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1.
J Agric Food Chem ; 67(32): 8919-8925, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31334658

RESUMO

Histone deacetylase (HDAC) performs important functions in plant growth and development, including fruit ripening. As a complex biological process, fruit ripening involves the histone acetylation modification of ripening-associated genes. Histone deacetylase genes (HDACs) have been well studied in Arabidopsis and rice, but the biological functions of HDACs in papaya are poorly understood. In the present work, three CpHDACs, belonging to the RPD3/HDA1 subfamily, were identified from papaya and named as CpHDA1, CpHDA2, and CpHDA3. CpHDA1 and CpHDA2 were induced by propylene, while CpHDA3 was propylene-repressed. Moreover, CpHDA3 protein could physically interact with CpERF9 and enhance the transcriptional repression activities of CpERF9 to downstream genes CpPME1, CpPME2 and CpPG5. Histone acetylation levels of CpPME1 and CpPG5 were increased during fruit ripening. Taken together, these results suggested that CpERF9 recruits CpHDA3 to form a histone deacetylase repressor complex to mediate pectin methylesterase and polygalacturonase genes expression during papaya fruit ripening and softening.


Assuntos
Hidrolases de Éster Carboxílico/genética , Carica/metabolismo , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/metabolismo , Proteínas de Plantas/metabolismo , Poligalacturonase/genética , Fatores de Transcrição/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Carica/genética , Carica/crescimento & desenvolvimento , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Histona Desacetilases/genética , Proteínas de Plantas/genética , Poligalacturonase/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Fatores de Transcrição/genética
2.
BMC Plant Biol ; 19(1): 309, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299898

RESUMO

BACKGROUND: Ethylene promotes fruit ripening whereas 1-methylcyclopropene (1-MCP), a non-toxic antagonist of ethylene, delays fruit ripening via the inhibition of ethylene receptor. However, unsuitable 1-MCP treatment can cause fruit ripening disorders. RESULTS: In this study, we show that short-term 1-MCP treatment (400 nL•L- 1, 2 h) significantly delays papaya fruit ripening with normal ripening characteristics. However, long-term 1-MCP treatment (400 nL•L- 1, 16 h) causes a "rubbery" texture of fruit. The comparative transcriptome analysis showed that a total of 5529 genes were differently expressed during fruit ripening compared to freshly harvested fruits. Comprehensive functional enrichment analysis showed that the metabolic pathways of carbon metabolism, plant hormone signal transduction, biosynthesis of amino acids, and starch and sucrose metabolism are involved in fruit ripening. 1-MCP treatment significantly affected fruit transcript levels. A total of 3595 and 5998 differently expressed genes (DEGs) were identified between short-term 1-MCP, long-term 1-MCP treatment and the control, respectively. DEGs are mostly enriched in the similar pathway involved in fruit ripening. A large number of DEGs were also identified between long-term and short-term 1-MCP treatment, with most of the DEGs being enriched in carbon metabolism, starch and sucrose metabolism, plant hormone signal transduction, and biosynthesis of amino acids. The 1-MCP treatments accelerated the lignin accumulation and delayed cellulose degradation during fruit ripening. Considering the rubbery phenotype, we inferred that the cell wall metabolism and hormone signal pathways are closely related to papaya fruit ripening disorder. The RNA-Seq output was confirmed using RT-qPCR by 28 selected genes that were involved in cell wall metabolism and hormone signal pathways. CONCLUSIONS: These results showed that long-term 1-MCP treatment severely inhibited ethylene signaling and the cell wall metabolism pathways, which may result in the failure of cell wall degradation and fruit softening. Our results reveal multiple ripening-associated events during papaya fruit ripening and provide a foundation for understanding the molecular mechanisms underlying 1-MCP treatment on fruit ripening and the regulatory networks.


Assuntos
Carica/genética , Ciclopropanos/farmacologia , Etilenos/antagonistas & inibidores , Reguladores de Crescimento de Planta/antagonistas & inibidores , Proteínas de Plantas/metabolismo , Transcriptoma , Carica/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética
3.
BMC Plant Biol ; 19(1): 238, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31170911

RESUMO

BACKGROUND: Papaya (Carica papaya L.) is a popular climacteric fruit, undergoing various physico-chemical changes during ripening. Although papaya is widely cultivated and consumed, few studies on the changes in metabolism during its ripening process at the proteasome level have been performed. Using a newly developed TMT-LCMS analysis, proteomes of papaya fruit at different ripening stages were investigated. RESULTS: In total, 3220 proteins were identified, of which 2818 proteins were quantified. The differential accumulated proteins (DAPs) exhibited various biological functions and diverse subcellular localizations. The KEGG enrichment analysis showed that various metabolic pathways were significantly altered, particularly in flavonoid and fatty acid metabolisms. The up-regulation of several flavonoid biosynthesis-related proteins may provide more raw materials for pigment biosynthesis, accelerating the color variation of papaya fruit. Variations in the fatty acid metabolism- and cell wall degradation-related proteins were investigated during the ripening process. Furthermore, the contents of several important fatty acids were determined, and increased unsaturated fatty acids may be associated with papaya fruit volatile formation. CONCLUSIONS: Our data may give an intrinsic explanation of the variations in metabolism during the ripening process of papaya fruit.


Assuntos
Carica/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteoma , Carica/crescimento & desenvolvimento , Frutas/genética , Proteínas de Plantas/metabolismo , Proteômica
4.
Food Chem ; 283: 596-603, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30722917

RESUMO

The spice made from the fruits of Piper nigrum L. (Piperaceae) has high economic value since the beginnings of international trade. Because its price has been increasing, adulterations with papaya seeds, cayenne pepper and maize flour were reported. These have been screened by methodologies dedicated to the detection of single adulterants lacking sensitivity and specificity. Herein we propose a specific, highly-sensitive, high-throughput and affordable qPCR-based methodology for the detection of P. nigrum contaminants (Carica papaya, Zea mays and Capsicum annuum) using plant DNA barcodes trnL and psbA-trnH. The method enables the specific detection of contaminants in a short time with low limits of detection (LOD6 values of 1, 2 and 10 Haploid Genome Equivalents). A market survey (29 samples) revealed 41% of samples contaminated, though about ¾ at very low levels indicating accidental contamination. The proposed tool will contribute to the improvement of quality of this much traded spice.


Assuntos
Código de Barras de DNA Taxonômico/métodos , DNA de Plantas/análise , Piper nigrum/genética , Capsicum/genética , Carica/genética , Primers do DNA/metabolismo , DNA de Plantas/genética , DNA de Plantas/metabolismo , Frutas/genética , Limite de Detecção , Hibridização de Ácido Nucleico , Proteínas de Plantas/genética , Reação em Cadeia da Polimerase em Tempo Real , Zea mays/genética
5.
Food Chem ; 274: 822-830, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30373016

RESUMO

With genetically modified (GM) food circulating on the market, a rapid transgenic food screening method is needed to protect consumer rights. The on-site screening efficiency of GM food testing is low. We report rapid sample-to-answer detection of GM papayas with loop-mediated isothermal amplification (LAMP) and a compact, portable, integrated microfluidic platform using microfluidic lab-on-a-disc (LOAD). GM samples were differentiated from non-GM papaya, based on the detection of a specific GM (P-35S (Cauliflower mosaic virus 35S promoter)) and non-GM DNA marker (papain) in 15 min. The detection limits for DNA and juice from papaya were 10 pg/µL and 0.02 µL, respectively. Our LOAD platform is a simple and robust solution for GM screening, which is anticipated to be a foundation for on-site testing of transgenic food.


Assuntos
Carica/genética , Análise de Alimentos/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Plantas Geneticamente Modificadas/genética , Análise de Alimentos/instrumentação , Sucos de Frutas e Vegetais , Marcadores Genéticos , Hong Kong , Dispositivos Lab-On-A-Chip , Limite de Detecção , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Papaína/genética , Regiões Promotoras Genéticas , Smartphone
6.
Food Chem ; 277: 362-372, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30502158

RESUMO

High hydrostatic pressure (HHP) processing is a non-thermal technology reported to increase desirable metabolites in plant foods. This work evaluated changes in carotenoid accumulation in fresh-cut papaya fruit as affected by HHP treatment (50-400 MPa for 3-60 min) and during subsequent storage at 4 °C; simultaneously, transcriptional activities of carotenoid biosynthetic genes and oxidative stress markers were evaluated. LC-MS analyses revealed that HHP treatment increased carotenoid precursors and carotenes contents following processing and storage: lycopene levels increased up to 11-fold compared to the non-treated samples, and H2O2 and lipid peroxidation were concomitantly increased. qRT-PCR of intact RNA showed that the amount of phytoene desaturase transcripts increased after HHP treatment, and that they were correlated with carotene accumulation. This is the first study to show that HHP treatment triggers de novo carotenoid biosynthesis, which is regulated at the transcriptional level, possibly by inducing oxidative stress signaling in fruit tissue.


Assuntos
Carica/metabolismo , Carotenoides/biossíntese , Frutas/metabolismo , Carica/genética , Cromatografia Líquida , Temperatura Baixa , Manipulação de Alimentos , Frutas/genética , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Pressão Hidrostática , Peroxidação de Lipídeos/efeitos dos fármacos , Licopeno/análise , Análise Multivariada , Estresse Oxidativo/efeitos dos fármacos , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ativação Transcricional/genética
7.
Plant Sci ; 272: 99-106, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29807610

RESUMO

Papaya is trioecious and an excellent system for studying sex determination and differentiation in plants. An ortholog of HUA1, CpHUA1, a gene controlling stamen and carpel development in Arabidopsis, was cloned and characterized in papaya. CpHUA1 consists of 12 exons with full genomic length of 19,313 bp in male AU9 and 19,312 bp in hermaphrodite SunUp, whereas the Arabidopsis HUA1 consists of 12 exons with full genomic length of 4300 bp. All the 324 SNPs between male and hermaphrodite varieties are in the 11th intron, which spans 8.5 kb. Quantitative RT-PCR revealed that CpHUA1 expression is highly elevated in carpels, suggesting that CpHUA1 may be involved in sex differentiation gene network. Southern blot analysis revealed a distinct restriction pattern in male AU9 compared to hermaphrodite Kapoho and SunUp, despite high DNA sequence identity and sharing of all but two EcoR I restriction sites in genomic CpHUA1 sequences of AU9 and SunUp. The methylation of cytosine at one restriction site in male but not in other two sex types may result in distinct restriction pattern of EcoR I in southern blot result. Bisulfite sequencing showed differential methylation of CpHUA1 among sex types, particularly the enrichment of sex-specific methylation in 9th and 11th intron. The methylation difference in cold stress induced male to hermaphrodite mutant mostly observed in the CHH context of CpHUA1, but no methylation difference detected in CHH context in other sex types, which may indicate the role of methylation in CHH context of CpHUA1 in temperature-related stress response and sex reversal.


Assuntos
Carica/metabolismo , Proteínas de Plantas/fisiologia , Proteínas de Ligação a RNA/fisiologia , Processos de Determinação Sexual , Carica/genética , Carica/crescimento & desenvolvimento , Metilação de DNA , Flores/genética , Flores/crescimento & desenvolvimento , Genes de Plantas/genética , Genes de Plantas/fisiologia , Filogenia , Proteínas de Plantas/genética , Proteínas de Ligação a RNA/genética , Processos de Determinação Sexual/fisiologia
8.
Plant Cell Rep ; 37(7): 967-980, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29564545

RESUMO

KEY MESSAGE: Global gene expression analysis indicates host stress responses, mainly those mediated by SA, associated to the tolerance to sticky disease symptoms at pre-flowering stage in Carica papaya. Carica papaya plants develop the papaya sticky disease (PSD) as a result of the combined infection of papaya meleira virus (PMeV) and papaya meleira virus 2 (PMeV2), or PMeV complex. PSD symptoms appear only after C. papaya flowers. To understand the mechanisms involved in this phenomenon, the global gene expression patterns of PMeV complex-infected C. papaya at pre-and post-flowering stages were assessed by RNA-Seq. The result was 633 and 88 differentially expressed genes at pre- and post-flowering stages, respectively. At pre-flowering stage, genes related to stress and transport were up-regulated while metabolism-related genes were down-regulated. It was observed that induction of several salicylic acid (SA)-activated genes, including PR1, PR2, PR5, WRKY transcription factors, ROS and callose genes, suggesting SA signaling involvement in the delayed symptoms. In fact, pre-flowering C. papaya treated with exogenous SA showed a tendency to decrease the PMeV and PMeV2 loads when compared to control plants. However, pre-flowering C. papaya also accumulated transcripts encoding a NPR1-inhibitor (NPR1-I/NIM1-I) candidate, genes coding for UDP-glucosyltransferases (UGTs) and several genes involved with ethylene pathway, known to be negative regulators of SA signaling. At post-flowering, when PSD symptoms appeared, the down-regulation of PR-1 encoding gene and the induction of BSMT1 and JA metabolism-related genes were observed. Hence, SA signaling likely operates at the pre-flowering stage of PMeV complex-infected C. papaya inhibiting the development of PSD symptoms, but the induction of its negative regulators prevents the full-scale and long-lasting tolerance.


Assuntos
Carica/genética , Carica/virologia , Doenças das Plantas/virologia , Proteínas de Plantas/genética , Carica/efeitos dos fármacos , Flores , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno/fisiologia , Doenças das Plantas/genética , Folhas de Planta/virologia , Vírus de RNA/patogenicidade , RNA Mensageiro , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Ácido Salicílico/metabolismo , Ácido Salicílico/farmacologia , Análise de Sequência de RNA
9.
PLoS One ; 13(3): e0194605, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29566053

RESUMO

Carica papaya L. is an important economic crop worldwide and is used as a model plant for sex-determination research. To study the different flower sex types, we screened sex-related genes using alternative splicing sequences (AS-seqs) from a transcriptome database of the three flower sex types, i.e., males, females, and hermaphrodites, established at 28 days before flowering using 15 bacterial artificial chromosomes (BACs) of C. papaya L. After screening, the cDNA regions of the three sex-related loci, including short vegetative phase-like (CpSVPL), the chromatin assembly factor 1 subunit A-like (CpCAF1AL), and the somatic embryogenesis receptor kinase (CpSERK), which contained eight sex-related single-nucleotide polymorphisms (SNPs) from the different sex types of C. papaya L., were genotyped using high-resolution melting (HRM). The three loci were examined regarding the profiles of the third whorl, as described below. CpSVPL, which had one SNP associated with the three sex genotypes, was highly expressed in the male and female sterile flowers (abnormal hermaphrodite flowers) that lacked the fourth whorl structure. CpCAF1AL, which had three SNPs associated with the male genotype, was highly expressed in male and normal hermaphrodite flowers, and had no AS-seqs, whereas it exhibited low expression and an AS-seqs in intron 11 in abnormal hermaphrodite flowers. Conversely, carpellate flowers (abnormal hermaphrodite flowers) showed low expression of CpSVPL and AS-seqs in introns 5, 6, and 7 of CpSERK, which contained four SNPs associated with the female genotype. Specifically, the CpSERK and CpCAF1AL loci exhibited no AS-seq expression in the third whorl of the male and normal hermaphrodite flowers, respectively, and variance in the AS-seq expression of all other types of flowers. Functional mapping of the third whorl of normal hermaphrodites indicated no AS-seq expression in CpSERK, low CpSVPL expression, and, for CpCAF1AL, high expression and no AS-seq expression on XYh-type chromosomes.


Assuntos
Carica/genética , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Loci Gênicos , Cromossomos Sexuais/genética , Processos de Determinação Sexual/genética , Cromossomos de Plantas/química , Flores/genética , Regulação da Expressão Gênica de Plantas , Genótipo
10.
BMC Genomics ; 19(1): 26, 2018 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-29306330

RESUMO

BACKGROUND: Papain-like cysteine proteases (PLCPs), a large group of cysteine proteases structurally related to papain, play important roles in plant development, senescence, and defense responses. Papain, the first cysteine protease whose structure was determined by X-ray crystallography, plays a crucial role in protecting papaya from herbivorous insects. Except the four major PLCPs purified and characterized in papaya latex, the rest of the PLCPs in papaya genome are largely unknown. RESULTS: We identified 33 PLCP genes in papaya genome. Phylogenetic analysis clearly separated plant PLCP genes into nine subfamilies. PLCP genes are not equally distributed among the nine subfamilies and the number of PLCPs in each subfamily does not increase or decrease proportionally among the seven selected plant species. Papaya showed clear lineage-specific gene expansion in the subfamily III. Interestingly, all four major PLCPs purified from papaya latex, including papain, chymopapain, glycyl endopeptidase and caricain, were grouped into the lineage-specific expansion branch in the subfamily III. Mapping PLCP genes on chromosomes of five plant species revealed that lineage-specific expansions of PLCP genes were mostly derived from tandem duplications. We estimated divergence time of papaya PLCP genes of subfamily III. The major duplication events leading to lineage-specific expansion of papaya PLCP genes in subfamily III were estimated at 48 MYA, 34 MYA, and 16 MYA. The gene expression patterns of the papaya PLCP genes in different tissues were assessed by transcriptome sequencing and qRT-PCR. Most of the papaya PLCP genes of subfamily III expressed at high levels in leaf and green fruit tissues. CONCLUSIONS: Tandem duplications played the dominant role in affecting copy number of PLCPs in plants. Significant variations in size of the PLCP subfamilies among species may reflect genetic adaptation of plant species to different environments. The lineage-specific expansion of papaya PLCPs of subfamily III might have been promoted by the continuous reciprocal selective effects of herbivore attack and plant defense.


Assuntos
Carica/enzimologia , Linhagem da Célula , Duplicação Gênica , Papaína/genética , Proteínas de Plantas/genética , Carica/genética , Genoma de Planta , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Família Multigênica , Papaína/classificação , Filogenia
11.
Plant Cell Physiol ; 58(12): 2155-2165, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29040739

RESUMO

Papaya is an important tropical fruit with a rich source of carotenoids. The ripening of papaya is a physiological and metabolic process with remarkable changes including accumulation of carotenoids, which depends primarily on the action of ethylene. Ethylene response is mediated by a transcriptional cascade involving the transcription factor families of EIN3/EILs and ERFs. Although ERF members have been reported to control carotenoid production in Arabidopsis and tomato, whether EIN3/EILs are also involved in carotenoid biosynthesis during fruit ripening remains unclear. In this work, two EIN3 genes from papaya fruit, namely CpEIN3a and CpEIN3b, were studied, of which CpEIN3a was increased during fruit ripening, concomitant with the increase of transcripts of carotenoid biosynthesis-related genes including CpPDS2/4, CpZDS, CpLCY-e and CpCHY-b, and carotenoid content. Electrophoretic mobility shift assays (EMSAs) and transient expression analyses revealed that CpEIN3a was able to bind to the promoters of CpPDS4 and CpCHY-b, and promoted their transcription. Protein-protein interaction assays indicated that CpEIN3a physically interacted with another transcription factor CpNAC2, which acted as a transcriptional activator of CpPDS2/4, CpZDS, CpLCY-e and CpCHY-b by directly binding to their promoters. More importantly, the transcriptional activation abilities of CpPDS2/4, CpLCY-e and CpCHY-b were more pronounced following their interaction. Collectively, our findings suggest that CpEIN3a interacts with CpNAC2 and, individually or co-operatively, activates the transcription of a subset of carotenoid biosynthesis-related genes, providing new insights into the regulatory networks of carotenoid biosynthesis during papaya fruit ripening.


Assuntos
Carica/fisiologia , Carotenoides/biossíntese , Frutas/fisiologia , Proteínas de Plantas/genética , Carica/genética , Carotenoides/genética , Ensaio de Desvio de Mobilidade Eletroforética , Frutas/genética , Regulação da Expressão Gênica de Plantas , Liases Intramoleculares/genética , Liases Intramoleculares/metabolismo , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
BMC Genomics ; 18(1): 671, 2017 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-28859626

RESUMO

BACKGROUND: Since papaya is a typical climacteric fruit, exogenous ethylene (ETH) applications can induce premature and quicker ripening, while 1-methylcyclopropene (1-MCP) slows down the ripening processes. Differential gene expression in ETH or 1-MCP-treated papaya fruits accounts for the ripening processes. To isolate the key ripening-related genes and better understand fruit ripening mechanisms, transcriptomes of ETH or 1-MCP-treated, and non-treated (Control Group, CG) papaya fruits were sequenced using Illumina Hiseq2500. RESULTS: A total of 18,648 (1-MCP), 19,093 (CG), and 15,321 (ETH) genes were detected, with the genes detected in the ETH-treatment being the least. This suggests that ETH may inhibit the expression of some genes. Based on the differential gene expression (DGE) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, 53 fruit ripening-related genes were selected: 20 cell wall-related genes, 18 chlorophyll and carotenoid metabolism-related genes, four proteinases and their inhibitors, six plant hormone signal transduction pathway genes, four transcription factors, and one senescence-associated gene. Reverse transcription quantitative PCR (RT-qPCR) analyses confirmed the results of RNA-seq and verified that the expression pattern of six genes is consistent with the fruit senescence process. Based on the expression profiling of genes in carbohydrate metabolic process, chlorophyll metabolism pathway, and carotenoid metabolism pathway, the mechanism of pulp softening and coloration of papaya was deduced and discussed. We illustrate that papaya fruit softening is a complex process with significant cell wall hydrolases, such as pectinases, cellulases, and hemicellulases involved in the process. Exogenous ethylene accelerates the coloration of papaya changing from green to yellow. This is likely due to the inhibition of chlorophyll biosynthesis and the α-branch of carotenoid metabolism. Chy-b may play an important role in the yellow color of papaya fruit. CONCLUSIONS: Comparing the differential gene expression in ETH/1-MCP-treated papaya using RNA-seq is a sound approach to isolate ripening-related genes. The results of this study can improve our understanding of papaya fruit ripening molecular mechanism and reveal candidate fruit ripening-related genes for further research.


Assuntos
Carica/crescimento & desenvolvimento , Carica/genética , Ciclopropanos/farmacologia , Etilenos/farmacologia , Genes de Plantas/genética , RNA de Plantas/genética , Análise de Sequência de RNA , Carica/efeitos dos fármacos , Frutas/efeitos dos fármacos , Frutas/crescimento & desenvolvimento , Anotação de Sequência Molecular , Transcrição Genética/efeitos dos fármacos
13.
BMC Genomics ; 18(1): 351, 2017 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-28476147

RESUMO

BACKGROUND: Auxin/indole-3-acetic acid (Aux/IAA) family genes encode short-lived nuclear proteins that mediate the responses of auxin-related genes and are involved in several plant developmental and growth processes. However, how Aux/IAA genes function in the fruit development and ripening of papaya (Carica papaya L.) is largely unknown. RESULTS: In this study, a comprehensive identification and a distinctive expression analysis of 18 C. papaya Aux/IAA (CpIAA) genes were performed using newly updated papaya reference genome data. The Aux/IAA gene family in papaya is slightly smaller than that in Arabidopsis, but all of the phylogenetic subfamilies are represented. Most of the CpIAA genes are responsive to various phytohormones and expressed in a tissues-specific manner. To understand the putative biological functions of the CpIAA genes involved in fruit development and ripening, quantitative real-time PCR was used to test the expression profiling of CpIAA genes at different stages. Furthermore, an IAA treatment significantly delayed the ripening process in papaya fruit at the early stages. The expression changes of CpIAA genes in ACC and 1-MCP treatments suggested a crosstalk between auxin and ethylene during the fruit ripening process of papaya. CONCLUSIONS: Our study provided comprehensive information on the Aux/IAA family in papaya, including gene structures, phylogenetic relationships and expression profiles. The involvement of CpIAA gene expression changes in fruit development and ripening gives us an opportunity to understand the roles of auxin signaling in the maturation of papaya reproductive organs.


Assuntos
Carica/crescimento & desenvolvimento , Carica/genética , Frutas/crescimento & desenvolvimento , Genômica , Ácidos Indolacéticos/metabolismo , Proteínas de Plantas/genética , Sequência de Aminoácidos , Genoma de Planta/genética , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética
14.
Genet Mol Res ; 16(1)2017 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-28252169

RESUMO

Papaya crop is important to Brazilian agribusiness. However, the expansion of papaya cultivation in the country is affected by the absence of commercial cultivars presenting good disease resistance. The black-spot caused by the fungus Asperisporium caricae is the most damaging foliar disease affecting Brazilian papaya crops. The use of genetically resistant cultivars is a promising strategy to reduce the dependence of papaya crops on fungicides. A field split-plot experiment was carried out in the municipality of Linhares, Espírito Santo State, and included 20 hybrids derived from the cross between 14 superior lines and four elite genotypes ('SS72/12', 'SEKATI', 'JS/12' and '41/7'), two commercial cultivars ('Golden' and 'Tainung 01'), and the superior line '36/7', which were evaluated for resistance to black-spot in the fruits and leaves. The treatments were arranged in a randomized block design with six repetitions of three plants per plot. The incidence and severity of black spot in the fruits and leaves were evaluated at three different times in the 2015-2016 crop season. Lines 4, 9, 21, and the parent SEKATI were notable for their capacity to reduce disease severity in the leaves and fruits. Lines 1, 2, 9, 16, and 19, and the parents 'SEKATI' and 'SS-72/12' had reduced disease incidence in their fruits. The most resistant hybrids 'SS-72/12 X 4', 'SS-72/12 X 6', 'SEKATI X 1', 'SEKATI X 2', 'SEKATI X 6', 'SEKATI X 9', and 'SEKATI X 20' presented negative heterosis values for improved black-spot resistance. The current study allowed the selection of black-spot resistant genotypes and hybrids, which presented a significantly reduced disease index in the field.


Assuntos
Carica/genética , Produtos Agrícolas/genética , Resistência à Doença/genética , Melhoramento Vegetal/métodos , Doenças das Plantas/genética , Ascomicetos/fisiologia , Brasil , Carica/microbiologia , Produtos Agrícolas/microbiologia , Frutas/genética , Frutas/microbiologia , Genótipo , Vigor Híbrido/genética , Hibridização Genética , Endogamia , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/microbiologia , Reprodutibilidade dos Testes
15.
Planta ; 245(5): 1037-1048, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28194565

RESUMO

MAIN CONCLUSION: Transgenic papaya callus lines expressing the components of the S3Pvac vaccine constitute a stable platform to produce an oral vaccine against cysticercosis caused by Taenia solium or T. crassiceps. The development of effective delivery systems to cope with the reduced immunogenicity of new subunit vaccines is a priority in vaccinology. Herein, experimental evidence supporting a papaya-based platform to produce needle-free, recombinant, highly immunogenic vaccines is shown. Papaya (Carica papaya) callus lines were previously engineered by particle bombardment to express the three protective peptides of the S3Pvac anti-cysticercosis vaccine (KETc7, KETc12, KETc1). Calli were propagated in vitro, and a stable integration and expression of the target genes has been maintained, as confirmed by PCR, qRT-PCR, and HPLC. These results point papaya calli as a suitable platform for long-term transgenic expression of the vaccine peptides. The previously demonstrated protective immunogenic efficacy of S3Pvac-papaya orally administered to mice is herein confirmed in a wider dose-range and formulated with different delivery vehicles, adequate for oral vaccination. This protection is accompanied by an increase in anti-S3Pvac antibody titers and a delayed hypersensitivity response against the vaccine. A significant increase in CD4+ and CD8+ lymphocyte proliferation was induced in vitro by each vaccine peptide in mice immunized with the lowest dose of S3Pvac papaya (0.56 ng of the three peptides in 0.1 µg of papaya callus total protein per mouse). In pigs, the obliged intermediate host for Taenia solium, S3Pvac papaya was also immunogenic when orally administered in a two-log dose range. Vaccinated pigs significantly increased anti-vaccine antibodies and mononuclear cell proliferation. Overall, the oral immunogenicity of this stable S3Pvac-papaya vaccine in mice and pigs, not requiring additional adjuvants, supports the interest in papaya callus as a useful platform for plant-based vaccines.


Assuntos
Antígenos de Helmintos/imunologia , Carica/metabolismo , Cisticercose/veterinária , Doenças dos Suínos/prevenção & controle , Taenia solium/imunologia , Vacinas Sintéticas/imunologia , Administração Oral , Animais , Antígenos de Helmintos/administração & dosagem , Carica/genética , Carica/imunologia , Cisticercose/parasitologia , Cisticercose/prevenção & controle , Feminino , Imunização , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Plantas Geneticamente Modificadas , Suínos , Doenças dos Suínos/parasitologia , Vacinas Sintéticas/administração & dosagem
16.
PLoS One ; 12(2): e0171357, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28231288

RESUMO

BACKGROUND: Ripening affects the quality and nutritional contents of fleshy fruits and is a crucial process of fruit development. Although several studies have suggested that ubiquitin-conjugating enzyme (E2s or UBC enzymes) are involved in the regulation of fruit ripening, little is known about the function of E2s in papaya (Carica papaya). METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we searched the papaya genome and identified 34 putative UBC genes, which were clustered into 17 phylogenetic subgroups. We also analyzed the nucleotide sequences of the papaya UBC (CpUBC) genes and found that both exon-intron junctions and sequence motifs were highly conserved among the phylogenetic subgroups. Using real-time PCR analysis, we also found that all the CpUBC genes were expressed in roots, stems, leaves, male and female flowers, and mature fruit, although the expression of some of the genes was increased or decreased in one or several specific organs. We also found that the expression of 13 and two CpUBC genes were incresesd or decreased during one and two ripening stages, respectively. Expression analyses indicates possible E2s playing a more significant role in fruit ripening for further studies. CONCLUSIONS: To the best of our knowledge, this is the first reported genome-wide analysis of the papaya UBC gene family, and the results will facilitate further investigation of the roles of UBC genes in fruit ripening and will aide in the functional validation of UBC genes in papaya.


Assuntos
Carica/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Enzimas de Conjugação de Ubiquitina/genética , Sequência de Aminoácidos , Carica/química , Carica/crescimento & desenvolvimento , Genes de Plantas , Filogenia , Proteínas de Plantas/análise , Alinhamento de Sequência , Enzimas de Conjugação de Ubiquitina/análise
17.
Am J Bot ; 104(1): 116-126, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28082282

RESUMO

PREMISE OF THE STUDY: The red flesh of some papaya cultivars is caused by a recessive loss-of-function mutation in the coding region of the chromoplast-specific lycopene beta cyclase gene (CYC-b). We performed an evolutionary genetic analysis of the CYC-b locus in wild and cultivated papaya to uncover the origin of this loss-of-function allele in cultivated papaya. METHODS: We analyzed the levels and patterns of genetic diversity at the CYC-b locus and six loci in a 100-kb region flanking CYC-b and compared these to genetic diversity levels at neutral autosomal loci. The evolutionary relationships of CYC-b haplotypes were assessed using haplotype network analysis of the CYC-b locus and the 100-kb CYC-b region. KEY RESULTS: Genetic diversity at the recessive CYC-b allele (y) was much lower relative to the dominant Y allele found in yellow-fleshed wild and cultivated papaya due to a strong selective sweep. Haplotype network analyses suggest the y allele most likely arose in the wild and was introduced into domesticated varieties after the first papaya domestication event. The shared haplotype structure between some wild, feral, and cultivated haplotypes around the y allele supports subsequent escape of this allele from red cultivars back into wild populations through feral intermediates. CONCLUSIONS: Our study supports a protracted domestication process of papaya through the introgression of wild-derived traits and gene flow from cultivars to wild populations. Evidence of gene flow from cultivars to wild populations through feral intermediates has implications for the introduction of transgenic papaya into Central American countries.


Assuntos
Carica/genética , Evolução Molecular , Variação Genética , Liases Intramoleculares/genética , Proteínas de Plantas/genética , Alelos , Carica/classificação , Carica/enzimologia , América Central , Fluxo Gênico , Frequência do Gene , Genética Populacional , Haplótipos , Liases Intramoleculares/classificação , Modelos Genéticos , Mutação , Fenótipo , Filogenia , Proteínas de Plantas/classificação , Plastídeos/genética
18.
Genome Biol ; 17(1): 244, 2016 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-27899139

RESUMO

A new study on sex chromosome evolution in papaya helps to illuminate sex chromosome biology, including deviations from expected trajectories.Please see related Research article: https://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-1095-9.


Assuntos
Cromossomos de Plantas/genética , Evolução Molecular , Variação Genética , Cromossomos Sexuais/genética , Carica/genética , Carica/crescimento & desenvolvimento
19.
Ann Bot ; 118(7): 1293-1306, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27974326

RESUMO

BACKGROUND AND AIMS: Few studies have evaluated the genetic structure and evolutionary history of wild varieties of important crop species. The wild papaya (Carica papaya) is a key element of early successional tropical and sub-tropical forests in Mexico, and constitutes the genetic reservoir for evolutionary potential of the species. In this study we aimed to determine how diverse and structured is the genetic variability of wild populations of C. papaya in Northern Mesoamerica. Moreover, we assessed if genetic structure and evolutionary history coincide with hypothetized (1) pre-Pleistocene events (Isthmus of Tehuantepec sinking), (2) Pleistocene refugia or (3) recent patterns. METHODS: We used six nuclear and two chloroplast (cp) DNA markers to assess the genetic diversity and phylogeographical structure of 19 wild populations of C. papaya in its natural distribution in Northern Mesoamerica. KEY RESULTS: We found high genetic diversity (Ho = 0·681 for nuclear markers, and h = 0·701 for cpDNA markers) and gene flow between populations of C. papaya (migration r up to 420 km). A lack of phylogeographical structure was found with the cpDNA markers (NST < GST), whereas a recent population structure was inferred with the nuclear markers. Evidence indicates that pre-Pleistocene events or refugia did not play an important role in the genetic structuring of wild papaya. CONCLUSIONS: Because of its life history characteristics and lack of an ancient phylogeographical structure found with the cpDNA markers, we suggest that C. papaya was dispersed throughout the lowland rain forests of Mexico (along the coastal plains and foothills of Sierras). This scenario supports the hypothesis that tropical forests in Northern Mesoamerica did not experience important climate fluctuations during the Pleistocene, and that the life history of C. papaya could have promoted long-distance dispersal and rapid colonization of lowland rainforests. Moreover, the results obtained with the nuclear markers suggest recent human disturbances. The fragmentation of tropical habitats in Northern Mesoamerica appears to be the main driver of genetic structuring, and the major threat to the dispersion and survival of the species in the wild.


Assuntos
Carica/genética , Cloroplastos/genética , Variação Genética/genética , Repetições de Microssatélites/genética , Carica/anatomia & histologia , América Central , DNA de Plantas/genética , Marcadores Genéticos/genética , México , Filogenia , Análise de Sequência de DNA
20.
Genome Biol ; 17(1): 230, 2016 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-27890017

RESUMO

BACKGROUND: The papaya Y-linked region showed clear population structure, resulting in the detection of the ancestral male population that domesticated hermaphrodite papayas were selected from. The same populations were used to study nucleotide diversity and population structure in the X-linked region. RESULTS: Diversity is very low for all genes in the X-linked region in the wild dioecious population, with nucleotide diversity π syn = 0.00017, tenfold lower than the autosomal region (π syn = 0.0017) and 12-fold lower than the Y-linked region (π syn = 0.0021). Analysis of the X-linked sequences shows an undivided population, suggesting a geographically wide diversity-reducing event, whereas two subpopulations were observed in the autosomes separating gynodioecy and dioecy and three subpopulations in the Y-linked region separating three male populations. The extremely low diversity in the papaya X-linked region was probably caused by a recent, strong selective sweep before domestication, involving either the spread of a recessive mutation in an X-linked gene that is beneficial to males or a partially dominant mutation that benefitted females or both sexes. Nucleotide diversity in the domesticated X samples is about half that in the wild Xs, probably due to the bottleneck when hermaphrodites were selected during domestication. CONCLUSIONS: The extreme low nucleotide diversity in the papaya X-linked region is much greater than observed in humans, great apes, and the neo-X chromosome of Drosophila miranda, which show the expected pattern of Y-linked genes < X-linked genes < autosomal genes; papaya shows an unprecedented pattern of X-linked genes < autosomal genes < Y-linked genes.


Assuntos
Carica/genética , Cromossomos de Plantas/genética , Variação Genética , Nucleotídeos/genética , Feminino , Genes Ligados ao Cromossomo X/genética , Genes Ligados ao Cromossomo Y/genética , Haplótipos , Humanos , Masculino , Mutação , Análise de Sequência de DNA , Processos de Determinação Sexual
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