Storage and Preservation of Carica papaya Using Composite Fungicidal Coatings

[Objectives]The paper was to investigate a method for the storage and preservation of Carica papaya utilizing chemical fungicides and composite biological coatings.[Methods]C.papaya fruits with red pulp sourced from Lianjiang were utilized as test materials.The fruit epidermis was subjected to treatment with composite fungicidal coatings at ambient temperature,and the nutritional and physiological indicators of the fruits were measured at regular intervals.[Results]Under ambient temperature conditions,a chemical fungicide composite consisting of 300 mg/L fludioxonil and 250 mg/L propiconazole was employed to soak the fruits for a duration of 2 min.Subsequently,a composite biological coating formulated with 8 g/L KGM and 1.0%Zein at a pH of 7.0 was applied to the fruits.This treatment effectively inhibited the decline in the content of total soluble solids(TSS)and vitamin C(V C)in C.papaya,reduced the weight loss rate and the decay index,and enhanced the yellow ripening index.[Conclusions]This study establishes a foundation for the advancement of additional methods and techniques for the storage and preservation of C.papaya.

Determination of the Mineral Composition of the Pulp and Evaluation of the Acute Toxicity of the Seeds of Carica papaya L. Consumed in Lubumbashi and Kinshasa in the Democratic Republic of the Congo

This work aimed, on the one hand, to determine the mineral and phytochemical composition of Carica papaya in order to guarantee the food safety of consumers and on the other hand, to evaluate the acute toxicity of papaya seeds. The papayas were bought at the Mzée market in Lubumbashi and Selembao in Kinshasa. Fruit sampling was done according to the ISO 7002 standard on agricultural and food products;the papayas were firm, mature, and without stains or physical damage. The analysis results of the papaya pulp showed both for the samples from the city of Lubumbashi and for the city province of Kinshasa that it contains respectively 85.87% and 84.46% water, 0.59% and 0.53% ash content. The mineral evaluation of our two samples presented a potassium content of 200 ± 8 mg, magnesium 13.12 ± 3 mg, calcium 22.15 ± 2 mg, sodium 3 mg ± 0.5 for the sample from Lubumbashi and 192.32 ± 8 mg of potassium, 14.458 ± 3 mg of magnesium, 20.58 ± 2 mg of calcium and 3.58 ± 0.5 mg of sodium for the sample from Kinshasa in macroelements. Concerning the trace elements, after analysis, we found zinc content (0.29 ± 0.1 mg and 0.12 ± 0.1 mg), copper (0.02 ± 0.01 mg and 0.14 ± 0.01 mg), and iron (2.22 ± 0.5 mg and 2.04 ± 0.5 mg) respectively for Lubumbashi and Kinshasa. The chemical screening indicates the presence of alkaloids, saponosides, tannins catechics, flavonoids and anthocyanins in the palm wine and ethanolic extract of the seeds of Carica papaya and an absence of cyanogenic glycosides and gallic tannins. With mild toxicity, the seeds of the fruit of Carica papaya L. can be used with moderate risk by the population.

Tissue Culture of Mini-Papaya

[Objective] The aim was to study the tissue culture of mini-Papaya.[Method] The pretreatment seeds of mini-Papaya were cultured in the MS medium containing 6-BA and IBA of different densities for rapid propagation.[Result] In the condition of aseptic strain,the surface of mini-Papaya peel was uniformly wiped by 75% alcohol,then seeds were removed and washed by aseptic water for 3 times,which was the best sterilization method,and the pollution rate of seed was only 2.52%.After seeds which had been soaked by the equi-volume mix-solution of 1 000 mg/L GA3 and 1 mg/L 6-BA for 18 h were further purified in MS medium,the germination rate of seed,the length of embryo bud and radicle and the height of seedling were 68.42%,2.25,0.80 and 1.52 cm respectively,furthermore the total situation of seedling growth was better.When subculture multiplication medium was MS＋0.5 mg/L 6-BA＋0.1 mg/L IBA medium,proliferation coefficient of subculture multiplication reached the highest （7.92）,and the seedlings grew better.The ratio of vitrified shoots decreasing with the increase of light intensity could reach the lowest level （3.21%） under the light intensity of 3 000 lx.[Conclusion] The research provides reference for studies on tissue culture and rapid propagation of mini-Papaya.

Effect of Internal Ethylene and 1-Methylcyclopropene on Ethylene Metabolism and Membrane Lipid Peroxidation in Papaya Fruit

[Objective] This study was conducted to evaluate the effect of 1-methylcy- clopropene （1-MCP） on fruit firmness, and the activity of the enzymes involved in ethylene metabolism and membrane lipid peroxidation. [Method] The nearly ripe fruits of the papaya cultivar Risheng were randomly assigned to one of four groups. Two groups were treated under hypobaric and hypoxic （HH） atmosphere condition for six hours, and immediately soaked in deionized water （HH alone）, or fumigated with 2.0 mg/L 1-MCP （HH＋I-MCP） for 24 h. The other two groups untreated under HH condition were also soaked in deionized water （negative control）, or fumigated with 2.0 mg/L 1-MCP （1-MCP alone） for 24 h. After that, the fruits of all the four treatments were stored at room temperature （23＋1） ℃. Cell membrane permeability, fruit firmness, respiration rate, ethylene release rate, SOD activity, POD activity, CAT activity, MAD content and LOX activity were measured once every three days during storage. [Result] Treatment with 1-MCP delayed the occurrence of the peaks of respiration rate and ethylene release rate, significantly reduced the accumulation of malondialdehyde （MDA）, and inhibited the decrease in papaya fruit firmness. Compared with the control, 1-MCP treatment significantly increased the SOD （su- peroxide dismutase）, POD （peroxidase） and CAT （catalase） activity, reduced the ac- tivity of lipoxygenase （LOX）, a product of lipid peroxidatlon in membranes, and in- hibited ethylene biosynthesis, thus delaying the aging process and prolonging the storage life of papaya fruits. [Conclusion] The results will provide a theoretical basis for analvzina the key factors controllinq postharvest maturity and aging of papaya fruits.

Preliminary Study on Callus Differentiation of Hermaphrodite Papaya

With calluses of hermaphrodite papaya as the tested material and MS as the basic medium, the effects of different plant growth regulators and their combinations on adventitious bud induction of calluses and rooting induction of sterile buds were investigated. The results showed that 6-BA and TDZ all showed certain induction effect on callus differentiation of papaya; the induction effect of 6-BA was better than that of TDZ, and the optimum concentration of 6-BA was 0.05 mg/L. GA3 could promote the induction effect of 6-BA for on callus differentiation. The optimum medium combination for inducing the callus differentiation of papaya was MS ＋ 6- BA 0.5 mg/L ＋ GA3 1.0 mg/L. Compared to NAA, IBA was more suitable for inducing the rooting of adventitious buds. The optimum rooting-induction medium combination was MS ＋ IBA 0.3 mg/L.

Field released transgenic papaya effect on soil microbial communities and enzyme activities

Soil properties, microbial communities and enzyme activities were studied in soil amended with replicase （RP）-transgenic or non-transgenic papaya under field conditions. Compared with non-transgenic papaya, significant differences （P〈0.05） were observed in total nitrogen in soils grown with transgenic papaya. There were also significant differences （P〈0.05） in the total number of colony forming units （CFUs） of bacteria, actinomycetes and fungi between soils amended with RP-transgenic plants and non-transgenic plants. Compared with non-transgenic papaya, the total CFUs of bacteria, actinomycetes and fungi in soil with transgenic papaya increased by 0.43-1.1, 0.21-0.80 and 0.46-0.73 times respectively. Significantly higher （P〈0.05） CFUs of bacteria, actinomycetes and fungi resistant to kanamycin （Km） were obtained in soils with RP-transgenic papaya than those with non-transgenic papaya in all concentrations of Km. Higher resistance quotients for Km＇ （kanamycin resistant） bacteria, actinomycetes and fungi were found in soil planted with RP-transgenic papaya, and the resistance quotients for Km＇ bacteria, actinomycetes and fungi in soils with transgenic papaya increased 1.6-4.46, 0.63-2.5 and 0.75-2.30 times. RP-transgenic papaya and non-transgenic papaya produced significantly different enzyme activities in arylsulfatase （5.4-5.9x）, polyphenol oxidase （0.7-1.4x）, invertase （0.5-0.79x）, cellulase （0.23-0.35x） and phosphodiesterase （0.16-0.2x）. The former three soil enzymes appeared to be more sensitive to the transgenic papaya than the others, and could be useful parameters in assessing the effects of transgenic papaya. Transgenic papaya could alter soil chemical properties, enzyme activities and microbial communities.

Content determination of benzyl glucosinolate and anti—cancer activity of its hydrolysis product in Carica papaya L.

Objective:To determine the content of benzyl glueosinolate（BG） in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performed on an Hypersil BDS C18 column at the wavelength of 214 nm with 0.1%trifluoroacelic acid（TFA） aqueous solution（A） and 0.1%TFA acelonilrile（B） as the mobile phase.In vitro activity test was adopted with cidtured human lung cancer H69 cell in vitro to investigate the inhibition rate of cell proliferation of benzyl isothiocyanale（BITC） againsl H69 cell.Results:The pulp has more BG before the maturation of papaya and it nearly disappeared after papaya matured,while the seed contains BG at every stage.Activity test demonstrated that the a higher concentration of BITC would have betler inhibition rate of cell proliferation on 1169 cell,and the IC50 was 6.5μmol/L.Conclusions:BG also can be produced in the pulp of papaya and it will be stored in the seed after the fruit has been matured.The hydrolysis product of BG has certain cancer-prevention anti-cancer activities for human.

Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study

Aim: To examine if the seed extracts of Carica papaya, which showed anfispermatogenic/sperm immobilizationproperties in animal models, could cause human sperm immobilization in vitro. Methods: Chloroform extract, ben-zene chromatographic fraction of the chloroform extract, its methanol and ethyl acetate sub-fractions and the isolatedcompounds from the sub-fractions i. e., ECP 1 & 2 and MCP 1 & 2, of the seeds of Carica papaya were used at con-centrations of 0.1%, 0.5%, 1% and 2%. Sperm motility was assessed immediately after addition of extracts and ev-ery 5 minutes thereafter for 30 minutes. Results: There were dose-dependent spermicidal effects showing an instantfall in the sperm motility to less than 20% at 2% concentration. Isolated compounds ECP 1 & 2 were more effective in-ducing a motility of less than 10%. Many of the spermatozoa became vibratory on the spot. Total inhibition of motilitywas observed within 20-25 rain at all concentrations of all products. Scanning and transmission electron microscopyrevealed deleterious changes in the plasma membrane of the head and mid-piece of spermatozoa. Sperm viability testand the number of abnormal spermatozoa after completion of incubation suggested that the spermatozoa were infertile.The effects were spermicidal but not spermiostatic as revealed by the sperm revival test. Conclusion: The results re-veal spermicidal activity in vitro of the seed extracts of Carica papaya.

Dengue fever treatment with Carica papaya leaves extracts

The main objective of the current study is to investigate the potential of Carica papaya leaves extracts against Dengue fever in 45 year old patient bitten by carrier mosquitoes.For the treatment of Dengue fever the extract was prepared in water.25 mL of aqueous extract of C.papaya leaves was administered to patient infected with Dengue fever twice daily i.e.morning and evening for five consecutive days.Before the extract administration the blood samples from patient were analyzed.Platelets count(PLT),White Blood Cells(WBC) and Neutrophils(NEUT) decreased from 176×10~3/μ L,8.10×10~3/μ L,84.0%to 55×10~3/μ L,3.7×10~3/μL and 46.0%.Subsequently,the blood samples were rechecked after the administration of leaves extract.It was observed that the PLT count increased from 55×10~3/μ L to 168×10~3/μ L,WBC from 3.7×10~3/μ L to 7.7×10~3/μ L and NEUT from 46.0%to 78.3%.From the patient feelings and blood reports it showed that Carica papaya leaves aqueous extract exhibited potential activity against Dengue fever.Furthermore,the different parts of this valuable specie can be further used as a strong natural candidate against viral diseases.

Sperm characteristics and ultrastructure of testes of rats after long-term treatment with the methanol subfraction of Carica papaya seeds

The contraceptive efficacy of Carica papaya seeds after short-term evaluation has been well established. We have examined the safety and mechanism of contraception in rats after long-term treatment with the methanol subfraction （MSF） of C. papaya seeds. The test substance was administered orally to the male albino rats （n = 40） at 50 mg per kg body weight each day for 360 days. Control animals （n = 40） received olive oil as a vehicle. Recovery was assessed up to 120 days after treatment withdrawal. Sperm parameters, serum testosterone levels, fertility, histology and ultrastructure of the testis, haematology and serum clinical chemistry were evaluated to establish the safety and efficacy of the test substance. Safety of long-term treatment was evidenced by unaltered health status, organ weight, haematology and clinical chemistry, and by an increase in body weight. The mechanism of contraception was shown by reduction in nuclear and cytoplasmic volume, normal nuclear characteristics and vacuolization in the cytoplasmic organelles of the Sertoli cells, as well as nuclear degeneration in spermatocytes and spermatids indicating disturbed spermatogenesis. Leydig cells were normal. Initial effects were observed in Sertoli cells at 60 days of treatment. Spermatocytes and spermatids were affected after 120-240 days of treatment. A significant decline in sperm count and viability, total inhibition of sperm motility, increased numbers of sperm abnormalities, normal serum testosterone levels and 100% sterility were evident after 60 days of treatment. All the altered parameters, including percent fertility, were restored to control level 120 days after treatment withdrawal. It is concluded that the MSF is safe for long-term treatment and the mechanism of contraception is shown by its effect on spermatid differentiation in the testis, possibly mediated by the Sertoli cell factors.

Papaya CpbHLH1/2 regulate carotenoid biosynthesis-related genes during papaya fruit ripening

The ripening of papaya is a physiological and metabolic process associated with accumulation of carotenoids,alternation of flesh color and flavor,which depending on genotype and external factors such as light and hormone.Transcription factors regulating carotenoid biosynthesis have not been analyzed during papaya fruit ripening.RNA-Seq experiments were implemented using different ripening stages of papaya fruit from two papaya varieties.Cis-elements in lycopeneβ-cyclase genes(CpCYC-B and CpLCY-B)were identified,and followed by genome-wide analysis to identify transcription factors binding to these cis-elements,resulting in the identification of CpbHLH1 and CpbHLH2,two bHLH genes.The expressions of CpbHLH1/2 were changed during fruit development,coupled with transcript increase of carotenoid biosynthesis-related genes including CpCYC-B,CpLCY-B,CpPDS2,CpZDS,CpLCY-E,and CpCHY-B.Yeast onehybrid(Y1H)and transient expression assay revealed that CpbHLH1/2 could bind to the promoters of CpCYC-B and CpLCY-B,and regulate their transcriptions.In response to strong light,the results of elevated expression of carotenoid biosynthesis-related genes and the changed expression of CpbHLH1/2 indicated that CpbHLH1/2 were involved in light-mediated mechanisms of regulating critical genes in the carotenoid biosynthesis pathway.Collectively,our findings demonstrated several TF family members participating in the regulation of carotenoid genes and proved that CpbHLH1 and CpbHLH2 individually regulated the transcription of lycopeneβ-cyclase genes(CpCYC-B and CpLCY-B).This study yielded novel findings on regulatory mechanism of carotenoid biosynthesis during papaya fruit ripening.

A comparative study of the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya(Caricaceae) on Heligmosomoides bakeri

Objective:To assess the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya（Caricaceae） on the eggs and first stage larvae（L1） of Heligmosomoides bakeri.Methods:Eggs of this parasite were obtained from experimentally infested mice（Mus musculus） and larvae were from eggs after incubation at 25℃for about 72 hours.The eggs and larvae were exposed to ten different concentrations（0.125,0.25,0.375,0.5, 0.75,1.0,1.25,1.75,2.25 and 2.75 mg/mL） of both aqueous and ethanolic extracts respectively for 72 hours.Distilled water and 0.05%ethanol used as placebo and negative control,respectively. Results:Placebo and negative control group all showed average 92%embryonnation,98%egg hatching and 2%larval mortality,and did not affect development and larval survival.The extracts inhibited embryonic development,egg hatching and larval survival.In general,the ovicidal and larvicidal activities increased with increasing concentration of different extracts.The aqueous extract was found to be more potent on eggs than on larvae.At 2.75 mg/mL,only 8%of eggs embryonnated and 50%hatched to L1 vs 57%embryonic development and 79%hatching occurred in the ethanolic extract.However,this later extract was more efficient in preventing larval development producing 96%mortality as against 68%with the aqueous extract.Conclusions: These results shows the ovicidal and larvicidal properties of aqueous and ethanolic pawpaw seeds extracts.

Reduction of hydrogen peroxide-induced erythrocyte damage by Carica papaya leaf extract

Objective:To investigate thein vitroantioxidant potential of Carica papaya(C. papaya) leaf extract and its effect on hydrogen peroxide-induced erythrocyte damage assessed by haemolysis and lipid peroxidation.Methods:Hydroxyl radical scavenging activities, hydrogen ion scavenging activity, metal chelating activity, and the ferrous ion reducing ability were assessed as antioxidant indices. In the other experiment, human erythrocytes were treated with hydrogen peroxide to induce erythrocyte damage. The extract(at various concentrations) was subsequently incubated with the erythrocytes and later analysed for haemolysis and lipid peroxidation as indices for erythrocyte damage.Results:Preliminary investigation of the extract showed that the leaf possessed significant antioxidant and free radical scavenging abilities usingin vitro models in a concentration dependent manner(P<0.05). The extract also reduced hydrogen peroxide induced erythrocyte haemolysis and lipid peroxidation significantly when compared with ascorbic acid(P<0.05). The IC50values were 7.33 mg/mL and 1.58 mg/mL for inhibition of haemolysis and lipid peroxidation, respectively. In all cases, ascorbic acid(the reference antioxidant) possessed higher activity than the extract.Conclusions:The findings show that C. papayaleaves possess significant bioactive potential which is attributed to the phytochemicals which act in synergy.Thus, the leaves can be exploited for pharmaceutical and nutritional purposes.

The interaction of CpEBF1 with CpMADSs is involved in cell wall degradation during papaya fruit ripening

Ethylene plays a pivotal role in climacteric fruit ripening;whereas 1-MCP,a non-toxic antagonist of ethylene,prevents ethylene-dependent responses and fruit ripening.In this study,a short-term treatment(1 h)with 400 nL L^(−1)1-MCP delayed the ripening of harvested papaya.However,long-term application of 1-MCP(400 nL L^(−1),16 h)resulted in abnormal fruit ripening,with the fruits exhibiting normal yellowing without softening,significantly higher cellulose and lignin contents,and intact cell walls(CW).Furthermore,we found that long-term treatment with 1-MCP significantly inhibited the expression of CpEBF1,an EIN3-binding F-box-1 gene.A protein interaction analysis using yeast two-hybrid,BiFC and GST pull-down assays showed that CpEBF1 interacts with the CpMADS1/3 and CpEIL1 proteins.The interaction of CpEBF1 with CpMADS1/3 further activated the activities of CW-degradation gene promoters.Subcellular localization showed that these proteins were localized in the nucleus.Additionally,the expression levels of CpMADS1/3,CpEIL1,and several CW-degradation-related genes were significantly downregulated by long-term 1-MCP treatment.Therefore,we propose that the inhibited expression of CpEBF1 and CpMADS1/3 resulted in the repressed activation of CW-degradation-related genes via their interaction,thereby resulting in fruit softening disorders.

Sperm motility inhibitory effect of the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in langur monkey, Presbytis entellus entellus

Aim： To assess the contraceptive efficacy of the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in langur monkeys. Methods： The test substance was given p.o. to five monkeys at 50 mg/kg body weight/day for 360 days. Control animals （n = 3） received olive oil as vehicle. Sperm parameters as per World Health Organization standards, sperm functional tests, morphology of testis and epididymis, haematology, clinical biochemistry, serum testosterone and libido were evaluated. Following completion of 360 days treatment the animals were withdrawn from the treatment and the recovery pattern was assessed by semen analysis and sperm functional tests. Results： Total inhibition of sperm motility was observed following 60 days of treatment that continued until 360 days study period. Sperm count, percent viability and percent normal spermatozoa showed a drastic decline following 30 days of treatment. Sperm morphology showed predominant mid piece abnormalities. Sperm functional tests scored in sterile range. Histology and ultrastructure of testis revealed vacuolization in the Sertoli cells and germ cells. Loss of cytoplasmic organelles was evident in spermatocytes and round spermatids. Histology and ultrastructure of epididymis of treated animals were comparable to those of control animals. Hematological and serum clinical parameters and testosterone levels fluctuated within the control range throughout the study period. Recovery was evident following 60--120 days of treatment withdrawal. Conclusion- The results suggest that the benzene chro- matographic fraction of the chloroform extract of the seeds of Carica papaya shows contraceptive efficacy without adverse toxicity, mediated through inhibition of sperm motility. （Asian JAndro12008 Mar; 10： 298-306）

Tissue differential expression of lycopene β-cyclase gene in papaya

Carotene pigments in flowers and fruits are distinct features related to fitness advantages such as attracting insects forpollination and birds for seed dispersal.In papaya,the flesh color of the fruit is considered a quality trait that correlateswith nutritional value and is linked to shelf-life of the fruit.To elucidate the carotenoid biosynthesis pathway in papaya,we took a candidate gene approach to clone the lycopene β-cyclase gene,LCY-B.A papaya LCY-B ortholog,cpLCY-B,was successfully identified from both cDNA and bacterial artificial chromosome(BAC)libraries and complete genomicsequence was obtained from the positive BAC including the promoter region.This cpLCY-B shared 80% amino acididentity with citrus LCY-B.However,full genomic sequences from both yellow- and red-fleshed papaya were identical.Quantitative real-time PCR(qPCR)revealed similar levels of expression at six different maturing stages of fruits forboth yellow-and red-fleshed genotypes.Further expression analyses of cpLCY-B showed that its expression levels wereseven- and three-fold higher in leaves and,respectively,flowers than in fruits,suggesting that cpLCY-B is down-regulatedduring the fruit ripening process.

Auxin regulation involved in gynoecium morphogenesis of papaya flowers

The morphogenesis of gynoecium is crucial for propagation and productivity of fruit crops.For trioecious papaya(Carica papaya),highly differentiated morphology of gynoecium in flowers of different sex types is controlled by gene networks and influenced by environmental factors,but the regulatory mechanism in gynoecium morphogenesis is unclear.Gynodioecious and dioecious papaya varieties were used for analysis of differentially expressed genes followed by experiments using auxin and an auxin transporter inhibitor.We first compared differential gene expression in functional and rudimentary gynoecium at early stage of their development and detected significant difference in phytohormone modulating and transduction processes,particularly auxin.Enhanced auxin signal transduction in rudimentary gynoecium was observed.To determine the role auxin plays in the papaya gynoecium,auxin transport inhibitor(N-1-Naphthylphthalamic acid,NPA)and synthetic auxin analogs with different concentrations gradient were sprayed to the trunk apex of male and female plants of dioecious papaya.Weakening of auxin transport by 10 mg/L NPA treatment resulted in female fertility restoration in male flowers,while female flowers did not show changes.NPA treatment with higher concentration(30 and 50 mg/L)caused deformed flowers in both male and female plants.We hypothesize that the occurrence of rudimentary gynoecium patterning might associate with auxin homeostasis alteration.Proper auxin concentration and auxin homeostasis might be crucial for functional gynoecium morphogenesis in papaya flowers.These results will lead to further investigation on the auxin homeostasis and gynoecium morphogenesis in papaya.

Antiinflammatory activity of the methanolic extract of the seeds of Carica papaya in experimental animals

Objective:To scientifically verify the claims of our traditional healers on the anti-inflammatory activity of Carica papaya(C.papaya) and possibly deduce its activities.Methods:0.1 mL of fresh egg albumin was injected into the right hind-paw of adult white Wistar rats to induce inflammation an hour post intraperitoneal(IP) administration of 50-200 mg/kg doses of the extract to 3 groups of 5 rats per group.The 4th group of 5 rats was used as negative control and received 2 mL/kg(IP) of physiological saline,while the 5th group of 5 rats was used as positive-comparative control and received(IP) 150 mg/kg of aspirin.Increases in diameter of the paw were measured with the aid of Veneer Calipers before extract administration and at interval of 30 minutes post administration for further 2 hours.Percentage inhibition of oedema was calculated for each dose group and results were subjected to statistical analysis using student /-test and analysis of variance(ANOVA).Results:All doses of extract showed a dose and time dependent inhibition effects of oedema(P【0.05).Conclusions:This work is at present though limited to animals,the anti-inflammatory activity of the seeds of C.papaya is perhaps proven.

An efficient papaya leaf distortion mosaic potyvirus vector for virus-induced gene silencing in papaya

Papaya(Carica papaya L.)is regarded as an excellent model for genomic studies of tropical trees because of its short generation time and its small genome that has been sequenced.However,functional genomic studies in papaya depend on laborious genetic transformations because no rapid tools exist for this species.Here,we developed a highly efficient virus-induced gene silencing(VIGS)vector for use in papaya by modifying an artificially attenuated infectious clone of papaya leaf distortion mosaic virus(PLDMV;genus:Potyvirus),PLDMV-E,into a stable Nimble Cloning(NC)-based PLDMV vector,pPLDMV-NC,in Escherichia coli.The target fragments for gene silencing can easily be cloned into pPLDMV-NC without multiple digestion and ligation steps.Using this PLDMV VIGS system,we silenced and characterized five endogenous genes in papaya,including two common VIGS marker genes,namely,phytoene desaturase,Mg-chelatase H subunit,putative GIBBERELLIN(GA)-INSENSITIVE DWARF1A and 1B encoding GA receptors;and the cytochrome P450 gene CYP83B1,which encodes a key enzyme involved in benzylglucosinolate biosynthesis.The results demonstrate that our newly developed PLDMV VIGS vector is a rapid and convenient tool for functional genomic studies in papaya.

超声波辅助农杆菌介导CP基因转化番小瓜(Carioca papaya L.)的有效方法

本研究探索了通过农杆菌介导,超声波辅助处理,转化番木瓜胚性愈伤组织,获得转基因植株的有效方法。分别将含有日本PLDMV 外壳蛋白基因(PTi-Epj-TL-PLDMV)和含有台湾PRSV 菌株、美国夏威夷PRSV 菌株、泰国PRSV 菌株及日本PLDMV 菌株的多元外壳蛋白基因编码序列(PTi-NP-YKT)插入双元载体质粒pGA482G,借助于农杆菌系LBA4404将双元载体上的外壳蛋白基因和新霉素磷酸转移酶基因(nptⅡ)转移到番木瓜品种Sunset 的胚性愈伤组织中,从而获得抗卡那霉素的转化再生植株。试验着重在转化方法上进行探索。结果表明,农杆菌过夜培养后,用高渗透压培养液(1/2 MS+6%蔗糖+1%葡萄糖,pH 5.7)调整至光密度OD_(600(?)m)=0.15-0.20,然后用该菌液感染材料30min,其间辅以超声波处理,可以大大提高转化效率。用15ml 无菌离心管装载胚性愈伤材料进行15s 的超声波处理,在80块被转化的胚性愈伤中获得21个CP 基因G 转化系(26.3%),而在对照处理64块胚性愈伤中仅获得1个转化系(1.6%);在经过15s 的超声波处理48块被转化的胚性愈伤中获得8个CP 基因B 转化系(16.7%),而在对照处理25块胚性愈伤中未出现转化系。上述操作方法用在两种CP 基因转化上均表现出相似的效果。试验还表明:120mg/L 是卡那霉素抗性筛选的最佳浓度。抗性筛选9个月后,在421块胚性愈伤组织中产生了42个抗卡那霉素的转化系。所获得的转基因植株分别用PCR 和Southern 印迹杂交进行了鉴定。