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.

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.

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）

Effects of the methanolic seeds extract of Carica Papaya on plasmodium Berghei infected mice

Objective:The leaves extract of Carica Papaya（C.Papaya）papaya has been shown to possess antimalarial activity, thus this work aims at finding out if the plants antimalarial activity is present in or extended to the seeds.Methods:The seeds of C.papaya were collected from its fruit,air dried for 5 days and ground into fine powder.80.65 g of the powder was then soaked for 48hours in 300 mL of methanol.Filtration was carried out using Whatman No.1 filter paper.The filtrate was evaporated to dryness by a three-day continuous heating on a hot plate of 30℃.The dry extract yield was scraped out of the Petri dish weighed and refrigerated until required. The percentage extract yield was calculated out from the initial powder weight.A preliminary phytochemical study was done by re-dissolving the appropriate amount of the dry extract in distilled water and appropriate test reagent added.The LD50 of the seeds of C.papaya was carried out using arithmetic method.Swiss albino Mice of both sexes and of average weight of 18-25 g were used as animals for antimalarial activity.They were housed in standard animal house,fed on Rats/Mice pellets and had non restricted excess to both feed and water throughout the 60day study period.While the non pregnant female Mice were used as test animals,the male animals were used as malaria parasite donors.Precautions were taken to ensure that all animals in the study groups were free from infection with Eperythrozoon coocoides.The female animals were then divided into three main groups（A-C） of 25 animals per group.Group A was used for malaria suppressive study（early infection -day 0-3） and was further subdivided to 5 subgroups（a-e） of 5animals per group.Group B was used for malaria curative study（established malaria infection-day 3-7） and was further subdivided to 5subgroups（a-e） of 5animals per group.Group C was used for malaria prophylactic study（repository-4days treatment prior to malaria parasite infection） and was also further subdivided into 5subgroups（a-e） of 5animals per group.At the appropriate time,50 mg/kg/day,100 mg/kg/day and 200 mg/kg/day of crude extract of C.papaya were administered orally to the different subgroups（b-d） within the three main groups.One subgroup（a） in each main group also received orally,5 mg/kg/day of chloroquine phosphate as positive control while one subgroup （e） in each main group also received orally,0.2 mL/kg/day of distilled water as negative control.Malaria parasites infected red blood cells numbering 1×10 and suspended in 0.2 mL of physiological saline was inoculated intraperitoneally,to each animal of the subgroups（a-d） in each of the three main groups at the appropriate time.Blood smears were made from animals’tail,stained with Lieshman and examined microscopically at 100×for the presence of malaria parasite.Percentage malaria parastaemia was calculated as well as average percentage malaria parasitaemia suppression.Results:Extraction yield of 25.29%was obtained while the LD50 was 620 mg/kg.The phytochemistry showed the richly presence of alkaloids,as well as glycosides,carbohydrates, resins,fats and fixed oils.The suppressive study at doses of 200,100 and 50mg/kg/day showed 53.02%,43.43%and 19.83%suppressive activity against Plasmodium berghei respectively.This activity compared to that of chloroquine,a standard antimalaria drug that gave 95.95%suppressive anti-parasitaemia. The prophylactic study at doses of 200,100 and 50 mg/kg/day showed 63.85%,61.12%and 48.08%prevention to malaria parasitaemia respectively as against 94.78%showed by chloroquine.The curative study however,at doses of 200,100 and 50 mg/kg/day failed to suppress malaria parasitaemia with a mean survival range of 6-8days as against 27.2 days showed by chloroquine.The seeds extract of C.papaya showed a significant malaria parasitaemia suppressive activity（P≤0.05）.These activities are dose dependent and comparable to those of Chloroquine phosphate.Conclusion:The results above suggest that the seeds extracts of C.papaya possess antimalarial activity like the leaf extracts.The antimalarial activity may be attributable to the richly presence of alkaloids and or the presence of its proteolytic enzyme（Papain）.The present finding justifies the inclusion of the seeds of C.papaya in the treatment of malaria by local herbalists.The seeds extracts therefore,if well purified and characterized may be used in treatment of very early plasmodiasis as well as a good prophylactic drug in human.This work at the moment is limited to animals,thus clinical trials in humans is be recommended particularly,when C.papaya seeds are non harmful/non toxic.

Analysis of Simple Sequence Repeats Information from Floral Expressed Sequence Tags Resources of Papaya (<i>Carica papaya</i>L.)

Papaya (Carica papaya L.) is one of the most economically, medicinally and nutritionally important tropical fruit crops. Expressed sequence tags (ESTs) derived simple sequence repeat (SSR) markers are more valuable as they are derived from conserved genic portion. Development of EST-SSRs markers through in silico approach is cheaper, less time consuming and labour-intensive. In this study, we aimed to mine SSRs and developed EST-SSR primers from papaya floral ESTs. A total of 75,846 papaya floral ESTs were downloaded from public database National Centre for Biotechnology Information (NCBI). A total of 26,039 floral unigenes (7961 contigs and 18,078 singletons) were generated after assembly of these ESTs. From these floral unigenes, 433,782 perfect SSRs, 204,968 compound SSRs and 6061 imperfect SSRs were mined, respectively. In perfect SSRs, mononucleotide repeats were most abundant (94.7%) followed by tri- (3.1%) and di-nucleotide repeats (1.7%). The frequencies of tetra-, hexa- and penta-nucleotide repeats accounted for only (0.17%), (0.04%) and (0.03%), respectively. In mononucleotide repeats, the most abundant motif was A/T (69.3%) and in di- and tri-nucleotide repeats were AG/CT (61%) and AAG/CTT (31%), respectively. In imperfect SSRs, mononucleotide repeats (56.5%) were most abundant. 176 different types of motifs were identified. A total of 3807 primer pairs for floral papaya ESTs were successfully designed. These developed EST-SSR primers are being used for the genetic improvement of papaya such as study of cross-transferability across genera/species, evaluation of genetic diversity, and identification of sex-specific markers. These EST derived SSRs can also be used in filling gaps in existing linkage maps 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。

CO_(2) Assimilation Rate in Production Systems for Papaya Crops

The aim of this study was to evaluate some physiological aspects of papaya crops in semi conventional and organic production systems.The following factors assessed in this experiment were:1.Production systems(organic and semi conventional);2.Genotypes(Maradol and Maradona F1),and 3.Cover crop plants(Canavalia,vegetative cover and no cover).Twelve treatments were obtained-product of factors’combination-and distributed under a threerepetition experimental design of subdivided parcels.The factors examined in this study,that changed the CO_(2) assimilation rate,were production system and genotype.It was determined that the greatest gas exchange in papaya crops happened at 13:40 h but achieving the highest CO_(2) assimilation was also affected by the production system and genotype.Similarly,they showed some effects in CO_(2) assimilation,transpiration,stomatal conductance,intercellular CO_(2),leaf temperature,chlorophyll,and temperature.In general,the combination of factors that accentuated in this experiment were the semi conventional-Maradona-Canavalia with a crop yield of 53.5 t ha^(-1),followed by treatments organic-Maradona-no cover and semi conventional-Maradona-vegetative cover.

基因沉默番木瓜环斑病毒复制酶基因(PRSV-Nib)获得抗病毒病番木瓜的研究

番木瓜是重要的热带经济水果。番木瓜环斑病毒(Papaya ringspot virus,PRSV)是番木瓜的重要病毒病,经常导致严重的产量损失和质量恶化。自从1998年第一例转基因番木瓜问世以来,使得基于“致病菌衍生的抗病性(pathogen-derived resistance,PDR)”的抗病育种策略获得成功广泛应用。然而依赖于序列同源性的抗病性与病毒突变导致多样性增加之间的矛盾成为番木瓜育种科学家的新挑战。本研究拟采用RNAi策略针对复制酶(nuclear inclusion b.Nib)获得广谱抗PRSV番木瓜新种质。通过团队已建立的胚性愈伤诱导-农杆菌介导转化-再生苗诱导的番木瓜遗传转化体系,共获得经过抗性筛选的再生苗52株,通过特异性PCR进行筛选共计获得24株转基因阳性植株。通过对T0代田间自然发病试验中,转基因番木瓜株系抗病性明显高于非转基因对照,其中NibB5-2田间抗病性最优。通过hiTAIL-PCR方法确定NibB5-2插入位点位于第2号染色体supercontig_30的1976766的位置。T1代接种试验中,无病毒积累且无发病症状,初步确认具有良好的病毒抗性,为番木瓜抗病育种提供新思路。

番木瓜β-Gal基因RNAi双T-DNA植物表达载体的构建及其遗传转化的初步研究

克隆了番木瓜(Carica papaya L.)果肉的细胞壁水解关键酶β-半乳糖苷酶(β-GAL)基因保守区,将其反向重复插入载体pKANNIBAL,构建RNAi中间表达载体pKAN/RG,将其上的发夹结构取代经改造的载体pCAMBIA1300上hptⅡ基因,构建中间表达载体p1300-/MFRG,分离单T-DNA区段,与载体pCAMBIA2301构建RNAi双T-DNA植物表达载体p2301/TTRG。酶切分析和PCR检测表明,p2301/TTRG已被成功导入农杆菌EHA105。通过遗传转化,初步获得了GUS染色呈阳性且具Kan抗性的番木瓜胚性愈伤组织。

番木瓜CpTIFY10A-like基因克隆及表达分析

【目的】克隆番木瓜CpTIFY10A-like基因序列,并分析其表达特性,为探索该基因功能和抗番木瓜环斑病毒(PRSV)分子机制提供理论依据。【方法】结合前期研究的抗PRSV转录组数据,利用RACE对上调表达基因Cp-TIFY10A-like进行克隆,获得该基因cDNA全长序列,分析其编码区序列(CDS)及进行生物信息学分析。利用已鉴定的PRSV对3月龄番木瓜植株进行不同处理,以感染PRSV且出现病症的植株(CK+)、1.0 mL/L禾甲安(CTS-N)灌施感染PRSV且出现病症的植株(B)为处理组,以清水灌施(不添加禾甲安)不感染PRSV的植株(CK-)为对照组,实时荧光定量PCR(qRT-PCR)检测不同处理下PRSV基因和CpTIFY10A-like基因在番木瓜叶片中的表达情况。最后将CpTIFY10A-like基因CDS序列连接至pET28a-sumo载体上构建原核表达载体,转化Rosetta(DE3)感受态细胞,通过不同浓度IPTG诱导蛋白表达,利用SDS-PAGE电泳检测原核表达情况。【结果】CpTIFY10A-like基因全长为1352 bp,CDS序列为822 bp,编码273个氨基酸残基;其编码蛋白理论等电点(pI)9.23,不稳定系数62.97,亲水性平均系数-0.458,属于不稳定的亲水性碱性蛋白,定位在细胞核上,其二级结构以无规则卷曲和α-螺旋为主,同时含有少量的β-折叠和延伸链。CpTIFY10A-like蛋白与酸枣和白梨TIFY蛋白的氨基酸序列相似性较高,均含有特定的TIFY结构域,属于TIFY蛋白家族,三者在系统发育进化树上聚在同一分支,表明亲缘关系较近。不同处理的番木瓜叶片中,PRSV基因的相对表达量排序为CK+(1.02)>B(0.39)>CK-(0),CpTIFY10A-like基因的相对表达量排序为B(53.12)>CK+(1.15)>CK-(1.02),且CpTIFY10A-like基因在经禾甲安处理的感染PRSV番木瓜叶片中相对表达量显著升高(P<0.05,下同),而PRSV基因的相对表达量显著降低。CpTIFY10A-like基因在原核细胞中表达蛋白的分子量与理论分子量(29.36 kD)相符,且不同浓度IPTG诱导下,IPTG浓度越高,蛋白表达量越多,表明该基因在原核细胞中成功表达。【结论】禾甲安可诱导CpTIFY10A-like基因高效表达,进而通过茉莉酸通路起调节作用以抵抗PRSV感染,即CpTIFY10A-like基因在番木瓜抗PRSV过程中发挥重要调控作用。

番木瓜不同性别基因表达cDNA-AFLP分析

在番木瓜幼苗期,利用cDNA-AFLP技术鉴定植株性别并分析不同植株性别基因表达的差异;通过对差异表达基因进行序列和功能分析,探讨调控番木瓜性别分化的分子机理。结果表明,每次反应扩增获得的稳定条带总数为25～75条,番木瓜3种植株性别基因表达存在明显差异,每种性别植株都有特异性条带,其中雄性株14条、雌性株13条、两性株9条。将获得的部分差异TDFs序列与GenBank数据库中的所有序列进行Blastx和Blastn比对,其中一部分差异片段为未知功能基因序列,另一部分差异片段序列与谷胱甘肽转移酶基因、植物甾醇类激素合成相关基因、分裂原活化蛋白酶基因、与端粒相连的核酸序列、杨树叶中克隆的未知功能基因及拟南芥花和花蕾中克隆的未知功能基因等具有较高的同源性。因此,cDNA-AFLP技术可在幼苗期鉴定番木瓜的植株性别,不同番木瓜植株性别基因的差异表达可能是其植物体一系列功能基因调控植株性别发育及生长发育的综合反应。

番木瓜β-Gal基因的克隆分析与植物表达载体构建

番木瓜果实采后贮藏期间的迅速软化与β-Gal基因的表达密切相关。利用常规PCR结合反向PCR技术,分离了一条4501bp的番木瓜β-Gal基因组序列。其共含有17个内含子,外显子部分与相应的cDNA序列只有1个碱基的差异。生物信息学分析结果表明,该番木瓜β-GAL属于糖苷水解酶超级家族42中家族35的成员,在进化过程中与拟南芥的亲缘关系较近,与鳄梨和北美云杉则较远。同时,它还具有一段定位于胞外的信号肽,再次表明其可能参与了果肉细胞壁的降解和果实软化。进一步分离了β-Gal基因启动子,初步验证了其果实表达特异性。将该启动子替换载体p2301/TTRG上的CaMV 35S启动子,构建出RNAi-β-Gal双T-DNA植物表达载体。酶切分析和PCR检测结果表明,载体p2301/BPTTRG已被成功导入农杆菌,可用于后续的遗传转化研究。

CaCl_2对番木瓜幼苗酸雨伤害的生理保护效应

用30mmol/L的CaCl2预处理番木瓜(CaricapapayaL.)幼苗,结果表明,钙预处理能有效减缓番木瓜幼苗因酸雨胁迫引起的光合速率、叶绿素含量的下降,增加超氧歧化酶(SOD)活性,减少膜质过氧化产物丙二醛(MDA)含量,降低细胞质膜透性,维持细胞汁液pH值稳定性,减轻酸雨对番木瓜幼苗的酸致损伤.

番木瓜WRKY转录因子CpWRKY11的克隆和表达

【目的】克隆番木瓜炭疽菌诱导的WRKY转录因子CpWRKY11,研究其在生物胁迫、外源激素处理及非生物胁迫条件下的表达特征,为CpWRKY11基因在后续番木瓜分子育种中的应用提供理论支持。【方法】从自主选育的炭疽病抗性品种中克隆WRKY转录因子CpWRKY11,采用SMART、ExPaSy、NetPhos和DNAMAN软件对该基因及其编码的蛋白序列进行生物信息学分析,利用MEGA-X软件进行系统进化树构建和分析;构建亚细胞定位载体CpWRKY11-GFP,通过转化水稻原生质体,确定CpWRKY11的亚细胞定位情况;利用酵母单杂交试验验证CpWRKY11是否具有转录激活活性;采用实时荧光定量PCR(qRT-PCR)分析CpWRKY11在番木瓜不同组织(根、茎、叶、花和果实)及生物胁迫(短孢炭疽菌和番木瓜畸形花叶病毒侵染)、外源激素(水杨酸(SA)、茉莉酸甲酯(MeJA)、乙烯利(ETH))和非生物胁迫(高盐、干旱和机械损伤)处理下的表达情况。【结果】CpWRKY11基因编码序列全长1719 bp,编码572个氨基酸;CpWRKY11含有60个磷酸化位点,理论分子量为62.31 ku,理论等电点为6.75,不稳定指数为51.17,亲水性为-0.792,是一个亲水不稳定蛋白。CpWRKY11有2个典型的WRKY结构域,同源氨基酸比对及进化树分析结果显示,CpWRKY11与拟南芥AtWRKY20的同源性最高,属于WRKY家族Ⅰ类。亚细胞定位结果显示,CpWRKY11只定位在细胞核上。酵母转录激活验证试验结果显示,CpWRKY11蛋白不具有转录激活活性。CpWRKY11在番木瓜中为组成型表达,在茎中表达量最高,其次为根、果实和花,在叶中的表达量最低。CpWRKY11受短孢炭疽菌和PLDMV的诱导上调表达,在短孢炭疽菌诱导48 h内持续上调,与0 h对照相比其表达量均显著上调,且在反应后期(24和48 h)表达量更高。在PLDMV处理条件下,除接种第3天外,CpWRKY11也均呈现出明显的上调趋势。外源激素处理结果显示,CpWRKY11受SA、ETH和MeJA的诱导上调表达,尤其是在MeJA处理下,CpWRKY11被强烈诱导而显著上调表达,处理48 h内的表达量较对照上调1.9倍以上。CpWRKY11受机械损伤的强烈诱导,表达量显著上调。【结论】CpWRKY11是调控番木瓜逆境胁迫响应,尤其是病原菌侵染及机械损伤响应的重要因子。CpWRKY11可能主要通过JA信号途径参与病原菌应答反应,是具有潜在利用价值的重要候选基因。

番木瓜胚性细胞悬浮系高效遗传转化体系的建立

【目的】建立番木瓜高效遗传转化体系,为番木瓜基因功能研究和重要农艺性状改良提供新的技术支撑。【方法】以紫晖番木瓜胚性细胞悬浮系(embryogenic cell suspensions,ECS)为遗传转化受体,利用植物表达载体pCAMBIA1301和农杆菌介导法进行遗传转化,对抗生素浓度筛选、侵染时间、继代培养、抗性胚的诱导与萌发以及植株再生整个过程进行探索,最后获得抗性再生植株。【结果】通过设置不同浓度的头孢霉素和潮霉素处理,观察ECS细胞状态,筛选、确定头孢霉素和潮霉素最适处理质量浓度分别为200 mg·L^(-1)和5 mg·L^(-1)。工程菌和ECS共培养侵染2 d后转到含有头孢霉素和潮霉素的液体筛选培养基上进行继代培养,继代周期为14 d。经GUS染色验证,表明继代3次后的ECS几乎全部为转化细胞。将以上ECS转移到液体胚诱导培养基中进行培养,2个月后可获得大量球形体细胞胚,且GUS组织染色为蓝色。将球形体细胞胚转到半固体成熟培养基上培养,2个月后可获得成熟子叶期体细胞胚。子叶期体细胞胚在萌发培养基上光培养30 d后,可获得再生芽。任意选取再生芽进行GUS染色,均可染成蓝色。抗性再生芽经促根培养可成功获得再生植株。利用PCR检测抗性再生植株,可以确定GUS基因已经整合到番木瓜基因组中。【结论】成功建立了一种以番木瓜ECS为转化受体的农杆菌介导的高效遗传转化体系。在该技术体系中,经农杆菌侵染后的ECS继代筛选3次后,几乎全部为转化细胞,这些转化细胞经体胚诱导、成熟、萌发和生根过程可成功获得再生植株,抗性体胚得胚率为43.65%,抗性体胚萌发率为73.26%,植株再生率为80.55%,大大提高了番木瓜遗传转化效率。该体系为番木瓜基因功能研究和分子育种提供了新的途径。

基于实时荧光定量PCR的番木瓜多重PCR高效检测方法

以pCaMV35S基因核酸检测试剂盒反应体系为基础,添加多重PCR反应所需的目标基因引物和番木瓜(Carica papaya L.)DNA,进行多重PCR反应,同时考察不合成荧光探针的情况下对目标基因进行实时荧光定量检测。结果表明,在实时荧光定量PCR反应体系中,多重PCR扩增的基因条带比常规PCR扩增的基因条带更亮,在不合成荧光探针的情况下实现目标基因的实时荧光定量PCR反应,以期建立一种基于实时荧光定量PCR的多重PCR检测方法。

Effects of Coated Capillary Column, Derivatization, and Temperature Programming on the Identification of Carica papaya Seed Extract Composition Using GC/MS Analysis

Some of the common practices to assess the composition of plant extract,including Carica papaya seed extract(CPSE)are direct injection of the extract,compound separation using polyethylene glycol capillary column(DB-WAX),and non-linear-temperature programming(NLTP)of GC/MS analysis.This study specifically compared the coating of capillary column,sample derivatization,and temperature programming of GC/MS to determine the composition of CPSE.The retention indices(RI)of the detected compounds were determined and compared to the reference RI.In particular,5%phenyl-95%methylpolysiloxane(HP-5MS)-,DB-WAX-,and biscyanopropyl polysiloxane(HP-88)-coated capillary columns were used to identify the composition of CPSE.For this study,HP-5MS column,which separated the highest number of compounds(26 compounds)from CPSE,was deemed as the most suitable column.The GC/MS analysis of derivatized CPSE identified 21 compound groups,where fatty acids and fatty acid methyl esters served as the major compounds(80.23%),followed by these compounds in decreasing order:amides>nitriles>sterols>fatty aldehydes>organic acids.A stronger correlation determination between the carbon number and alkane retention time of linear-temperature programming(LTP)(R^(2)=0.9859)was found,as compared to its correlation determination with NLTP(R^(2)=0.9175),which exhibited an almost equal RI of LTP to the reference RI.Conclusively,GC/MS analysis for the derivatized CPSE using HP-5MS column separation and LTP is highly recommended.

侵染广州番木瓜的曲叶病毒DNA-A分子特征及生物学测定

从中国广州番木瓜上检测获得双生病毒分离物GT,核苷酸序列测定表明,GT分离物DNA-A全长2769个核苷酸,编码6个ORFs,其中病毒链编码AV1(CP)和AV2两个ORFs,互补链编码AC1～AC4四个ORFs。DNA-A全序列、基因间隔区核苷酸序列及各ORF编码的氨基酸序列比较表明,GT与广东番木瓜曲叶病毒分离物GD2亲缘关系最近(96.7%)。生物学初步测定表明,该病毒可通过烟粉虱(Bemisiatabaci)传播到番木瓜、烟草和番茄植株上。

番木瓜茎尖超低温保存过程中的细胞超微结构

采用透射电子显微镜对番木瓜(CaricapapayaL.)茎尖超低温保存过程中细胞超微结构变化进 行观察。结果表明:细胞在经过预培养、60%PVS2预处理和PVS2脱水处理,细胞质壁分离程度逐渐加重, 细胞的抗冻力增加。细胞严重伤害主要发生在液氮保存的降温及解冻的过程中,一部分细胞的细胞壁、细胞 膜以及细胞核膜均有不可逆的损伤,可能是导致部分细胞致死的原因之一。也有部分细胞结构完整,虽然细 胞结构发生了变化,但是程度不深,是可逆的伤害,在恢复培养3d时可自动修复,然后再生出植株。

番木瓜茎尖的玻璃化法超低温保存及其植株再生

研究了番木瓜 (CaricapapayaL .)茎尖玻璃化法超低温保存的一些影响因素。结果表明 :无菌试管苗在MS +BA 0 5mg/L +NAA 0 1mg/L +GA3 1 0mg/L的培养基上生长较好。番木瓜茎尖超低温保存较佳体系是 :3～ 5cm的茎尖在含有 5 %二甲基亚砜 (DMSO)培养基上预培养 3d ,解剖镜下剥取含 1～ 2个叶原基的茎尖 (1 5～ 2 5mm长 ) ,先在室温下于 6 0 %的玻璃化溶液 (PVS2 )中装载 4 0～ 5 0min ,再用PVS2于 0℃下处理 30min ,换 1次PVS2 溶液后迅速投入液氮。保存 2 4h后 ,在 4 0℃水浴中化冻 ,用 1 2mol/L的蔗糖培养液洗涤两次 ,转入继代培养基上再培养 ,成活率和再生率分别达 5 3 7%和 5 2 6 %。