Multivariate analysis to determine the genetic distance among backcross papaya (Carica papaya) progenies

Morpho-agronomic and molecular (RAPD and ISSR markers) data were used to evaluate genetic distances between papaya backcross progenies in order to help identify agronomically superior genotypes. Thirty-two papaya progenies were evaluated based on 15 morpho-agronomic characteristics, 20 ISSR and 19 RAPD primers. Manhattan, Jaccard and Gower distances were used to estimate differences based on continuous and binary data and combined analyses, respectively. Except for production, there were significant differences in the continuous variables among the genotypes. The molecular analysis revealed 193 dominant markers (ISSR and RAPD), being 53 polymorphic loci. Among the various clusters that were generated, the one based on a combined analysis of morpho-agronomic and molecular data gave the highest cophenetic correlation (0.72) compared to individual analysis, consistently allocating the progenies into six groups. We found that the Gower algorithm was more coherent in the discrimination of the genotypes, demonstrating that a combination of molecular and agronomic data is valuable for studies of genetic dissimilarity in papaya.     

Anther culture of papaya (Carica papaya L.)

Papaya (Carica papaya L.) anther containing microspores in tetrad to early-binucleate stages were successfully cultured on 1/2 strength MS salts and vitamins with full strength Na-Fe-EDTA supplemented with 2 mg/l NAA, 1 mg/l BA and 6% sucrose for callus initiation and formation. Highest frequencies of callus induction were obtained when anthers at the uninucleate stage were cultured in the dark. Haploid plantlets and pollen-derived embryoids were obtained from anthers cultured at the uninucleate stage on solidified MS medium containing 3% sucrose without any growth regulators under a low light intensity (1,500 lux). Large quantities of embryoids were obtained when the original embryoids were transferred to MS medium with 3% sucrose and no growth regulators. Cytology of root tips of embryoid-derived plants confirmed the haploid chromosome number of 9 indicating that the embryoids originated from pollen.Abbreviations MS Murashige and Skoog (1962) - MAA naphthaleneacetic acid - BA 6-benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid     

Proteomic analysis of papaya (Carica papaya L.) displaying typical sticky disease symptoms

Papaya (Carica papaya L.) hosts the only described laticifer-infecting virus (Papaya meleira virus, PMeV), which is the causal agent of papaya sticky disease. To understand the systemic effects of PMeV in papaya, we conducted a comprehensive proteomic analysis of leaf samples from healthy and diseased plants grown under field conditions. First, a reference 2-DE map was established for proteins from healthy samples. A total of 486 reproducible spots were identified, and MALDI-TOF-MS/MS data identified 275 proteins accounting for 159 distinct proteins from 231 spots that were annotated. Second, the differential expression of proteins from healthy and diseased leaves was determined through parallel experiments, using 2-DE and DIGE followed by MALDI-TOF-MS/MS and LC-IonTrap-MS/MS, respectively. Conventional 2-DE analysis revealed 75 differentially expressed proteins. Of those, 48 proteins were identified, with 26 being upregulated (U) and 22 downregulated (D). In general, metabolism-related proteins were downregulated, and stress-responsive proteins were upregulated. This expression pattern was corroborated by the results of the DIGE analysis, which identified 79 differentially expressed proteins, with 23 identified (17 U and 6 D). Calreticulin and the proteasome subunits 20S and RPT5a were shown to be upregulated during infection by both 2-DE and DIGE analyses. These data may help shed light on plant responses against stresses and viral infections.     

Redox activities in plasma membrane vesicles isolated from papaya (Carica papaya) leaves

Plasma membrane vesicles were isolated from papaya (Carica papaya) leaf cells by a two-phase partition system. Redox activities of these vesicles were determined by ferricyanide reduction and NADH oxidation. Ferricyanide reductase activity was accompanied by continuous acidification of the medium and was stimulated by fusicoccin. NADH oxidase activity was inhibited by catalase.Abbreviations FC fusicoccin - PCMBS parachloromercuri-benzenesulfonic acid     

Rapid sex identification of papaya (Carica papaya) using multiplex loop-mediated isothermal amplification (mLAMP)

Papaya (Carica papaya L.) is established as a cash crop throughout the tropical and subtropical regions due to its easy adaptation to diverse agricultural conditions, high yields, and prompt returns. The sex types of papaya plants are hermaphrodite, male, and female. Among them, hermaphroditic plants are the major type in papaya production, because the fruit has commercial advantages over that of the other sexes. Sex inheritance in papaya is determined by the M and M ^h dominant alleles in males and hermaphrodites, respectively, and a recessive m allele in females. Currently, all hermaphrodite seeds are not available due to the lethality of dominant homozygosity. Therefore, in this study, six male–hermaphrodite-specific markers were developed for a rapid sex identification using multiplex loop-mediated isothermal amplification (mLAMP) to efficiently and precisely select hermaphroditic individuals in the seedling or early growth stage. The LM1-LAMP assay consisted of two sex-LAMP reactions for amplifying two male-specific markers (T12 and Cpsm90) in one reaction, and showed several advantages in terms of a rapid reaction time (<1 h), isothermal conditions (less equipment required), a high efficiency (0.5 ng of DNA required in the reaction mixture), and an economical reaction system (5 μl in volume). The established method can be easily performed in the field by visual inspection and facilitates the selection of all hermaphroditic individuals in papaya production.     

Field biology and control of Phytophthora parasitica on papaya (Carica papaya) in Hawaii

Epidemic attacks of Phytophthora parasitica on papaya fruits developed during wet, windy weather, but declined rapidly when the weather became dry. During rain, abundant sporangia were liberated from the mycelial mats on infected fruits, but none was trapped in dry air. Collar rots and tree collapse caused by root rot occur irrespective of spray treatments and previous aerial infections on the same tree: they are no more prevalent in blocks with abundant aerial infections than in blocks with none. Basal rots occurred earlier and more frequently on plantings near abandoned diseased fields: they were scattered randomly and appeared before aerial infections. It is suggested that new outbreaks might be initiated from seeds of infected fruit, in which chlamydospores have been found, or from infected nursery seedlings. Drosophila spp. were found to be occasional vectors of sporangia. Control of aerial infections was obtained with maneb, basic copper sulphate, captan or difolatan. Spraying only the upper half of the acropetally developing fruit cluster gave much better control than spraying only the lower fruits.     

超声波辅助农杆菌介导CP基因转化番木瓜（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(PT—NP—YKT)插入双元栽体质粒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(1／2MS 6％蔗糖 1％葡萄糖,pH5．7)调整至光密度OD600nm=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。     

Lateral bud culture of papaya (Carica papaya L.) for clonal propagation

Lateral buds may be preferred to shoot tips for in vitro propagation of papaya because of its unbranched nature. Proliferating shoot cultures from lateral buds appeared extremely compact with shortened internodes and leaf lamina of the cytokinin level (BAP 2 M) reported for multiple shoot production from shoot tips. ZEA (4 M) and 2iP (8 M) although reduced the proliferation rate, resulted in better growth of the shoot from lateral bud. Rooting was observed with IBA 20 M but plantlets so produced remained stunted.     

Structured triacylglycerols resembling human milk fat by transesterification catalyzed by papaya (Carica papaya) latex

Structured triacylglycerols resembling human milk fat, that contain palmitoyl (16:0) moieties predominantly at the sn-2- position of the glycerol backbone and oleoyl (18:1) and linoleoyl (18:2) moieties at the sn-1,3-positions, have been prepared by regiospecific transesterification of tripalmitin with fatty acids of low-erucic rapeseed oil using a plant lipase – papaya latex – and for comparison Lipozyme, as biocatalyst. © Rapid Science Ltd. 1998     

Cyanogenesis in glucosinolate-producing plants: Carica papaya and Carica quercifolia

(R)-2-(beta-D-Glucopyranosyloxy)-2-phenylacetonitrile (prunasin) was isolated from Carica papaya L. and C. quercifolia (A. St.-Hil.) Hieron. (syn. C. hastata Brign.). Earlier reported presence of cyclopentanoid cyanohydrin glycosides in C. papaya could not be confirmed, and no cyclopentanoid amino acids could be detected in extracts of C. papaya and C. quercifolia. Conversion of [2,3,4,5,6-3H]phenylalanine into tritiated prunasin was demonstrated in both species. On the other hand, when the plants were administered [2-14C]-2-(2'cyclopentenyl)glycine, extracted, and the extracts hydrolyzed with beta-glucosidase (Helix pomatia), formation of labelled cyanide was not observed. The absence of cyclopentanoids, which are typical for the Passifloraceae, and the inability of Carica species to utilize 2-(2'-cyclopentenyl)glycine as a precursor of cyanogenic glycosides are in agreement with the relative phylogenetic position of the Caricaceae and the Passifloraceae. Carica species are thus rare examples of taxa in which glucosinolates and cyanogenic glycosides co-occur, both types of natural products being derived from the same amino acid, phenylalanine.     

番木瓜蛋白酶的免疫荧光定位

番木瓜在我国广东、广西、云南等地栽种,它的乳汁富含番木瓜蛋白酶,该酶主要应用于食品工业、酿造业及化妆品等。目前我们已完成精酶生产工艺的研究并投入了批量生产,然而该酶在果实里的分布特征及组织定位尚不清楚。我们通过幼果切片的组织学染色,观察到番木瓜的乳汁管结构,并用间接免疫荧光法初步确定了番木瓜凝乳蛋白酶的存在部位。     

番木瓜的离体繁殖

建立番木瓜离体繁殖体系.用0.1%HgCl2溶液对番木瓜的新生嫩茎进行消毒,适宜的消毒时间为12min,1mm茎尖的成苗率达到87.6%.随蔗糖浓度的提高,番木瓜试管苗的株高显著降低,增殖系数显著增加.在附加IBA0.3mg/L的1/2MS培养基上新梢的生根率达到89.3%,试管苗大规模移栽的成活率达90%以上.基因型显著地影响番木瓜离体增殖的效率.     

Carica papaya lipase (CPL): an emerging and versatile biocatalyst

In recent years, the Carica papaya lipase (CPL) is attracting more and more interest. This hydrolase, being tightly bonded to the water-insoluble fraction of crude papain, is thus considered as a "naturally immobilized" biocatalyst. To date, several CPL applications have already been described: (i) fats and oils modification, derived from the sn-3 selectivity of CPL as well as from its preference for short-chain fatty acids; (ii) esterification and inter-esterification reactions in organic media, accepting a wide range of acids and alcohols as substrates; (iii) more recently, the asymmetric resolution of different non-steroidal anti-inflammatory drugs (NSAIDs), 2-(chlorophenoxy)propionic acids, and non-natural amino acids. Taking into account the novelty and the current interest of the topic, this review aims to highlight the origin, features, and applications of the C. papaya lipase, with the objective to prompt research groups to further investigate the spectra of applications that this emerging and versatile CPL could have in the future.     

Callus culture and plantlet production in Carica papaya (Var. Honey Dew)

Summary In order to develop techniques for efficient callus production and regeneration in Carica papaya (Var. Honey Dew), lamina, petiole, stem and root explants from in vitro plantlets were cultured in media supplemented with 2.0 mg/1 IBA and 0.5 mg/1 BAP. Use of in vitro-grown plantlets as an explant source helped to avoid contamination common in papaya tissue culture. Callusing was maximum in root explants cultured in a modified MS (half-strength) medium. Shoot reganeration was maxium in root-derived callus grown in full-strength modified MS medium supplemented with 0.5 mg/1 IBA and 1 to 2 mg/1 kinetin. A histological study indicated that shoot buds originated from peripheral cell layers of the callus. Each shoot regenerated from callus was subcultured using a multiplication medium. Root formation was induced in all shoots treated in half-strength of modified MS medium containing 2 mg/1 IBA and rooted shoots were transferred successfully to the field.Abbreviations MS Murashige and Skoog medium, 1962 - LS Linsmaier and Skoog medium, 1965 - BAP 6-Benzylaminopurine - FAA Formalin Acetic acid 30% Ethanol, 1110 - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid - NAA Napthaleneacetic acid - SH Schenk and Hilderbrandt medium, 1972     

Comparative transcriptome analysis to identify putative genes related to trichome development in Ocimum species

Molecular Biology Reports - Genus Ocimum is known to have&nbsp;species possessing important therapeutic essential oil. The major phytoconstituents of essential oil in Ocimum species are...