As an important ornamental flower, Cymbidium sinense needs to undergo a long period of low temperature dormancy during its flower development to achieve flowering. SHORT VEGETATIVE PHASE (SVP) is a key regulator in plant flowering pathway and plays an important role in plant dormancy and flowering. In this study, three SVP homologous genes, named CsSVP1, CsSVP2 and CsSVP3, were cloned from Xiaoxiang. The results of bioinformatics analysis showed that the full-length of the three CsSVPs genes were 651 bp, 687 bp and 714 bp, encoding 216, 228 and 237 amino acids, respectively, and all of them contained conserved MADS-box and K-box domains. Amino acid sequence alignment and phylogenetic analysis showed that CsSVP1 had the highest similarity with CgSVP, CsSVP2 and CsSVP3 had the highest similarity with EpMADS18 and DhcSVP, respectively. CsSVP1 was closely related to CgSVP of C. goeringii. CsSVP2 was closely related to EpMADS18, while CsSVP3 was closely related to DhcSVP. Promoter cis-element analysis showed that the CsSVPs gene contained many light response, hormone response and other elements. The results of qRT-PCR showed that the three CsSVPs genes were expressed in roots, stems, leaves, flowers and fruits of C. sinense. The expression patterns of CsSVP1 and CsSVP3 genes were similar, which were accumulated in leaves and stems, and the expression levels in flowers and fruits were significantly decreased. The expression of CsSVP2 was the highest in fruit, followed by leaves, stems and flowers, suggesting that their biological functions may be quite different. At the same time, the expression in different floral organs was detected, and it was found that the three CsSVPs had the highest expression in sepals. Furthermore, the expression of CsSVP2 gene in different flower development stages was also detected. It was found that the expression level of CsSVP2 gene was the highest in the S₁ stage of early development, and decreased with the development of flower organs, and the expression level was the lowest in the S₅ stage of mature flowers. The overall expression levels of CsSVP1 and CsSVP3 in floral organs were not high. The expression level of CsSVP1 was the highest in S₂ period and the lowest in S₅ period. The expression level of CsSVP3 was the lowest in S₂ period, and the expression level continued to increase in the late stage of flower development. In addition, low temperature treatment found that the expression of CsSVP1 and CsSVP2 increased slightly after low temperature treatment, while CsSVP3 decreased significantly. In ABA treatment, only the expression of CsSVP1 was significantly inhibited, while CsSVP2 and CsSVP3 did not respond. The results suggest that different CsSVPs genes have different functions and may play different roles in the process of low temperature dormancy promoting flowering of orchids, which would provide an experimental basis for further analysis of the specific functions of SVP genes in the process of flower development.

Aquilaria sinensis, a plant belonging to the genus Aquilaria of the Thymelaeaceae family, can produce agarwood when exposed to natural factors (such as lightning strikes, fire, and insect bite) or artificial factors (such as cuts, holes, and inoculation of fungi). MADS is a transcription factor that plays a significant role in plant growth and development and stress response. However, its function in A. sinensis remains unclear. To elucidate the stress response of MADS-box genes in A. sinensis after injury, this study utilized transcriptomic data derived from A. sinensis to expression heatmaps and screen for differentially expressed genes, leading to the identification and cloning of a MADS-box encoding gene, designated AsMADS12, which exhibited significant differential expression. Comprehensive analyses were subsequently conducted on the domain architecture, physicochemical properties, phylogenetic relationships, and predicted secondary and tertiary structures of AsMADS12. The expression dynamics of the AsMADS12 at various time points after methyl jasmonate (MeJA) treatment were assessed via real-time quantitative PCR (RT-qPCR). Furthermore, subcellular localization of the AsMADS12 was determined by transiently expressing in onion epidermal cells (Agrobacterium-mediated infiltration) and observing fluorescence under a confocal laser scanning microscope. Sequence and evolutionary analyses revealed that AsMADS12 possessed a complete open reading frame (ORF) of 678 bp, encoding a protein of 255 amino acids. The predicted molecular weight of the encoded protein was 25.28 kDa. AsMADS12 contained a typical MEF2-like MADS domain and was classified as a MIKC-type transcription factor. The secondary structure of the protein was mainly composed of 52.00% α-helix, 11.56% extended chain, and 36.44% random coil. Phylogenetic cluster analysis revealed that AsMADS12 was clustered in the same branch as the MADS of Citrus sinensis and Citrus trifoliata. The subcellular localization experiment showed that the AsMADS12 protein was located in the nucleus. The real-time fluorescence quantitative results indicated that methyl jasmonate treatment could induce the expression of AsMADS12, and the expression level was the highest at 24 hours after treatment. It was speculated that AsMADS12 might play a potential role in the formation of agarwood in A. sinensis. This study completed the cloning of the gene for the first time and conducted preliminary exploration, laying the foundation for further research on whether it participates in the formation of agarwood and its role in biotic or abiotic stress responses, thereby providing a theoretical basis for understanding the molecular regulatory mechanism of agarwood formation in A sinensis.

Coffee, one of the most important economic crops worldwide, is widely cultivated in tropical and subtropical regions and serves as a major source of income for many countries and regions. Caffeine (1,3,7-trimethylxanthine) is the main metabolite in coffee beans and related products, which not only imparts the characteristic bitter taste and stimulates effect of coffee but also exerts multiple biological functions. The N-methyltransferase (NMT) gene family plays a key role in the caffeine biosynthetic pathway. Therefore, systematic identification of coffee NMT family members and analysis of the expression patterns at different developmental stages are of great importance for investigating caffeine metabolism, improving coffee quality, and breeding stress-resistant varieties. In this study, a total of 27 NMT genes were identified in allotetraploid Coffea arabica, including 14 genes from the C subgenome and 13 from the E subgenome, distributed across 10 chromosomes. Gene structure analysis revealed that family members shared similar motif compositions but differed in intron arrangement and number. Cis-acting element analysis showed that the promoters of C. arabica NMT genes were enriched with various regulatory elements related to light response, stress response and hormone signaling, and contained transcription factor binding sites such as MYB, MYC and W-box. Transcriptome analysis further demonstrated that NMT genes exhibited dynamic expression during fruit development, with the ripening stage showing the highest number of differentially expressed genes (14 703), while the expansion stage showed the lowest (4419). Moreover, C. arabica NMT genes displayed clear temporal and tissue-specific expression patterns. Weighted gene co-expression network analysis (WGCNA) identified 12 co-expression modules, among which the ivory, coral1 and darkolivegreen modules were enriched in pathways related to environmental stress and protein folding, energy metabolism and nucleic acid metabolism, respectively. Core gene network analysis revealed the critical roles of NMT genes in caffeine metabolism, stress response, and developmental regulation. Taken together, this study systematically identified the NMT gene family in allotetraploid C. arabica, characterized the expression patterns during different stages of fruit development, and elucidated the potential functional differentiation, thereby providing a theoretical basis for coffee breeding.

This study investigated the differences in soil physicochemical properties under three different land-use types, eucalyptus forest, orchard and rubber plantation, developed from granite-derived soils in Danzhou city, Hainan province. The results demonstrated that land use significantly influenced soil nutrient and acidity characteristics: rubber plantation soils showed significantly higher organic matter and total nitrogen content compared to other land uses, but also the most severe acidification with exchangeable aluminum content approximately 3.06 and 3.53 times higher than that in eucalyptus forests and orchards; Orchard soils were characterized by abnormal phosphorus enrichment, with available phosphorus content about 5.62 and 10.46 times higher than that in rubber plantations and eucalyptus forests, respectively, accompanied by strong base cation leaching and the lowest cation exchange capacity (CEC); Soils in Eucalyptus forests exhibited intermediate properties with relatively milder acidification. In terms of soil structure, rubber plantations were dominated by >5 mm aggregates. Combined with its most severe acidification and highest exchangeable aluminum content, this aggregate distribution pattern may indicate poor stability of large aggregates under strong acid and high aluminum toxicity environments. Although rubber plantation soils had CEC values approximately 2.47 and 3.02 times higher than those in Eucalyptus forests and orchards, respectively, the base saturation was extremely low, reflecting a significant contradiction between nutrient retention capacity and actual fertility availability. This study preliminarily suggests that the accumulation of high organic matter in rubber plantation soils may be associated with substantial litter input from rubber trees, while strong acidification and high aluminum toxicity are likely driven by continuous nitrogen cycling processes. The phosphorus enrichment in orchards primarily results from long-term excessive phosphorus fertilization. These findings provide a scientific basis for soil management and acidification control in tropical granite-derived regions under different land-use types.

Fruit quality is the key indicator to measure the commodity value of fruit, and the indicators such as single fruit weight, fruit shape and fruit determination degree (DD) are particularly crucial, which directly affect consumers' desire to buy. In addition, primary metabolites are indispensable substances in the process of plant growth and development, which are widely present in all plants, providing basal metabolites and energy support for plant growth, development and reproduction. Primary metabolites such as sugars, organic acids, amino acids and inositol are the key factors affecting fruit quality, and they are also important criteria for measuring fruit flavor and texture. With the improvement of consumers' living standards and the pursuit of healthy fruits, a large amount of data is needed to screen out Annona squamosa varieties with high nutritional value and high sugar. Yunnan's hot and dry valley climate provides an excellent environment for the fruit to thrive. In order to explore the differences in fruit quality and the composition and content of primary metabolites in the pulp of the four varieties of A. squamosa in the dry and hot river valley of Yunnan Province, the varieties with high nutritional value and high sugar were screened. Four varieties (AP, Damu, Fengli and Liulian) from the planting base of Yuanjiang County, Yuxi City, Yunnan Province were used as the test materials. Gas chromatography-mass spectrometry (GC-MS) was used to determine the composition and content of primary metabolites per unit weight of fresh fruit pulp, and the one-way analysis of variance (ANOVA), principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used for comprehensive analysis and evaluation. Among the four cultivars in the dry-hot valley area of Yunnan, AP A. squamosa had the largest single fruit weight. The content of soluble solids (TSS) in Liulian A. squamosa was the highest. The fruit shape of the Damu A. squamosa is oval, and the other three varieties are oblong; The fruit DD of Fengli A. squamosa was the smallest, and there was no significant difference among the other three cultivars. A total of 43 primary metabolites were detected in the pulp of the four cultivars, including 9 amino acids, 13 organic acids, inositol and 20 soluble sugars. Further analysis of the contents of various primary metabolites in the pulp of the four varieties showed that the contents of sucrose, fructose, glucose, allulose, citric acid and malic acid were the main among the 43 primary metabolites. The contents of glucose, allulose, citric acid and malic acid in Liulian A. squamosa were significantly higher than those of other varieties, and the contents of sucrose and fructose in AP A. squamosa were significantly higher than those of other varieties. In addition, some primary metabolites had significant cultivarity specificity, among which leucine, acetamide acid, xylulose and threonate were only detected in AP A. squamosa. Trehalose is only detected in Liulian A. squamosa. Principal component analysis (PCA) showed that the variance contribution rate of PC1 was 48.3%, that of PC2 was 25.8%, and that of cumulative variance was 74.1%. Partial least squares discriminant analysis (PLS-DA) was used to screen 19 primary metabolites as the characteristic differential metabolites in VIP≥1, including 5 amino acids, serine, L-hydroxyproline, leucine, L-norvaline and L-glutamic acid. 2 organic acids, acetamide and 2-ketoglutarate; 7 soluble sugars, namely D-(+)-xylose, D-arabinose, hexapyranose, xylulose, L-threonose, L-(-)-fucose, sucrose, d-galactose, D-(+)-pinedisinose, maltose and D-(+)-cellobiose; and inositol. From the perspective of basic quality and primary metabolite level, the fruit TSS and primary metabolite content of Liulian A. squamosa were the highest, while the TSS of Fengli A. squamosa was moderate and the outer gauge was the most regular. Therefore, the two varieties can be promoted and planted as A. squamosa varieties with high nutritional value and high sugar in dry and hot river valleys.

This study aimed to investigate the effects of the root exudates from Cyperus rotundus, a common weed in Guizhou tabacco fields, on the tobacco bacterial wilt pathogen Ralstonia solanacearum strain AS-1 and the biocontrol agent Bacillus velezensis strain JXF-16. Non-targeted metabolomics (LC-MS) was employed to identify the chemical composition of C. rotundus root exudates and to explore the effects of specific bioactive constituents on the two bacterial strains. Turbidimetric assays were used to measure the impact of the active compounds on bacterial growth, crystal violet staining was applied to quantify biofilm formation, and semi-solid plate culture assays were conducted to assess bacterial motility. Additionally, pot experiments were performed to evaluate the efficacy of the exogenous active compounds in controlling bacterial wilt. Results revealed that a total of 21 types of chemical compounds and 3176 active substances were detected by LC-MS. At the concentration of 50 μmol/L, myristic acid, 4-ethyloctanoic acid, ligustrazine and betaine significantly promoted the growth, biofilm formation and motility of R. solanacearum. However, at higher concentrations, the compounds exhibited inhibitory effects on bacterial growth and biofilm formation. Tetramethylpyrazine (50 μmol/L) and betaine (100 μmol/L) significantly enhanced the growth, biofilm formation and motility of B. velezensis. Conversely, lauric acid and 2-dodecylbenzenesulfonic acid at concentrations above 50 μmol/L significantly inhibited the growth, biofilm formation, and motility of both R. solanacearum and B. velezensis. Pot experiments demonstrated that lauric acid and 2-dodecylbenzenesulfonic acid at 150 μmol/L and 200 μmol/L effectively controlled bacterial wilt, with the relative control efficacies surpassing those of chemical pesticides and biocontrol agents. Notably, 2-dodecylbenzenesulfonic acid at 200 μmol/L achieved a control efficacy of 80.28%. The results would provide important theoretical insights into the role of C. rotundus root exudates within the tobacco field ecosystem and lay an applied foundation for developing novel bioactive compound-based strategies to control tobacco bacterial wilt.

With the aim of obtaining a new type of green fungicide that is low-cost, safe and highly efficient, this study investigated the antibacterial activity of Cinnamon leaf essential oil and its feasibility as a quorum sensing inhibitor (QSI), and explored its biocontrol effect on bacterial soft rot disease. In this study, the chemical composition of Cinnamon leaf essential oil was analyzed by gas chromatography-mass spectrometry (GC-MS), and the effect of Cinnamon leaf essential oil on the biological control of bacterial soft rot disease was studied, and the effect of Cinnamon leaf essential oil on inhibiting the soft rot pathogen Dickeya fangzhongdai Onc5 quorum sensing system was determined. It was indicated that a total of 16 major constituents were identified in Cinnamon essential oil and the main components were isopropyl palmitate (52.15%), cinnamaldehyde (23.02%) and isopropyl myristic acid (18.80%). Broad-spectrum antibacterial tests showed that the Cinnamon essential oil extracted from leaves had a significant inhibitory effect on five types of bacteria, including Chromobacterum violaceum ATCC31532, Pectobacterium carotovorum subsp. carotovorum, Escherichia coli ATCC25922, Serratia marcescens H30, and D. fangzhongdai Onc5. The minimum inhibitory concentration (MIC) of Cinnamon essential oil against the soft rot pathogen Onc5 was determined to be 2.5‰. Without affecting the normal growth of D. fangzhongdai Onc5, Cinnamon essential oil could weaken its flagellar motility and the release of PCWDEs, controlled the swimming and swarming of D. fangzhongdai Onc5, and effectively inhibited the soft rot pathogen. At sub-inhibitory concentrations (1/2MIC and 1/4MIC), Cinnamon essential oil was able to inhibit the activity of the plant cell wall degrading enzymes (Cel, Pel, Prt) of D. fangzhongdai Onc5, thereby limiting the ability of pathogen to invade plant cells. In order to further verify the antibacterial effect of Cinnamon essential oil, D. fangzhongdai Onc5 treated with 1/2MIC Cinnamon essential oil was inoculated on carrots, cabbage, potatoes and white radishes, and the results revealed that the pathogenicity of the bacterial liquid attenuated significantly. The research found that Cinnamon leaf essential oil exerts antibacterial effects by reducing the secretion activity of extracellular degrading enzymes and flagellar motility of D. fangzhongdai Onc5, thereby influencing its quorum sensing system. It has application prospects employed to control postharvest soft rot in fruits and vegetables as biological means, providing theoretical basis and technical support for the preservation of agricultural products and the green prevention and control of diseases.

Tropical mountain ecosystems are vital repositories of medicinal plant resources, and understanding the altitudinal distribution patterns is crucial for sustainable resource utilization, biodiversity conservation, and research into environmental drivers of medicinal bioactive compounds. To elucidate the altitudinal distribution patterns of the medicinal plants in Wuzhishan Mountain, Hainan, this study conducted quadrat surveys across different elevation gradients (low: 200–400 m; mid: 400-600 m; mid-high: 600-800 m; high: 800–1100 m), documenting 447 species from 260 genera and 99 families, with angiosperms comprising 93.51% of the total species. Tropical families and genera accounted for 83.35% and 86.55%, respectively (excluding cosmopolitan elements), while temperate components increased significantly with elevation. Angiosperms dominated across all elevations, whereas ferns, initially comprising only 1.80% at low elevations, increased significantly to 4.79% and 6.50% at mid-high and high elevations, emerging as a key group. The comprehensive importance value of the tree layer exhibited a bimodal distribution, with dominant species transitioning from tropical at low elevations to temperate transitional species at high elevations, reflecting a tropical-to-temperate floristic shift. The shrub layer’s importance value fluctuated downward with elevation, indicating a synergistic response to the overlying tree structure, while the herb layer shifted from shade-tolerant herbs to medicinal ferns with increasing elevation. α-diversity analysis revealed that tree layer species richness and Shannon diversity peaked at mid-high elevations, aligning with the “mid-domain effect”, while herb layer diversity peaked at mid-elevations, with Simpson dominance significantly higher than in the tree and shrub layers. β-diversity indicated that tree layer species turnover was driven by hydrothermal gradients, whereas shrub and herb layers were primarily influenced by microhabitat heterogeneity. In summary, this study systematically elucidated the vertical distribution patterns of medicinal plants in Wuzhishan Mountain, providing a theoretical foundation for the conservation and utilization of tropical mountain medicinal plant resources and insights into the environmental drivers of medicinal plant quality. Future research should focus on ecological factor analysis in the mid-high elevation (600–1100 m) fern-rich zones.

The study analyzed the soil chemical properties, nutrient contents and distribution characteristics in the litchi gardens from the major growing regions in Yunnan aimed to provide supports for nutrient and fertilization management in litchi gardens. Soil samples were collected from 22 litchi gardens in 6 major production regions. Soil pH, organic matter and multi-elements content were analyzed and used as the indicators to evaluate soil fertility via fuzzy comprehensive analysis. The results showed that soil pH was 5.62, with 22.73% of soil samples were suitable for litchi growth (pH=5.0~5.5). The cation exchange capacity (CEC) of 27.28% of soils was lower than 10.00 cmol/kg, indicating fertilizer retention ability should be improved. Organic matter content was relatively high (14.81-57.06 g/kg). Soil total N content (0.84-2.70 g/kg) was higher than medium level (>1.00 g/kg) excepting for Baoshan region. Soil alkaline hydrolyzed N (78.61-259.19 mg/kg), available P (21.14-92.48 mg/kg) and available K (35.00-642.50 mg/kg) were all higher than medium level excepting one orchard in Yongde, where the available K content (36.67 mg/kg) was at deficiency level (<50.00 mg/kg). Among the trace elements, available Ca (415.63-4900.00 mg/kg) and available S (20.43-127.89 mg/kg) were relatively abundant. Soil available Mg (3.13-512.50 mg/kg) was at moderate level, with 42.43% of samples were below the limit value (<100.00 mg/kg). Available Zn (0.51-9.68 mg/kg) and available Fe (7.18-124.82 mg/kg) were abundant. Available Mn (2.56-104.78 mg/kg) and available Cu (0.76-6.06 mg/kg) were at moderate level, with 8.60% of the samples showing available Mn lowering than 5.00 mg/kg. Available B and Mo were at sufficient level in Yingjiang at 0.88 and 0.43 mg/kg, while those in Pingbian (B: 0.44 mg/kg, Mo: 0.13 mg/kg), Yuanyang (B: 0.31 mg/kg, Mo: 0.15 mg/kg), Baoshan (Mo: 0.10 mg/kg), Yongde (B: 0.42 mg/kg, Mo: 0.10 mg/kg) and Xinping (B: 0.41 mg/kg, Mo: 0.10 mg/kg) were at deficient levels. The integrated fertility index (IFI) was 0.51-0.97, with average value at 0.79. All IFI values were above level II excepting Baoshan region at level III. The principal component analysis showed that total N, alkaline hydrolyzed N, organic matter and pH were the most important factors affecting soil fertility. The data suggested that the overall soil fertility of the studied 22 litchi gardens was above the medium level. Mg and Mo fertilizers can be improved in Baoshan, and B and Mo fertilizers can be improved in Pingbian, Yuanyang, Yongde and Xinping.

The absence of standardized protocols for harvesting green betel nut fruits has led to significant inconsistencies in the quality of fresh produce. Therefore, this experiment used Hainan betel nuts as the test material, sampling every 30 days starting from 30 days after fruit setting, measuring the developmental dynamics of fruit phenotype and inclusions, exploring the development law of betel nut fruits, and determining the optimal harvesting period for green betel nuts. The fruit shape index showed a trend of first increasing and then decreasing, with a variation range of 1.69-1.87. Among them, when the fruit developed to 120 days (1.79)-150 days (1.61), the fruit shape index met the first-grade standard, presenting a long elliptical shape. The chlorophyll content was high at 120-180 days, and the fruit color was emerald green. The pulp hardness showed a trend of first increasing and then decreasing, with a variation range of 85.2-274.49 gf. The hardness at 120-150 days was lower than the average (197.34 gf), meeting the first-grade standard. The soluble sugar contents in both the pulp and kernel showed a trend of first increasing and then decreasing, with variation ranges of 1.23%-4.47% and 5.56%-7.12%, respectively. The soluble sugar contents in the pulp and kernel were high at 120-180 days. The arecoline contents in both the pulp and kernel showed a gradual decreasing trend, with variation ranges of 3.55%-0.19% and 3.42%-0.40%, respectively. The arecoline content in betel nut fruits reached a relatively high level at 120-180 days. After standardizing the data for several key nodes and performing Principal Component Analysis (PCA), the comprehensive score of the pulp and kernel was the highest (1.18) at approximately 150 days after flowering. Combining the variation laws of fruit phenotype and internal quality, the optimal harvesting period for green betel nuts is approximately 150 days after fruit setting.