Asian citrus psyllid(ACP)is a significant pest of citrus crops that can transmit citrus Huanglongbing(HLB)by feeding on the phloem sap of citrus plants,which poses a significant threat to citrus production.Volatile si...Asian citrus psyllid(ACP)is a significant pest of citrus crops that can transmit citrus Huanglongbing(HLB)by feeding on the phloem sap of citrus plants,which poses a significant threat to citrus production.Volatile signal chemicals with plant communication functions can effectively enhance the resistance of recipient plants to herbivorous insects with minimal impacts on plant growth.While(E)-4,8-dimethyl-1,3,7-nonatriene(DMNT),(E,E)-4,8,12-trimethyl-1,3,7,11-tridecene(TMTT),(E)-β-caryophyllene,and dimethyl disulfide(DMDS),are known as signaling molecules in guava-sweet orange communication,whether these four chemical signals can enhance the resistance of Citrus sinensis to feeding by ACP adults with no apparent costs in terms of plant growth remains unclear.Therefore,this study measured the effect of non-damaging induction by DMNT,TMTT,(E)-β-caryophyllene,and DMDS on the ability of C.sinensis to resist feeding by ACP,as well as their impacts on the defensive phytochemicals,defensive enzymes,functional nutrients,Photosystem II's utilization and allocation of light energy,photosynthetic pigments,growth conditions,and leaf stomatal aperture in C.sinensis.The results indicate that non-damaging induction by these four chemicals can enhance the activity of the defensive enzyme polyphenol oxidase(PPO)and increase the contents of total phenols,tannins,and terpenoid defensive phytochemicals within C.sinensis,thereby enhancing the resistance of C.sinensis to ACP feeding.Specifically,DMNT and DMDS exhibit more significant effects in inducing resistance compared to TMTT and(E)-β-caryophyllene.The characteristics of chlorophyll fluorescence parameters and changes in photosynthetic pigments in C.sinensis during different post-exposure induction periods revealed these chemicals can maintain the stability of the photosynthetic system in C.sinensis and regulate its capacity to capture,transmit,and distribute light energy,which significantly enhances the non-photochemical quenching ability of C.sinensis.In addition,detailed measurements of the water content,leaf mass per unit area(LMA),functional nutrients(soluble protein,soluble sugar,and amino acids),and stomatal parameters in C.sinensis leaves further indicated that the non-destructive induction by these chemicals can optimize the levels of functional nutrients in C.sinensis,primarily manifesting as the upregulation of soluble sugars,proline,or soluble proteins,and reduction of stomatal area and aperture,which maintains a stable leaf water content and LMA,thereby enhancing resistance to ACP while sustaining the healthy growth of C.sinensis.These results fully substantiate that the non-damaging induction by the signal chemicals DMNT,TMTT,(E)-β-caryophyllene,and DMDS can enhance the resistance of C.sinensis to ACP feeding while maintaining the balance between pest resistance and growth.This balance prevents any catastrophic effects on the growth of C.sinensis,so these agents can potentially be integrated with other pest management strategies for the collective protection of crops.This study provides theoretical support and assistance for the development of signal chemical inducers for the prevention and management of ACP in agricultural systems.展开更多
[Objective] The aim was to identify genetic variation in Citrus sinensis （sweet orange） germplasm from Hunan Province according to the Start Codon Targeted （SCoT） Polymorphism. [Method] The reaction system for SCo...[Objective] The aim was to identify genetic variation in Citrus sinensis （sweet orange） germplasm from Hunan Province according to the Start Codon Targeted （SCoT） Polymorphism. [Method] The reaction system for SCoT amplification from sweet orange was first optimized, and then the SCoT fragments were amplified from 24 sweet orange cultivars collected in Hunan Province and sequenced for genetic variation analysis. [Result] The optimum reaction system for SCoT markers amplification was 2.0 μl containing 80 ng of template DNA, 0.3 mmol/L dNTPs, 0.2 μmol/L primer, 1.6 mmol/L Mg2＋, 1.6 U of Taq DNA polymerase and 10×PCR buffer. By using this reaction system, the PCR products from the sweet orange cultivars produced clear and reproducible bands at 100-2 000 bp through electrophoresis. The SCoT fragments of the 24 sweet orange cultivars were 1 090-1 091 bp, with the homology of 99.84% and nucleotide deletion and substitution. After being sequenced, the SCoT polymorphisms could distinguish 12 sweet orange cultivars. In addition, the BLAST result showed that part of the SCoT fragments coding region shared high homology with ribosomal protein S3 N superfamily. [Conclusion] This study will provide a theoretical basis for breeding sweet orange cultivars.展开更多
An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments ofNewhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with...An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments ofNewhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with plant growthregulators affected the adventitious bud regeneration frequency and efficiency. The initial 15 d darkness inoculation isbeneficial for the adventitious bud regeneration. The highest regeneration frequency (85.2%) and bud formationefficiency (3.7 per responsive internodal stem segment) were obtained in the media supplemented with 1.0 mg L-1 BAPand 0.5 mg L-1 NAA. ABA at 0.2 mg L-1 positively affected the bud formation efficiency, which amounted to 8.5 buds perinternodal segment in the presence of BAP at 1.0 mg L-1. The adventitious shoots successfully rooted and weretransferred to the soil.展开更多
Silver nanoparticles are considerecl as good antimicrobial agent. AgNPs were synthesized by mixing silver nitrate solution with citrus sinesb extract for 2 h at 37 and analyzed by UV-visible spectra, SEM, XRD, and FT...Silver nanoparticles are considerecl as good antimicrobial agent. AgNPs were synthesized by mixing silver nitrate solution with citrus sinesb extract for 2 h at 37 and analyzed by UV-visible spectra, SEM, XRD, and FTIR. AgNPs were tested against B. subtilis, Shigello, S. oureus, ond E. coli. Minimum inhibitory concentration of AgNPs was 20 I^g/mL for B. subtilis and Shigello and 30 I^g/mL for S. oureus and E. coll. Antibiofilm activity （80% to 90%） was observed at 25 IJg/mL. AgNPs were stable for five months with sustained an＇timicrobial activity. Biosynthesized AgNPs can bE： used to inhibit food poisoning microbial growth.展开更多
Using the mRNA from the fruit of Cara Cara as the template, the cDNA of phytoene synthase （PSY） gene was amplified by reverse transcription polymerse chain reaction （RT-PCR）. Sequence analysis indicated that the c...Using the mRNA from the fruit of Cara Cara as the template, the cDNA of phytoene synthase （PSY） gene was amplified by reverse transcription polymerse chain reaction （RT-PCR）. Sequence analysis indicated that the cDNA was of 1 520 bp, which had an open reading frame of 1 308 bp and encoded a protein of 436 amino acids. The homology analysis showed that PSY of Cara Cara shared high similarities of nucleotides and deduced amino acids with those in other plants up to more than 75 and 70%, respectively. A putative signal transit peptide for plastid targeting was found in the N-terminal region of PSY. The mature forms of PSY included a transmembrane （TM） domain. The recombinant plasmid pET-CitPSY was constructed by subcloning the full coding sequence of PSY cDNA into pET-28 （＋）. After transformation of E. coli BL21 and induced by 1 mmol L^-1 isopropyl-β-D-thiogalacropyranoside （IPTG）, the fusion protein （6× His-PSY） with 52 kD was produced at a high level by prokaryotic expression system. The results of Western blot demonstrated that the fusion protein （6× His-PSY） could be recognized by anti-6 × His monoclonal antibody. The study could establish a basis for molecular improvement of Citrus fruit colors.展开更多
In this study, essential oils from Cymbopogon citratus and Ceasalpinia decapitala leaves, Citrus lemon and Citrus sinens＆ peels, were extracted, chemically characterized and evaluated on both Gram positive and Gram n...In this study, essential oils from Cymbopogon citratus and Ceasalpinia decapitala leaves, Citrus lemon and Citrus sinens＆ peels, were extracted, chemically characterized and evaluated on both Gram positive and Gram negative bacteria, Salmonella Typhimurium, Escherichia coli, Listeria innocua, Staphylococcus aureus, Klebsiella pneumonia and Streptococcus pyogenes. Essential oil of C. citratus was found to be rich in geranial （33.0%） and neral （49.7%）, that from C. decapitala in 13-pinene （8.4%）, ct-pinene （25.5%）, 13-ocymene （31.6%）, 15-phellandrene （8.4%）, caryophyllene （7.5%） and geranial （5.9%）. The essential oil from C. lemon and C. sinensis where mainly composed by limonene with percentages of 77.5% and 83.3% respectively, and 13-phellandrene with percentages of 8.1% and 10.8% for the essential oil of C. lemon and C. sinensis, respectively. The antibacterial activity assessment realized on different microorganisms contaminating food showed that essential oil from C. citratus was shah more effective against all tested bacteria while that from C. sinensis was the less active essential oil. The incorporation of essential oils in HPC （hydroxy-propyl cellulose） films showed that those essential oils, especially essential oils from C. citratus, maintained their antibacterial activities against targeted microorganisms and therefore can be applied in food packing.展开更多
Citrus sinensis commonly called sweet orange belongs to the family Rutaceae. Nutritionally, it is highly recommended due to its high content of micronutrients. However, the rejection of a large amount of epicarp in na...Citrus sinensis commonly called sweet orange belongs to the family Rutaceae. Nutritionally, it is highly recommended due to its high content of micronutrients. However, the rejection of a large amount of epicarp in nature contributes to the emission of greenhouse gas and the development of leachate which contaminate surface water and groundwater. The aim of this work was to identify the essential oil components from Citrus sinensis epicarp, and then look after the biological activity of these components in order to underline the worth to reuse the Citrus sinensis epicarp as a gainful mean. The essential oil of 4,000 g of Citrus sinensis epicarp was done through the water steam distillation and 0.0287 g of essential oil was obtained; so a yield of 0.0007%. The essential oil was then submitted to gas chromatography-flame ionization detector （GC-F1D）. The result revealed that the essential oil was teemed with 28 volatile compounds, including terpene compounds （50%）, aldehydes （32%） and alcohols （18%） whose anti-inflammatory, anti-diabetic, larvicidal and antioxidant activities were underlined.展开更多
The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this ca...The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.展开更多
Background:Silver nanoparticles(SNPs)play important role in the field of optics and electronics and also as a novel antibacterial agents.Here,we report a simple and green method for the biosynthesis of SNPs using aque...Background:Silver nanoparticles(SNPs)play important role in the field of optics and electronics and also as a novel antibacterial agents.Here,we report a simple and green method for the biosynthesis of SNPs using aqueous leaf extract of Origanum majorana and Citrus sinensis as a novel bio source of cost-effective,non-hazardous reducing,and stabilizing agents.A 3 mM solution of silver nitrate was prepared.Five milliliter aqueous leaf extract was slowly added to 20 ml silver salt solution(3 mM)with constant stirring.No noticeable color change was observed.The solution was then heated in domestic microwave for variable time intervals.The intense brown colored solution was obtained on 1 min heating with O.majorana and 5 min heating with C.sinensis extract.The intense brown color indicated the formation of SNPs.The antibacterial activity of synthesized SNPs was investigated.Results:SNPs were rapidly synthesized using aqueous leaf extract of O.majorana and C.sinensis on microwave irradiation.Formation of SNPs was confirmed by the change in color from yellowish green to brown and absorption maximum around~420 and 410 nm due to surface plasmon resonance of SNPs.They were also characterized by other physical-chemical techniques like Fourier transform infrared spectroscopy(FT-IR),scanning electron microscope coupled with X-ray energy dispersive spectroscopy,and high-resolution transmission electron microscopy.TEM analysis showed the presence of feather-shaped NPs in O.majorana and spherical as well as cubical-shaped NPs in C.sinensis-mediated SNPs.The synthesized SNPs showed significance antibacterial activity against two human pathogenic strains.Conclusion:The SNPs were synthesized using leaf extract of plants.This synthesis method is nontoxic,eco-friendly,and a low-cost technology for the large-scale production.The SNPs can be used as a new generation of antibacterial agents.展开更多
Segment drying is a severe physiological disorder of citrus fruit,and vesicles become granulated or collapsed.Aside from the hypothesis that alteration of cell wall metabolism is the main factor of citrus granulation,...Segment drying is a severe physiological disorder of citrus fruit,and vesicles become granulated or collapsed.Aside from the hypothesis that alteration of cell wall metabolism is the main factor of citrus granulation,little is known about vesicle collapse.This study aimed to elucidate the changes in pectin metabolism during vesicle collapse in blood orange.Vesicle collapse was characterized by decreased nutrients and increased chelate-and sodium carbonate-soluble pectin and calcium content.The nanostructure of chelate-soluble pectin became complex and developed multi-branching upon collapse.The activity of pectin methylesterase increased,while that of polygalacturonase and pectate lyase decreased upon collapse.Genome-wide transcriptional analysis revealed an increasing pattern of genes encoding pectin methylesterase and other enzymes involved in pectin synthesis and demethylesterification upon collapse.Drying vesicles were characterized by increased abscisic acid content and relevant gene expression.In conclusion,we discovered alteration in pectin metabolism underlying citrus vesicle collapse,mainly promoting pectin demethylesterification,remodeling pectin structures,and further inhibiting pectin degradation,which was hypothesized to be a main factor for citrus collapse.This is the first study to disclose the potential intrinsic mechanism underlying vesicle collapse in orange fruit.展开更多
Sesquiterpene valencene is dominant in flavedo tissues of sweet oranges and imparts a unique woody aroma.However,the interaction between the biosynthetic pathways of valencene and other nutritional compounds is less s...Sesquiterpene valencene is dominant in flavedo tissues of sweet oranges and imparts a unique woody aroma.However,the interaction between the biosynthetic pathways of valencene and other nutritional compounds is less studied.Sesquiterpenoids were significantly accumulated in a previously reported glossy mutant of orange(MT)than the wild type(WT),especially valencene and caryophyllene.In addition,we identified several other pathways with variations at both the transcriptional and metabolic levels in MT.It’s interesting to found those upregulated metabolites in MT,such as eukaryotic lipids,kaempferol and proline also showed strong positive correlation with valencene along with fruit maturation while those down-regulated metabolites,such as phenylpropanoid coumarins and most of the modified flavonoids exhibited negative correlation.We then categorized these shifted pathways into the‘sesquitepenoid-identical shunt’and the sesquitepenoid-opposite shunt’and confirmed the classification result at transcriptional level.Our results provide important insights into the connections between various fruit quality-related properties.展开更多
This study investigated the protective effects of secondary bacterial metabolites, produced by Pseudomonas sp. (bacterium strain LN), on citrus canker disease caused by Xanthomonas axonopodis pv. citri (Xac 306). The ...This study investigated the protective effects of secondary bacterial metabolites, produced by Pseudomonas sp. (bacterium strain LN), on citrus canker disease caused by Xanthomonas axonopodis pv. citri (Xac 306). The LN bacteria strain was cultured in liquid medium and the supernatant free-cells was treated with methanol (AMF) and ethyl acetate (AEF), respectively, and then the extract was concentrated, filtrated, lyophilized and fractionated by vacuum liquid chromatography (VLC). After VLC, eight fractions were obtained. All fractions’ activity against Xac 306 by agar well diffusion assay and minimum inhibitory concentration but in different concentrationswere tested. Cytotoxicity effects were observed in all fractions in 50 μg·mL-1 concentration. The comet assay demonstrated that the fractions EAF, VLC2 and VLC3 presented no genotoxic effects at tested concentrations. In plants only VLC3 showed significant results (p<0.05), reducing the incidence of citrus canker lesions.展开更多
Citrus sinensis(L.)Osbeck fruit peels contain polyphenols which are known for its therapeutic properties.However,these polyphenols have limitations like astringent taste,low bioavailability,instability,and susceptibil...Citrus sinensis(L.)Osbeck fruit peels contain polyphenols which are known for its therapeutic properties.However,these polyphenols have limitations like astringent taste,low bioavailability,instability,and susceptibility to oxidation.To overcome these limitations,encapsulation techniques are being studied.Our study focuses on enriching polyphenols from Citrus sinensis fruit peels using amberlite XAD 16-N resin thereby developing efficient microspheres by extrusion technique using alginate matrix.Further,SEM and FTIR were used to characterise these microspheres.Additionally,it was also studied for swelling ability,polyphenols release at various pH,temperature,time,and bio-accessibility under simulated digestion condition.The results showed that the enriched polyphenols from Citrus sinensis fruit peels(EPCSP)were successfully encapsulated and maintained its stability significantly by retaining its total polyphenol content(63.08±2.2 mg/g of GAE)and total antioxidant activity(288.3±8.9 mg/g of AAE)in comparison to unencapsulated extract(p<0.05)throughout a period of 12 months.It was also observed that,at pH 7.4,the encapsulated microspheres showed significant swelling,resulting in an increased total polyphenol release than at pH 1.6.Furthermore,the EPCSP loaded alginate microspheres were also efficient in significantly maintaining the biological activities(p<0.05)thereby leading to a higher bio-accessibility index in the intestine.The present work highlighted the potential of alginate matrix which has shown improved stability of polyphenols and may be used as a drug delivery system which may lead to its wide applications in nutraceuticals/pharmaceutical industries.展开更多
Anthocyanins are enriched in blood oranges(Citrus sinensis L.Osbeck)in response to external environmental stimulation during postharvest storage,while the role of plant hormones in anthocyanin accumulation in response...Anthocyanins are enriched in blood oranges(Citrus sinensis L.Osbeck)in response to external environmental stimulation during postharvest storage,while the role of plant hormones in anthocyanin accumulation in response to low-temperature inducement is still poorly studied.Here,we investigated the anthocyanin profiles and fruit quality of blood oranges treated with different temperatures and then further focused on the mechanisms of plant hormone-mediated anthocyanin biosynthesis induced by low temperatures using proteomics.Total and individual anthocyanins were significantly increased in blood oranges under the low-temperature storage at 8℃,among which cyanidin 3-glucoside and cyanidin 3-(6″-malonylglucoside)were increased by 6.51 and 6.77 times at the end of storage,respectively.Low temperature effectively delayed the weight loss and maintained the water status.For flavor changes,high levels of sucrose,citric acid,and malic acid were observed in fruits stored at 8℃,and low temperature delayed the changes of overall volatile flavor compounds,in which aroma-active compounds were closer to those in fresh fruit.The proteomic analysis found that differentially expressed proteins between fruit stored at 8 and 25℃ were enriched in“Phenylalanine metabolism”,“Flavonoid biosynthesis”,“Brassinosteroid biosynthesis”and“Cysteine and methionine metabolism”pathways,indicating that low temperature induced the biosynthesis and signal transduction of brassinosteroids and ethylene(CYP90A1,CYP90C1/D1,CYP92A6,SAMS,ACC oxidase,ETR1),upregulated the expression of anthocyaninrelated proteins(PAL,4CL,CHS1,CHS2,F3′5′H,DFR,ANS,and UFGT),and ultimately promoted anthocyanin accumulation in the postharvest blood oranges.展开更多
The objective of the study was to determine the influence of temperature, relative humidity, and shoot size of Valencia orange trees Citrus sinensis (L.) Osbeck (Sapindales: Rutaceae) on the abundance of eggs and nymp...The objective of the study was to determine the influence of temperature, relative humidity, and shoot size of Valencia orange trees Citrus sinensis (L.) Osbeck (Sapindales: Rutaceae) on the abundance of eggs and nymphal stages of Diaphorina citri Kuwayama (Hemiptera: Liviidae). The experiment was established on 3.18 hectares cultivated with Valencia orange. The number of eggs, nymphs, temperature, relative humidity, and scale of the size of the shoot were recorded from January to July and from September to November 2020. The association of these variables was determined by multiple correspondence analyses. The conservation of the same number of individuals between consecutive samples and the increase in the number of eggs and nymphs was associated with temperature (17˚C - 23˚C), relative humidity (75% - 78%) and the availability of shoots from V1 to VS in March, April, June, and July. The largest number of N1 and N2 nymphs was recorded in January, February, May, and October. The highest population of eggs and nymphs N3 and N5 occurred in September. In November, there was a reduction in eggs and nymphs. Meanwhile, the nymph N4 was presented independently of the variables analyzed.展开更多
Genetic transformation with mature material as the explants could shorten the transgenic period and avoid seed dependence compared with genetic transformation using the epicotyl seedling stem segments as the receptor....Genetic transformation with mature material as the explants could shorten the transgenic period and avoid seed dependence compared with genetic transformation using the epicotyl seedling stem segments as the receptor. Here, we constructed an Agrobacterium tumefaciensmediated transformation for generation of marker-free transgenic plants from navel orange(Citrus sinensis Osbeck) mature stems using a CreloxP recombination system. To efficiently recover the regenerated buds from mature tissues, five recovery methods were compared: in vitro micrografting of 0.1-0.5(1-2 weeks), > 0.5 cm(3-4 weeks) and > 1 cm long lignified bud and in vitro micrografting of explants with a bud and rooting regenerated bud. The data showed that in vitro micrografting of > 1 cm long regenerated bud with expanded leaves after one month of continuous culture for lignification was the optimal solution for plant recovery from mature tissues. Transgenic plants without selectable marker genes were created from navel orange(Citrus sinensis Osbeck) tissue using a transformation vector PLI-35SPR1aCB containing a Cre/loxP system recombination together with genes encoding the selectable marker isopentenyl transferase(IPT) and an anti-bacterial peptide(PR1aCB).Using IPT positive selection, the transformation efficiency determined by PCR was 0.9%, and in total, 20 transgenic plants were obtained.Southern blotting confirmed further their transgenicity. PCR and sequencing analysis demonstrated that both the Cre and IPT genes had been successfully removed from the transgenic plants(deletion efficiency 100%). Over all, using Cre/loxP system recombination together with the IPT positive selection, marker-free transgenic plants can be recovered efficiently from mature tissues of navel orange(Citrus sinensis Osbeck), which provides a potential method for production of transgenic plants from citrus mature tissue.展开更多
Mites belonging to the family Phytoseiidae are the most important and most widely studied among predatory mites of phytophagous mites. The phytophagous mites Brevipalpus phoenicis (Geijskes, 1939) (Tenuipalpidae) and ...Mites belonging to the family Phytoseiidae are the most important and most widely studied among predatory mites of phytophagous mites. The phytophagous mites Brevipalpus phoenicis (Geijskes, 1939) (Tenuipalpidae) and Oligonychus ilicis (McGregor, 1917) (Tetranychidae) on coffee (Coffea spp.), are frequently found in combination with the predaceous mites Iphiseiodes zuluagai Denmark & Muma, 1972;Euseius alatus DeLeon, 1966 and Amblyseius herbicolus (Chant, 1959) (Acari: Phytoseiidae), among others. The purpose of this research was to study the effects of the product CyazypyrTM (cyantraniliprole 100 OD) on these three species of Phytoseiidae, relevant to coffee, citrus and other agricultural crops in Brazil, following standard laboratory procedures. Mated female mites were exposed to fresh-dried residues on a glass surface, with 8 treatments, 5 mites per glass plate and 6 replicates, in a completely randomized experimental design. Each test lasted eight days, with a daily count of the surviving females and of eggs laid. CyazypyrTM, in all tested doses (75, 100, 125, 150, 175 and 200 g a.i./ha), was selective for the studied species, A. herbicolus, I. zuluagai, and E. alatus. Overall the treatments resulted in low mortality rates and negligible impact on the reproduction. Therefore, based on IOBC standards, CyazypyrTMcan be classified as not harmful (class 1) or slightly harmful (class 2), comparable to the agrochemical TalentoTM (hexythiazox 500 WP-12 g a.i./ha) equivalent to a harmless standard of selectivity in the laboratory. CyazypyrTM is therefore a complement to programs of integrated pest management, to preserve the populations of predatory mites in crops of coffee and citrus, among others, in Brazil.展开更多
基金supported by the National Natural Science Foundation of China(31971424)。
文摘Asian citrus psyllid(ACP)is a significant pest of citrus crops that can transmit citrus Huanglongbing(HLB)by feeding on the phloem sap of citrus plants,which poses a significant threat to citrus production.Volatile signal chemicals with plant communication functions can effectively enhance the resistance of recipient plants to herbivorous insects with minimal impacts on plant growth.While(E)-4,8-dimethyl-1,3,7-nonatriene(DMNT),(E,E)-4,8,12-trimethyl-1,3,7,11-tridecene(TMTT),(E)-β-caryophyllene,and dimethyl disulfide(DMDS),are known as signaling molecules in guava-sweet orange communication,whether these four chemical signals can enhance the resistance of Citrus sinensis to feeding by ACP adults with no apparent costs in terms of plant growth remains unclear.Therefore,this study measured the effect of non-damaging induction by DMNT,TMTT,(E)-β-caryophyllene,and DMDS on the ability of C.sinensis to resist feeding by ACP,as well as their impacts on the defensive phytochemicals,defensive enzymes,functional nutrients,Photosystem II's utilization and allocation of light energy,photosynthetic pigments,growth conditions,and leaf stomatal aperture in C.sinensis.The results indicate that non-damaging induction by these four chemicals can enhance the activity of the defensive enzyme polyphenol oxidase(PPO)and increase the contents of total phenols,tannins,and terpenoid defensive phytochemicals within C.sinensis,thereby enhancing the resistance of C.sinensis to ACP feeding.Specifically,DMNT and DMDS exhibit more significant effects in inducing resistance compared to TMTT and(E)-β-caryophyllene.The characteristics of chlorophyll fluorescence parameters and changes in photosynthetic pigments in C.sinensis during different post-exposure induction periods revealed these chemicals can maintain the stability of the photosynthetic system in C.sinensis and regulate its capacity to capture,transmit,and distribute light energy,which significantly enhances the non-photochemical quenching ability of C.sinensis.In addition,detailed measurements of the water content,leaf mass per unit area(LMA),functional nutrients(soluble protein,soluble sugar,and amino acids),and stomatal parameters in C.sinensis leaves further indicated that the non-destructive induction by these chemicals can optimize the levels of functional nutrients in C.sinensis,primarily manifesting as the upregulation of soluble sugars,proline,or soluble proteins,and reduction of stomatal area and aperture,which maintains a stable leaf water content and LMA,thereby enhancing resistance to ACP while sustaining the healthy growth of C.sinensis.These results fully substantiate that the non-damaging induction by the signal chemicals DMNT,TMTT,(E)-β-caryophyllene,and DMDS can enhance the resistance of C.sinensis to ACP feeding while maintaining the balance between pest resistance and growth.This balance prevents any catastrophic effects on the growth of C.sinensis,so these agents can potentially be integrated with other pest management strategies for the collective protection of crops.This study provides theoretical support and assistance for the development of signal chemical inducers for the prevention and management of ACP in agricultural systems.
基金Supported by National Key Technology Research and Development Program(2006BAD01A1702)~~
文摘[Objective] The aim was to identify genetic variation in Citrus sinensis （sweet orange） germplasm from Hunan Province according to the Start Codon Targeted （SCoT） Polymorphism. [Method] The reaction system for SCoT amplification from sweet orange was first optimized, and then the SCoT fragments were amplified from 24 sweet orange cultivars collected in Hunan Province and sequenced for genetic variation analysis. [Result] The optimum reaction system for SCoT markers amplification was 2.0 μl containing 80 ng of template DNA, 0.3 mmol/L dNTPs, 0.2 μmol/L primer, 1.6 mmol/L Mg2＋, 1.6 U of Taq DNA polymerase and 10×PCR buffer. By using this reaction system, the PCR products from the sweet orange cultivars produced clear and reproducible bands at 100-2 000 bp through electrophoresis. The SCoT fragments of the 24 sweet orange cultivars were 1 090-1 091 bp, with the homology of 99.84% and nucleotide deletion and substitution. After being sequenced, the SCoT polymorphisms could distinguish 12 sweet orange cultivars. In addition, the BLAST result showed that part of the SCoT fragments coding region shared high homology with ribosomal protein S3 N superfamily. [Conclusion] This study will provide a theoretical basis for breeding sweet orange cultivars.
基金The authors acknowledge the financial support by the National Natural Science Foundation of China(002002)
文摘An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments ofNewhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with plant growthregulators affected the adventitious bud regeneration frequency and efficiency. The initial 15 d darkness inoculation isbeneficial for the adventitious bud regeneration. The highest regeneration frequency (85.2%) and bud formationefficiency (3.7 per responsive internodal stem segment) were obtained in the media supplemented with 1.0 mg L-1 BAPand 0.5 mg L-1 NAA. ABA at 0.2 mg L-1 positively affected the bud formation efficiency, which amounted to 8.5 buds perinternodal segment in the presence of BAP at 1.0 mg L-1. The adventitious shoots successfully rooted and weretransferred to the soil.
文摘Silver nanoparticles are considerecl as good antimicrobial agent. AgNPs were synthesized by mixing silver nitrate solution with citrus sinesb extract for 2 h at 37 and analyzed by UV-visible spectra, SEM, XRD, and FTIR. AgNPs were tested against B. subtilis, Shigello, S. oureus, ond E. coli. Minimum inhibitory concentration of AgNPs was 20 I^g/mL for B. subtilis and Shigello and 30 I^g/mL for S. oureus and E. coll. Antibiofilm activity （80% to 90%） was observed at 25 IJg/mL. AgNPs were stable for five months with sustained an＇timicrobial activity. Biosynthesized AgNPs can bE： used to inhibit food poisoning microbial growth.
文摘Using the mRNA from the fruit of Cara Cara as the template, the cDNA of phytoene synthase （PSY） gene was amplified by reverse transcription polymerse chain reaction （RT-PCR）. Sequence analysis indicated that the cDNA was of 1 520 bp, which had an open reading frame of 1 308 bp and encoded a protein of 436 amino acids. The homology analysis showed that PSY of Cara Cara shared high similarities of nucleotides and deduced amino acids with those in other plants up to more than 75 and 70%, respectively. A putative signal transit peptide for plastid targeting was found in the N-terminal region of PSY. The mature forms of PSY included a transmembrane （TM） domain. The recombinant plasmid pET-CitPSY was constructed by subcloning the full coding sequence of PSY cDNA into pET-28 （＋）. After transformation of E. coli BL21 and induced by 1 mmol L^-1 isopropyl-β-D-thiogalacropyranoside （IPTG）, the fusion protein （6× His-PSY） with 52 kD was produced at a high level by prokaryotic expression system. The results of Western blot demonstrated that the fusion protein （6× His-PSY） could be recognized by anti-6 × His monoclonal antibody. The study could establish a basis for molecular improvement of Citrus fruit colors.
文摘In this study, essential oils from Cymbopogon citratus and Ceasalpinia decapitala leaves, Citrus lemon and Citrus sinens＆ peels, were extracted, chemically characterized and evaluated on both Gram positive and Gram negative bacteria, Salmonella Typhimurium, Escherichia coli, Listeria innocua, Staphylococcus aureus, Klebsiella pneumonia and Streptococcus pyogenes. Essential oil of C. citratus was found to be rich in geranial （33.0%） and neral （49.7%）, that from C. decapitala in 13-pinene （8.4%）, ct-pinene （25.5%）, 13-ocymene （31.6%）, 15-phellandrene （8.4%）, caryophyllene （7.5%） and geranial （5.9%）. The essential oil from C. lemon and C. sinensis where mainly composed by limonene with percentages of 77.5% and 83.3% respectively, and 13-phellandrene with percentages of 8.1% and 10.8% for the essential oil of C. lemon and C. sinensis, respectively. The antibacterial activity assessment realized on different microorganisms contaminating food showed that essential oil from C. citratus was shah more effective against all tested bacteria while that from C. sinensis was the less active essential oil. The incorporation of essential oils in HPC （hydroxy-propyl cellulose） films showed that those essential oils, especially essential oils from C. citratus, maintained their antibacterial activities against targeted microorganisms and therefore can be applied in food packing.
文摘Citrus sinensis commonly called sweet orange belongs to the family Rutaceae. Nutritionally, it is highly recommended due to its high content of micronutrients. However, the rejection of a large amount of epicarp in nature contributes to the emission of greenhouse gas and the development of leachate which contaminate surface water and groundwater. The aim of this work was to identify the essential oil components from Citrus sinensis epicarp, and then look after the biological activity of these components in order to underline the worth to reuse the Citrus sinensis epicarp as a gainful mean. The essential oil of 4,000 g of Citrus sinensis epicarp was done through the water steam distillation and 0.0287 g of essential oil was obtained; so a yield of 0.0007%. The essential oil was then submitted to gas chromatography-flame ionization detector （GC-F1D）. The result revealed that the essential oil was teemed with 28 volatile compounds, including terpene compounds （50%）, aldehydes （32%） and alcohols （18%） whose anti-inflammatory, anti-diabetic, larvicidal and antioxidant activities were underlined.
文摘The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.
文摘Background:Silver nanoparticles(SNPs)play important role in the field of optics and electronics and also as a novel antibacterial agents.Here,we report a simple and green method for the biosynthesis of SNPs using aqueous leaf extract of Origanum majorana and Citrus sinensis as a novel bio source of cost-effective,non-hazardous reducing,and stabilizing agents.A 3 mM solution of silver nitrate was prepared.Five milliliter aqueous leaf extract was slowly added to 20 ml silver salt solution(3 mM)with constant stirring.No noticeable color change was observed.The solution was then heated in domestic microwave for variable time intervals.The intense brown colored solution was obtained on 1 min heating with O.majorana and 5 min heating with C.sinensis extract.The intense brown color indicated the formation of SNPs.The antibacterial activity of synthesized SNPs was investigated.Results:SNPs were rapidly synthesized using aqueous leaf extract of O.majorana and C.sinensis on microwave irradiation.Formation of SNPs was confirmed by the change in color from yellowish green to brown and absorption maximum around~420 and 410 nm due to surface plasmon resonance of SNPs.They were also characterized by other physical-chemical techniques like Fourier transform infrared spectroscopy(FT-IR),scanning electron microscope coupled with X-ray energy dispersive spectroscopy,and high-resolution transmission electron microscopy.TEM analysis showed the presence of feather-shaped NPs in O.majorana and spherical as well as cubical-shaped NPs in C.sinensis-mediated SNPs.The synthesized SNPs showed significance antibacterial activity against two human pathogenic strains.Conclusion:The SNPs were synthesized using leaf extract of plants.This synthesis method is nontoxic,eco-friendly,and a low-cost technology for the large-scale production.The SNPs can be used as a new generation of antibacterial agents.
基金funded by the National Natural Science Foundation of China(No.32172262)the Fundamental Research Funds for the Central Universities(No.XDJK2021F008)Chongqing Graduate Student Research Innovation Project(No.CYS21118),China.
文摘Segment drying is a severe physiological disorder of citrus fruit,and vesicles become granulated or collapsed.Aside from the hypothesis that alteration of cell wall metabolism is the main factor of citrus granulation,little is known about vesicle collapse.This study aimed to elucidate the changes in pectin metabolism during vesicle collapse in blood orange.Vesicle collapse was characterized by decreased nutrients and increased chelate-and sodium carbonate-soluble pectin and calcium content.The nanostructure of chelate-soluble pectin became complex and developed multi-branching upon collapse.The activity of pectin methylesterase increased,while that of polygalacturonase and pectate lyase decreased upon collapse.Genome-wide transcriptional analysis revealed an increasing pattern of genes encoding pectin methylesterase and other enzymes involved in pectin synthesis and demethylesterification upon collapse.Drying vesicles were characterized by increased abscisic acid content and relevant gene expression.In conclusion,we discovered alteration in pectin metabolism underlying citrus vesicle collapse,mainly promoting pectin demethylesterification,remodeling pectin structures,and further inhibiting pectin degradation,which was hypothesized to be a main factor for citrus collapse.This is the first study to disclose the potential intrinsic mechanism underlying vesicle collapse in orange fruit.
基金financed by the National Natural Science Foundation of China (31772261)the Huazhong Agricultural University Scientific & Technological Self-Innovation Foundation (Program No.2017RC002) to Dr. Weiwei Wen
文摘Sesquiterpene valencene is dominant in flavedo tissues of sweet oranges and imparts a unique woody aroma.However,the interaction between the biosynthetic pathways of valencene and other nutritional compounds is less studied.Sesquiterpenoids were significantly accumulated in a previously reported glossy mutant of orange(MT)than the wild type(WT),especially valencene and caryophyllene.In addition,we identified several other pathways with variations at both the transcriptional and metabolic levels in MT.It’s interesting to found those upregulated metabolites in MT,such as eukaryotic lipids,kaempferol and proline also showed strong positive correlation with valencene along with fruit maturation while those down-regulated metabolites,such as phenylpropanoid coumarins and most of the modified flavonoids exhibited negative correlation.We then categorized these shifted pathways into the‘sesquitepenoid-identical shunt’and the sesquitepenoid-opposite shunt’and confirmed the classification result at transcriptional level.Our results provide important insights into the connections between various fruit quality-related properties.
基金the National Council of Scientific and Technological Development(CNPq)who enabled the execution of this study by conceding PIBIC,M.Sc.,PhD and Productivity in research grants.
文摘This study investigated the protective effects of secondary bacterial metabolites, produced by Pseudomonas sp. (bacterium strain LN), on citrus canker disease caused by Xanthomonas axonopodis pv. citri (Xac 306). The LN bacteria strain was cultured in liquid medium and the supernatant free-cells was treated with methanol (AMF) and ethyl acetate (AEF), respectively, and then the extract was concentrated, filtrated, lyophilized and fractionated by vacuum liquid chromatography (VLC). After VLC, eight fractions were obtained. All fractions’ activity against Xac 306 by agar well diffusion assay and minimum inhibitory concentration but in different concentrationswere tested. Cytotoxicity effects were observed in all fractions in 50 μg·mL-1 concentration. The comet assay demonstrated that the fractions EAF, VLC2 and VLC3 presented no genotoxic effects at tested concentrations. In plants only VLC3 showed significant results (p<0.05), reducing the incidence of citrus canker lesions.
文摘Citrus sinensis(L.)Osbeck fruit peels contain polyphenols which are known for its therapeutic properties.However,these polyphenols have limitations like astringent taste,low bioavailability,instability,and susceptibility to oxidation.To overcome these limitations,encapsulation techniques are being studied.Our study focuses on enriching polyphenols from Citrus sinensis fruit peels using amberlite XAD 16-N resin thereby developing efficient microspheres by extrusion technique using alginate matrix.Further,SEM and FTIR were used to characterise these microspheres.Additionally,it was also studied for swelling ability,polyphenols release at various pH,temperature,time,and bio-accessibility under simulated digestion condition.The results showed that the enriched polyphenols from Citrus sinensis fruit peels(EPCSP)were successfully encapsulated and maintained its stability significantly by retaining its total polyphenol content(63.08±2.2 mg/g of GAE)and total antioxidant activity(288.3±8.9 mg/g of AAE)in comparison to unencapsulated extract(p<0.05)throughout a period of 12 months.It was also observed that,at pH 7.4,the encapsulated microspheres showed significant swelling,resulting in an increased total polyphenol release than at pH 1.6.Furthermore,the EPCSP loaded alginate microspheres were also efficient in significantly maintaining the biological activities(p<0.05)thereby leading to a higher bio-accessibility index in the intestine.The present work highlighted the potential of alginate matrix which has shown improved stability of polyphenols and may be used as a drug delivery system which may lead to its wide applications in nutraceuticals/pharmaceutical industries.
基金supported by the National Natural Science Foundation of China(Grant No.32172334)the Fundamental Research Funds for the Central Universities(Grant No.226-2024-00110)the 75th batch of general funding from the China Postdoctoral Science Foundation(2024M752815).
文摘Anthocyanins are enriched in blood oranges(Citrus sinensis L.Osbeck)in response to external environmental stimulation during postharvest storage,while the role of plant hormones in anthocyanin accumulation in response to low-temperature inducement is still poorly studied.Here,we investigated the anthocyanin profiles and fruit quality of blood oranges treated with different temperatures and then further focused on the mechanisms of plant hormone-mediated anthocyanin biosynthesis induced by low temperatures using proteomics.Total and individual anthocyanins were significantly increased in blood oranges under the low-temperature storage at 8℃,among which cyanidin 3-glucoside and cyanidin 3-(6″-malonylglucoside)were increased by 6.51 and 6.77 times at the end of storage,respectively.Low temperature effectively delayed the weight loss and maintained the water status.For flavor changes,high levels of sucrose,citric acid,and malic acid were observed in fruits stored at 8℃,and low temperature delayed the changes of overall volatile flavor compounds,in which aroma-active compounds were closer to those in fresh fruit.The proteomic analysis found that differentially expressed proteins between fruit stored at 8 and 25℃ were enriched in“Phenylalanine metabolism”,“Flavonoid biosynthesis”,“Brassinosteroid biosynthesis”and“Cysteine and methionine metabolism”pathways,indicating that low temperature induced the biosynthesis and signal transduction of brassinosteroids and ethylene(CYP90A1,CYP90C1/D1,CYP92A6,SAMS,ACC oxidase,ETR1),upregulated the expression of anthocyaninrelated proteins(PAL,4CL,CHS1,CHS2,F3′5′H,DFR,ANS,and UFGT),and ultimately promoted anthocyanin accumulation in the postharvest blood oranges.
文摘The objective of the study was to determine the influence of temperature, relative humidity, and shoot size of Valencia orange trees Citrus sinensis (L.) Osbeck (Sapindales: Rutaceae) on the abundance of eggs and nymphal stages of Diaphorina citri Kuwayama (Hemiptera: Liviidae). The experiment was established on 3.18 hectares cultivated with Valencia orange. The number of eggs, nymphs, temperature, relative humidity, and scale of the size of the shoot were recorded from January to July and from September to November 2020. The association of these variables was determined by multiple correspondence analyses. The conservation of the same number of individuals between consecutive samples and the increase in the number of eggs and nymphs was associated with temperature (17˚C - 23˚C), relative humidity (75% - 78%) and the availability of shoots from V1 to VS in March, April, June, and July. The largest number of N1 and N2 nymphs was recorded in January, February, May, and October. The highest population of eggs and nymphs N3 and N5 occurred in September. In November, there was a reduction in eggs and nymphs. Meanwhile, the nymph N4 was presented independently of the variables analyzed.
基金supported by the Fundamental Research Funds for the Central Universities (Grant No. XDJK 2018B016)the National Natural Sciences Foundation of China (Grant No. 31972393)+1 种基金he earmarked fund for China Agriculture Research System (Grant No. CARS-26)the Natural Science Foundation of Chongqing (Grant No. cstc2020jcyj-msxmX1064)。
文摘Genetic transformation with mature material as the explants could shorten the transgenic period and avoid seed dependence compared with genetic transformation using the epicotyl seedling stem segments as the receptor. Here, we constructed an Agrobacterium tumefaciensmediated transformation for generation of marker-free transgenic plants from navel orange(Citrus sinensis Osbeck) mature stems using a CreloxP recombination system. To efficiently recover the regenerated buds from mature tissues, five recovery methods were compared: in vitro micrografting of 0.1-0.5(1-2 weeks), > 0.5 cm(3-4 weeks) and > 1 cm long lignified bud and in vitro micrografting of explants with a bud and rooting regenerated bud. The data showed that in vitro micrografting of > 1 cm long regenerated bud with expanded leaves after one month of continuous culture for lignification was the optimal solution for plant recovery from mature tissues. Transgenic plants without selectable marker genes were created from navel orange(Citrus sinensis Osbeck) tissue using a transformation vector PLI-35SPR1aCB containing a Cre/loxP system recombination together with genes encoding the selectable marker isopentenyl transferase(IPT) and an anti-bacterial peptide(PR1aCB).Using IPT positive selection, the transformation efficiency determined by PCR was 0.9%, and in total, 20 transgenic plants were obtained.Southern blotting confirmed further their transgenicity. PCR and sequencing analysis demonstrated that both the Cre and IPT genes had been successfully removed from the transgenic plants(deletion efficiency 100%). Over all, using Cre/loxP system recombination together with the IPT positive selection, marker-free transgenic plants can be recovered efficiently from mature tissues of navel orange(Citrus sinensis Osbeck), which provides a potential method for production of transgenic plants from citrus mature tissue.
基金For DuPont do Brasil S.A.-Agricultura e Nutricao for the financial supportCNPq and INCT do CaféCNPq-Fapemig for the fellowship.
文摘Mites belonging to the family Phytoseiidae are the most important and most widely studied among predatory mites of phytophagous mites. The phytophagous mites Brevipalpus phoenicis (Geijskes, 1939) (Tenuipalpidae) and Oligonychus ilicis (McGregor, 1917) (Tetranychidae) on coffee (Coffea spp.), are frequently found in combination with the predaceous mites Iphiseiodes zuluagai Denmark & Muma, 1972;Euseius alatus DeLeon, 1966 and Amblyseius herbicolus (Chant, 1959) (Acari: Phytoseiidae), among others. The purpose of this research was to study the effects of the product CyazypyrTM (cyantraniliprole 100 OD) on these three species of Phytoseiidae, relevant to coffee, citrus and other agricultural crops in Brazil, following standard laboratory procedures. Mated female mites were exposed to fresh-dried residues on a glass surface, with 8 treatments, 5 mites per glass plate and 6 replicates, in a completely randomized experimental design. Each test lasted eight days, with a daily count of the surviving females and of eggs laid. CyazypyrTM, in all tested doses (75, 100, 125, 150, 175 and 200 g a.i./ha), was selective for the studied species, A. herbicolus, I. zuluagai, and E. alatus. Overall the treatments resulted in low mortality rates and negligible impact on the reproduction. Therefore, based on IOBC standards, CyazypyrTMcan be classified as not harmful (class 1) or slightly harmful (class 2), comparable to the agrochemical TalentoTM (hexythiazox 500 WP-12 g a.i./ha) equivalent to a harmless standard of selectivity in the laboratory. CyazypyrTM is therefore a complement to programs of integrated pest management, to preserve the populations of predatory mites in crops of coffee and citrus, among others, in Brazil.
