into a large branch with similar motif patterns. Many cis-elements involved in light response and plant hormone response were identified in the promoter region of CoANX. Chromosome localization showed that the three CoANX genes were distributed on three chromosomes (A_chr 09/13/14) of C. oleifera. The expression pattern analysis showed that CoANX showed tissue-specific patterns in different growth stages and tissues. In addition, stress analysis showed that CoANX3 showed a high expression trend under drought conditions, while the expression of CoANX3 in the treatment group sprayed with brassinolide decreased. Under phosphorus and aluminum stress, the expression of ANX in C. oleifera increased significantly. The above results indicate that CoANX may play a key role in the stress resistance of C. oleifera. This study would lay a foundation for elucidating the molecular mechanism of ANXs in regulating the biological processes of plant growth and development.

The aim of the study was to characterize the chloroplast genome structure and phylogenetic relationships within the genus Bulbophyllum. We sequenced, assembled, and annotated the chloroplast genomes of B. rothschildianum and B. longissimum for the first time. Comparative analyses of codon usage bias, repeat sequences, and sequence variation were then conducted with the available chloroplast genomes from four previously published Bulbophyllum species. The chloroplast genome of B. rothschildianum and B. longissimum was 148 447 bp and 151 095 bp, respectively, both showing a typical circular quadripartite structure containing 126 and 129 functional genes. Codons encoding leucine exhibited the strongest usage bias, with codons ending in A/U being particularly abundant. SSR analysis revealed mononucleotide repeats (predominantly A/T type) were most abundant, and palindromic repeats dominated among long repeats. Highly variable regions were mainly located in non-coding regions and selected coding genes (e.g., matK and ycf1), with evident expansion and contraction at IR/SC boundaries. Phylogenetic analysis showed that the 32 Bulbophyllum species formed a strongly supported clade and exhibited clear geographic differentiation into Asian and Central and South American lineages, with B. rothschildianum and B. longissimum clustering together within the Asian lineage and being closely related. The study would provide molecular insights into resource development, genetic conservation, and systematic research in the genus Bulbophyllum.