Effects of fertilization on soil ecological stoichiometry and fruit quality in Karst pitaya orchard.

Pitaya (Hylocereus undulatus) is a significant cash crop in the karst region of Southwest China. Ecological stoichiometry is an essential method to research biogeochemical cycles and limiting elements. The purpose of this study was to explore the stoichiometric characteristics of C, N, and P in Karst pitaya orchards and fruit quality and to elucidate the mechanism and process of nutrient cycling. The results showed that: (1) Fruit quality was highest under the combination of chemical and organic fertilizers. Compared to the control, the contents of per-fruit weight, vitamin C, and soluble sugar increased significantly by 55.5%, 60.7%, and 23.0%, respectively, while the content of titratable acidity decreased significantly by 22.0%. (2) The content of soil nutrients under fertilization stress showed a downward trend in general, as did microbial biomass and extracellular enzyme activities. (3) Different fertilization treatments significantly affected the soil-microbial stoichiometry C:N ratio, C:P ratio, with research areas being significantly limited by C and P. (4) Spearman and PLS-SEM (partial least squares-structural equation model) analysis results showed that under the influence of fertilization, there was a significant positive effect between microorganisms and soil nutrients, but a significant negative effect between soil nutrients and quality. The results of this study offer an innovative perspective on pitaya quality research in Karst areas.

YOLOv8-G: An Improved YOLOv8 Model for Major Disease Detection in Dragon Fruit Stems.

Dragon fruit stem disease significantly affects both the quality and yield of dragon fruit. Therefore, there is an urgent need for an efficient, high-precision intelligent detection method to address the challenge of disease detection. To address the limitations of traditional methods, including slow detection and weak micro-integration capability, this paper proposes an improved YOLOv8-G algorithm. The algorithm reduces computational redundancy by introducing the C2f-Faster module. The loss function was modified to the structured intersection over union (SIoU), and the coordinate attention (CA) and content-aware reorganization feature extraction (CARAFE) modules were incorporated. These enhancements increased the model's stability and improved its accuracy in recognizing small targets. Experimental results showed that the YOLOv8-G algorithm achieved a mean average precision (mAP) of 83.1% and mAP50:95 of 48.3%, representing improvements of 3.3% and 2.3%, respectively, compared to the original model. The model size and floating point operations per second (FLOPS) were reduced to 4.9 MB and 6.9 G, respectively, indicating reductions of 20% and 14.8%. The improved model achieves higher accuracy in disease detection while maintaining a lighter weight, serving as a valuable reference for researchers in the field of dragon fruit stem disease detection.

Exploring the potential of red pitaya pulp (Hylocererus sp.) as a plant-based matrix for probiotic delivery and effects on betacyanin content and flavoromics.

This study evaluated the potential of red pitaya pulp fermented with Lacticaseibacillus paracasei subsp. paracasei F-19 (F-19) as a base for probiotic products. Physicochemical parameters, sugar, betacyanin, and phenolic contents, and antioxidant activity were analyzed over 28 days at 4 °C and compared to a non-fermented pulp, and to a pulp fermented with Bifidobacterium animalis subsp. lactis BB-12 (BB-12). Volatile compounds were identified using HS-SPME/GC-MS. Probiotic viability during storage and survival through in vitro-simulated gastrointestinal tract (GIT) stress were assessed. Red pitaya pulp, rich in moisture (85.83 g/100 g), carbohydrates (11.65 g/100 g), and fibers (2.49 g/100 g), supported fermentation by both strains. F-19 and BB-12 lowered pH, with F-19 showing stronger acidification, and maintained high viability (8.85-8.90 log CFU/mL). Fermentation altered sugar profiles and produced unique volatile compounds, enhancing aroma and sensory attributes. F-19 generated 2-phenylethanol, a unique flavor compound, absent in BB-12. Phenolic content initially increased but antioxidant activity decreased during storage. Betacyanin remained stable for up to 14 days. Red pitaya improved F-19 viability through the simulated GIT, while BB-12 populations significantly decreased (p < 0.05). These results suggest red pitaya pulp is a promising plant-based matrix for F-19, offering protection during digestion and highlighting its potential as a functional food with enhanced bioactive compound bioavailability and sensory attributes.

Plant drugs: Transcending the mescaline biosynthesis.

Our knowledge of the biosynthesis of medicinal compounds from plants remains limited. A new study has deciphered the complete metabolic pathway leading to the biosynthesis of the psychedelic mescaline in the cactus peyote, suggesting the development of biotechnological strategies for a sustainable supply of this important plant drug.

Unique regulatory network of dragon fruit simultaneously mitigates the effect of vanadium pollutant and environmental factors.

Under changing climatic conditions, plants are simultaneously facing conflicting stresses in nature. Plants can sense different stresses, induce systematic ROS signals, and regulate transcriptomic, hormonal, and stomatal responses. We performed transcriptome analysis to reveal the integrative stress response regulatory mechanism underlying heavy metal stress alone or in combination with heat and drought conditions in pitaya (dragon fruit). A total of 70 genes were identified from 31,130 transcripts with conserved differential expression. Furthermore, weighted gene co-expression network analysis (WGCNA) identified trait-associated modules. By integrating information from three modules and protein-protein interaction (PPI) networks, we identified 10 interconnected genes associated with the multifaceted defense mechanism employed by pitaya against co-occurring stresses. To further confirm the reliability of the results, we performed a comparative analysis of 350 genes identified by three trait modules and 70 conserved genes exhibiting their dynamic expression under all treatments. Differential expression pattern of genes and comparative analysis, have proven instrumental in identifying ten putative structural genes. These ten genes were annotated as PLAT/LH2, CAT, MLP, HSP, PB1, PLA, NAC, HMA, and CER1 transcription factors involved in antioxidant activity, defense response, MAPK signaling, detoxification of metals and regulating the crosstalk between the complex pathways. Predictive analysis of putative candidate genes, potentially governing single, double, and multifactorial stress response, by several signaling systems and molecular patterns. These findings represent a valuable resource for pitaya breeding programs, offering the potential to develop resilient "super pitaya" plants.

Detection of GSH with a dual-mode biosensor based on carbon quantum dots prepared from dragon fruit peel and the T-Hg(II)-T mismatch.

Glutathione (GSH) is commonly used as a diagnostic biomarker for many diseases. In this study, based on carbon quantum dots prepared from dragon fruit peel (D-CQDs) and the T-Hg(II)-T mismatch, a dual-mode biosensor was developed for the detection of GSH. This system consists of two single-stranded DNA (ssDNA). DNA1 was the T-rich sequence; DNA2 was attached to streptavidin-coated magnetic beads and consisted of T-rich and G-rich fragments. Due to the presence of Hg(II), the T-Hg(II)-T mismatch was formed between T-rich fragments of two ssDNA. In the presence of GSH, Hg(II) detached from dsDNA and bound with GSH to form a new complex. The G-rich fragment assembled with the hemin shed from D-CQDs to form the G-quadruplex/hemin complex. At this time, in fluorescence mode, the fluorescence of D-CQDs quenched by hemin could be restored. In colorimetric mode, after the magnetic beads separate, a visual signal could be produced by catalyzing the oxidation of ABTS using the peroxide-like activity of the G-quadruplex/hemin complex. This biosensor in both fluorescence mode and colorimetric mode had excellent selectivity and sensitivity, and the limit of detection was 0.089 µM and 0.26 µM for GSH, respectively. Moreover, the proposed dual-mode biosensor had good application prospects for detection of GSH.

The Development of a Fluorescent Microsatellite Marker Assay for the Pitaya Canker Pathogen (Neoscytalidium dimidiatum).

Pitaya canker, caused by Neoscytalidium dimidiatum, is a destructive disease that significantly threatens the safety of the pitaya industry. The authors of previous studies have mainly focused on its biological characteristics and chemical control. However, there are no molecular markers available thus far that can be used for the population genetics study of this pathogen. In the present study, a draft genome of N. dimidiatum with a total length of 41.46 MB was assembled in which 9863 coding genes were predicted and annotated. In particular, the microsatellite sequences in the draft genome were investigated. To improve the successful screening rate of potentially polymorphic microsatellite makers, another five N. dimidiatum isolates were resequenced and assembled. A total of eight pairs of polymorphic microsatellite primers were screened out based on the polymorphic microsatellite loci after investigating the sequencing and resequencing assemblies of the six isolates. A total of thirteen representative isolates sampled from different pitaya plantations were genotyped in order to validate the polymorphism of the resulting eight markers. The results indicated that these markers were able to distinguish the isolates well. Lastly, a neighbor-joining tree of 35 isolates, sampled from different pitaya plantations located in different regions, was constructed according to the genotypes of the eight molecular markers. The developed tree indicated that these molecular markers had sufficient genotyping capabilities for our test panel of isolates. In summary, we developed a set of polymorphic microsatellite markers in the following study that can effectively genotype and distinguish N. dimidiatum isolates and be utilized in the population genetics study of N. dimidiatum.

Comparative analysis of nutrient composition and antioxidant activity in three dragon fruit cultivars.

Dragon fruit has significant economic value in many countries due to has excellent nutritional content, health advantages, and adaptability to different climates, making it an important crop in the global fruit industry. This study aimed to gather comprehensive nutritional data on three dragon fruit cultivars by analysing the levels of micronutrients, fibre, carbohydrates, antioxidants, vitamins, and minerals in their pulps. Uniform dragon fruit samples underwent thorough analysis for proximate composition, mineral content, pigments, antioxidants, and vitamin C, with statistical methods used to assess significant differences among the parameters studied. The proximate composition analysis revealed significant differences among the three dragon fruit cultivars. Among the proximate components, protein (0.40 ± 0.02 g/100 g), moisture (91.33 ± 0.88%), crude fibre (0.32 ± 0.07 g/100 g), and ash (1.27 ± 0.09 g/100 g) were more abundant in Hylocereus costaricensis than in Hylocereus undatus and Hylocereus megalanthus. On the other hand, Hylocereus undatus had higher carbohydrate (17.02 ± 0.63 g/100 g) and energy (69.74 ± 2.44 kcal/100 g) contents. K (7.23 ± 0.35 mg/100 g), Ca (1.61 ± 0.13 mg/100 g), Fe (1.84 ± 0.05 mg/100 g), and Zn (0.37 ± 0.034 mg/100 g) are highly abundant in H. costaricensis. Additionally, Hylocereus costaricensis had the highest anthocyanin content (120.15 ± 3.29 mg/g FW) and total carotenoid content (72.51 ± 1.62 mg/g FW), along with the highest vitamin C content (8.92 ± 0.13 mg/g FW) and total soluble phenolic content (572.48 ± 20.77 mg/100 g). Its remarkable antioxidant activity was further highlighted by the lowest SC50 value (13.50 ± 0.4 mg/mL) for its DPPH radical scavenging capacity. The total soluble sugar content was highest in Hylocereus megalanthus (8.72 ± 0.30 g/100 g FW). Hierarchical clustering analysis revealed distinct trait and genotype associations; among the studied cultivars, Hylocereus costaricensis demonstrated superior performance across multiple traits. Correlation analysis indicated significant positive correlations among several traits, while principal component analysis highlighted the contribution of each trait to overall variance, with PC1 explaining 73.95% of the total variance. This study highlights the nutritional variations among dragon fruit cultivars, with Hylocereus costaricensis showing superior performance, guiding dietary planning and functional food development.

Pectin extracted from red dragon fruit (Hylocereus polyrhizus) peel and its usage in edible film.

Pectin was extracted from red dragon fruit (Hylocereus polyrhizus) peel using two different extraction methods: subcritical water extraction (SCWE) and conventional acid extraction (AE), from two different types of peels, fresh peel puree and dried peel powder. SCWE method on fresh peel puree showed an ∼18.88 % increase in pectin yield compared to AE. Extracted pectin is classified as low methoxyl pectin (DE: 8.51-50.64 %), with an average molecular weight ranging from 115.23 kDa to 577.84 kDa and a Gal-A content of 44.09 % - 53.90 %. The potential of pectin from fresh peel puree to be applied as a biodegradable film was further explored. Different pectin concentrations (3-5 % w/v) were used to prepare the films. Regarding the film performance, PF-S5, which was produced from SCWE with 5 % of pectin concentration, exhibits better thermal stability (Tdmax 250 °C, residue of 28.69 %) and higher moisture barrier (WVP 5.59 × 10-11 g.cm-1.s-1.Pa-1). In comparison, PF-A showed lower water solubility (45.14-69.15 %), higher water contact angle (33.01° - 44.35°), and better mechanical properties (TS: 2.12-4.11 MPa, EB: 48.72-61.39 %). Higher molecular weight accompanied by higher DE and Gal-A content contributes to better pectin film properties.

The invasion threat of the emerging alien cactus Cylindropuntia pallida (Rosa), F.M. Knuth in South Africa and the potential for control using herbicides.

The emerging alien cactus Cylindropuntia pallida (Rose) F.M. Knuth originates from northern Mexico and introduced into South Africa in 1940s as an ornamental plant.  Multiple populations of C. pallida have been detected in various areas of South Africa. C. pallida has effective propagule dispersal and rapid recruitment making it a likely key future invader, and thus, is a target for eradication in South Africa. To eradicate C. pallida populations, a foliar spray (i.e. using a 2% concentration of herbicide with fluroxypyr and triclopyr) has been applied to plants in nine populations, with population sizes ranging between 535 and 2701 plants and populations covering areas of 100 -1000 ha. The aims of the study were to investigate the efficacy of the foliar spray method used to eradicate C. pallida; to investigate the impacts of C. pallida invasions on native vegetation integrity; to apply species distribution models (SDMs) to identify suitable climates for C. pallida in South Africa; and to document the biomes vulnerable to the negative impact of C. pallida in South Africa. Results show that foliar spray killed many C. pallida plants (mean percentage of dead plants ± SE, 83.3 ± 6.4; n = 9; range, 70-96%), with adult plants taking about 2 months to die completely. The efficacy of the herbicide was not affected by plant size or the concentration of the herbicide used. The invaded site had significantly greater vegetation cover which persisted across winter compared to the uninvaded site, but the latter site's vegetation cover significantly dropped in winter. Also, the invaded site had lower plant species diversity than the uninvaded site and was dominated by species in the Poaceae and Asteraceae plant families. Additionally, a normalised difference vegetation index (NDVI) analysis shows that the uninvaded site has higher vegetation cover and health than the invaded site wherein a notable decline in vegetation health was observed between 2019 and 2022. A large area (> 15 million hectares) was predicted to be suitable for invasion by C. pallida in provinces with arid and warm temperate climates - the fynbos and grassland biomes are the most vulnerable. Because of the observed negative impacts, high environmental compatibility, and high cost of clearing large infestations, we advocate for considering the biocontrol method for effectively managing C. pallida invasion in South Africa.

Physiological and molecular analysis of pitaya (Hylocereus polyrhizus) reveal up-regulation of secondary metabolites, nitric oxide, antioxidant defense system, and expression of responsive genes under low-temperature stress by the pre-treatment of hydrogen peroxide.

Low-temperature events are one of the leading environmental cues that considerably reduce plant growth and shift species biodiversity. Hydrogen peroxide (H2O2) is a signaling molecule that has a distinguished role during unfavorable conditions and shows outstanding perspectives in low-temperature stress. Herein, we elucidated the protective role and regulatory mechanism of H2O2 in alleviating the deleterious effects of low-temperature stress in pitaya plants. Micropropagated pitaya plants were cultured in Murashige and Skoog media supplemented with different levels of H2O2 (0, 5, 10, and 20 mM) and then exposed to low-temperature stress (5 °C for 24 h). H2O2 at 10 mM, improved low-temperature stress tolerance by relieving oxidative injuries and ameliorating growth parameters in terms of fresh weight (66.7%), plant length (16.7%), and pigments content viz., chlorophyll a (157.4%), chlorophyll b (209.1%), and carotenoids (225.9%). H2O2 counteracted the low-temperature stress by increasing amino acids (224.7%), soluble proteins (190.5%), and sugars (126.6%). Simultaneously, secondary metabolites like ascorbic acid (ASA), anthocyanins, phenolics, flavonoids, total antioxidant (TOA), and proline were also up-regulated by H2O2 (104.9%, 128.8%, 166.3%, 141.4%, and 436.4%, respectively). These results corresponded to the stimulative role triggered by H2O2 in boosting the activities of catalase (22.4%), ascorbate peroxidase (20.7%), superoxide dismutase (88.4%), polyphenol oxidase (60.7%), soluble peroxidase (23.8%), and phenylalanine ammonia-lyase (57.1%) as well as the expression level of HpCAT, HpAPX, HpSOD, HpPPO, and HpPAL genes, which may help to moderate low-temperature stress. In conclusion, our findings stipulate new insights into the mechanisms by which H2O2 regulates low-temperature stress tolerance in pitaya plants.

Optimizing germination: comparative assessment of various growth media on dragon fruit germination and early growth.

Dragon fruit (Selenicereus undatus), known for its captivating appearance and remarkable nutritional profile, has garnered considerable attention in recent years. Despite its popularity, there's a dearth of research on optimal conditions for seed germination and early growth stages such as seedling shoot length, which are crucial for optimal crop yield. This study aims to bridge this gap by evaluating various growing media's performance on dragon fruit germination and early growth stages. Dragon fruit seeds were obtained from local markets in Pakistan and evaluated in five different growing media: cocopeat, peat moss, sand, vermiculite, and compost. Germination parameters were observed for 45 days, including seed germination percentage, mean germination time, and mean daily germination percentage, among others while early growth was monitored for 240 days. Statistical analysis was conducted using ANOVA and Tukey's HSD test. Significant differences were found among the growing media regarding germination percentage, mean germination time, and mean daily germination. Vermiculite exhibited the highest germination rate (93.33%), while compost showed the least (70%). Peat moss and sand media facilitated rapid germination, while compost showed slower rates. Stem length was significantly influenced by the growth media, with compost supporting the longest stems. Vermiculite emerged as the most effective medium for dragon fruit seed germination, while compost showed slower but steady growth. These findings provide valuable insights for optimizing dragon fruit cultivation, aiding commercial growers and enthusiasts in achieving higher yields and quality. Further research could explore additional factors influencing dragon fruit growth and development.

Nutritional value and kinetics of in vitro fermentation of spineless cactus of the genus Nopalea in different phenological phases.

The objective was to evaluate the chemical composition and in vitro fermentation of spineless cactus of the genus Nopalea, F-21 (Nopalea cochenillifera Dyck), IPA-Sertânia (Nopalea cochenillifera Dyck) and Miúda (Nopalea cochenillifera Salm Dyck), in different phenophases. There was no effect (P < 0.05) of the phenological phases of spineless cactus on DM, ash, OM, EE, and CP. Varieties F-21 and Miúda presented higher values of DM and OM, whereas the CP was higher for IPA-Sertânia. The contents of NDF, ADF, and ADL, as well as the fractions of carbohydrates B2 and C were higher in the mature stage, irrespective of the variety. The Miúda variety showed higher levels of NFC and fractions A + B1 and the lower levels of pectin compared to the F-21 and IPA-Sertânia varieties, but not differ of TC to F-21. The volume of gas produced via the degradation of NFC was higher for young phenological phases. The young and intermediate stages showed a higher in vitro digestibility of DM. Based on the results, varieties IPA-Sertânia and Miúda have a high potential for use in animal feed because of their high nutritional quality. Mature cladodes showed a higher fibrous fraction and lower digestibility in all varieties.

Preharvest Elicitors as a Tool to Enhance Bioactive Compounds and Quality of Both Peel and Pulp of Yellow Pitahaya (Selenicereus megalanthus Haw.) at Harvest and during Postharvest Storage.

Yellow pitahaya is a tropical fruit that has gained popularity in recent years. Natural elicitors are compounds that can stimulate the resistance and quality of fruits. The objective of this study was to evaluate the effects of natural elicitors, methyl salicylate (MeSa), methyl jasmonate (JaMe), salicylic acid (SA) and oxalic acid (OA) at concentrations of 0.1 mM (MeSa and JaMe) and 5 mM (SA and OA), applied to the yellow pitahaya fruits under greenhouse conditions. After full blossom, four applications were made with a frequency of 15 days. At the time of harvest and after storage, the following variables were evaluated: firmness (whole fruit), total soluble solids (TSS), total acidity (TA), phenolics and carotenoids (in the pulp), while phenolics, carotenoids, macronutrients and micronutrients were determined in the peel. The results showed MeSa advanced the fruit maturation, according to higher TSS, lower TA and firmness than MeJa-treated fruits, for which a delayed ripening process was shown. All treatments induced a higher polyphenolic concentration during storage. Regarding the alternative use of the peel as a by-product, the application of natural elicitors significantly increased the content of polyphenols, carotenoids, macronutrients and micronutrients in the peel, especially MeSa, which can be used as a bioactive compound in the food industry. In conclusion, the results indicate that natural elicitors can be an alternative to improve the quality and shelf life of yellow pitahaya fruits.

Pitahaya (Hylocereus ocamponis)-Peel and -Flesh Flour Obtained from Fruit Co-Products-Assessment of Chemical, Techno-Functional and In Vitro Antioxidant Properties.

The aim of this work was to assess the chemical composition and physico-chemical, techno-functional, and in vitro antioxidant properties of flours obtained from the peel and flesh of pitahaya (Hylocereus ocamponis) to determine their potential for use as ingredients for food enrichment. The chemical composition, including total betalains, mineral content, and polyphenolic profile, was determined. The techno-functional properties (water holding, oil holding, and swelling capacities) were also evaluated. For the antioxidant capacity, four different methodologies, namely ferrous ion-chelating ability assay, ferric-reducing antioxidant power assay; 1,1-Diphenyl-2-picrylhydrazyl radical scavenging ability assay, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical assay, were used. Pitahaya-peel flour had higher values for protein (6.72 g/100 g), ash (11.63 g/100 g), and dietary fiber 56.56 g/100 g) than pitahaya-flesh flour, with values of 6.06, 3.63, and 8.22 g/100 g for protein, ash, and dietary fiber, respectively. In the same way, pitahaya peel showed a higher content of minerals, betalains, and polyphenolic compounds than pitahaya-flesh flour, with potassium (4.43 g/100 g), catechin (25.85 mg/g), quercetin-3-rhamnoside (11.66 mg/g) and myricetrin (12.10 mg/g) as principal compounds found in the peel. Again, pitahaya-peel flour showed better techno-functional and antioxidant properties than pitahaya-flesh flour. The results obtained suggest that the flours obtained from the peel and pulp of pitahaya (H. ocamponis) constitute a potential material to be utilized as an ingredient in the food industry due to the high content of bioactive compounds such as betalains, phenolic acids, and flavonoids, with notable antioxidant capacity.

Effect of BvAgNP on growth, development, and glyoxalase gene expression analysis in Mammillaria bombycina and Selenicereus undatus.

BACKGROUND: Silver nanoparticles (AgNPs) have been used in plant tissue culture as growth stimulants, promoting bud initiation, germination, and rooting. In prior studies, AgNPs were synthesized and characterized by green synthesis using extracts from Beta vulgaris var. cicla (BvAgNP), and their functionality as seed disinfectant and antimicrobial was verified. In this study, we evaluated the effect of BvAgNP on the growth and development of Mammillaria bombycina and Selenicereus undatus in vitro, as well as the expression of glyoxalase genes. METHODS: Explants from M. bombycina and S. undatus in vitro were treated with 25, 50, and 100 mg/L of BvAgNP. After 90 days, morphological characteristics were evaluated, and the expression of glyoxalase genes was analyzed by qPCR. RESULTS: All treatments inhibited rooting for M. bombycina and no bud initiation was observed. S. undatus, showed a maximum response in rooting and bud generation at 25 mg/L of BvAgNP. Scanning electron microscopy (SEM) results exhibited a higher number of vacuoles in stem cells treated with BvAgNP compared to the control for both species. Expression of glyoxalase genes in M. bombycina increased in all treatments, whereas it decreased for S. undatus, however, increasing in roots. CONCLUSIONS: This study presents the effects of BvAgNP on the growth and development of M. bombycina and S. undatus, with the aim of proposing treatments that promote in vitro rooting and bud initiation.

Deciphering the inhibitory mechanisms of betanin and phyllocactin from Hylocereus polyrhizus peel on protein glycation, with insights into their application in bread.

Protein glycation closely intertwines with the pathogenesis of various diseases, sparking a growing interest in exploring natural antiglycation agents. Herein, high-purity betacyanins (betanin and phyllocactin) derived from Hylocereus polyrhizus peel were studied for their antiglycation potential using an in vitro bovine serum albumin (BSA)-glucose model. Notably, betacyanins outperformed aminoguanidine, a recognized antiglycation agent, in inhibiting glycation product formation across different stages, especially advanced glycation end-products (AGEs). Interestingly, phyllocactin displayed stronger antiglycation activity than betanin. Subsequent mechanistic studies employing molecular docking analysis and fluorescence quenching assay unveiled that betacyanins interact with BSA endothermically and spontaneously, with hydrophobic forces playing a dominant role. Remarkably, phyllocactin demonstrated higher binding affinity and stability to BSA than betanin. Furthermore, the incorporation of betacyanins into bread dose-dependently suppressed AGEs formation during baking and shows promise for inhibiting in vivo glycation process post-consumption. Overall, this study highlights the substantial potential of betacyanins as natural antiglycation agents.

Comparative transcriptome analysis reveals lineage- and environment-specific adaptations in cacti from the Brazilian Atlantic Forest.

MAIN CONCLUSION: Natural selection influenced adaptive divergence between Cereus fernambucensis and Cereus insularis, revealing key genes governing abiotic stress responses and supporting neoteny in C. insularis. Uncovering the molecular mechanisms driving adaptive divergence in traits related to habitat adaptation remains a central challenge. In this study, we focused on the cactus clade, which includes Cereus sericifer F.Ritter, Cereus fernambucensis Lem., and Cereus insularis Hemsley. These allopatric species inhabit distinct relatively drier regions within the Brazilian Atlantic Forest, each facing unique abiotic conditions. We leveraged whole transcriptome data and abiotic variables datasets to explore lineage-specific and environment-specific adaptations in these species. Employing comparative phylogenetic methods, we identified genes under positive selection (PSG) and examined their association with non-synonymous genetic variants and abiotic attributes through a PhyloGWAS approach. Our analysis unveiled signatures of selection in all studied lineages, with C. fernambucensis northern populations and C. insularis showing the most PSGs. These PSGs predominantly govern abiotic stress regulation, encompassing heat tolerance, UV stress response, and soil salinity adaptation. Our exclusive observation of gene expression tied to early developmental stages in C. insularis supports the hypothesis of neoteny in this species. We also identified genes associated with abiotic variables in independent lineages, suggesting their role as environmental filters on genetic diversity. Overall, our findings suggest that natural selection played a pivotal role in the geographic range of these species in response to environmental and biogeographic transitions.

Single-cell and spatial RNA sequencing reveal the spatiotemporal trajectories of fruit senescence.

The senescence of fruit is a complex physiological process, with various cell types within the pericarp, making it highly challenging to elucidate their individual roles in fruit senescence. In this study, a single-cell expression atlas of the pericarp of pitaya (Hylocereus undatus) is constructed, revealing exocarp and mesocarp cells undergoing the most significant changes during the fruit senescence process. Pseudotime analysis establishes cellular differentiation and gene expression trajectories during senescence. Early-stage oxidative stress imbalance is followed by the activation of resistance in exocarp cells, subsequently senescence-associated proteins accumulate in the mesocarp cells at late-stage senescence. The central role of the early response factor HuCMB1 is unveiled in the senescence regulatory network. This study provides a spatiotemporal perspective for a deeper understanding of the dynamic senescence process in plants.

Integrated metabolic profiles and microbial communities to reveal the beneficial effect of red pitaya on early constipation.

Pitaya is a well-known fruit widely cultivated in tropical and subtropical tropical regions, and is characterized by its flesh colour into red, white, and yellow pitaya. Red pitaya has dark red flesh and is the preferred choice among consumers due to its superior taste compared to other varieties. Red pitaya has been known to cause diarrhoea, and studies have reported that pitaya does this by drawing moisture into the intestines, resulting in defecation. However, the exact mechanism of action is still unclear. In this study, mass spectrometry was employed to identify small molecular compounds in red pitaya powder, and a loperamide hydrochloride-induced early constipation mouse model was used to assess the efficacy of red pitaya. 16S rDNA and non-targeted metabolomics techniques were used to systematically reveal the regulatory characteristics of the intestinal flora and to identify the intestinal metabolites associated with constipation. The results showed that 44 novel small molecular compounds were identified from red pitaya powder, including a variety of phenolic acids and flavonoids. Pathological results showed that administration of red pitaya powder at a high dose (1000 mg kg-1) significantly ameliorated the abnormal expansion of intestinal goblet cells observed in the early stages of constipation. In addition, early constipation increased metabolites such as serotonin and 5-hydroxytryptophol, which were normalized following the ingestion of red pitaya powder. Furthermore, Erysipelatoclostridium, Parasutterella, and other abnormal gut microbiota associated with early constipation returned to healthy levels after the ingestion of red pitaya powder. Finally, significant correlations were observed between the expression of 33 different serum metabolites and the abundance of eight kinds of intestinal flora. Consequently, red pitaya holds potential as a safe food supplement for the prevention or amelioration of early-stage constipation.