Metabolomic and transcriptomic analyses of peach leaves and fruits in response to pruning.

BACKGROUND: Pruning is an important cultivation management option that has important effects on peach yield and quality. However, the effects of pruning on the overall genetic and metabolic changes in peach leaves and fruits are poorly understood. RESULTS: The transcriptomic and metabolomic profiles of leaves and fruits from trees subjected to pruning and unpruning treatments were measured. A total of 20,633 genes and 622 metabolites were detected. Compared with those in the control, 1,127 differentially expressed genes (DEGs) and 77 differentially expressed metabolites (DEMs) were identified in leaves from pruned and unpruned trees (pdLvsupdL), whereas 423 DEGs and 29 DEMs were identified in fruits from the pairwise comparison pdFvsupdF. The content of three auxin analogues was upregulated in the leaves of pruned trees, the content of all flavonoids detected in the leaves decreased, and the expression of almost all genes involved in the flavonoid biosynthesis pathway decreased. The phenolic acid and amino acid metabolites detected in fruits from pruned trees were downregulated, and all terpenoids were upregulated. The correlation analysis revealed that DEGs and DEMs in leaves were enriched in tryptophan metabolism, auxin signal transduction, and flavonoid biosynthesis. DEGs and DEMs in fruits were enriched in flavonoid and phenylpropanoid biosynthesis, as well as L-glutamic acid biosynthesis. CONCLUSIONS: Pruning has different effects on the leaves and fruits of peach trees, affecting mainly the secondary metabolism and hormone signalling pathways in leaves and amino acid biosynthesis in fruits.

Rational design, synthesis, and antimicrobial evaluation of novel 1,2,4-trizaole-substituted 1,3,4-oxadiazole derivatives with a dual thioether moiety.

In this paper, a series of novel 1,2,4-trizaole-substituted 1,3,4-oxadiazole derivatives with a dual thioether moiety were constructed. The synthetic compounds were characterized by 1H NMR, 13C NMR, HRMS, and single crystal diffraction. The antimicrobial activities of title compounds against fungi (Pyricutaria oryzae Cav., Phomopsis sp., Botryosphaeria dothidea, cucumber Botrytis cinerea, tobacco Botrytis cinerea, blueberry Botrytis cinerea) and bacteria (Xanthomonas oryzae pv. oryzicola, Xoc; Xanthomonas axonopodis pv. citri, Xac) revealed these compounds possessed excellent antibacterial activity through mycelial growth rate method and turbidity method, respectively. Among them, compounds 7a, 7d, 7g, 7k, 7l, and 7n had the antibacterial inhibition rate of 90.68, 97.86, 93.61, 97.70, 97.26, and 92.34%, respectively. The EC50 values of 7a, 7d, 7g, 7k, 7l, and 7n were 58.31, 48.76, 58.50, 40.11, 38.15, and 46.99 µg/mL, separately, superior to that of positive control pesticide thiodiazole copper (104.26 µg/mL). The molecular docking simulation of compound 7l and glutathione s-transferase also confirmed its good activity. The in vivo bioassay toward Xac infected citrus leaves was also performed to evaluate the potential of compounds as efficient antibacterial reagent. Further study of antibacterial mechanism was also carried out, including extracellular polysaccharide production, permeability of bacterial membrane, and scanning electron microscope observations. The excellent antibacterial activities of these compounds provided a strong support for its application for preventing and control plant diseases.

[A pedigree analysis of a rare RhD 336-1G>A intron variant].

OBJECTIVE: To explore the molecular mechanism of a case where RhD genotyping did not match serological results. METHODS: The serological results of 8 members from two generations of this family were analyzed. And according to Mendelian law of inheritance, RhD genotyping, zygotic type determination and gene sequencing were performed for the family members. RESULTS: The proband and one of her cousins have the same RhD alleles, both of them have a 336-1G>A intron variant RhD allele and a complete RhD deletion allele. The variant alleles are inherited from two of their parents with blood relationship, while the complete-deleted alleles come from the other. 336-1G>A means that the last base G of the second intron of the RhD gene is mutated to A, which leads to a negative RhD serology and a positive genotype in the proband. CONCLUSION: There was a rare 336-1G> A intron variant gene (RhD * 01N.25) in this family, which was a recessive gene relative to the RhD gene and resulted in RhD phenotype negative.

Functional interplay between SA1 and TRF1 in telomeric DNA binding and DNA-DNA pairing.

Proper chromosome alignment and segregation during mitosis depend on cohesion between sister chromatids. Cohesion is thought to occur through the entrapment of DNA within the tripartite ring (Smc1, Smc3 and Rad21) with enforcement from a fourth subunit (SA1/SA2). Surprisingly, cohesin rings do not play a major role in sister telomere cohesion. Instead, this role is replaced by SA1 and telomere binding proteins (TRF1 and TIN2). Neither the DNA binding property of SA1 nor this unique telomere cohesion mechanism is understood. Here, using single-molecule fluorescence imaging, we discover that SA1 displays two-state binding on DNA: searching by one-dimensional (1D) free diffusion versus recognition through subdiffusive sliding at telomeric regions. The AT-hook motif in SA1 plays dual roles in modulating non-specific DNA binding and subdiffusive dynamics over telomeric regions. TRF1 tethers SA1 within telomeric regions that SA1 transiently interacts with. SA1 and TRF1 together form longer DNA-DNA pairing tracts than with TRF1 alone, as revealed by atomic force microscopy imaging. These results suggest that at telomeres cohesion relies on the molecular interplay between TRF1 and SA1 to promote DNA-DNA pairing, while along chromosomal arms the core cohesin assembly might also depend on SA1 1D diffusion on DNA and sequence-specific DNA binding.

Evidence for the requirement of CydX in function but not assembly of the cytochrome bd oxidase in Shewanella oneidensis.

BACKGROUND: Cytochrome bd oxidase, existing widely in bacteria, produces a proton motive force by the vectorial charge transfer of protons and more importantly, endows bacteria with a number of vitally important physiological functions, such as enhancing tolerance to various stresses. Although extensively studied as a CydA-CydB two-subunit complex for decades, the complex in certain groups of bacteria is recently found to in fact consist of an additional subunit, which is functionally essential. METHODS: We investigated the assembly of the CydA-CydB complex using BiFC. We investigated the function of CydX using mutational analysis. RESULTS: CydX, a 38-amino-acid inner-membrane protein, is associated with the CydA-CydB complex in Shewanella oneidensis, a facultative anaerobe renowned for its respiratory versatility. It is clear that CydX is neither required for the in vivo assembly of the CydA-CydB complex nor relies on the complex for its translocation and integration into the membrane. The N-terminal segment (1-25 amino acid residues) and short periplasmic overhang of CydX, with respect to functionality, are important whereas the remaining C-terminal segment is rather flexible. CONCLUSION: Based on these findings, we postulate that CydX may function by positioning and stabilizing the prosthetic hemes, especially heme d in the CydA-CydB complex although a role of participating in catalytic reaction is not excluded. GENERAL SIGNIFICANCE: The work provides novel insights into our understanding of the small subunit of the cytochrome bd oxidase.

Carotenoid accumulation affects redox status, starch metabolism, and flavonoid/anthocyanin accumulation in citrus.

BACKGROUND: Carotenoids are indispensable plant secondary metabolites that are involved in photosynthesis, antioxidation, and phytohormone biosynthesis. Carotenoids are likely involved in other biological functions that have yet to be discovered. In this study, we integrated genomic, biochemical, and cellular studies to gain deep insight into carotenoid-related biological processes in citrus calli overexpressing CrtB (phytoene synthase from Pantoea agglomerans). Fortunella hindsii Swingle (a citrus relative) and Malus hupehensis (a wild apple) calli were also utilized as supporting systems to investigate the effect of altered carotenoid accumulation on carotenoid-related biological processes. RESULTS: Transcriptomic analysis provided deep insight into the carotenoid-related biological processes of redox status, starch metabolism, and flavonoid/anthocyanin accumulation. By applying biochemical and cytological analyses, we determined that the altered redox status was associated with variations in O2 (-) and H2O2 levels. We also ascertained a decline in starch accumulation in carotenoid-rich calli. Furthermore, via an extensive cellular investigation of the newly constructed CrtB overexpressing Fortunella hindsii Swingle, we demonstrated that starch level reducation occurred in parallel with significant carotenoid accumulation. Moreover, studying anthocyanin-rich Malus hupehensis calli showed a negative effect of carotenoids on anthocyanin accumulation. CONCLUSIONS: In citrus, altered carotenoid accumulation resulted in dramatic effects on metabolic processes involved in redox modification, starch degradation, and flavonoid/anthocyanin biosynthesis. These findings provided new perspectives to understand the biological importance of carotenogenesis and of the developmental processes associated with the nutritional and sensory qualities of agricultural products that accumulate carotenoids.

Investigation of roles of divalent cations in Shewanella oneidensis pellicle formation reveals unique impacts of insoluble iron.

BACKGROUND: Bacteria adopt a variety of lifestyles in their natural habitats and can alternate among different lifestyles in response to environmental changes. At high cell densities, bacteria can form extracellular matrix encased cell population on submerged tangible surfaces (biofilms), or at the air-liquid interface (pellicles). Compared to biofilm, pellicle lifestyle allows for better oxygen access, but is metabolically more costly to maintain. Further understanding of pellicle formation and environmental cues that influence cellular choices between these lifestyles will definitely improve our appreciation of bacterial interaction with their environments. METHODS: Shewanella oneidensis cells were cultured in 24-well plates with supplementation of varied divalent cations, and pellicles formed under such conditions were evaluated. Mutants defective in respiration of divalent cations were used to further characterize and confirm unique impacts of iron. RESULTS AND CONCLUSIONS: Small amount of Fe(2+) was essential for pellicle formation, but presence of over-abundant iron (0.3mM Fe(2+) or Fe(3+)) led to pellicle disassociation without impairing growth. Such impacts were found due to S. oneidensis-mediated formation of insoluble alternative electron acceptors (i.e., Fe3O4) under physiologically relevant conditions. Furthermore, we demonstrated that cells preferred a lifestyle of forming biofilm and respiring on such insoluble electron acceptors under tested conditions, even to living in pellicles. GENERAL SIGNIFICANCE: Our finding suggests that bacterial lifestyle choice involves balanced evaluation of multiple aspects of environmental conditions, and yet-to-be-characterized signaling mechanism is very likely underlying such processes.

Spatiotemporal evolution and driving factors of agricultural land transfer in China.

This paper systematically analyzes the spatiotemporal evolution trends and macroeconomic driving factors of farmland transfer at the provincial level in China since 2005, aiming to offer a new perspective for understanding the dynamic mechanisms of China's farmland transfer. Through the integrated use of kernel density estimation, the Markov model, and panel quantile regression methods, this study finds the following: (1) Farmland transfer rates across Chinese provinces show an overall upward trend, but regional differences exhibit a "U-shaped" evolution characterized by initially narrowing and then widening; (2) although provinces have relatively stable farmland transfer levels, there is potential for dynamic transitions; (3) factors such as per capita arable land, farmers' disposable income, the social security level, the urban‒rural income gap, the urbanization rate, government intervention, and the marketization level significantly promote farmland transfer, while inclusive finance inhibits transfer, and agricultural mechanization level and population aging have heterogeneous impacts. Therefore, to achieve convergence of low farmland transfer regions to medium levels while promoting medium-level regions to higher levels, it is recommended that the government increase support for agricultural mechanization, increase farmers' income and social security levels, and optimize marketization processes and government intervention strategies. The main contributions of this paper are (1) systematically revealing the spatiotemporal evolution patterns of China's farmland transfer and (2) employing panel quantile regression methods to explore the heterogeneous impacts of driving factors, providing more precise and detailed empirical support for the government's formulation of farmland transfer policies.

Synthesis, biological evaluation, and molecular docking of novel ferulic acid derivatives containing a 1,3,4-oxadiazole thioether and trifluoromethyl pyrimidine skeleton.

In this study, 24 novel ferulic acid derivatives containing 1,3,4-oxadiazole thioether and trifluoromethyl pyrimidine were designed and synthesized. Bioactivity assay showed that some of the target compounds exhibited moderate to good antifungal activity against Botryosphaeria dothidea BD), Phomopsis sp. (PS), Botrytis cinerea (BC), Fusarium spp. (FS), Fusarium graminearum (FG), and Colletotrichum sp. (CS). Especially, compound 6f demonstrated superior antifungal activity against Phomopsis sp., with an EC50 value of 12.64 µg mL-1, outperforming pyrimethanil (35.16 µg mL-1) and hymexazol (27.01 µg mL-1). Meanwhile, compound 6p showed strong antibacterial activity against X. axonopodis pv. citri (XAC) in vitro, with an inhibition ratio of 85.76%, which was higher than thiodiazole copper's 76.59% at 100 µg mL-1. Furthermore, molecular docking simulations elucidated that compound 6f engaged in hydrogen bonding with the succinate dehydrogenase (SDH) enzyme at SER-17, SER-39, ARG-14 and ARG-43 sites, clarifying its mode of action. This study highlights the potential of these novel ferulic acid derivatives as promising agents for controlling fungal and bacterial threats to plant health. To the best of our knowledge, this study represents the first report on the antifungal and antibacterial properties of ferulic acid derivatives containing 1,3,4-oxadiazole thioether and trifluoromethyl pyrimidine skeleton.

Discovery of Novel Compounds for Combating Rising Severity of Plant Diseases Caused by Fungi and Viruses.

In recent years, the severity of plant diseases caused by plant pathogenic fungi and viruses has been on the rise. However, there is a limited availability of pesticide chemicals in the market for effectively controlling both fungal and viral infections. To solve this problem, a series of novel pyrimidine derivatives containing a 1,3,4-oxadiazole thioether fragment were synthesized. Among them, compound 6s exhibited remarkable in vivo protection activity against tobacco mosaic virus, demonstrating the superior 50% effective concentration (EC50) value of 0.42 µM, outperforming ningnanmycin (0.60 µM). Meanwhile, compound 6s exhibited remarkable antifungal activity against Botrytis cinerea Pers. in postharvest blueberry in vitro, with an EC50 value of 0.011 µM, surpassing the inhibition rate of Pyrimethanil (0.262 µM). Additionally, compound 6s also demonstrated remarkable curative and protection activities against blueberry fruit gray mold in vivo, with control efficiencies of 54.2 and 60.4% at 200 µg/mL concentration, respectively, which were comparable to those of Pyrimethanil (49.3 and 63.9%, respectively). Scanning electron microscopy showed that the compound 6s-treated hyphae of B. cinerea Pers. in postharvest blueberry became abnormally collapsed and shriveled. Furthermore, the molecular docking simulation demonstrated that compound 6s formed hydrogen bonds with SER-17, ARG-43, and SER-39 of succinate dehydrogenase (SDH), providing a possible explanation for the mechanism of action between the target compounds and SDH. This study represents the first report on the antiviral and antifungal activities of novel pyrimidine derivatives containing a 1,3,4-oxadiazole thioether fragment.

Dynamic Changes of Active Components and Volatile Organic Compounds in Rosa roxburghii Fruit during the Process of Maturity.

Rosa roxburghii (R. roxburghii), native to the southwest provinces of China, is a fruit crop of important economic value in Guizhou Province. However, the changes in fruit quality and flavor during R. roxburghii fruit ripening have remained unknown. Here, this study investigated the changes of seven active components and volatile organic compounds (VOCs) during the ripening of the R. roxburghii fruit at five different ripening stages including 45, 65, 75, 90, and 105 days after anthesis. The results indicated that during the ripening process, the levels of total acid, vitamin C, and soluble sugar significantly increased (p < 0.05), while the levels of total flavonoids, superoxide dismutase (SOD), and soluble tannin significantly decreased (p < 0.05). Additionally, the content of total phenol exhibited a trend of first decreasing significantly and then increasing significantly (p < 0.05). A total of 145 VOCs were detected by HS-SPME-GC-MS at five mature stages, primarily consisting of aldehydes, alcohols, esters, and alkenes. As R. roxburghii matured, both the diversity and total quantity of VOCs in the fruit increased, with a notable rise in the contents of acids, ketones, and alkenes. By calculating the ROAV values of these VOCs, 53 key substances were identified, which included aromas such as fruit, citrus, green, caramel, grass, flower, sweet, soap, wood, and fat notes. The aromas of citrus, caramel, sweet, and wood were predominantly concentrated in the later stages of R. roxburghii fruit ripening. Cluster heatmap analysis revealed distinct distribution patterns of VOCs across five different maturity stages, serving as characteristic chemical fingerprints for each stage. Notably, stages IV and V were primarily characterized by a dominance of alkenes. OPLS-DA analysis categorized the ripening process of R. roxburghii fruit into three segments: the first segment encompassed the initial three stages (I, II, and III), the second segment corresponded to the fourth stage (IV), and the third segment pertained to the fifth stage (V). Following the variable importance in projection (VIP) > 1 criterion, a total of 30 key differential VOCs were identified across the five stages, predominantly comprising ester compounds, which significantly influenced the aroma profiles of R. roxburghii fruit. By integrating the VIP > 1 and ROAV > 1 criteria, 21 differential VOCs were further identified as key contributors to the aroma changes in R. roxburghii fruit during the ripening process. This study provided data on the changes in quality and aroma of R. roxburghii fruit during ripening and laid the foundation for the investigation of the mechanism of compound accumulation during ripening.

PpSAUR5 promotes plant growth by regulating lignin and hormone pathways.

Introduction: Peach (Prunus persica) has a high nutritional and economic value. However, its overgrowth can lead to yield loss. Regulating the growth of peach trees is challenging. The small auxin-up RNA (SAUR) gene family is the largest family of auxin-responsive genes, which play important roles in plant growth and development. However, members of this gene family are rarely reported in peach. Methods: In this study, we measured leaf area, chlorophyll and lignin content to detect the role of PpSAUR5 on growth through transgenic Arabidopsis. Results: PpSAUR5 responds to auxin and gibberellin, promoting and inhibiting the synthesis of gibberellin and auxin, respectively. The heterologous transformation of PpSAUR5 in Arabidopsis led to enhanced growth of leaves and siliques, lightening of leaf color, decrease in chlorophyll content, increase in lignin content, abnormalities in the floral organs, and distortion of the inflorescence axis. Transcriptome data analysis of PpSAUR5 overexpression and wild-type lines revealed 854 differentially expressed genes (DEGs). GO and KEGG analyses showed that the DEGs were primarily involved in biological processes, such as cellular processes, metabolic processes, response to stimuli, and catalytic activity. These genes were mainly enriched in pathways, such as phenylalanine biosynthesis, phytohormone signaling, and MAPK signaling. Discussion: In summary, these results suggested that PpSAUR5 might regulate tree vigor by modulating the synthesis of auxin and gibberellin. Future studies can use PpSAUR5 as a candidate gene to elucidate the potential regulatory mechanisms underlying peach tree vigor.

Effect of hot-air drying processing on the volatile organic compounds and maillard precursors of Dictyophora Rubrovalvata based on GC-IMS, HPLC and LC-MS.

The dynamic changes in volatile organic compounds (VOCs), reducing sugars, and amino acids of Dictyophora rubrovalvata (DR) at various drying temperatures were analyzed using GC-IMS, HPLC, and LC-MS. Orthogonal partial least squares discriminant analysis (OPLS-DA) combined with VOCs indicated that drying temperature of 80 °C was optimal. Variable importance in the projection (VIP) and relative odor activity value (ROAV) were employed to identify 22 key VOCs. The findings suggested that esters played a predominant role among the VOCs. Pearson correlation analysis revealed that serine (Ser), glutamine (Gln), lysine (Lys), alanine (Ala), threonine (Thr), glutamic acid (Glu), asparagine (Asn), ribose, and glucose were closely associated with the formation of esters, aldehydes, ketones, pyrimidines, and pyrazines. In conclusion, this study laid a foundational theory for elucidating the characteristics aroma substances and their production pathways, providing a valuable reference for analysing the flavor characteristics of DR.

Exoprotein production correlates with morphotype changes of nonmotile Shewanella oneidensis mutants.

We report a previously undescribed mechanism for the rugose morphotype in Shewanella oneidensis, a research model for investigating redox transformations of environmental contaminants. Bacteria may form smooth or rugose colonies on agar plates. In general, conversion from the smooth to rugose colony morphotype is attributed to increased production of exopolysaccharide (EPS). In this work, we discovered that aflagellate S. oneidensis mutants grew into rugose colonies, whereas those with nonfunctional flagellar filaments remained smooth. EPS production was not altered in either case, but mutants with the rugose morphotype showed significantly reduced exoprotein secretion. The idea that exoproteins at a reduced level correlate with rugosity gained support from smooth suppressor strains of an aflagellate rugose fliD (encoding the capping protein) mutant, which restored the exoprotein level to the levels of the wild-type and mutant strains with a smooth morphotype. Further analyses revealed that SO1072 (a putative GlcNAc-binding protein) was one of the highly upregulated exoproteins in these suppressor strains. Most intriguingly, this study identified a compensatory mechanism of SO1072 to flagellins possibly mediated by bis-(3'-5')-cyclic dimeric GMP.

Crp-dependent cytochrome bd oxidase confers nitrite resistance to Shewanella oneidensis.

Shewanella oneidensis is able to respire on a variety of organic and inorganic substrates, including nitrate and nitrite. Conversion of nitrate to nitrite and nitrite to ammonium is catalysed by periplasmic nitrate and nitrite reductases (NAP and NRF) respectively. Global regulator Crp (cyclic AMP receptor protein) is essential for growth of S. oneidensis on both nitrate and nitrite. In this study, we discovered that crp mutants are not only severely deficient in nitrate or nitrite respiration, but are also hypersensitive to nitrite. This hypersusceptibility phenotype is independent of nitrite respiration. Using random transposon mutagenesis, we obtained 73 Δcrp suppressor strains resistant to nitrite. Transposon insertion sites in 24 suppressor strains were exclusively mapped in the region upstream of the cyd operon encoding a cytochrome bd oxidase, resulting in expression of the operon now driven by a Crp-independent promoter. Further investigation indicated that the promoter in suppressor strains comes from the transposon. Mutational analysis of the cydB gene (encoding the essential subunit II of the bd oxidase) confirmed that the cytochrome bd oxidase confers nitrite resistance to S. oneidensis.

BCH1 expression pattern contributes to the fruit carotenoid diversity between peach and apricot.

Peach (Prunus persica L. Batsch) and apricot (Prunus armeniaca L.) are two species of economic importance for fruit production in the genus Prunus. Peach and apricot fruits exhibit significant differences in carotenoid levels and profiles. HPLC-PAD analysis showed that a greater content of ß-carotene in mature apricot fruits is primarily responsible for orange color, while peach fruits showed a prominent accumulation of xanthophylls (violaxanthin and cryptoxanthin) with yellow color. There are two ß-carotene hydroxylase genes in both peach and apricot genomes. Transcriptional analysis revealed that BCH1 expresses highly in peach but lowly in apricot fruit, showing a correlation with peach and apricot fruit carotenoid profiles. By using a carotenoid engineered bacterial system, it was demonstrated that there was no difference in the BCH1 enzymatic activity between peach and apricot. Comparative analysis about the putative cis-acting regulatory elements between peach and apricot BCH1 promoters provided important information for our understanding of the differences in promoter activity of the BCH1 genes in peach and apricot. Therefore, we investigated the promoter activity of BCH1 gene through a GUS detection system, and confirmed that the difference in the transcription level of the BCH1 gene resulted from the difference of the promoter function. This study provides important perspective to understanding the diversity of carotenoid accumulation in Prunus fruits such as peach and apricot. In particular, BCH1 gene is proposed as a main predictor for ß-carotene content in peach and apricot fruits during the ripening process.

Effects of Ozone Fumigation on the Main Postharvest Pathogenic Fungi Penicillium sp. and the Storage Quality of Blueberry in Majiang County, China.

In this study, the fungus Penicillium sp. was isolated from rotting postharvest blueberry fruits at different storage stages and identified into genera. Inoculation of this strain on the surface of fresh fruits was able to cause rotting. The strain was then used as a reference strain to test the chemical control effect of ozone fumigation during storage. The results showed that ozone fumigation had an obvious inhibitory effect on Penicillium sp. in a dose- and time-dependent manner. Meanwhile, ozone fumigation treatment could prevent the loss of fruit firmness, slow down the decrease of soluble solids, total phenolics, and anthocyanins, and maintain a lower activity of PPO and higher activities of POD and CAT. As far as we know, this is the first report on the effects of ozone fumigation on the postharvest pathogenic fungi Penicillium sp. and on the storage quality of postharvest blueberry collected from Majiang County, Guizhou province, China.

Laboratory Screening of Control Agents Against Isolated Fungal Pathogens Causing Postharvest Diseases of Pitaya in Guizhou, China.

Pitaya, or dragon fruit, is a typical tropical fruit with an appealing taste and diverse health benefits to humans. The plantation of pitaya in Guizhou province in China has greatly boosted the income of local farmers and alleviated poverty. However, the frequent occurrence of postharvest diseases has brought large economic loss. To find a solution, we set out to identify the postharvest disease-causing agents of Guizhou pitaya. Several fungi were isolated from diseased pitaya and identified as species based on the ITS1 sequence similarity. Of them, Penicillium spinulosum, Phoma herbarum, Nemania bipapillata, and Aspergillus oryzae were, for the first time, found to cause dragon fruit disease. In consideration of their prevalence in postharvest fruit diseases, Alternaria alternata H8 and Fusarium proliferatum H4 were chosen as representative pathogens for the drug susceptibility test. Among the tested drugs and plant extracts, 430 g/L tebuconazole and 45% prochloraz were found to be the most potent fungicides against H8 and H4, respectively. The research provides insights into the mechanism and control of postharvest diseases of dragon fruits in Guizhou, China, and thus could be of economic and social significance to local farmers and the government.

An improved transformer network for skin cancer classification.

BACKGROUND: Use of artificial intelligence to identify dermoscopic images has brought major breakthroughs in recent years to the early diagnosis and early treatment of skin cancer, the incidence of which is increasing year by year worldwide and poses a great threat to human health. Achievements have been made in the research of skin cancer image classification by using the deep backbone of the convolutional neural network (CNN). This approach, however, only extracts the features of small objects in the image, and cannot locate the important parts. OBJECTIVES: As a result, researchers of the paper turn to vision transformers (VIT) which has demonstrated powerful performance in traditional classification tasks. The self-attention is to improve the value of important features and suppress the features that cause noise. Specifically, an improved transformer network named SkinTrans is proposed. INNOVATIONS: To verify its efficiency, a three step procedure is followed. Firstly, a VIT network is established to verify the effectiveness of SkinTrans in skin cancer classification. Then multi-scale and overlapping sliding windows are used to serialize the image and multi-scale patch embedding is carried out which pay more attention to multi-scale features. Finally, contrastive learning is used which makes the similar data of skin cancer encode similarly so that the encoding results of different data are as different as possible. MAIN RESULTS: The experiment is carried out based on two datasets, namely (1) HAM10000: a large dataset of multi-source dermatoscopic images of common skin cancers; (2)A clinical dataset of skin cancer collected by dermoscopy. The model proposed has achieved 94.3% accuracy on HAM10000 and 94.1% accuracy on our datasets, which verifies the efficiency of SkinTrans. CONCLUSIONS: The transformer network has not only achieved good results in natural language but also achieved ideal results in the field of vision, which also lays a good foundation for skin cancer classification based on multimodal data. This paper is convinced that it will be of interest to dermatologists, clinical researchers, computer scientists and researchers in other related fields, and provide greater convenience for patients.

Isolation of an acidic polysaccharide from the flowers of Leucosceptrum canum Smith and its immunomodulatory activity evaluation.

A water-soluble polysaccharide (LCP-05) was isolated from the flowers of Leucosceptrum canum Smith. LCP-05 was an acidic polysaccharide with a molecular weight of approximately 8.9 kDa. Monosaccharide composition analysis indicated that LCP-05 was composed of Man, Rha, GlcA, GalA, Glc, Gal and Ara in a molar ratio of 0.83:1.68:0.33:2.15:1.00:1.45:1.22. The framework of LCP-05 was speculated to be a branched rhamnogalacturonan with the backbone consisting of α-1,2,4-linked Rhap and α-1,4-linked GalAp, and bearing branches at the O-4 position of the Rha residues. The side chains are terminated primarily with the Araf and Glcp residues. LCP-05 was found to be able to significantly induce the production of NO, IL-6, and TNF-α in RAW 264.7 cells, and to induce RAW 264.7 cell's suppressive effect on both cell growth and cell migration of 4 T1 mammary breast cancer cells.