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1.
Environ Pollut ; 249: 1011-1018, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31146307

RESUMO

Iron fertilizers are worthy to be studied due to alleviate the Fe deficiency. Different forms of iron oxide nanoparticles are selected to better understand possible particle applications as an Fe source for crop plants. In this study, we assessed the different effects of γ-Fe2O3 and Fe3O4 NPs on the physiology and fruit quality of muskmelon plants in a pot experiment for five weeks. Results showed that no increased iron content was found under NPs treatment in root, stem, leaf and fruit, except 400 mg/L Fe3O4 NPs had a higher iron content in muskmelon root. With the extension of NPs exposure, both γ-Fe2O3 and Fe3O4 NPs began to promote plant growth. In addition, γ-Fe2O3 and Fe3O4 NPs could increase chlorophyll content at a certain stage of exposure. Happily, 200 mg/L γ-Fe2O3 NPs and 100, 200 mg/L Fe3O4 NPs significantly increased fruit weight of muskmelon by 9.1%, 9.4% and 11.5%. It is noteworthy that both γ-Fe2O3 and Fe3O4 NPs caused positive effects on VC content, particularly 100 mg/L Fe3O4 NPs increased the VC content by 46.95%. To the best of our knowledge, little research has been done on the effect of nanoparticles on the whole physiological cycle and fruit quality of melon. The assessment of physiology and fruit quality of muskmelon plants in vitro upon γ-Fe2O3 and Fe3O4 NPs exposure could lay a foundation for NPs potential impact at every growth period of muskmelon plants.


Assuntos
Cucumis melo/efeitos dos fármacos , Compostos Férricos/farmacologia , Óxido Ferroso-Férrico/farmacologia , Frutas/efeitos dos fármacos , Nanopartículas/química , Antioxidantes/metabolismo , Clorofila , Cucumis melo/crescimento & desenvolvimento , Cucumis melo/fisiologia , Compostos Férricos/química , Óxido Ferroso-Férrico/química , Fertilizantes , Qualidade dos Alimentos , Frutas/crescimento & desenvolvimento , Frutas/fisiologia
2.
Gene ; 707: 65-77, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31059736

RESUMO

The genic male sterility (MS) plays a major role in melon hybrids production, it could reduce the cost of pollination and increase the yield and quality. However, the molecular mechanism underlying genetic male sterility is yet poorly understood. The morphological differences of flower buds of melon were observed showed that the flower buds were tetrad when they were 1 mm stage and monocyte microspore when they were 2 mm stage. Electron microscopy showed that there was significant difference between MS lines and MF (male fertility) lines. In order to detect the global expression of the genes during the melon anther development and association with MS, 12 DEGs (differentially expressed genes) libraries were constructed from the anther of MS and MF in the bud stage with 1 and 2 mm diameter, respectively. A total of 765 DEGs expressed in anther during different developmental stage (MS 1 mm vs. MS 2 mm), 148 and 309 DEGs were found to be related to MS as compared to MF (MS 1 mm vs. MF 1 mm, and MS 2 mm vs. MF 2 mm) at a false discovery rate FDR <0.01. Among these, 10 DEGs were expressed in all the three comparisons, including transcription factor bHLH genes. Among the DEGs in RNA-seq analysis, 28 were validated by qRT-PCR. Of these, a number of genes were involved in ABC transfactor B family, cytochrome-related genes, hormone-related genes (auxin transporter, gibberellin-regulated protein), MADS-box protein genes, F-box protein genes, peroxidase-related, and Zinc finger protein genes. These genes are involved in many biological pathways, including starch and sucrose metabolism, signal transduction mechanisms and transcription factors, etc. Compared to the same developmental stage of MS and MF, the different developmental stages of MS indicated diverse gene regulation pathways involved in the anther development in MS. These results would provide novel insight into the global network to male sterility in melon.


Assuntos
Cucumis melo/fisiologia , Perfilação da Expressão Gênica/métodos , Infertilidade das Plantas , Proteínas de Plantas/genética , Quimera/genética , Quimera/fisiologia , Cucumis melo/genética , Cucumis melo/ultraestrutura , Flores/genética , Flores/fisiologia , Flores/ultraestrutura , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Microscopia Eletrônica , Análise de Sequência de RNA
3.
Acta Biochim Biophys Sin (Shanghai) ; 51(3): 301-312, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30883647

RESUMO

Salinity is one of the major limiting factors in plant growth and productivity. Cucumis melo L. is a widely cultivated plant, but its productivity is significantly influenced by the level of salinity in soil. Symbiotic colonization of plants with Piriformospora indica has shown a promotion in plants growth and tolerance against biotic stress. In this study, physiological markers such as ion analysis, antioxidant determination, proline content, electrolyte leakage and chlorophyll measurement were assessed in melon cultivar under two concentrations (100 and 200 mM) of NaCl with and without P. indica inoculation. Results showed that the endophytic inoculation consistently upregulated the level of antioxidants, enhanced plants to antagonize salinity stress. The expression level of an RNA editing factor (SLO2) which is known to participate in mitochondria electron transport chain was analyzed, and its full mRNA sequence was obtained by rapid amplification of cDNA ends (RACE). Under salinity stress, the expression level of SLO2 was increased, enhancing the plant's capability to adapt to the stress. However, P. indica inoculation further elevated the expression level of SLO2. These findings suggested that the symbiotic association of fungi could help the plants to tolerate the salinity stress.


Assuntos
Basidiomycota/fisiologia , Cucumis melo/fisiologia , Biomassa , Clorofila/análise , Eletrólitos/metabolismo , Prolina/análise , Edição de RNA , Salinidade , Estresse Fisiológico , Simbiose
4.
BMC Plant Biol ; 19(1): 75, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30770731

RESUMO

BACKGROUND: Lipoxygenases (LOXs) play significant roles in abiotic stress responses, and identification of LOX gene promoter function can make an important contribution to elucidating resistance mechanisms. Here, we cloned the CmLOX08 promoter of melon (Cucumis melo) and identified the main promoter regions regulating transcription in response to signalling molecules and abiotic stresses. RESULTS: The 2054-bp promoter region of CmLOX08 from melon leaves was cloned, and bioinformatic analysis revealed that it harbours numerous cis-regulatory elements associated with signalling molecules and abiotic stress. Five 5'-deletion fragments obtained from the CmLOX08 promoter-2054 (LP1), 1639 (LP2), 1284 (LP3), 1047 (LP4), and 418 bp (LP5)-were fused with a GUS reporter gene and used for tobacco transient assays. Deletion analysis revealed that in response to abscisic acid, salicylic acid, and hydrogen peroxide, the GUS activity of LP1 was significantly higher than that of the mock-treated control and LP2, indicating that the - 2054- to - 1639-bp region positively regulates expression induced by these signalling molecules. However, no deletion fragment GUS activity was induced by methyl jasmonate. In response to salt, drought, and wounding treatments, LP1, LP2, and LP4 promoted significantly higher GUS expression compared with the control. Among all deletion fragments, LP4 showed the highest GUS expression, indicating that - 1047 to - 1 bp is the major region regulating promoter activity and that the - 1047 to - 418-bp region positively regulates expression induced by salt, drought, and wounding, whereas the - 1284 to - 1047-bp region is a negative regulatory segment. Interestingly, although the GUS activity of LP1 and LP2 was not affected by temperature changes, that of LP3 was significantly induced by heat, indicating that the - 1284- to - 1-bp region is a core sequence responding to heat and the - 2054- to - 1284-bp region negatively regulates expression induced by heat. Similarly, the - 1047- to - 1-bp region is the main sequence responding to cold, whereas the - 2054- to - 1047-bp region negatively regulates expression induced by cold. CONCLUSIONS: We cloned the CmLOX08 promoter and demonstrated that it is a signalling molecule/stress-inducible promoter. Furthermore, we identified core and positive/negative regulatory regions responding to three signalling molecules and five abiotic stresses.


Assuntos
Cucumis melo/genética , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Planta/farmacologia , Regiões Promotoras Genéticas/genética , Transdução de Sinais , Estresse Fisiológico , Ácido Abscísico/farmacologia , Acetatos/farmacologia , Cucumis melo/fisiologia , Ciclopentanos/farmacologia , Secas , Genes Reporter , Peróxido de Hidrogênio/farmacologia , Oxilipinas/farmacologia , Ácido Salicílico/farmacologia , Cloreto de Sódio/farmacologia
5.
Protoplasma ; 255(3): 873-883, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29248969

RESUMO

A new protocol for in vitro regeneration through direct somatic embryogenesis for two muskmelon cultivars (Cucumis melo L., "Mashhadi" and "Eivanaki") is reported. Somatic embryos were obtained culturing 4- and 8-day-old cotyledons, seeds, and hypocotyls on Murashige and Skoog medium supplemented with three different hormonal combinations never tested so far for melon (naphthoxyacetic acid (NOA) + thidiazuron (TDZ), NOA + 6-banzylaminopurine (BAP), and 2,4-dichlorophenoxyacetic acid (2,4-D) + N-(2-chloro-4-pyridyl)-N'-phenylurea (4-CPPU)). Results were compared with those obtained when explants were cultivated in the presence of 2,4-D + BAP, previously used on melon. Embryogenesis occurred more successfully in 4-day-old cotyledons and seeds than hypocotyls and 8-day-old cotyledons. The best result was achieved with NOA + BAP. Genotypes significantly affected embryogenesis. The number of embryos in "Eivanaki" was significantly higher than that in "Mashhadi." Embryo proliferation when explants were maintained in jars (9.3%) was found to be higher compared to that in petri dishes. For the first time, genetic stability of regenerated melon plants was evaluated using inter-simple sequence repeat markers. Polymerase chain reaction (PCR) products demonstrated a total of 102 well-resolved bands, and regenerants were 93% similar compared to the mother plant. Somaclonal changes during embryogenesis were evaluated by flow cytometry, showing 91% of the same patterns in regenerated plants. The results suggest that the new hormone components are effective when applied for in vitro embryogenesis of muskmelon as they show a high frequency in regeneration and genetic homogeneity.


Assuntos
Cucumis melo/genética , Cucumis melo/fisiologia , Repetições de Microssatélites/genética , Técnicas de Embriogênese Somática de Plantas/métodos , Regeneração , Citometria de Fluxo , Marcadores Genéticos , Genótipo , Germinação , Ploidias
6.
Plant Physiol ; 175(2): 904-915, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28794259

RESUMO

In many species, Suc en route out of the leaf migrates from photosynthetically active mesophyll cells into the phloem down its concentration gradient via plasmodesmata, i.e. symplastically. In some of these plants, the process is entirely passive, but in others phloem Suc is actively converted into larger sugars, raffinose and stachyose, and segregated (trapped), thus raising total phloem sugar concentration to a level higher than in the mesophyll. Questions remain regarding the mechanisms and selective advantages conferred by both of these symplastic-loading processes. Here, we present an integrated model-including local and global transport and kinetics of polymerization-for passive and active symplastic loading. We also propose a physical model of transport through the plasmodesmata. With these models, we predict that (1) relative to passive loading, polymerization of Suc in the phloem, even in the absence of segregation, lowers the sugar content in the leaf required to achieve a given export rate and accelerates export for a given concentration of Suc in the mesophyll and (2) segregation of oligomers and the inverted gradient of total sugar content can be achieved for physiologically reasonable parameter values, but even higher export rates can be accessed in scenarios in which polymers are allowed to diffuse back into the mesophyll. We discuss these predictions in relation to further studies aimed at the clarification of loading mechanisms, fitness of active and passive symplastic loading, and potential targets for engineering improved rates of export.


Assuntos
Cucumis melo/fisiologia , Malus/fisiologia , Floema/fisiologia , Plasmodesmos/fisiologia , Transporte Biológico , Biofísica , Cucumis melo/ultraestrutura , Malus/ultraestrutura , Células do Mesofilo/fisiologia , Células do Mesofilo/ultraestrutura , Oligossacarídeos/metabolismo , Floema/ultraestrutura , Folhas de Planta/fisiologia , Folhas de Planta/ultraestrutura , Plasmodesmos/ultraestrutura , Rafinose/metabolismo , Xilema/fisiologia , Xilema/ultraestrutura
7.
PLoS One ; 12(6): e0178638, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28570590

RESUMO

Cucumis melo L. var. agrestis Naud. (field muskmelon) is an annual invasive weed in many parts of Asia. However, there is very little available information about the germination and emergence of this species. Therefore, laboratory experiments were conducted to evaluate the effects of light, temperature, salt stress, osmotic stress, pH, and depth of planting on field muskmelon germination and seedling emergence. Light had no effect on seed germination, and the seeds germinated at a wide range of temperatures. More than 90% of the seeds germinated at constant temperatures between 20°C and 35°C, and fluctuating day/night temperatures between 15/25 and 30/40°C. The seeds were tolerant to salinity as germination occurred up to the 200 mM NaCl treatment. However, the seeds were sensitive to osmotic stress as seed germination was completely inhibited at -0.6 MPa. The seeds germinated over a pH range of 4 to 10, which suggested that pH was not a limiting factor for germination. Seedling emergence was greatest (97.86%) when the seeds were planted on the soil surface, but emergence declined as the burial depth increased. Information from this study can be used to predict future infestations in China and help develop strategies to manage this species.


Assuntos
Cucumis melo/fisiologia , Germinação , Cucumis melo/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Luz , Pressão Osmótica , Temperatura Ambiente
8.
Genet Mol Res ; 15(3)2016 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-27706747

RESUMO

Melon (Cucumis melo L.) is an important vegetable crop that ranks second in salt tolerance among the Cucurbitaceae. Previous studies on the two muskmelon cultivars 'Bing XueCui' (BXC) and 'Yu Lu' (YL) revealed that they had different characteristics under salt stress, but the molecular basis underlying their different physiological responses is unclear. Here, we combined a physiological study with a genome-wide transcriptome analysis to understand the molecular basis of genetic variation that responds to salt stress in the melon. BXC performed better under salt stress than YL in terms of biomass and photosynthetic characteristics, because it exhibited less reduction in transpiration rate, net photosynthesis rate, and stomatal conductance under 150-mM NaCl stress than YL. A transcriptome comparison of the leaves of the cultivars revealed that 1171 genes responded to salt stress in BXC while 1487 genes were identified as salt-stress-responsive in YL. A real-time polymerase chain reaction analysis of 12 of the responsive genes revealed that there was a strong, positive correlation with RNA sequencing data. The genes were involved in several pathways, including photosynthesis, the biosynthesis of secondary metabolites, metabolism, and plant hormone signal transduction, and their expression levels differed between the two cultivars in response to salt stress. This study provides a molecular perspective of two melon cultivars in response to salt stress, and its results could be used to investigate the complex molecular mechanisms underlying salt tolerance in the melon.


Assuntos
Cucumis melo/fisiologia , Plantas Tolerantes a Sal/fisiologia , Cucumis melo/genética , Expressão Gênica , Perfilação da Expressão Gênica , Salinidade , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/genética , Estresse Fisiológico/genética , Transcriptoma
9.
Plant Cell Rep ; 35(9): 1827-39, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27229006

RESUMO

KEY MESSAGE: 82 melon NAC (CmNAC) genes were identified in melon. We putatively identified the function of CmNAC gene in melon under salt stress. NAC transcription factor proteins play important roles in many biological processes, including plant development and stress responses. To date, few full-length melon NAC proteins have been identified. In this study, 82 melon NAC (CmNAC) genes were identified in the Cucumis melo L. genome. By interrogating our cDNA libraries and transcriptome data from melon under salt stress, and comparison of their phylogenetic relationship with Arabidopsis NAC salt stress-related genes, we putatively identified that the fourth clade of CmNAC genes were involved in the salt stress response, especially the second clade of the group IV of the phylogenetic tree. Expression analysis confirmed that eleven of the twelve CmNAC genes from the group IV were induced in melon seedling roots by salt stress; the other gene was down regulated by salt stress. The expression of CmNAC14 continually increased in 12 h under salt stress, and was selected for transformation into Arabidopsis for functional verification. Overexpression of CmNAC14 increased the sensitivity of transgenic Arabidopsis lines to salt stress, which were simultaneously demonstrated by reduced expression of abiotic stress-response genes and variation in several physiological indices. This study increases our knowledge and may enable further characterization of the roles of CmNAC family in the response to salt stress.


Assuntos
Cucumis melo/genética , Cucumis melo/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genoma de Planta , Família Multigênica , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/fisiologia , Cromossomos de Plantas/genética , Cucumis melo/efeitos dos fármacos , Perfilação da Expressão Gênica , Biblioteca Gênica , Genes Duplicados , Genes de Plantas , Anotação de Sequência Molecular , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Plantas Geneticamente Modificadas , Plântula/efeitos dos fármacos , Plântula/genética , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética
10.
Plant Cell Environ ; 39(6): 1216-27, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26437210

RESUMO

Resistance to Aphis gossypii in melon is attributed to the presence of the single dominant R gene virus aphid transmission (Vat), which is biologically expressed as antibiosis, antixenosis and tolerance. However, the mechanism of resistance is poorly understood at the molecular level. Aphid-induced transcriptional changes, including differentially expressed miRNA profiles that correspond to resistance interaction have been reported in melon. The potential regulatory roles of miRNAs in Vat-mediated aphid resistance were further revealed by identifying the specific miRNA degradation targets. A total of 70 miRNA:target pairs, including 28 novel miRNA:target pairs, for the differentially expressed miRNAs were identified: 11 were associated with phytohormone regulation, including six miRNAs that potentially regulate auxin interactions. A model for a redundant regulatory system of miRNA-mediated auxin insensitivity is proposed that incorporates auxin perception, auxin modification and auxin-regulated transcription. Chemically inhibiting the transport inhibitor response-1 (TIR-1) auxin receptor in susceptible melon tissues provides in vivo support for the model of auxin-mediated impacts on A. gossypii resistance.


Assuntos
Afídeos , Cucumis melo/metabolismo , Ácidos Indolacéticos/metabolismo , MicroRNAs/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/fisiologia , Transdução de Sinais/fisiologia , Animais , Cucumis melo/fisiologia , Reguladores de Crescimento de Planta/metabolismo , Receptores de Superfície Celular/fisiologia
11.
J Proteomics ; 120: 179-93, 2015 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-25779462

RESUMO

UNLABELLED: Benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) is a chemical plant elicitor capable of inducing disease resistance in many crops. In this study, the climacteric fruit muskmelon (cv. Yujinxiang) was treated with BTH at 0.1g/L for assaying the changes in physiology, biochemistry and protein profile during ripening. The results showed that BTH treatment enhanced respiration rate, while reduced titratable acid content and retarded the decline of fruit firmness and ascorbic acid content. Ethylene production increased after BTH treatment at early stages of ripening, but decreased after 6days of treatment. Of the detected protein spots separated by means of 2-DE, 69 spots changed in abundance significantly after BTH treatment. Fifty-two spots out of 69 were identified using MALDI-TOF/TOF by blasting against NCBInr database. Functional classification revealed that the protein species identified were related to defense and stress responses, protein synthesis, destination and storage, energy metabolism, primary metabolism, cell structure, secondary metabolism, signal transduction and transporters. This study demonstrates an overview of major physiological, biochemical and proteomic changes in muskmelon fruit during ripening after BTH treatment and provides potentially useful information for maintaining fruit quality and delaying the ripening and senescence process. BIOLOGICAL SIGNIFICANCE: The study offers new proteomic evidences for elucidating the regulatory mechanism of muskmelon fruit ripening by BTH treatment at proteomic level, and provides a valuable reference for further research on the relationship between fruit quality and induction disease resistance in BTH-treated fruits.


Assuntos
Cucumis melo/fisiologia , Frutas/fisiologia , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Tiadiazóis/farmacologia , Cucumis melo/efeitos dos fármacos , Frutas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/fisiologia
12.
Protoplasma ; 252(3): 911-24, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25398649

RESUMO

Cadmium (Cd) is a widespread toxic heavy metal that usually causes deleterious effects on plant growth and development. Salicylic acid (SA), a naturally existing phenolic compound, is involved in specific responses to various environmental stresses. To explore the role of SA in the tolerance of melon (Cucumis melo L.) to Cd stress, the influence of SA application on the growth and physiological processes was compared in the two melon cultivars Hamilv (Cd-tolerant) and Xiulv (Cd-sensitive) under Cd stress. Under 400-µM Cd treatment, Hamilv showed a higher biomass accumulation, more chlorophyll (Chl), greater photosynthesis, and less oxidative damage compared to Xiulv. Foliar spraying of 0.1 mM SA dramatically alleviated Cd-induced growth inhibition in the two melon genotypes. Simultaneously, SA pretreatment attenuated the decrease in Chl content, photosynthetic capacity, and PSII photochemistry efficiency in Cd-stressed plants. Furthermore, exogenous SA significantly reduced superoxide anion production and lipid peroxidation, followed by increase in the activities of antioxidant enzyme superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase, and content of soluble protein and free proline in both the genotypes under Cd stress. The effect of SA was more conspicuous in Xiulv than Hamilv, reflected in the biomass, photosynthetic pigments, stomatal conductance, water use efficiency, and antioxidant enzymes. These results suggest that exogenous spray of SA can alleviate the adverse effects of Cd on the growth and photosynthesis of both the melon cultivars, mostly through promoting antioxidant defense capacity. It also indicates that SA-included protection against Cd damage is to a greater extent more pronounced in Cd-sensitive genotype than Cd-tolerant genotype.


Assuntos
Antioxidantes/metabolismo , Cádmio/toxicidade , Cucumis melo/crescimento & desenvolvimento , Cucumis melo/fisiologia , Fotossíntese/efeitos dos fármacos , Ácido Salicílico/farmacologia , Regulação para Cima/efeitos dos fármacos , Biomassa , Clorofila/metabolismo , Cucumis melo/efeitos dos fármacos , Fluorescência , Gases/metabolismo , Luz , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/enzimologia , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Prolina/metabolismo , Solubilidade , Superóxidos/metabolismo
13.
Transgenic Res ; 24(3): 497-507, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25416172

RESUMO

Ethylene is a key factor regulating sex expression in cucurbits. Commercial melons (Cucumis melo L.) are typically andromonoecious, producing male and bisexual flowers. Our prior greenhouse studies of transgenic melon plants expressing the dominant negative ethylene perception mutant gene, etr1-1, under control of the carpel- and nectary-primordia targeted CRAB'S CLAW (CRC) promoter showed increased number and earlier appearance of carpel-bearing flowers. To further investigate this phenomenon which could be potentially useful for earlier fruit production, we observed CRC::etr1-1 plants in the field for sex expression, fruit set, fruit development, and ripening. CRC::etr1-1 melon plants showed increased number of carpel-bearing open flowers on the main stem and earlier onset by 7-10 nodes. Additional phenotypes observed in the greenhouse and field were conversion of approximately 50% of bisexual buds to female, and elongated ovaries and fruits. Earlier and greater fruit set occurred on the transgenic plants. However, CRC::etr1-1 plants had greater abscission of young fruit, and smaller fruit, so that final yield (kg/plot) was equivalent to wild type. Earlier fruit set in line M5 was accompanied by earlier appearance of ripe fruit. Fruit from line M15 frequently did not exhibit external ripening processes of rind color change and abscission, but when cut open, the majority showed a ripe or overripe interior accompanied by elevated internal ethylene. The non-ripening external phenotype in M15 fruit corresponded with elevated etr1-1 transgene expression in the exocarp. These results provide insight into the role of ethylene perception in carpel-bearing flower production, fruit set, and ripening.


Assuntos
Cucumis melo/fisiologia , Etilenos/metabolismo , Frutas/fisiologia , Cucumis melo/genética , Flores/genética , Frutas/genética , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas , Transgenes
14.
Methods Mol Biol ; 1224: 195-203, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25416259

RESUMO

Genetic transformation is an important technique used in plant breeding and to functionally characterize genes of interest. The earliest reports of Agrobacterium-mediated transformation in the melon (Cucumis melo) were from the early 1990s (Fang and Grumet, Plant Cell Rep, 9: 160-164, 1990; Dong et al., Nat Biotechnol 9: 858-863, 1991; Valles and Lasa, Plant Cell Rep 13: 145-148, 1994). These early studies described three problems that decreased the efficiency of transformation: tetraploidy, chimeras, and escape. Using a liquid culture system for somatic embryogenesis, Akasaka-Kenedy et al. (Plant Sci 166: 763-769, 2004) overcame these problems and established an efficient transformation system; the protocol introduced in this chapter is based on this method.


Assuntos
Cucumis melo/crescimento & desenvolvimento , Cucumis melo/genética , Engenharia Genética/métodos , Aclimatação , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/crescimento & desenvolvimento , Técnicas de Cocultura , Cucumis melo/fisiologia , Ambiente Controlado , Plantas Geneticamente Modificadas , Regeneração , Sementes/crescimento & desenvolvimento , Transformação Genética
15.
Artigo em Inglês | MEDLINE | ID: mdl-25375520

RESUMO

Plants create sugar in the mesophyll cells of their leaves by photosynthesis. This sugar, mostly sucrose, has to be loaded via the bundle sheath into the phloem vascular system (the sieve elements), where it is distributed to growing parts of the plant. We analyze the feasibility of a particular loading mechanism, active symplasmic loading, also called the polymer trap mechanism, where sucrose is transformed into heavier sugars, such as raffinose and stachyose, in the intermediary-type companion cells bordering the sieve elements in the minor veins of the phloem. Keeping the heavier sugars from diffusing back requires that the plasmodesmata connecting the bundle sheath with the intermediary cell act as extremely precise filters, which are able to distinguish between molecules that differ by less than 20% in size. In our modeling, we take into account the coupled water and sugar movement across the relevant interfaces, without explicitly considering the chemical reactions transforming the sucrose into the heavier sugars. Based on the available data for plasmodesmata geometry, sugar concentrations, and flux rates, we conclude that this mechanism can in principle function, but that it requires pores of molecular sizes. Comparing with the somewhat uncertain experimental values for sugar export rates, we expect the pores to be only 5%-10% larger than the hydraulic radius of the sucrose molecules. We find that the water flow through the plasmodesmata, which has not been quantified before, contributes only 10%-20% to the sucrose flux into the intermediary cells, while the main part is transported by diffusion. On the other hand, the subsequent sugar translocation into the sieve elements would very likely be carried predominantly by bulk water flow through the plasmodesmata. Thus, in contrast to apoplasmic loaders, all the necessary water for phloem translocation would be supplied in this way with no need for additional water uptake across the plasma membranes of the phloem.


Assuntos
Transporte Biológico/fisiologia , Modelos Biológicos , Floema/fisiologia , Metabolismo dos Carboidratos , Cucumis melo/fisiologia , Difusão , Plasmodesmos/fisiologia , Polímeros/metabolismo , Porosidade , Água/metabolismo
16.
New Phytol ; 203(4): 1128-45, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24975482

RESUMO

Iron (Fe) and copper (Cu) homeostasis are tightly linked across biology. In previous work, Fe deficiency interacted with Cu-regulated genes and stimulated Cu accumulation. The C940-fe (fefe) Fe-uptake mutant of melon (Cucumis melo) was characterized, and the fefe mutant was used to test whether Cu deficiency could stimulate Fe uptake. Wild-type and fefe mutant transcriptomes were determined by RNA-seq under Fe and Cu deficiency. FeFe-regulated genes included core Fe uptake, metal homeostasis, and transcription factor genes. Numerous genes were regulated by both Fe and Cu. The fefe mutant was rescued by high Fe or by Cu deficiency, which stimulated ferric-chelate reductase activity, FRO2 expression, and Fe accumulation. Accumulation of Fe in Cu-deficient plants was independent of the normal Fe-uptake system. One of the four FRO genes in the melon and cucumber (Cucumis sativus) genomes was Fe-regulated, and one was Cu-regulated. Simultaneous Fe and Cu deficiency synergistically up-regulated Fe-uptake gene expression. Overlap in Fe and Cu deficiency transcriptomes highlights the importance of Fe-Cu crosstalk in metal homeostasis. The fefe gene is not orthologous to FIT, and thus identification of this gene will provide clues to help understand regulation of Fe uptake in plants.


Assuntos
Cobre/metabolismo , Cucumis melo/genética , Cucumis melo/fisiologia , Genes de Plantas , Ferro/metabolismo , Mutação/genética , Transcriptoma/genética , Cobre/deficiência , Cucumis melo/enzimologia , FMN Redutase/genética , FMN Redutase/metabolismo , Regulação da Expressão Gênica de Plantas , Modelos Biológicos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Regulação para Cima/genética
17.
Ying Yong Sheng Tai Xue Bao ; 25(12): 3563-72, 2014 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-25876409

RESUMO

The effects of grafting on physiological characters of melon (Cucumis melo) seedlings under copper stress were investigated with Pumpkin Jingxinzhen No. 3 as stock and oriental melon IVF09 as scion. The results showed that the physiological characters of melon seedlings were inhibited significantly under copper stress. Compared with self-rooted seedlings, the biomass, the contents of photosynthetic pigment, glucose and fructose, the photosynthetic parameters, the activities of sucrose phosphate synthase, neutral invertase and acid invertase in the leaves of the grafted seedlings were increased significantly. The uptake of nutrients was improved with the contents of K, P, Na increased and the content of Cu decreased. When the concentration of Cu2+ stress was 800 micromol L(-1), the contents of Cu in the leaves and roots of the grafted seedlings were decreased by 31.3% and 15.2%, respectively. Endogenous hormone balance of seedlings was improved by grafting. In the grafted seedlings, the content of IAA and peroxidase activity were higher, whereas the contents of ABA, maleicdialdehyde, the activities of superoxide dismutase and catalase were lower than that in the control. It was concluded that the copper stress on the physiological characters of melon seedlings was relieved by grafting which improved the resistance of the grafted seedlings.


Assuntos
Cobre/química , Cucumis melo/fisiologia , Ácido Abscísico/metabolismo , Agricultura/métodos , Biomassa , Catalase/metabolismo , Cucurbita , Malondialdeído/metabolismo , Fotossíntese , Folhas de Planta/enzimologia , Raízes de Plantas , Plântula/fisiologia , Estresse Fisiológico , Superóxido Dismutase/metabolismo , beta-Frutofuranosidase/metabolismo
18.
Ying Yong Sheng Tai Xue Bao ; 24(7): 1938-44, 2013 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-24175525

RESUMO

For developing an estimation method of muskmelon transpiration in greenhouse, an estimation model for the daily transpiration of greenhouse muskmelon in its vegetative growth period was established, based on the greenhouse environmental parameters, muskmelon growth and development parameters, and soil moisture parameters. According to the specific environment in greenhouse, the item of aerodynamics in Penman-Monteith equation was modified, and the greenhouse environmental sub-model suitable for calculating the reference crop evapotranspiration in greenhouse was deduced. The crop factor sub-model was established with the leaf area index as independent variable, and the form of the model was linear function. The soil moisture sub-model was established with the soil relative effective moisture content as independent variable, and the form of the model was logarithmic function. With interval sowing, the model parameters were estimated and analyzed, according to the measurement data of different sowing dates in a year. The prediction accuracy of the model for sufficient irrigation and water-saving irrigation was verified, according to measurement data when the relative soil moisture content was 80%, 70%, and 60%, and the mean relative error was 11.5%, 16.2% , and 16.9% respectively. The model was a beneficial exploration for the application of Penman-Monteith equation under greenhouse environment and water-saving irrigation, having good application foreground and popularization value.


Assuntos
Irrigação Agrícola/métodos , Cucumis melo/fisiologia , Sistemas Ecológicos Fechados , Modelos Teóricos , Transpiração Vegetal/fisiologia , China , Cucumis melo/crescimento & desenvolvimento , Cucumis melo/metabolismo
19.
Ying Yong Sheng Tai Xue Bao ; 24(10): 2871-7, 2013 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-24483082

RESUMO

By using aeroponics culture system, this paper studied the effects of elevated rhizosphere CO2 concentration on the leaf photosynthesis and the fruit yield and quality of muskmelon during its anthesis-fruiting period. In the fruit development period of muskmelon, as compared with those in the control (350 microL CO2 x L (-1)), the leaf chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), and the maximal photochemical efficiency of PS II (Fv/Fm) in treatments 2500 and 5000 microL CO2 x L(-1) decreased to some extents, but the stomatal limitation value (Ls) increased significantly, and the variation amplitudes were larger in treatment 5000 microL CO2 x L(-1) than in treatment 2500 microL CO2 x L(-1). Under the effects of elevated rhizosphere CO2 concentration, the fruit yield per plant and the Vc and soluble sugar contents in fruits decreased markedly, while the fruit organic acid content was in adverse. It was suggested that when the rhizosphere CO2 concentration of muskmelon during its anthesis-fruiting period reached to 2500 microL x L(-1), the leaf photosynthesis and fruit development of muskmelon would be depressed obviously, which would result in the decrease of fruit yield and quality of muskmelon.


Assuntos
Biomassa , Dióxido de Carbono/análise , Cucumis melo/fisiologia , Fotossíntese/fisiologia , Solo/química , Cucumis melo/metabolismo , Controle de Qualidade , Rizosfera
20.
PLoS One ; 7(11): e48579, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23173035

RESUMO

BACKGROUND: The regulatory role of small RNAs (sRNAs) in various biological processes is an active area of investigation; however, there has been limited information available on the role of sRNAs in plant-insect interactions. This study was designed to identify sRNAs in cotton-melon aphid (Aphis gossypii) during the Vat-mediated resistance interaction with melon (Cucumis melo). METHODOLOGY/PRINCIPAL FINDINGS: The role of miRNAs was investigated in response to aphid herbivory, during both resistant and susceptible interactions. sRNA libraries made from A. gossypii tissues feeding on Vat⁺ and Vat⁻ plants revealed an unexpected abundance of 27 nt long sRNA sequences in the aphids feeding on Vat⁺ plants. Eighty-one conserved microRNAs (miRNAs), twelve aphid-specific miRNAs, and nine novel candidate miRNAs were also identified. Plant miRNAs found in the aphid libraries were most likely ingested during phloem feeding. The presence of novel miRNAs was verified by qPCR experiments in both resistant Vat⁺ and susceptible Vat⁻ interactions. The comparative analyses revealed that novel miRNAs were differentially regulated during the resistant and susceptible interactions. Gene targets predicted for the miRNAs identified in this study by in silico analyses revealed their involvement in morphogenesis and anatomical structure determination, signal transduction pathways, cell differentiation and catabolic processes. CONCLUSION/SIGNIFICANCE: In this study, conserved and novel miRNAs were reported in A. gossypii. Deep sequencing data showed differences in the abundance of miRNAs and piRNA-like sequences in A. gossypii. Quantitative RT-PCR revealed that A. gossypii miRNAs were differentially regulated during resistant and susceptible interactions. Aphids can also ingest plant miRNAs during phloem feeding that are stable in the insect.


Assuntos
Afídeos/genética , Cucumis melo/fisiologia , Regulação da Expressão Gênica , RNA Interferente Pequeno/genética , Animais , Afídeos/crescimento & desenvolvimento , Afídeos/fisiologia , Sequência de Bases , Cucumis melo/genética , Cucumis melo/metabolismo , MicroRNAs/genética , Proteínas de Plantas/metabolismo , RNA de Plantas/genética , Análise de Sequência de RNA
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