Calreticulin (CRT) is an endoplasmic reticulum calcium-binding protein proven to play important roles in plant growth, development, and stress resistance. This study identified a total of five MeCRTs members in the cassava genome, which were evenly distributed on chromosomes 6, 8, 11, 13, and 14. The physicochemical properties of MeCRTs proteins showed minor variations, and the conserved motifs and gene structures were similar. The promoter regions of MeCRTs contained multiple cis-acting elements related to stress response and hormone signaling. Collinearity relationships existed between MeCRTs and CRT genes from Arabidopsis, maize, rice and tomato. Cassava transcriptome data revealed differential expression of MeCRTs genes across various tissues: MeCRT1 and MeCRT5 showed the highest expression in callus, MeCRT2 was the highest in somatic embryos, while MeCRT4 exhibited low expression across all tissues. Analysis of transcriptomes under abiotic/biotic stress indicated that MeCRT2,MeCRT3, and MeCRT5 responded to drought (PEG treatment), low temperature, and salt stress. MeCRT2 and MeCRT3 exhibit differential expression patterns among different cassava varieties infected with Sri Lankan cassava mosaic virus (SLCMV). MeCRT3 was involved in the resistance response to cassava bacterial blight (Xanthomonas axonopodis pv. manihotis). qRT-PCR analysis demonstrated that MeCRT2, MeCRT3, and MeCRT4 responded to low-temperature stress, and MeCRT1-5 participated in the response to cassava bacterial blight resistance. This study would provide a reference for further elucidating the functions of the CRT gene family in cassava and lay a foundation for the genetic improvement of stress resistance in cassava.

Cassava (Manihot esculenta Crantz) is a globally important food crop and industrial raw material, with very promising industrial prospects. CIPK23 (CBL-interacting protein kinase 23) is a key kinase in the calcium signaling pathway, and RAV5 is a transcription factor of the AP2/ERF family. Both play crucial regulatory roles in cassava’s responses to biotic and abiotic stresses. Previous yeast screening library experiments preliminarily confirmed the protein interaction between MeCIPK23 and MeRAV5, but the core domain of the interaction has not been clarified. To explore the interaction between MeCIPK23 and MeRAV5 and to identify the interaction domains, this study conducted systematic research through bioinformatics analysis and yeast two-hybrid experiments. Our results showed that MeCIPK23 interacts with MeRAV5; MeCIPK23 contained two conserved domains, among which the serine/threonine kinase catalytic domain (STKc_SnRK3) could specifically interact with MeRAV5, while its C-terminal regulatory domain (CIPK_C) did not participate in the interaction. The research results clarified the interaction relationship and key domains of MeCIPK23 and MeRAV5, laying a solid theoretical foundation for in-depth analysis of the molecular mechanism and biological functions of the key kinase CIPK23 of the calcium signaling pathway and the transcription factor RAV5 of the AP2/ERF family.

Cassava is an important tropical food and cash crop, but the production is severely threatened by Sri Lankan cassava mosaic virus (SLCMV). In this study, healthy and SLCMV-infected cassava cultivar NZ199 were used as materials to systematically analyze the impact of SLCMV infection on gene transcriptional activity in cassava leaves. Transcriptome data analysis identified a total of 4728 differentially expressed genes. Compared with healthy leaves, 4495 genes were up-regulated and 233 genes were down-regulated in infected leaves. Further analysis revealed that in infected leaves, the expression of key genes in the isochorismate synthase (ICS) pathway of salicylic acid biosynthesis was suppressed, while key genes in the phenylalanine ammonia-lyase (PAL) pathway were activated. Liquid chromatography-mass spectrometry (LC-MS) detection showed that, compared to healthy leaves, salicylic acid content in infected leaves increased by 51.98%, while the content of salicylic acid glucoside decreased by 10.95%. In conclusion, SLCMV infection inhibited the expression of genes such as ICS and PBS3 in the ICS pathway, while activating genes such as PAL, CNL and BEBT in the PAL pathway, ultimately leading to increased salicylic acid accumulation in cassava leaves. This study would provide a theoretical basis for understanding the molecular mechanisms of cassava’s response to SLCMV and for breeding disease-resistant varieties.

Phytocyanin (PC) is a class of plant-specific type I copper-binding proteins that play crucial roles in plant growth and development. To date, genome-wide identification of the PC gene family and its function in pollen development remain unreported in pepper. In this study, based on the genomic and transcriptomic data of pepper (Capsicum annuum L.), we conducted systematic identification and preliminary functional characterization of the PC gene family (CaPC) in pepper by integrating genomic, bioinformatic, and molecular biological approaches. The results revealed that the pepper genome contained a total of 45 CaPC genes, which were unevenly distributed across 11 chromosomes with partial clustering. Phylogenetic analysis indicated that CaPCs could be classified into three subfamilies, UCL, SCL and ENODL, comprising 6, 8 and 31 members, respectively. Gene structure and conserved domain analyses showed that most CaPC genes contained two exons, and all CaPC members possessed the conserved Cu_bind-like domain. Whole-genome synteny analysis revealed that 11 pairs of CaPC genes were generated by segmental duplication in the pepper genome. Synteny analysis with closely related species indicated that the number of syntenic PC gene pairs was highly conserved among pepper, tomato, and eggplant. Promoter cis-acting element analysis showed that the promoter regions of CaPC genes harbored multiple regulatory elements associated with light responsiveness, hormone response, stress response, and growth and development. Expression profiling analysis identified four CaPC genes specifically expressed in anthers. Among them, CaENODL10.1 exhibited specific expression in anthers at developmental stages 6-9. Further RT-PCR analysis revealed that CaENODL10.1 was not expressed in anthers of either cytoplasmic-nuclear interaction male sterility (CMS) or genetic male sterility (GMS) pepper lines, suggesting that this gene may serve as a key factor in pollen development. In conclusion, this study conducted a systematic analysis of the CaPC family genes in pepper. The findings would provide novel insights into the role of PC genes in plant pollen development and offer potential molecular targets for the development of male sterile lines in pepper.

To elucidate the molecular regulatory mechanisms underlying bulb bud regeneration in Hippeastrum reticulatum, this study conducted de novo transcriptome sequencing on the ‘Bailei’ cultivar across six time points of bulb buds (D₀, D₃, D₆, D₉, D₁₂, D₁₅). The results revealed significant temporal dynamics in gene expression during bulb bud regeneration. The number of differentially expressed genes (DEGs) progressively decreased as development proceeded, and overall transcriptional activity stabilized after D₁₂, preliminarily identifying D₁₂ as a critical transition phase for bulb bud growth. GO and KEGG enrichment analyses indicated that DEGs during this key phase were primarily involved in hormone signal transduction, carbohydrate transport and metabolism, phenylpropanoid biosynthesis, and enzymatic reaction pathways.To characterize the dynamic patterns of gene expression, this study integrated Mfuzz time-series analysis with WGCNA, distinguishing transient response genes from continuously regulated genes. Thirteen co-expression modules significantly associated with developmental stages were identified. The Turquoise module, significantly enriched at D₀, comprised genes involved in wound response, hormone remodeling, and starch degradation (e.g., ACS1, AOS1, BAM1), suggesting that the initiation phase of regeneration is dominated by stress perception and carbon source mobilization. Modules associated with the mid-to-late phase (D₁₂) were significantly enriched in organ growth, starch/sucrose synthesis, and auxin signaling pathways (e.g., APL2, BT1, IAA4), supporting D₁₂ as a critical establishment node. Genes at the D₁₅ stage participated in cell wall remodeling, oxidative homeostasis, and carbohydrate storage, marking the entry of bulb buds into a functional maturation phase. Integrating differential expression, time-series, and co-expression network analyses, this study proposes a molecular regulatory model for H. reticulatum bulb bud regeneration. The initiation phase (D₀) is driven by wound signaling and sugar signaling to activate metabolism. The critical phase (D₆-D₁₂) involves enhanced hormone signaling accompanied by a shift in carbon flux from degradation to synthesis, and the formation phase (D₁₂-D₁₅) is characterized by stabilized transcriptional regulation and the gradual establishment of structural and metabolic homeostasis. This study systematically reveals the temporal expression patterns of key metabolic pathways and regulatory genes during bulb bud regeneration in H. reticulatum, providing critical data to elucidate the molecular mechanisms underlying this process.

Plukenetia volubilis is a high-quality woody oil crop. The MYB transcription factor family, one of the largest transcription factor families in plants, are widely involved in the regulation of plant growth and development, signal transduction and secondary metabolism. Based on the transcriptome data of P. volubilis seeds, bioinformatics methods were adopted in this study to systematically identify the members of the PvMYB family and analyze the correlation with polyunsaturated fatty acids. Family members were screened by homologous alignment of MYB conserved domains, and the physicochemical properties were analyzed using TBtools. A phylogenetic tree was constructed by the neighbor- joining method with MEGA 7.0 software, and the characteristics of protein conserved domains and motifs were analyzed combined with MEME and Batch CD-Search. Differential expression analysis and heat map visualization were performed via TBtools software, and SPSS 27 software was used to analyze the correlation between the expression levels of differential genes and the contents of linolenic acid and linoleic acid. The results showed that 57 members of the PvMYB family were identified and divided into 9 subgroups. PvMYB proteins were typical hydrophilic proteins, most of which were unstable proteins, and 10 conserved motifs were predicted in total. Correlation analysis demonstrated that PvAPL-3 and PvMYB1R1-4 were characterized as core negative regulatory genes, which showed extremely significant negative correlations with both fatty acids (absolute value of correlation coefficient≥0.98). In contrast, PvMYB44-6 functioned as a core positive regulatory gene, exhibiting extremely significant positive correlations with the two fatty acids, with correlation coefficients reaching 0.988 and 0.991, respectively. Furthermore, PvGAMYB-2 and PvGAMYB-3 also displayed strong positive regulatory effects on these fatty acids. This study clarified the sequence characteristics and expression patterns of the PvMYB family and the potential association with polyunsaturated fatty acid accumulation, which would provide a theoretical basis for the molecular mechanism of MYB regulating lipid synthesis in P. volubilis, and also supply key gene targets for the genetic improvement of lipid metabolism in this plant.

To elucidate the biosynthesis pathway of stemona alkaloids, a cytochrome P450 gene, SpCYP1, was cloned from Stemona parviflora. The open reading frame of this gene was 1521 bp, encoding 506 amino acids. Phylogenetic analysis indicated that SpCYP1 belonged to the CYP76 family but formed an independent branch at the base of the phylogenetic tree. Multiple sequence alignment confirmed that the protein contained all the characteristic conserved motifs of P450 enzymes, with a single transmembrane helix at the N-terminus, classifying it as a typical type I membrane-anchored P450 enzyme. Molecular docking simulations showed that the stemona alkaloid precursor, Stemonamide, could stably bind near the active center of SpCYP1 (binding energy: -38.78 kJ/mol). Co-expression network analysis identified 341 significantly co-expressed genes, and KEGG enrichment analysis revealed that the genes were primarily enriched in pathways such as plant-pathogen interaction, MAPK signaling pathway, and cytochrome P450-mediated metabolism of foreign substances. UPLC-MS/MS detection showed that the relative total alkaloid content in the roots of S. parviflora was significantly higher than that in stems and leaves. RT-qPCR results indicated that the expression level of SpCYP1 was the highest in the roots, suggesting that this gene may be involved in the biosynthesis of stemona alkaloids. This study is the first systematic investigation of a P450 gene in Stemona plants and would provide important genetic resources for subsequent elucidation of the stemona alkaloid biosynthesis pathway.

To clarify the genetic background and phylogenetic relationships of currently cultivated loquat cultivars (lines) in Putian, and to provide scientific and theoretical support for regional loquat breeding, a total of 30 loquat germplasm accessions were subjected to whole-genome resequencing in this study. High-quality SNP loci and InDel fragments were obtained for analysis of population genetic diversity. After effective filtering and screening of the sequencing data, 158.98 Gb of clean data were generated, with an average sample mapping rate of 97.70%, an average sequencing depth of 6×, and a genome coverage rate of 93.86%. Annotation and analysis of SNP loci, InDel fragments and variant genes revealed that red-fleshed loquats exhibited higher values than white-fleshed loquats in multiple indicators, including the total number of genome-wide SNP and InDel, the average number of SNP and InDel in coding regions, the number of non-synonymous mutation genes, the number of frameshift mutation genes, and the population genetic distance. GO enrichment analysis demonstrated that differential genes were mainly involved in cellular processes and metabolic processes. KEGG enrichment analysis indicated that the differential genes were primarily enriched in biological pathways such as plant-pathogen interaction, MAPK signaling pathway, plant hormone signal transduction, and starch and sucrose metabolism. Population analysis results showed that the phylogenetic tree constructed based on whole-genome variation data divided the 30 Putian loquat germplasm accessions into five groups. Germplasm accessions with consistent pulp color, those with parent-hybrid progeny relationships, and clonally propagated loquat germplasm exhibited obvious aggregation trends in the cluster analysis. Meanwhile, gene flow was detected among different groups, with the genetic differentiation index (Fst) ranging from 0.115 to 0.434 between groups. This study concluded that red-fleshed loquats had higher variation potential at the DNA level and possessed greater genetic diversity than white-fleshed loquats. The classification of Putian loquat germplasm was affected by factors such as pulp color and genetic relationships, and the germplasm accessions still retained moderate to strong genetic differentiation ability. The findings would provide an important basis for the systematic classification, precise evaluation and efficient breeding utilization of Putian loquat germplasm resources.

This study aimed to breed a high-yielding, high-starch, and low-hydrogen-cyanide excellent dual-purpose cassava cultivar. The high-yield variety XX 048 was used as the maternal parent, and excellent F₁ individuals were selected through open pollinated hybridization. After a series of systematic breeding procedures including sprouting and seedling cultivation, field transplantation, individual plant selection, single-row evaluation, line comparison test, regional experiment, and production experiment, a new dual-purpose cassava variety Gui 1508 with high yield, high starch, low hydrogen cyanide, and strong adaptability for both fresh food and processing was developed. The key characteristics were an upright plant type, gray-white outer skin and light green inner skin on mature stems. The tubers were concentrated and grew horizontally with cylindrical-conical shapes. The outer skin of the tuber outer skin was light brown, the inner skin was light red, and the flesh was white. The average fresh potato yield of Gui 1508 in regional and production trials reached 47.04 t/hm² and 50.16 t/hm², compared with control NZ 199 (CK₁), the yield increased by 19.15% and 20.63%, and compared with control SC 9 (CK₂), the yield increased by 30.45% and 34.08%. Quality appraisal showed that the total starch content was 32.70 g/100 g, the amylopectin content was 47.80%; the hydrogen cyanide content was 24.00 mg/kg, the soluble sugar content was 2.43%, the protein content was 1.69 g/100 g, and the dietary fiber content was 0.90%. Gui 1508 had wide adaptability and stable high yield performance. Its field resistance to mites was identified as medium., making it suitable for large-scale promotion in cassava planting areas such as Guangxi, Yunnan, and Guangdong. This study provides high-quality germplasm materials for cassava variety improvement and efficient cultivation in China, effectively contributing to the quality improvement and upgrade of the industry, and inject new impetus into the income increase of cassava farmers and the growth of enterprises.

To optimize propagation techniques for rubber tree (Hevea brasiliensis) seedling rootstocks and to improve the quality and production efficiency of bud-grafted seedlings, fresh seeds of the cold-tolerant cultivar GT1 were used to systematically investigate the effects of sowing orientation (B₁, laid flat with the dorsal ridge facing upward; B₂, laid flat with the dorsal ridge facing downward; B₃, placed on the side with the micropyle downward; B₄, placed on the side with the micropyle upward) and covering substrate type (F₁, river sand; F₂, peat soil; F₃, coco coir; F₄, coco coir and peat soil evenly mixed at a 1:1 ratio) on seed germination and emergence, seedling vigor, and usability. Sowing orientation significantly affected emergence rate, seedling growth parameters, and utilization rate (P<0.05). Emergence rate followed the order B₃>B₂>B₁>B₄, and from day 21 onward, the emergence rate of B₄ was significantly lower than that of the other treatments. The emergence rate, plant height, and utilization rate under B₁, B₂, and B₃ were significantly higher than those under B₄. Although some growth parameters under B₄ were acceptable, its utilization rate was only 40.66% due to pronounced bending of the taproot. Correlation analysis indicated that emergence rate and seedling height were the key positive determinants of seedling utilization rate. Covering substrate type had an extremely significant effect on propagation efficiency (P<0.01). River sand (F₁) was extremely significantly superior to the other substrates in emergence rate, plant height, stem diameter, taproot diameter, and utilization rate. Correlation analysis further showed extremely significant positive correlations among emergence rate, plant height, stem diameter, and taproot diameter, indicating that high emergence and robust taproot development jointly promote shoot growth. In conclusion, sowing seeds laid flat with the dorsal ridge facing upward or downward, or sowing on the side with the micropyle downward, together with river sand as the covering substrate, can effectively improve emergence rate, seedling vigor, and utilization rate, thereby providing key technical support for efficient large-scale propagation of rubber tree seedling rootstocks.

Aiming at the production problem of pale pericarp and poor marketability of Xianjinfeng litchi, this study explored the regulatory effects and physiological and molecular mechanisms of foliar application of potassium fertilizer (KCl, K₂SO₄), calcium fertilizer (CaCl₂) and iron fertilizer (EDTA-Fe) on its pericarp pigmentation. Using 5-year-old Xianjinfeng litchi plants as test materials, the corresponding fertilizers were sprayed three times at the fruit expansion stage. The mineral element content, phenolic components, key enzyme activities related to anthocyanin synthesis in pericarp were determined, and the differential expression of related genes was analyzed combined with transcriptomic sequencing. The results showed that compared with the water control, 0.1% CaCl₂ and 0.02% EDTA-Fe treatments significantly increased pericarp Ca and Fe contents by 18.2% and 22.7%, respectively, and significantly reduced pericarp Mn accumulation. The pericarp PAL activity of EDTA-Fe treatment significantly increased by 32.6% compared with the control, the UFGT activity of CaCl₂ and EDTA-Fe treatments increased by 47.2% and 51.8%, respectively, and the GST activity increased by 42.5% and 45.3%, respectively. The contents of cyanidin-3-glucoside and cyanidin-3-rutinoside in pericarp of CaCl₂ treatment significantly increased by 38.7% and 42.1%, respectively, and the content of cyanidin-3-rutinoside in EDTA-Fe treatment significantly increased by 35.4%. At the same time, both treatments significantly increased the contents of co-pigments such as epicatechin, proanthocyanidin A2, quercetin-3-glucoside and ferulic acid, with increases ranging from 15.6% to 41.2%. Transcriptome analysis showed that CaCl₂ and EDTA-Fe treatments could significantly up-regulate the expression of structural genes such as C4H, 4CL, CHI, F3H, UFGT, GST in anthocyanin synthesis pathway, and key transcription factors such as MYB, bHLH, NAC, and regulate the expression of ion transport-related genes such as ACA and VIT, thereby reshaping pericarp cation homeostasis. However, 0.2% KCl and 0.23% K₂SO₄ treatments did not significantly improve the pericarp pigmentation of Xianjinfeng, and significantly reduced the soluble solids and soluble sugar contents in pulp; CaCl₂ and EDTA-Fe treatments had no negative effect on the core quality of fruits, and the pulp sugar-acid ratio of EDTA-Fe treatment was significantly increased by 14.8% compared with the control. In conclusion, foliar application of 0.1% CaCl₂ and 0.02% EDTA-Fe can significantly improve the pericarp pigmentation of Xianjinfeng litchi by regulating the mineral element homeostasis of pericarp, activating the activity of genes and enzymes related to anthocyanin synthesis and transport, and increasing the content of co-pigments, without impacting fruit internal quality, This approach can serve as a safe and efficient agronomic measure for fruit color regulation of this variety.

Heat stress is a major abiotic factor limiting the growth, development, and ornamental quality of Oncidium. To clarify the physiological responses of Oncidium to elevated temperature and the association with changes in root endophytic microorganisms, heat treatment was simulated in a controlled growth chamber. Leaf photosynthetic pigments, osmolytes, antioxidant enzyme activities, and negative air ion (NAIs) release were systematically evaluated, and 16S rRNA and ITS high-throughput sequencing were employed to characterize root endophytic microbial communities. Heat stress significantly suppressed NAIs release and disrupted its diurnal rhythm. Chlorophyll b content decreased, whereas proline and soluble protein accumulated markedly. The antioxidant system exhibited selective responses, superoxide dismutase (SOD) and peroxidase (POD) activities decreased, while catalase (CAT) and ascorbate peroxidase (APX) showed slight increases, indicating that Oncidium alleviates oxidative damage through enhanced osmotic adjustment and partial activation of antioxidant pathways. At the microbial level, overall bacterial β-diversity showed no clear separation between treatments, although genus-level composition displayed trend-like shifts; with increased relative abundances of Chujaibacter and Conexibacter and decreasing tendencies in the Burkholderia-Caballeronia-Paraburkholderia complex and Sphingobacterium. Fungal communities exhibited limited overall differentiation; however, Fusarium and Exophiala increased significantly, whereas Glutomyces and Rhodotorula decreased significantly. Correlation analysis revealed significant associations between NAI release and variations in chlorophyll content, proline, and soluble protein. Redundancy analysis identified NAI release, proline accumulation, and chlorophyll b content as important physiological variables explaining microbial community variation. Overall, heat stress induced coordinated adjustments in photosynthetic pigments, osmotic regulation, and antioxidant systems in Oncidium, accompanied by genus-level shifts in root endophytic microbial communities, reflecting dynamic plant-microbe responses under stress conditions.

The tropical montane cloud forest environment is characterized by low temperatures, high humidity and strong seasonal fluctuations. The mechanisms by which these conditions influence the morphological development and secondary metabolism of endangered epiphytic orchids remain unclear. Taking Dendrobium sinense, an epiphytic species in the tropical cloud forest of Bawangling, Hainan, as the research object, this study systematically investigated the seasonal dynamics of its pseudobulb morphological traits (number and length) and the contents of major active components (crude polysaccharides, total flavonoids and total phenolics). Key environmental drivers affecting its growth were identified, and the optimal harvest period was comprehensively evaluated. The results showed that the number and length of D. sinense pseudobulbs exhibited significant seasonal fluctuations, characterized by rapid growth in the early rainy season and conservative morphology during the dry season. Morphological growth peaked in autumn, while the accumulation of active components was asynchronous with morphological growth. Storage substances (crude polysaccharides) reached the peak earlier than defensive substances (total flavonoids and total phenolics). Crude polysaccharide content peaked in December [(13.14±0.94)mg/g], whereas total flavonoids [(13.05±0.84)mg/g] and total phenolics [(11.27±0.25)mg/g] reached the highest levels in February. Environmental fluctuations were the key drivers of pseudobulb morphological growth, with average humidity, temperature variance and humidity variance having the significant effects: average humidity was positively correlated with pseudobulb length, while temperature variance negatively affected pseudobulb number, and humidity variance negatively impacted pseudobulb length. Principal component analysis indicated that pseudobulb length during the senescence period, length during the reproductive period, and crude polysaccharide content were the top three contributing quality indicators. Comprehensive evaluation showed that October achieved a relatively optimal balance between morphological traits and active component accumulation, making it the most suitable harvest period for D. sinense. This study reveals the seasonal dynamics patterns of morphological development and active component accumulation in endangered epiphytic plants under tropical cloud forest conditions, providing a scientific basis for the conservation and sustainable utilization of D. sinense resources.

Addressing the soil quality degradation caused by continuous cropping obstacles in high-intensity tropical multiple-cropping areas, this study investigated the impacts of Brassica rapa var. (CK), B. rapa var. glabra-Allium fistulosum L. rotation (BAR), and B. rapa var. glabra-Ipomoea aquatica rotation (BIR) on soil properties, enzymatic activities and fungal community structure. The objective was to provide a theoretical basis for the sustainable cultivation of tropical vegetables. A randomized block design was implemented, and soil environmental factors driving fungal community evolution were characterized using Illumina NovaSeq high-throughput sequencing. The results showed that rotation regimes significantly re-engineered the soil environment factors. Compared to CK, rotation significantly increased soil pH and the contents of alkaline nitrogen (AN), available potassium (AK), exchangeable calcium (ECa) and exchangeable magnesium (EMg) (P<0.05). Although available phosphorus (AP) and organic matter (OM) contents decreased significantly under rotation, likely due to the intensive mineralization and high nutrient extraction common in tropical climates, the replenishment of base cations effectively mitigated the trend of soil acidification. Soil enzyme activities exhibited high sensitivity to cropping modifications. In the BAR treatment, the activities of acid phosphatase, β-1,4-N-acetylglucosaminidase (NAG) and β-1,4-glucosidase were remarkably superior, respectively. Conversely, the BIR treatment significantly enhanced urease (UA) activity, which peaked at 3.34 nmol/(g·h). Fungal community diversity and structure exhibited significant differentiation across treatments. PCoA and Adonis analysis (R²=0.346, P=0.001) confirmed that the cropping system was the primary determinant driving fungal community assembly. Compared to CK, rotation treatments increased the Chao1 index but reduced the Shannon index and evenness, reflecting the enrichment of specific dominant functional taxa. Specifically, BIR significantly reduced the relative abundance of Ascomycota while promoting the enrichment of beneficial genera such as Mortierella and Penicillium. In contrast, while the BAR treatment enhanced microbial diversity, it led to the accumulation of the phytopathogen Colletotrichum. FUNGuild functional prediction further confirmed that the relative abundance of pathotrophic fungi reached its maximum level under the BAR regime. Redundancy analysis (RDA) and correlation heatmaps demonstrated that soil pH, UA, NAG and exchangeable magnesium (EMg) were the core regulatory factors driving the structural evolution of the fungal community. In summary, rotation reshapes the soil fungal community by optimizing the physicochemical environment and modulating enzymatic activity fluxes. The synergistic interaction among the factors facilitates nutrient transformation and restructures the soil microbial habitat. Among the tested models, B. rapa var. glabra-Ipomoea aquatica rotation (BIR) exhibited the best performance in maintaining fungal community homeostasis and suppressing potential soil-borne pathogens, making it an ideal cropping strategy to alleviate continuous cropping obstacles in tropical vegetable production regions.

Powdery mildew is a widespread global disease affecting plants and has a significant economic impact on agriculture and ecosystems. Its pathogen, Erysiphales, is an obligate parasitic fungus. In the infection process, powdery mildew effector proteins interfere with or suppress the host immune system. Research on the virulence functions of the effector proteins has consistently attracted considerable attention. Currently, relevant studies have been focused on the functions of powdery mildew effector proteins that infect major economic crops, including cereals, cucurbits, and rubber trees. The studies cover core research areas including gene identification, evolutionary analysis of effector proteins, investigation of pathogenic mechanisms, and the discovery of avirulence genes. We have summarized and elaborated on the research findings related to powdery mildew effector proteins and explored approaches and directions for future research, aiming to provide theoretical support for both fundamental and applied studies.

The MAPK kinase Fus3 plays an important regulatory role in host signal recognition and pathogenic processes of various pathogenic fungi, yet its functions in powdery mildew fungi remains uncharacterized. Erysiphe quercicola, the causal agent of rubber tree powdery mildew, is a pathogenic fungus infecting rubber trees (Hevea brasiliensis), and this study focused on the functions of EqFus3 in host signal recognition and pathogenicity of this pathogen. Gene expression analysis demonstrated that EqFus3 was significantly up-regulated at the early infection stage and reached its expression peak at 13 hours post-inoculation. The dsRNA-mediated silencing of EqFus3 in fungal spores at the time of inoculation resulted in a marked decrease in fungal invasion rate and attenuated pathogenicity. Exogenous application of cellulose and potassium ions enabled the pathogen to form hyphae and haustoria on glass slides (a non-plant surface), which suggested that cellulose (a major component of plant cell walls) and environmental potassium ions may act as signal molecules for the pathogen to recognize and induce the formation of infection structures. Notably, dsRNA-mediated silencing of EqFus3 abrogated the inductive effects of cellulose and potassium ions on the pathogen, indicating that EqFus3 is involved in the recognition of host-derived and environmental signals. This study clarifies the functional role of Fus3 kinase in host recognition and infection processes of the pathogen.

This study systematically evaluated the antifungal activity, field efficacy, and potential mechanism of action of isobavachalcone against Peronophthora litchii, the causal agent of litchi downy blight. Indoor toxicity assays showed that the EC₅₀ value of isobavachalcone against this pathogen was 0.4564 mg/mL. In field efficacy trials, two applications of 0.2% isobavachalcone microemulsion (formulation dilutions of 1500, 1000 and 500-fold, corresponding to active ingredient dosages of 1.33, 2.00 and 4.00 mg/kg, respectively) were applied at a 10-day interval. The control efficacy of pre-harvest was 58.14%, 65.21%, 70.38%, and after 2 days of post-harvest storage, the control efficacy was 48.24%, 53.85%, 57.86%, respectively. The high-dose treatment showed better pre-harvest efficacy than the chemical control agent, 250 g/L azoxystrobin suspension concentrate at 1600-fold dilution. Transcriptomic analysis revealed that isobavachalcone treatment significantly enriched differentially expressed genes in pathways related to metabolic reprogramming, energy metabolism inhibition, cell membrane structure disruption, and stress response. Additionally, the expression of several transcription factor families (HSF, zf-C2H2, HLH) was significantly altered, suggesting that isobavachalcone may exert its antifungal activity by regulating transcriptional networks and disrupting cellular metabolic homeostasis. This study would provide efficacy evidence for isobavachalcone as a potential biopesticide against litchi downy blight and preliminarily elucidates its mechanism of action, laying a theoretical foundation for its further development and application.

Ganoderma multipileum is a key pathogenic fungus responsible for Delonix regia root rot, yet effective control measures against this disease remain limited to date. The Trichoderma genus serves as a crucial fungal resource in the field of biological control. This study aimed to screen Trichoderma strains with significant antagonistic activity against G. multipileum from the strains preserved in the laboratory, clarify the taxonomic status and biological characteristics of the optimal antagonistic strain, and thereby provide data support for the subsequent exploitation of this strain and the biological control of D. regia root rot. Using G. multipileum strain WDFGZ69 as the target pathogen, strains with prominent antagonistic effects were screened via an in vitro dual culture assay. Combined with morphological observation, ITS sequence alignment and concatenated sequence analysis of rpb2 and tef1 genes, the taxonomic status of the target strain was confirmed. The growth rate method was employed to determine the biological characteristics of the selected strain, including its optimal carbon source, nitrogen source, inorganic salt, as well as the optimal growth temperature and pH value. The results of the in vitro dual culture assay showed that six tested strains, namely P18-5, P21-3, P38-1, G42-5, P45-1 and P45-2, exhibited significant and stable inhibitory effects on G. multipileum. Among them, strain P21-3 displayed the strongest antagonistic activity, with a mycelial growth inhibition rate of 85.75% after 7 days of dual culture. The volatile organic compound (VOC) assay indicated that the volatile components produced by the tested strains had no significant inhibitory effect on G. multipileum. In the fermentation broth antagonism test, the fermentation broth of P21-3 achieved an inhibition rate of 57.65% against the target pathogen. Combined with morphological characteristics and phylogenetic tree analysis constructed based on ITS, rpb2 and tef1 dual-gene sequences, the strains were identified as follows, P18-5 as T. hamatum, P21-3 as T. breve, P38-1 as T. koningiopsis, and both G42-5 and P45-2 as T. asperellum. Considering the overall antagonistic performance of all tested strains, P21-3 was selected for further biological characteristic analysis. The results showed that the optimal carbon sources for the mycelial growth of P21-3 were xylose and glucose, the optimal nitrogen source was yeast extract, and the optimal inorganic salt was potassium dihydrogen phosphate. In contrast, ferrous sulfate and manganese sulfate exerted significant inhibitory effects on its mycelial growth. The optimal growth temperature of P21-3 was 30 ℃, and it had a broad acid-base tolerance range, capable of growing at pH 4.0-12.0, with the optimal pH range of 4.5-5.5. In conclusion, the T. breve strain P21-3 screened in this study exhibited excellent antagonistic activity against G. multipileum, making it a potential candidate strain for the biological control of D. regia root rot. The clarified biological characteristics of P21-3 defined the optimal conditions for its mycelial growth, laying a critical foundation for the subsequent optimization of fermentation culture and field application of this strain.

Fusarium wilt is one of the most destructive diseases affecting melon (Cucumis melo L.) production and is caused by Fusarium oxysporum f. sp. melonis. Melatonin (MT), a multifunctional signaling molecule and plant growth regulator widely distributed in plants, plays important roles in regulating plant resistance to both biotic and abiotic stresses. To investigate the physiological regulatory effects of exogenous melatonin on melon resistance to Fusarium wilt, the susceptible melon cultivar Dongfangmi No. 1 was used as the experimental material. Plants were treated with different concentrations of melatonin (0, 12.5, 25, 50, 100, 200 μmol/L), and a series of physiological and biochemical parameters were determined to systematically evaluate the effects of melatonin treatments.The results showed that exogenous melatonin treatment significantly reduced the disease incidence and disease index of melon Fusarium wilt, and also decreased the contents of relative electrical conductivity (REC), malondialdehyde (MDA) and hydrogen peroxide (H₂O₂). Exogenous melatonin significantly enhanced the activities of antioxidant enzymes including peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR), as well as increased the content of reduced glutathione (GSH). In addition, exogenous melatonin markedly elevated the contents of osmotic adjustment substances, such as free proline (Pro), soluble sugar (SS) and soluble protein (SP), and secondary metabolites including total phenols (TP) and total flavonoids (TF). Comprehensive evaluation using the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) indicated that 25 μmol/L melatonin was the optimal concentration for improving melon resistance to Fusarium wilt. This study would provide a theoretical basis for elucidating the physiological mechanisms underlying melatonin-induced resistance to Fusarium wilt in melon and support its potential application in green disease control strategies.

Root-knot nematode disease is a common agricultural pest that severely affects crop growth and yield. This study evaluated the efficacy of Sargassum polycystum extract (E-PS) against Meloidogyne incognita in pepper through in vitro immersion assays, root irrigation for inducing resistance-related enzyme activities, and pot experiments. The results showed that the highest corrected mortality rate of second-stage juveniles of M. incognita treated with 0.6 g/L E-PS for 72 hours reached 21.02%. Different concentrations of E-PS significantly enhanced the activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD) and chitinase in pepper roots. When treated with 0.6 g/L E-PS, the activities of PAL, PPO, POD and chitinase increased by 244.40%, 279.20%, 62.10% and 77.10%, respectively, compared to CK. In pot experiments, the control efficacy of 0.1 g/L, 0.3 g/L and 0.6 g/L E-PS treatments against M. incognita in pepper was 62.16%, 64.86% and 72.97%, respectively. Additionally, all E-PS treatments significantly promoted pepper growth and enhanced root activity. Among them, the 0.1 g/L E-PS treatment increased plant height, root fresh mass, and root activity by 69.60%, 68.00% and 96.20%, respectively. This study is the first to report that E-PS can effectively control M. incognita in pepper. It preliminarily elucidates that E-PS achieves comprehensive control of M. incognita through lethal effects on its second-stage juveniles and enhancement of resistance-related enzyme activities in pepper roots.

Roasting temperature is a key parameter for improving the edible quality of macadamia nuts. Compared with conventional roasting, microwave roasting exhibits advantages including high heat transfer efficiency and shortened processing time. However, the effects of microwave roasting temperature on the appearance and flavor quality of macadamia nuts remain unclear. Therefore, this study investigated the impacts of different microwave roasting temperatures on the texture, color and sensory properties of shelled macadamia nuts. Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the content and composition of flavor compounds, thereby elucidating the regulatory patterns of volatile flavor quality under different roasting temperatures. Results showed that as the roasting temperature increased from 100 ℃ to 150 ℃, the hardness and brittleness of shelled macadamia kernels decreased significantly by 22.97% and 20.17%, respectively, while the elasticity, cohesiveness and resilience were less affected. Among the color parameters, the values of a^*, b^*, chroma (C) and color difference (ΔE) increased with elevated roasting temperature, whereas L^* and hue angle (h°) exhibited a declining tendency. Additionally, the browning intensity increased remarkably with increasing temperature. Sensory evaluation indicated that shelled macadamia nuts roasted at microwave temperatures of 140-150 ℃ achieved higher scores across all sensory attributes, particularly for overall acceptability, taste and color. GC-MS/MS analysis revealed that high-temperature roasting (140 ℃ and 150 ℃) significantly promoted the formation of aldehydes (33.81%‒35.31%) and pyrazines (18.52%‒23.00%). The OPLS-DA model demonstrated an excellent fit (R²X=0.990, R²Y=0.964, Q²=0.890), identifying 14 key aroma substances with VIP>1. Among these, aldehydes, pyrazines and furans contributed greatly to the flavor of the high-temperature group. 2,5-Dimethylpyrazine began to be detected at 120 ℃, while most pyrazine compounds were generated in large amounts only above 140 ℃. Two benzopyran derivatives dominated the aroma of the low-temperature roasting group and raw nuts. Comprehensive multidimensional quality analysis confirmed that microwave roasting temperatures between 140 ℃ and 150 ℃ represented the optimal range for achieving macadamia nuts with moderate hardness and crisp texture, uniform roasting color, and rich aroma compounds. The results would provide a theoretical basis for promoting the application of microwave roasting in the processing of macadamia nuts.

This study examined the effects of different melatonin (MT) concentrations on the postharvest quality of cut flowers from the tropical water lily cultivar Nymphaea Blue Butterfly (subgenus Anecphya), aiming to determine the optimal MT concentration for extending vase life. To investigate this, cut flowers were treated with varying MT levels, and physiological parameters including water status (water loss, uptake, and balance), soluble sugar, soluble protein, malondialdehyde (MDA), proline (Pro), superoxide anion (O₂•^-) levels, and the activities of antioxidant enzymes (SOD and APX) were measured during the vase period. Additionally, endogenous hormones (IAA, ABA) and MT precursors (TAM, 5-HT, NAS) were analyzed on day 3. The results showed that MT treatments extended vase life by 1-3 days, with the 4 mmol/L concentration demonstrating the most significant effects. It delayed the onset of negative water balance by 2 days, extended total vase life by 2.24 days, and led to peak values of soluble sugar (98.46%), soluble protein (28.79%), Pro content (41.56%), and APX (42.94%) and SOD (52.78%) activities, while reducing MDA and O₂•^- levels by 49.25% and 32.85%, respectively. Furthermore, IAA, MT, 5-HT and NAS contents were significantly elevated in the MT-treated group, whereas ABA and TAM levels were significantly reduced. The findings indicate that 4 mmol/L MT effectively preserves postharvest quality by enhancing endogenous IAA and MT levels, improving antioxidant capacity, reducing water loss, and mitigating membrane lipid peroxidation, thereby delaying senescence. This study would provide valuable theoretical and practical insights for developing targeted preservatives in cut water lily postharvest management.

Plastic pollution has become increasingly severe in mangrove ecosystems. To examine the interactive effects of mangrove root exudates (RE) and microplastics (MPs) on the microbial communities of both the plastisphere and sediments, a laboratory microcosm experiment was conducted. Two types of MPs, polyethylene (PE-MPs) and biodegradable polylactic acid (PLA-MPs), together with RE from two mangrove species, were added to sediments and incubated for 45 days. After incubation, the structural characteristics of microbial communities on MPs and in sediments under different treatments were analyzed using 16S rDNA high-throughput sequencing, and the key driving factors were identified. The results indicated that in mangrove systems, MPs form a distinct ecological niche, with significantly higher microbial community diversity on their surfaces compared to the surrounding sediments, and this feature was primarily determined by MPs polymer type rather than RE input. At the phylum level, the dominant phylum Desulfobacterota was less abundant on MPs (10.49%) than in sediments (20.12%), with RE enhancing its presence on PLA-MPs but reducing it on PE-MPs. As a typical sulfate-reducing microorganism, the Desulfobacterota-driven sulfur cycle in mangrove systems warrants further investigation. Proteobacteria were markedly enriched on MPs (27.78%), yet its sedimentary abundance declined with MPs addition. Actinobacteriota were more abundant in PE-MPs and associated sediments compared to PLA-MPs. At the genus level, In contrast, the relative abundance of Ketobacter on PE-MPs was 321.20 times higher than that on PLA-MPs, and was 3.89 times higher on PE-MPs with added RE than on those without. In terms of community stability, RE addition enhanced the complexity and stability of microbial co-occurrence networks in both the plastisphere and sediments, promoting cooperative interactions largely driven by Firmicutes. These results demonstrated that MPs type was a key factor regulating differential microbial colonization on the surfaces, while RE played a significant role in shaping microbial community structure and stability through resource input. Furthermore, the microbial community structures of both MPs and sediments were mainly driven by environmental factors such as salinity and dissolved organic carbon (DOC), with distinct driving patterns observed between the plastisphere and sediments. These results provide insights into the ecological impacts of MPs in mangrove systems under the influence of RE.

This study investigated the mechanism by which Lvnonglin^® 41 compound microbial fertilizer alleviating the continuous cropping obstacle in black pepper from the perspectives of bacterial and fungal community assembly and the potential functions in the rhizosphere soil, aiming to provide technical and theoretical guidance for healthy pepper cultivation. A field with a history of severe continuous cropping obstacle was selected for the experiment. Four treatments were established, water control (CK), Lvnonglin^® 41 composite microbial fertilizer (LV41), composite microorganisms (CM), and nutrient substrate (NS). The incidence of Fusarium wilt was determined, and high-throughput sequencing was employed to analyze the community structure, diversity, and functional characteristics of bacteria and fungi. The results showed that compared with CK, all treatments exhibited some mitigating effects, with the LV41 treatment showing the most significant effect. The control efficacy of LV41 against Fusarium wilt incidence across different growth stages of pepper reached 83.01% to 86.50%. CM had the highest number of unique bacterial OTUs, while NS had the highest number of unique fungal OTUs. For bacterial communities, both Chao1 and Shannon indices followed the order CM>LV41>NS>CK. For fungal communities, the Chao1 index followed CM>LV41>NS>CK, whereas the Shannon index followed CK>NS>LV41>CM. PCoA results indicated distinct separations in both bacterial and fungal communities among the treatments. Treatment LV41 enriched beneficial bacteria Bacillus and Nitrospira, as well as beneficial fungus Chaetomium, with relative abundances of 2.09%, 1.74% and 18.40% respectively, which were markedly higher than those in other treatments. The relative abundances of potential pathogen Fusarium and beneficial fungus Trichoderma were 1.92% and 0.33%, obviously lower than other groups. LEfSe analysis revealed that differentially abundant species in the LV41 treatment included 4 bacterial and 5 fungal taxa. Co-occurrence network analysis indicated that LV41 increased the complexity of the bacterial network and the clustering coefficient of the fungal network. Functional prediction showed that in LV41, the bacterial group Gram negative increased most significantly, while stress tolerant decreased most significantly. Fungal functional groups such as animal pathogen‒dung saprotroph‒endophyte‒ epiphyte‒plant saprotroph‒wood saprotroph showed the most pronounced increase. The bacterial community assembly in LV41 was dominated by deterministic processes, whereas the fungal community assembly remained primarily stochastic. In conclusion, Lvnonglin^® 41 composite microbial fertilizer reduced the incidence of Fusarium wilt in continuously cropped pepper by improving bacterial and fungal community structure, network complexity and stability, functional composition, and assembly processes, demonstrating good potential for alleviating the continuous cropping obstacle in pepper.