Endophytic fungi can be used as a source of herbal antioxidants to overcome the limitations of low yield and lengthy growth cycles associated with using plants as raw materials for antioxidant production. Papaya fruit is often susceptible to infection by Colletotrichum gloeosporioides after harvest, leading to postharvest rot. Endophytic fungi were extracted with ethyl acetate, and the initial screening concentration was 100 mg/L. Seven strains were identified, with scavenging rates exceeding 50% and strong antioxidant activity. The IC50 values in DPPH and ABTS free radical scavenging assays ranged from 19.72 to 84.06 mg/L and from 14.34 to 64.63 mg/L, respectively. Strain Y17 exhibited robust antioxidant activity (IC50 < 20 mg/L) and was identified as Penicillium rolfsii (MT729953) through ITS sequencing. Treatment of papaya fruit wounds with a fermentation broth of strain Y17 significantly inhibited the infection and colonization of anthracnose pathogens, resulting in a slowed disease incidence rate. This promoted the activity of protective enzymes, such as CAT, POD, and SOD, in the papaya fruit and slowed down the rate of MDA accumulation. This strain, which was found to have antioxidant activity in this study, has the potential to control anthracnose in papaya and has value in terms of further development and utilization.

[Objective]The antioxidant activity and the contents of total phenolics and flavonoids of eight kinds of tropical fruits in Hainan were determined,and the differences of antioxidant activity and antioxidant substances in eight kinds of fruits were compared,so as to provide certain nutritional reference value for people to eat tropical fruits,it also provided reference for the development and utilization of tropical fruit related products with strong antioxidant activity.[Method]Eight tropical fruits including Manilkara zapota,Syzygium samarangense,Garcinia mangostana,Durio zibet-hinus,Lucuma nervosa,Passiflora edulis,Annona squamosa and Artocarpus heterophyllus were studied in this experi-ment.The antioxidant activity of the samples was determined by 1,1-dipheny1-2-picrylhydrazyl(DPPH)free radical method,ferric reducing antioxidant power(FRAP)and diammonium 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)cation free radical scavenging activity method.The total phenolics content was determined by the Folin-Ciocalteu method,and the total flavonoids content was determined by AlCl3 chromotest method.The correlation analysis of three different determination methods and two antioxidant substances were carried out,and the results of antioxidant activity were analyzed by technique for order preference by similarity to ideal solution(TOPSIS)method.[Result]The most effective antioxidant activity measured by DPPH method and FRAP method was L.nervosa(178.62 and 140.83 μmol Trolox/g),and that of M.zapota was the weakest.The highest antioxidant activity was found in G.mangostana(157.06 μmol Trolox/g)and that of M.zapota was the weakest by ABTS method.At the same time,the content of total phenolics(3.80%)and total flavonoids(7.60%)in L.nervosa was the highest among the eight kinds of fruits,the con-tent of total phenolics in M.zapota was the lowest(0.09%),and the content of total flavonoids in D.zibethinus was the lowest(1.07%).Correlation analysis of three different determination methods and two antioxidant substances was found,the correlation coefficient between DPPH method and total phenolics and total flavonoids contents reached more than 0.81,the correlation between FRAP method and total phenolics and total flavonoids contents was more than 0.90.The re-sults were analyzed by the TOPSIS method,and the antioxidant activity was ranked as:L.nervosa>G.mangostana>S.sa-marangense>P.edulis>A.squamosa>A.heterophyllus.>D.zibethinus>M.zapota.[Conclusion]All the eight kinds of tropical fruits have antioxidant activity,the antioxidant activity of L.nervosa is strong,and that of M.zapota is weak.

Toxocara canis is a roundworm that resides in the gastrointestinal tract of dogs and causes various pathological changes. The dog’s intestinal system consists of a diverse and dynamic bacterial community that has extensive effects on intestinal physiology, immunity and metabolics. In the case of intestinal parasites, interactions with the host intestinal flora are inevitable during the process of parasitism. We studied the role of T. canis in regulating the composition and diversity of the intestinal flora of the host by high-throughput sequencing of the 16S ribosomal RNA gene and various bioinformatics analyses. The α-diversity analysis showed that Toxocara canis infection resulted in a significant decrease in the abundance and diversity of host intestinal flora. The β-diversity analysis showed that the intestinal flora of infected dogs was similar to that carried by T. canis. Analysis of the microflora composition and differences at the phylum level showed that the ratio of Firmicutes to Bacteroidetes (F/B ratio) increased with T. canis infection. Analysis of species composition and differences at the genus level revealed that the proportion of some of the pathogenic bacteria, such as Clostridium sensu stricto and Staphylococcus, increased after T. canis infection. Toxocara canis infection affected the composition and diversity of the flora in the host intestinal tract. These results not only shed light on the potential mechanism of T. canis invasion and long-term survival in the intestinal tract, but also provide a new basis for the development of anthelmintic drugs.

Sodium nitroprusside (SNP), as a nitric oxide donor, is widely used in postharvest fruit physiology and metabolism. Our previous study has indicated that SNP plays a crucial role in postharvest browning control of rambutan, but the molecular mechanism underlying this process is still unclear. In this research, we investigated the gene expression and function of postharvest rambutan in response to SNP during browning. We found 7336 differentially expressed genes (DEGs), among which 2206 were upregulated and 5130 were downregulated. Gene Ontology (GO) enrichment as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed, and the real-time quantitative PCR (qPCR) data were consistent with transcriptome data. The DEGs relevant to rambutan pericarp browning were mainly involved in anthocyanin biosynthesis, phenolic oxidation, reactive oxygen species (ROS) production, and energy supply. It was shown that SNP regulated the synthesis and degradation of anthocyanins, accumulation of phenols, level of ROS and energy metabolism to suppress the postharvest browning of rambutan. Also, one WRKY transcription factor involved in ROS metabolism was observed to be differentially regulated. These findings add to our insights into the molecular mechanisms of the SNP-induced browning delays of rambutan, which has implications for subsequent studies on molecular mechanisms of fruit browning.

Background Oil palm is the most efficient oil-producing crop in the world, and the yield of palm oil is associated with embryonic development. However, a comprehensive understanding of zygotic embryo development at the molecular level remains elusive. In order to address this issue, we report the transcriptomic analysis of zygotic embryo development in oil palm, specifically focusing on regulatory genes involved in important biological pathways. Results In this study, three cDNA libraries were prepared from embryos at S1 (early-stage), S2 (middle-stage), and S3 (late-stage). There were 16,367, 16,500, and 18,012 genes characterized at the S1, S2, and S3 stages of embryonic development, respectively. A total of 1522, 2698, and 142 genes were differentially expressed in S1 vs S2, S1 vs S3, and S2 vs S3, respectively. Using Gene Ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to identify key genes and pathways. In the hormone signaling pathway, genes related to auxin antagonize the output of cytokinin which regulates the development of embryo meristem. The genes related to abscisic acid negatively regulating the synthesis of gibberellin were strongly up-regulated in the mid-late stage of embryonic development. The results were reported the early synthesis and mid-late degradation of sucrose, as well as the activation of the continuous degradation pathway of temporary starch, providing the nutrients needed for differentiation of the embryonic cell. Moreover, the transcripts of genes involved in fatty acid synthesis were also abundantly accumulated in the zygotic embryos. Conclusion Taken together, our research provides a new perspective on the developmental and metabolic regulation of zygotic embryo development at the transcriptional level in oil palm.

油棕是世界上产油效率最高的热带木本油料作物,其棕榈油产量与合子胚发育密切相关.油棕的合子胚发育是一个系统且复杂的生物过程,其中涉及许多基因的精确调控.MicroRNAs(miRNAs)是重要的信号分子,调节植物的各种发育过程.一些miRNAs已经被整合到基因调控网络中协调植物胚发育的可塑性,但对于其在油棕合子胚发育过程中的作用知之甚少.本研究采用小RNA测序对油棕S1(早期)、S2(中期)和S3(晚期)的合子胚进行高通量测序分析,鉴定了6个已存在的和334个已知的miRNAs,并预测到376个新的miRNAs.其中97、102和19个miRNAs在S1与S2、S1与S3、S2与S3之间差异表达;从S1到S3共有7个miRNAs持续差异表达.另外,miRNAs在调控胚胎早期和晚期的发育差异明显,即与S1相比,S2有36个miRNAs上调和61个miRNAs下调,但与S2相比,S3只有12个miRNAs上调和7个miRNAs下调.依据表达量的变化将135个miRNAs划分为4种趋势,并将对应的938个靶基因与转录组数据进行关联分析,检测到71个miRNA靶基因对.GO富集分析显示7个miRNAs的9个靶基因富集到152个生物过程,且与生长发育相关的基因被鉴定为miRNAs的靶标,表明miRNAs可能在调控油棕胚发育的激素信号、生殖生长等生物学过程中发挥作用.另外,KEGG分析表明miRNAs通过调控次生代谢途径相关基因影响合子胚的成熟.进一步筛选出4个miRNAs家族参与植物激素的合成和信号传导调控:miR159-MYB调控赤霉素和脱落酸来维持胚的发生潜力以及诱导胚成熟,miR 164-NAC调控乙烯和生长素参与胚细胞扩增,miR 172-AP2调控乙烯和脱落酸诱导胚成熟,novel-m004-SPL调控赤霉素来诱导胚的形态建成.本研究初步鉴定了参与油棕合子胚发育相关的miRNAs,为后续研究miRNAs调控合子胚发育的分子机制奠定基础.

CTS-N is deacetylation chitosan that can induce the expression of defence genes in plants. PRSV is a virus that can infect papaya and cause disease. It is mainly distributed in tropical and subtropical regions all over the world. The epidemic spread of the virus may seriously affect the papaya industry. In this study, we analysed differently expressed genes that are related to disease resistance after applying CTS-N using RNA-seq and subsequent qPCR analysis. Several genes related to plant defence responses, such as PR-1 and WRKY33, were up-regulated. Among the genes, 10 up-regulated and 2 down-regulated genes were involved in the ‘plant pathogen interaction pathway’, ‘phytohormones signal transduction pathway’ and ‘amino sugars pathway’. The CTS-N treatment(1.0 ml/L) can significantly prevent the damage to papaya plants caused by PRSV. The RNA profiling results indicated that CTS-N can induce the expression of defence related genes to enhances a degree of plant defence. Future research may include comparable methodologies for disease resistance research in other plant species.

萜类化合物在医药、农业、食品和日化等领域具有重要的应用价值,但其在药用植物中的天然含量普遍较低,限制其规模化发展.光和茉莉酸信号是调控植物萜类化合物合成中常用的诱导子.本文综述光与茉莉酸信号介导的药用植物萜类化合物合成的分子机制,提出了未来药用植物萜类化合物可重点研究的方向.

The papaya industry is mainly impacted by viral diseases, especially papaya ringspot disease (PRSD) caused by papaya ringspot virus (PRSV). So far, research on the interaction between Chitosan, Lentinan and Ningnanmycin on PRSD has not been reported. This research studied the controlled and interactive effect of three biological agents, namely, Chitosan (C), Lentinan (L) and Ningnanmycin (N), on PRSV in papaya, individually and collectively. The changes in disease index, controlled effect, Peroxidase (POD), Polyphenol oxidase (PPO), Superoxide dismutase (SOD), growth and development of plants were observed at the seedling stage, in pots, and at the fruiting stage, in the field. The appearance and nutrient contents of fruits were measured during the fruit stage. The disease index of PRSV, at seedling and fruiting stages, was significantly lower for chitosan, lentinan and ningnanmycin and their interactive effect, compared to a control check treatment. The activity of the defense enzymes could be improved by the three kinds of biological agents and their interactive effect, especially lentinan and ningnanmycin. The chlorophyll content, plant height, stem diameter and fruit quality rose significantly under chitosan, lentinan and ningnanmycin treatments. The interaction of LN could inhibit PRSV disease at the seedling and fruiting stages of papaya, and promote the growth of plants and the quality of fruit at the fruit stage. Hence, this study provides the theoretical foundation for the biological control of papaya ringspot disease.

Research and development of natural antioxidants are gaining popularity with their wide application in food and medicine. Papaya (Carica papaya L.), a plant of medicinal and food value, is widely planted in tropical regions. This study was conducted to compare the tissues of different organs of papaya as well as the leaves and flowers of 9 cultivars of papaya. The three methods, namely, the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay and the ferric reducing antioxidant power (FRAP) assay, were used to determine the total antioxidant activities. Also, the total phenolic content and the total flavonoid content were investigated to evaluate the antioxidant capacity. Our research shows that leaves and roots of papaya manifested higher antioxidant properties among all tested organs, and leaves and flowers of Daqing cultivar exhibited the strongest antioxidant ability. Overall, our results indicate papaya has the potential to become a natural antioxidant resource.

Papaya is the fourth most favored tropical fruit in the global market; it has rich nutrition and can be used for medicine and food processing. However, it will soften and mature in a short time after harvest, resulting in a lot of economic losses. In this study, papaya fruits were soaked in 0, 12.5, 25, 50, and 100 ml/L ethanol solutions for 2 h and stored at 25°C for 14 days, by which we explored the effects of ethanol treatment in papaya after harvest. At an optimal concentration of ethanol treatment, color changing of the papaya fruits was delayed for 6 days, and decay incidence and average firmness of the fruits were shown as 20% and 27.7 N, respectively. Moreover, the effect of ethanol treatment on antioxidant systems in the papaya fruits was explored. It was observed that ethanol treatment contributed to diminish the development of malondialdehyde (MDA), ethylene, and superoxide anions. Furthermore, the activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) were promoted than those of control group, while the activities of peroxidase (POD), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO) were brought down. In addition, the principal component analysis (PCA) showed that PAL, ethylene, and superoxide anions were the main contributors for the maturity and senescence of postharvest papaya. In this experiment, ethanol treatment had the potential of delaying the ripening and maintaining the storage quality of papaya fruits.

DWARF5(DWF5)基因,编码7-脱氢胆固醇还原酶(7-dehydrocholesterol reductase),是甾醇合成的关键酶,通过调控甾醇的合成参与植物油体(oil bodies,OBS)的形成.为了探究DWF5基因对油棕果肉中油体发育的影响,以'热油4号'为材料,提取油棕果肉的RNA,以反转录的cDNA为模板进行基因的全长克隆,获得2个EgDWF5基因并分别命名为EgDWF5-1和EgDWF5-2.运用生物信息学的方法对其理化性质、结构特点和亲缘关系等进行分析预测,利用实时荧光定量PCR对其在油棕的根、茎、叶、花及花后不同时期的果实进行表达水平分析.结果表明:EgDWF5-1和EgDWF5-2基因编码的氨基酸数量分别为434个和374个,相对分子质量为49.71 kDa和42.68 kDa,等电点为8.61和8.69,其蛋白不稳定指数为38.60和38.13,脂肪族指数为98.80和96.68,总平均亲水性为0.347和0.313,均具有疏水性.EgDWF5与水稻和玉米亲缘关系最近,与其他物种关系较远.qRT-PCR分析表明,EgDWF5基因在油棕的各个器官均有表达,其中EgDWF5-1基因在果肉中高表达,显著高于根、叶、花等部位,其表达趋势为花后12～18周升高,至20周时达到最高后表达量逐渐降低,这与油棕果肉中油体的发育趋势基本一致.EgDWF5-2基因在根和茎中高表达而在果肉中表达量低,其果肉中表达趋势为花后12～18周逐渐降低.因此,推测EgDWF5-1参与调控油棕的油体发育,EgDWF5-2未参与该调控而可能在油棕的生长发育中发挥功能.本研究为进一步探索EgDWF5基因调控油棕中油体的形成机制奠定基础.

Surface browning after harvest is the primary constraint affecting the storage life and market circulation of rambutans. In this study, rambutan fruits were soaked in sodium nitroprusside at different concentrations and stored at 25°C for 8 days to explore the effects on postharvest quality and browning. The weight loss, browning index and superoxide anion radical, hydrogen peroxide and malondialdehyde contents of the treated fruits were reduced compared to those of the control fruits (soaked in distilled water). And fruits treated with sodium nitroprusside had a higher total phenolic content and lower polyphenol oxidase and peroxidase activity. In addition, compared with the control, the treated fruits exhibited higher phenylalanine ammonia lyase, ascorbate peroxidase and superoxide dismutase activities; titratable acidity; and soluble solid, vitamin C and protein contents, indicating high fruit quality. Overall, sodium nitroprusside treatment at 200 μmol L−1 demonstrated the most positive preservation effects. Therefore, sodium nitroprusside treatment, particularly at 200 μmol L−1, can be used as an eco-friendly, safe and convenient method for postharvest quality management and high-efficiency preservation of rambutan fruits.

本文对一株来自中华紫蛤的附生真菌HNMF114进行次生代谢产物的研究。从中分离鉴定了1个新化合物和8个已知化合物。分别鉴定为clavatone（1）、cyclo（L-Trp-L-Trp）（2）、2,4（1H,3H）-quinazolinedione （3）、clavatol（4）、kotanin（5）、orlandin（6）、desmethylkotanin（7）、（S）-2-（1-Hydroxy-2,2-dimethylpropyl）quinazolin-4（3H）-one（8）、（S）-2-methyl-1-（4-oxo-3,4-dihydroquinazolin-2-yl）propyl acetate（9）。新化合物1对大肠杆菌的生长具有一定的抑制作用,最小抑菌浓度（MIC）为2μg/mL。化合物4、9对金黄色葡萄球菌有一定的抑制作用,最小抑制浓度分别为1μg/mL和4μg/mL。化合物5对枯草芽孢杆菌有一定的抑制作用,最小抑制浓度分别为8μg/mL。化合物4、5和9对李斯特菌有一定的抑制作用,最小抑制浓度分别为4、4和8μg/mL。

百秋李醇是广藿香主要活性成分之一,也是《中国药典》中评价广藿香药材的重要指标,可通过天然提取或合成生物学工程两种方式获得.广藿香中百秋李醇含量低,是其规模化应用的瓶颈.本文从百秋李醇的合成途径、分子调控机制和合成生物学工程三方面综述近年来相关研究进展,为百秋李醇的开发与应用提供参考.

Pitaya fruit canker is an important disease in pitaya production. Facilitating resistance through the application of biological control principles is a promising alternative to traditional control strategies. This study evaluated the induced resistance of Penicillium rolfsii, numbered Y17 isolated from papaya leaves in pitaya fruit, and evaluated the activity of the defense enzymes, total antioxidant capacity (T-AOC), and malondialdehyde (MDA) content of the treated fruit. The results demonstrate that treatment with Y17 effectively induced resistance of pitaya fruit to canker disease caused by Neoscytalidium dimidiatum , with an inhibition rate of 70.87%. In addition, Y17 notably improved the activities of peroxidase, catalase, and polyphenol oxidase as well as the T-AOC of the treated samples. Y17 treatment reduced the MDA content in these fruits. Taken together, our results suggest that Y17 treatment could trigger pitaya fruit defense responses and effectively induce resistance to fruit canker disease.

Pogostemon cablin, a medicinally and economically important perennial herb, is cultivated around the world due to its medicinal and aromatic properties. Different P. cablin cultivars exhibit different morphological traits and patchouli oil components and contents (especially patchouli alcohol (PA) and pogostone (PO)). According to the signature constituent of the leaf, P. cablin was classified into two different chemotypes, including PA-type and PO-type. To better understand the molecular mechanisms of PA biosynthesis, the transcriptomes of Chinese-cultivated P. cablin cv. PA-type “Nanxiang” (NX) and PO-type “Paixiang” (PX) were analyzed and compared with ribonucleic acid sequencing (RNA-Seq) technology. We obtained a total of 36.83 G clean bases from the two chemotypes, compared them with seven databases and revealed 45,394 annotated unigenes. Thirty-six candidate unigenes participating in the biosynthesis of PA were found in the P. cablin transcriptomes. Overall, 8,390 differentially expressed unigenes were identified between the chemotypes, including 2,467 upregulated and 5,923 downregulated unigenes. Furthermore, six and nine differentially expressed genes (DEGs) were mapped to the terpenoid backbone biosynthetic and sesquiterpenoid and triterpenoid biosynthetic pathways, respectively. One key sesquiterpene synthase gene involved in the sesquiterpenoid and triterpenoid biosynthetic pathways, encoding patchoulol synthase variant 1, was significantly upregulated in NX. Additionally, GC-MS analysis of the two chemotypes in this study showed that the content of PA in NX was significantly higher than that of PX, while the content of PO showed the opposite phenotype. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that the DEG expression tendency was consistent with the transcriptome sequencing results. Overall, 23 AP2/ERF, 13 bHLH, 11 MYB, 11 NAC, three Trihelix, 10 WRKY and three bZIP genes that were differentially expressed may act as regulators of terpenoid biosynthesis. Altogether, 8,314 SSRs were recognized within 6,825 unigenes, with a distribution frequency of 18.32%, among which 1,202 unigenes contained more than one SSR. The transcriptomic characteristics of the two P. cablin chemotypes are comprehensively reported in this study, and these results will contribute to a better understanding of the molecular mechanism of PA biosynthesis. Our transcriptome data also provide a valuable genetic resource for further studies on P. cablin.

Three new humulane-type sesquiterpenoids, penirolide A (1), penirolide B (2), and 10-acetyl-phomanoxide (3), together with three known compounds aurasperone A (4), pughiinin A (5), and cyclo(l-Leu-l-Phe) (6) were isolated from the endophytic fungus Penicillium sp. derived from the leaves of Carica papaya L. Their structures including their absolute configurations were determined based on the analysis of NMR and HRESIMS spectra, NMR chemical shifts, and ECD calculations. Compounds 2, 3, 5, and 6 significantly inhibited glucagon-induced hepatic glucose production, with EC50 values of 33.3, 36.1, 18.8, and 32.1 μM, respectively. Further study revealed that compounds 2, 3, 5, and 6 inhibited hepatic glucose production by suppression of glucagon-induced cAMP accumulation.

Wax apple is one of the most important commercially grown fruits and is consumed worldwide due to its excellent quality attributes and high degree of acceptance by consumers. However, wax apple is highly perishable and the application of storage and other postharvest technologies is necessary to maintain fruit quality from harvest to consumption. In this study, the effects of sodium nitroprusside (SNP) on the postharvest quality and senescence of wax apple (Syzygium samarangense (Blume) Merr. & Perry) was investigated. The wax apples were treated with three concentrations of SNP (1, 2.5, and 5 mu mol.L-1), and the control was treated with distilled water. The treated fruits were air dried naturally and stored at 25 degrees C (the relative humidity was 90%) for 7 days to determine the various parameters. The results demonstrated that soaking in SNP maintained higher titratable acidity (TA) and soluble solids content (SSC) and sustained a stable Brix-acid ratio (BAR). SNP also suppressed the degradation of anthocyanins and the decrease of firmness. Additionally, it functioned in delayed polyphenol oxidase (PPO) and peroxidase (POD) activities in the early period and suppressed the decrease of the two enzyme activities in the late period. Increases in malondialdehyde (MDA) content were inhibited. In summary, 2.5 mu mol.L-1 SNP significantly maintained the quality and suppressed the senescence of postharvest wax apple fruit compared to the control. Therefore, the application of SNP may represent a promising and practical methodology for extending the shelf life of fruit.

禾生素是一种新型的绿色生物源农药、植物功能性营养剂.经过研究发现,禾生素对农作物、园艺植物的生长发育都会起到一定的促进和辅助作用.对于不同种属的植物使用一定剂量的禾生素或将其与其他功能性营养剂、农药等按一定比例施用都会在一定程度上起到抵御病虫害、抗寒抗旱、缓解药害肥害、增产增质、调节土壤等的效果.基于此,分析禾生素在不同植物中的应用,并对其发展前景进行展望,为禾生素在绿色安全的农产品生产上的推广及应用提供参考.