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1.
Plant Mol Biol ; 103(4-5): 489-505, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32306368

RESUMO

KEY MESSAGE: Cucumber plants adapt their transcriptome and metabolome as result of spider mite infestation with opposite consequences for direct and indirect defences in two genotypes. Plants respond to arthropod attack with the rearrangement of their transcriptome which lead to subsequent phenotypic changes in the plants' metabolome. Here, we analysed transcriptomic and metabolite responses of two cucumber (Cucumis sativus) genotypes to chelicerate spider mites (Tetranychus urticae) during the first 3 days of infestation. Genes associated with the metabolism of jasmonates, phenylpropanoids, terpenoids and L-phenylalanine were most strongly upregulated. Also, genes involved in the biosynthesis of precursors for indirect defence-related terpenoids were upregulated while those involved in the biosynthesis of direct defence-related cucurbitacin C were downregulated. Consistent with the observed transcriptional changes, terpenoid emission increased and cucurbitacin C content decreased during early spider-mite herbivory. To further study the regulatory network that underlies induced defence to spider mites, differentially expressed genes that encode transcription factors (TFs) were analysed. Correlation analysis of the expression of TF genes with metabolism-associated genes resulted in putative identification of regulators of herbivore-induced terpenoid, green-leaf volatiles and cucurbitacin biosynthesis. Our data provide a global image of the transcriptional changes in cucumber leaves in response to spider-mite herbivory and that of metabolites that are potentially involved in the regulation of induced direct and indirect defences against spider-mite herbivory.


Assuntos
Cucumis sativus/imunologia , Cucumis sativus/metabolismo , Metaboloma , Infestações por Ácaros/imunologia , Infestações por Ácaros/metabolismo , Tetranychidae , Transcriptoma , Animais , Vias Biossintéticas/genética , Cucumis sativus/genética , Cucumis sativus/parasitologia , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Genoma de Planta , Genótipo , Herbivoria , Oxilipinas/metabolismo , Fenilalanina/metabolismo , Fenilpropionatos/metabolismo , Doenças das Plantas , Folhas de Planta/metabolismo , Metabolismo Secundário/genética , Terpenos/metabolismo , Fatores de Transcrição/genética , Triterpenos/metabolismo , Compostos Orgânicos Voláteis/metabolismo
2.
Sheng Wu Gong Cheng Xue Bao ; 36(4): 643-651, 2020 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-32347059

RESUMO

Cucumber (Cucumis sativus) is an important vegetable crop in the world. Agrobacterium-mediated transgenic technology is an important way to study plant gene functions and improve varieties. In order to further accelerate the transgenic research and breeding process of cucumber, we described the progress and problems of Agrobacterium tumefaciens-mediated transgenic cucumber, from the influencing factors of cucumber regeneration ability, genetic transformation conditions and various additives in the process. We prospected for improving the genetic transformation efficiency and safety selection markers of cucumber, and hoped to provide reference for the research of cucumber resistance breeding and quality improvement.


Assuntos
Agrobacterium tumefaciens , Cucumis sativus , Plantas Geneticamente Modificadas , Transformação Genética , Agrobacterium tumefaciens/metabolismo , Cruzamento , Cucumis sativus/genética , Cucumis sativus/microbiologia , Plantas Geneticamente Modificadas/microbiologia , Pesquisa
3.
PLoS Biol ; 18(3): e3000671, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32203514

RESUMO

Domesticated crops with high yield and quality are frequently susceptible to pathogen attack, whereas enhancement of disease resistance generally compromises crop yield. The underlying mechanisms of how plant development and disease resistance are coordinately programed remain elusive. Here, we showed that the basic Helix-Loop-Helix (bHLH) transcription factor Cucumis sativus Irregular Vasculature Patterning (CsIVP) was highly expressed in cucumber vascular tissues. Knockdown of CsIVP caused severe vasculature disorganization and abnormal organ morphogenesis. CsIVP directly binds to vascular-related regulators YABBY5 (CsYAB5), BREVIPEDICELLUS (CsBP), and AUXIN/INDOLEACETIC ACIDS4 (CsAUX4) and promotes their expression. Knockdown of CsYAB5 resulted in similar phenotypes as CsIVP-RNA interference (RNAi) plants, including disturbed vascular configuration and abnormal organ morphology. Meanwhile, CsIVP-RNAi plants were more resistant to downy mildew and accumulated more salicylic acid (SA). CsIVP physically interacts with NIM1-INTERACTING1 (CsNIMIN1), a negative regulator in the SA signaling pathway. Thus, CsIVP is a novel vasculature regulator functioning in CsYAB5-mediated organ morphogenesis and SA-mediated downy mildew resistance in cucumber.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/imunologia , Proteínas de Plantas/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Cucumis sativus/classificação , Cucumis sativus/genética , Resistência à Doença/genética , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Morfogênese , Filogenia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Proteínas de Plantas/genética , Feixe Vascular de Plantas/genética , Feixe Vascular de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Ligação Proteica , Ácido Salicílico/metabolismo , Transdução de Sinais/genética
4.
Artigo em Inglês | MEDLINE | ID: mdl-32142987

RESUMO

Peptide: N-glycanase (PNGase; EC 3.5.1.52) is a deglycosylation enzyme that is responsible for deglycosylating misfolded glycoproteins in the endoplasmic reticulum. However, the role of PNGase in plants is largely unknown. Here, we cloned and characterized the function of peptide: N-glycanase (CsPNG1) from cucumber. The amino acid encoded by CsPNG1 gene contained a typical transglutaminase (TGase) catalytic triad domain and belonged to the "TGase superfamily". Subcellular localization showed that CsPNG1 was located in the cell membrane and nucleus. Promoter sequence analysis and qPCR tests showed that CsPNG1 could respond to a variety of abiotic stresses and hormone treatments. Yeast one-hybrid assays revealed the interaction between the transcription factor CsGT-3b and CsPNG1 promoter. Importantly, overexpression of CsPNG1 in tobacco increased the tolerance to salt stress of transgenic plants. In addition, CsPNG1 interacted with CsRAD23 family proteins and the C-terminal UBA domain of CsRAD23 protein was responsible for binding to CsPNG1, indicating that CsPNG1 was involved in the ER-associated degradation pathway (ERAD). Taken together, our study demonstrated that CsPNG1 plays a positive role in improving plant salt tolerance, and these findings might provide a basis for further functional analysis of CsPNG1 genes in abiotic stress and ERAD.


Assuntos
Cucumis sativus , Proteínas de Plantas , Estresse Fisiológico , Cucumis sativus/genética , Cucumis sativus/metabolismo , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica de Plantas , Glicoproteínas , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase/genética , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Estresse Fisiológico/genética , Tabaco/genética
5.
Development ; 147(7)2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32165491

RESUMO

The WUSCHEL-CLAVATA3 pathway genes play an essential role in shoot apical meristem maintenance and floral organ development, and under intense selection during crop domestication. The carpel number is an important fruit trait that affects fruit shape, size and internal quality in cucumber, but the molecular mechanism remains elusive. Here, we found that CsCLV3 expression was negatively correlated with carpel number in cucumber cultivars. CsCLV3-RNAi led to increased number of petals and carpels, whereas overexpression of CsWUS resulted in more sepals, petals and carpels, suggesting that CsCLV3 and CsWUS function as a negative and a positive regulator for carpel number variation, respectively. Biochemical analyses indicated that CsWUS directly bound to the promoter of CsCLV3 and activated its expression. Overexpression of CsFUL1A , a FRUITFULL-like MADS-box gene, resulted in more petals and carpels. CsFUL1A can directly bind to the CsWUS promoter to stimulate its expression. Furthermore, we found that auxin participated in carpel number variation in cucumber through interaction of CsARF14 with CsWUS. Therefore, we have identified a gene regulatory pathway involving CsCLV3, CsWUS, CsFUL1A and CsARF14 in determining carpel number variation in an important vegetable crop - cucumber.


Assuntos
Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/genética , Flores/citologia , Frutas , Redes Reguladoras de Genes/fisiologia , Contagem de Células , Flores/embriologia , Flores/genética , Frutas/citologia , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Meristema/embriologia , Meristema/genética , Fenótipo , Plantas Geneticamente Modificadas
6.
Plant Sci ; 293: 110407, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32081257

RESUMO

Leaf color mutants are an ideal tool to study chlorophyll biosynthesis, chloroplast development and photosynthesis. In this study, we identified an EMS-induced yellow young leaf mutant C777. The mutant exhibited yellow cotyledons and emerging true leaves with stay-green dots that turn green gradually with leaf growth. Segregation analysis in several populations indicated that the mutant C777 was controlled by a recessive gene yyl-1. Fine mapping delimited the yyl-1 locus to a 45.3 kb region harboring 8 putative genes, but only one SNP (G to A) was identified between C777 and its wild-type parental line in this region which occurred in the 13th exon of CsHD that encodes a histidine and aspartic acid (HD) domain containing protein. This nonsense mutation introduced a stop codon and thus a premature protein. Uniqueness of this mutant allele was verified in 515 cucumber lines. Quantitative real-time PCR revealed significantly reduced expression of CsHD gene in the mutant. Further, silencing the NbHD gene by VIGS in tobacco resulted in virescent young leaves and significantly down-regulated expression of HD gene. These results strongly supported the association of the CsHD gene with the virescent young leaf phenotype in C777. This is the first report to clone and characterize the CsHD gene in the horticultural crops. The results may help understand the functions of the HD gene in chloroplast development and chlorophyll biosynthesis in plants.


Assuntos
Ácido Aspártico/genética , Cucumis sativus/genética , Genes de Plantas/genética , Histidina/genética , Mutação , Proteínas de Plantas/genética , Clorofila/biossíntese , Clorofila/genética , Cloroplastos/genética , Mapeamento Cromossômico , Clonagem Molecular , Cor , DNA de Plantas/genética , Éxons , Regulação da Expressão Gênica de Plantas , Genes Recessivos , Fenótipo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Domínios Proteicos , Tabaco
7.
Genome ; 63(4): 225-238, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32027525

RESUMO

Plant lipid transfer proteins (LTPs) are small basic proteins that play important roles in the regulation of various plant biological processes as well as the response to biotic and abiotic stresses. However, knowledge is limited on how this family of proteins is regulated in response to nematode infection in cucumber. In the present study, a total of 39 CsLTP_2 genes were identified by querying databases for cucumber-specific LTP_2 using a Hidden Markov Model approach and manual curation. The family has a five-cysteine motif (5CM) with the basic form CC-Xn-CXC-Xn-C, which differentiates it from typical nsLTPs. The members of CsLTP_2 were grouped into six families according to their structure and their phylogenetic relationships. Expression data of CsLTP_2 genes in 10 cucumber tissues indicated that they were tissue-specific genes. Two genes showed significant expression change in roots of resistant and susceptible lines during nematode infection, indicating their involvement in response to Meloidogyne incognita. This systematic analysis provides a foundation of knowledge for future studies of the biological roles of CsLTP_2 genes in cucumber in response to nematode infection and may help in the efforts to improve M. incognita-resistance breeding in cucumber.


Assuntos
Antígenos de Plantas/metabolismo , Proteínas de Transporte/metabolismo , Cucumis sativus/genética , Resistência à Doença/genética , Genoma de Planta/genética , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Tylenchoidea/fisiologia , Motivos de Aminoácidos , Animais , Antígenos de Plantas/genética , Proteínas de Transporte/genética , Cucumis sativus/imunologia , Cucumis sativus/parasitologia , Perfilação da Expressão Gênica , Especificidade de Órgãos , Filogenia , Doenças das Plantas/virologia , Proteínas de Plantas/genética , Alinhamento de Sequência , Sintenia
8.
Ecotoxicol Environ Saf ; 192: 110285, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32035398

RESUMO

Iron deficiency severely affects crop yield and quality. Gamma-aminobutyric acid (GABA) plays a vital role in plant responses to multifarious stresses. However, the role of GABA in Fe deficiency responses and the potential mechanisms remain largely unknown in cucumber. Here, we found that Fe deficiency raised the GABA levels in leaves and roots of cucumber. To probe the role of GABA in Fe deficiency, the seedlings were subjected to five levels of GABA concentrations (0, 5, 10, 20 and 40 mmol L-1) for 7 days under Fe deficiency. The results demonstrated that 20 mM GABA in alleviating the Fe deficiency-induced stress was the most effective. GABA pretreatment reduced the Fe deficiency-induced chlorosis and inhibition of photosynthesis and growth, and significantly enhanced the contents of iron in shoots and roots. Exogenous GABA significantly decreased the pH of nutrient solution and increased ferric-chelate reductase (FCR) activity induced by Fe deficiency and the transcript levels of Fe uptake-related genes HA1, FRO2 and IRT1 in roots. GABA also increased the content of auxin (IAA) and expression of auxin biosynthesis (YUC4), response (IAA1), and transport (PIN1) genes under Fe deficiency. Furthermore, exogenous the auxin transport inhibitor 1-naphthylphthalamic acid (NPA) application abolished the GABA-induced changes in Fe deficiency. In summary, we found that GABA improves tolerance to iron deficiency via an auxin-dependent mechanism in cucumber.


Assuntos
Cucumis sativus/metabolismo , Ácidos Indolacéticos/metabolismo , Ferro/metabolismo , Ácido gama-Aminobutírico/metabolismo , Transporte Biológico , Cucumis sativus/efeitos dos fármacos , Cucumis sativus/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Plântula/metabolismo , Transdução de Sinais , Ácido gama-Aminobutírico/farmacologia
9.
Gene ; 736: 144412, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32007586

RESUMO

The emergence of somaclonal variability in in vitro cultures is undesirable during micropropagation, but this phenomenon may be a source of genetic variability sought by breeders. The main factors that affect the appearance of variability are known, but the exact mechanism has not yet been determined. In this paper, we used next-generation sequencing and comparative genomics to study changes in the genomes of cucumber lines resulting from in vitro regeneration and somaclonal mutation in comparison to a reference, the highly inbred B10 line. The total number of obtained polymorphisms differed between the three somaclonal lines S1, S2 and S3, with 8369, 7591 and 44510, respectively. Polymorphisms occurred most frequently in non-coding regions and were mainly SNPs. High-impact changes accounted for 1%-3% of all polymorphisms and most often caused an open reading frame shift. Functional analysis of genes affected by high impact variants showed that they were related to transport, biosynthetic processes, nucleotide-containing compounds and cellular protein modification processes. The obtained results indicated significant factors affecting somaclonal variability and the appearance of changes in the genome, and demonstrated a lack of dependence between phenotype and the number of genomic polymorphisms.


Assuntos
Cucumis sativus/genética , DNA/genética , Genoma de Planta/genética , Mutação/genética , Polimorfismo de Nucleotídeo Único/genética , Estudo de Associação Genômica Ampla , Genômica/métodos , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Fases de Leitura Aberta/genética , Fenótipo , Análise de Sequência de DNA/métodos
10.
Ecotoxicol Environ Saf ; 193: 110351, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32109583

RESUMO

Microcystins (MCs) have become an important global environmental issue, causing oxidative stress, which is an important toxic mechanism for MCs in plants. However, the regulating mechanism of antioxidative enzymes in plants in adapting to MCs stress remains unclear. We studied the dynamic effects of MCs at different concentrations (5, 10, 50 and 100 µg/L) in rice and cucumber seedlings on relative growth rate (RGR), and reactive oxygen species and malondialdehyde (MDA) content, and antioxidative enzyme activities, during a stress period (MCs exposed for 1, 3, 5 and 7 d) and recovery period (7 d). During the stress period, MCs at 5 µg/L inhibited RGR in cucumber and promoted RGR in rice. The contents of superoxide anion (O2·-), hydrogen peroxide (H2O2) and MDA increased and RGR declined in both crops with time and intensity of MCs stress. For cucumber, all these parameters responded earlier to MCs stress, and O2·-, MDA and RGR were more responsive to MCs stress than in rice. Moreover, catalase (CAT) and peroxidase (POD), and the relative expressions of CAT genes increased in both crops at 5-100 µg/L MCs, whereas relative expression of POD genes increased only in cucumber. Diversely, superoxide dismutase (SOD) response to MCs in cucumber leaves was later than for rice. MCs at 100 µg/L decreased the relative expression of SOD genes in cucumber but did not change SOD activity. During the recovery period, all the above indicators in both crops were higher than the control and lower than in the stress period. Conversely, RGR was lower than in the control and higher than in the stress period, except for cucumber which was lower, and MDA content higher than the stress period at 100 µg/L MCs. Overall, these results indicated that cucumber was more sensitive to MCs than rice, and SOD, CAT and POD play an important role in plant response to MCs stress.


Assuntos
Cucumis sativus/efeitos dos fármacos , Microcistinas/toxicidade , Oryza/efeitos dos fármacos , Antioxidantes/metabolismo , Catalase/genética , Catalase/metabolismo , Cucumis sativus/enzimologia , Cucumis sativus/genética , Cucumis sativus/crescimento & desenvolvimento , Expressão Gênica/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Oryza/enzimologia , Oryza/genética , Oryza/crescimento & desenvolvimento , Estresse Oxidativo , Peroxidase/genética , Peroxidase/metabolismo , Folhas de Planta/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/genética , Plântula/metabolismo , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
11.
Plant Biotechnol J ; 18(7): 1598-1609, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31916321

RESUMO

Fruit neck length (FNL) is an important quality trait in cucumber because it directly affects its market value. However, its genetic basis remains largely unknown. We identified a candidate gene for FNL in cucumber using a next-generation sequencing-based bulked segregant analysis in F2 populations, derived from a cross between Jin5-508 (long necked) and YN (short necked). A quantitative trait locus (QTL) on chromosome 7, Fnl7.1, was identified through a genome-wide comparison of single nucleotide polymorphisms between long and short FNL F2 pools, and it was confirmed by traditional QTL mapping in multiple environments. Fine genetic mapping, sequences alignment and gene expression analysis revealed that CsFnl7.1 was the most likely candidate Fnl7.1 locus, which encodes a late embryogenesis abundant protein. The increased expression of CsFnl7.1 in long-necked Jin5-508 may be attributed to mutations in the promoter region upstream of the gene body. The function of CsFnl7.1 in FNL control was confirmed by its overexpression in transgenic cucumbers. CsFnl7.1 regulates fruit neck development by modulating cell expansion. Probably, this is achieved through the direct protein-protein interactions between CsFnl7.1 and a dynamin-related protein CsDRP6 and a germin-like protein CsGLP1. Geographical distribution differences of the FNL phenotype were found among the different cucumber types. The East Asian and Eurasian cucumber accessions were highly enriched with the long-necked and short-necked phenotypes, respectively. A further phylogenetic analysis revealed that the Fnl7.1 locus might have originated from India. Thus, these data support that the CsFnl7.1 has an important role in increasing cucumber FNL.


Assuntos
Cucumis sativus , Locos de Características Quantitativas , Cucumis sativus/genética , Frutas/genética , Índia , Fenótipo , Filogenia , Locos de Características Quantitativas/genética
12.
Int J Mol Sci ; 21(3)2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31991638

RESUMO

Autotoxicity of root exudates is one of the main reasons for consecutive monoculture problem (CMP) in cucumber under greenhouse cultivation. Rootstock grafting may improve the tolerance of cucumber plants to autotoxic stress. To verify the enhanced tolerance to autotoxic stress and illuminate relevant molecular mechanism, a transcriptomic comparative analysis was performed between rootstock grafted (RG) and non-grafted (NG) cucumber plants by a simulation of exogenous cinnamic acid (CA). The present study confirmed that relatively stable plant growth, biomass accumulation, chlorophyll content, and photosynthesis was observed in RG than NG under CA stress. We identified 3647 and 2691 differentially expressed genes (DEGs) in NG and RG cucumber plants when compared to respective control, and gene expression patterns of RNA-seq was confirmed by qRT-PCR. Functional annotations revealed that DEGs response to CA stress were enriched in pathways of plant hormone signal transduction, MAPK signaling pathway, phenylalanine metabolism, and plant-pathogen interaction. Interestingly, the significantly enriched pathway of photosynthesis-related, carbon and nitrogen metabolism only identified in NG, and most of DEGs were down-regulated. However, most of photosynthesis, Calvin cycle, glycolysis, TCA cycle, and nitrogen metabolism-related DEGs exhibited not or slightly down-regulated in RG. In addition, several stress-related transcription factor families of AP2/ERF, bHLH, bZIP, MYB. and NAC were uniquely triggered in the grafted cucumbers. Overall, the results of this study suggest that rootstock grafting improve the tolerance of cucumber plants to autotoxic stress by mediating down-regulation of photosynthesis, carbon, and nitrogen metabolism-related DEGs and activating the function of stress-related transcription factor. The transcriptome dataset provides an extensive sequence resource for further studies of autotoxic mechanism at molecular level.


Assuntos
Cucumis sativus/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Sistema de Sinalização das MAP Quinases , Proteínas de Plantas/biossíntese , Plântula/metabolismo , Estresse Fisiológico , Cucumis sativus/genética , Proteínas de Plantas/genética , Plântula/genética
13.
Artigo em Inglês | MEDLINE | ID: mdl-31926460

RESUMO

Alternative polyadenylation (APA) is a pervasive mechanism for gene regulation in eukaryotes. Stachyose is the main assimilate translocated in the cucumber phloem. Stachyose synthase (CsSTS) catalyzes the last step of stachyose biosynthesis in cucumber leaves and plays a key role in the regulation of assimilate partitioning between source and sink. In this study, three CsSTS mRNAs with the same open reading frame and the 5`untranslated region (UTR), but differing in their 3`UTRs, named CsSTS1 (short), CsSTS2 (medium), and CsSTS3 (long), were identified. Southern blot and sequence analysis of the cucumber genome confirmed that these transcripts are regulated through APA from a single gene. No significant difference of in vitro translation efficiency was found among three mRNAs. However, the relative stabilities of three transcripts varied among different tissues and different leaf development stages of cucumber. CsSTS1 expression in cucumber calli was up-regulated by the raffinose (substrate of CsSTS) and down-regulated by stachyose (product of CsSTS), respectively. In cucumber plants, all three isoforms have considerable expression in non-fruit node leaves. However, in fruit-carrying node leaves, the expression of CsSTS2 and CsSTS3 was severely inhibited and only CsSTS1 was highly expressed, indicating fruit setting has a remarkable effect on the relative expression level of three transcripts. This "fruit setting" effect could be observed until at least 36 h after the fruit was removed from the node. Our results suggest that abundant expression of CsSTS1 is beneficial for stachyose loading in source leaves, and APA is a delicate mechanism for CsSTS to regulate cucumber source-sink balance.


Assuntos
Cucumis sativus/genética , Galactosiltransferases/genética , Oligossacarídeos/metabolismo , Poliadenilação/genética , Regiões 3' não Traduzidas/genética , Metabolismo dos Carboidratos , Cucumis sativus/metabolismo , Frutas/metabolismo , Galactosiltransferases/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Floema/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Isoformas de RNA/metabolismo , Rafinose/metabolismo
14.
Artigo em Inglês | MEDLINE | ID: mdl-31928658

RESUMO

Recent reports have uncovered the multifunctional role of H2S in the physiological response of plants to biotic and abiotic stresses. Here, we studied whether NaHS (an H2S donor) pretreatment could provoke the tolerance of cucumber (Cucumis sativus L.) seedlings subsequently exposed to chilling stress and whether glutathione was involved in this process. Results showed that cucumber seedlings sprayed with NaHS exhibited remarkably increased chilling tolerance, as evidenced by the observed plant tolerant phenotype, as well as the lower levels of electrolyte leakage (EL), malondialdehyde (MDA) content, hydrogen peroxide (H2O2) content and RBOH mRNA abundance, compared with the control plants. In addition, NaHS treatment increased the endogenous content of the reduced glutathione (GSH) and the ratio of reduced/oxidized glutathione (GSH/GSSG), meanwhile, the higher net photosynthetic rate (Anet), the light-saturated CO2 assimilation rate (Asat), the photochemical efficiency (Fv/Fm) and the maximum photochemical efficiency of PSII in darkness (ФPSII) as well as the mRNA levels and activities of the key photosynthetic enzymes (Rubisco, TK, SBPase and FBA) were observed in NaHS-treated seedlings under chilling stress, whereas this effect of NaHS was weakened by buthionine sulfoximine (BSO, an inhibitor of glutathione) or 6-Aminonicotinamide (6-AN, a specific pentose inhibitor and thus inhibits the NADPH production), which preliminarily proved the interaction between H2S and GSH. Moreover, transcription profiling analysis revealed that the GSH-associated genes (GST Tau, MAAI, APX, GR, GS and MDHAR) were significantly up-regulated in NaHS-treated cucumber seedlings, compared to the H2O-treated seedlings under chilling stress. Thus, novel results highlight the importance of glutathione as a downstream signal of H2S-induced plant tolerance to chilling stress.


Assuntos
Temperatura Baixa , Cucumis sativus/fisiologia , Glutationa/metabolismo , Sulfeto de Hidrogênio/química , Cucumis sativus/genética , Cucumis sativus/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Estresse Fisiológico
15.
Artigo em Inglês | MEDLINE | ID: mdl-31928680

RESUMO

The cucumber (Cucumis sativus L.), a type of fleshy fruit, is covered with spines (multicellular trichomes), which have a crucial impact on the economic value of the crop. Previous studies have found that CsTTG1 plays important roles in the initiation and further differentiation of cucumber spines, but how spine formation is regulated at the molecular level by CsTTG1 remains poorly understood. In this study, we characterized a cucumber 35S:CsTTG1 transgenic T2 line, OE-2, which bears relatively large and long spines compared with the small and short spines of the wild type (WT). Phenotypic measurements and histological analyses revealed that this phenotypic change was attributed to significant increases in cell number and size. Comparison of ovary epidermis transcriptomes between OE-2 and WT by DGE (Digital Gene Expression) analysis identified 1241 differentially expressed genes, among which 712 genes were dramatically upregulated and 529 downregulated in the ovary epidermis of OE-2. XTH23 and Cyclin family genes were significantly activated in OE-2, and transcription factors (TFs) were found to participate in spine size regulation in OE-2. Further analyses confirmed that GA was implicated in the regulation of fruit spine development in cucumber. Thus, our study provides a foundation for dissecting the molecular regulatory networks of fruit spine control in cucumber.


Assuntos
Cucumis sativus/genética , Frutas/crescimento & desenvolvimento , Genes de Plantas , Proteínas de Plantas/genética , Tricomas/crescimento & desenvolvimento , Cucumis sativus/crescimento & desenvolvimento , Frutas/genética , Perfilação da Expressão Gênica , Proteínas de Plantas/metabolismo , Transdução de Sinais , Transcriptoma , Tricomas/genética
16.
Physiol Plant ; 168(3): 736-754, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31125116

RESUMO

Researchers have shown that long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) act as competitive endogenous RNAs (ceRNAs) and are mutually regulated by competition for binding to common microRNA response elements (MREs). However, a comprehensive identification and analysis of lncRNAs and circRNAs as ceRNAs have not yet been completed in cucumber (Cucumis sativus L.) exposed to high-temperature stress. In our study, 32 663 coding transcripts, 2085 lncRNAs, 2477 circRNAs and 348 differentially expressed miRNAs were identified using RNA sequencing. In addition, six heat-stress-responsive miRNAs (five known and one novel miRNAs) and eight lncRNAs were selected for qPCR to confirm their expression profiles. By analyzing the cis effects of lncRNAs, we constructed a lncRNA-mRNA co-expression network. Based on the results, the corresponding lncRNAs play a regulatory role in the stress response in cucumber plants. In our study, the PatMatch software was used to predict the potential function of lncRNAs and circRNAs as ceRNAs. A total of 18 lncRNAs and seven circRNAs were predicted to bind to 114 differentially expressed miRNAs and compete with 359 mRNAs for miRNA binding sites. These mRNAs are predicted to be involved in various pathways, such as plant hormone signal transduction, plant-pathogen interaction and glutathione metabolism. Among them, TCONS_00031790, TCONS_00014332, TCONS_00014717, TCONS_00005674, novel_circ_001543 and novel_circ_000876 may interact with miR9748 by plant hormone signal transduction pathways in response to high-temperature stress. Moreover, indole-3-acetic acid (IAA) and 1-aminocyclopropane-l-carboxylic acid (ACC) levels decreased in the high-temperature treatment group, indicating that IAA and ethylene signaling might be involved in response to high-temperature stress. In this study, we conducted a full transcriptomic analysis in response to high-temperature stress in cucumber and, for the first time, integrated the potential ceRNA functions of lncRNAs/circRNAs. The results provide a basis for studying the potential functions of lncRNAs/circRNAs in response to high-temperature stress.


Assuntos
Cucumis sativus/genética , Resposta ao Choque Térmico , MicroRNAs/genética , RNA Circular/genética , RNA Longo não Codificante/genética , Cucumis sativus/fisiologia , Redes Reguladoras de Genes , Temperatura Alta , RNA de Plantas/genética
17.
Mol Genet Genomics ; 295(1): 177-193, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31620884

RESUMO

Genetic variation is expressed by the presence of polymorphisms in compared genomes of individuals that can be transferred to next generations. The aim of this work was to reveal genome dynamics by predicting polymorphisms among the genomes of three individuals of the highly inbred B10 cucumber (Cucumis sativus L.) line. In this study, bioinformatic comparative genomics was used to uncover cucumber genome dynamics (also called real-time evolution). We obtained a new genome draft assembly from long single molecule real-time (SMRT) sequencing reads and used short paired-end read data from three individuals to analyse the polymorphisms. Using this approach, we uncovered differentiation aspects in the genomes of the inbred B10 line. The newly assembled genome sequence (B10v3) has the highest contiguity and quality characteristics among the currently available cucumber genome draft sequences. Standard and newly designed approaches were used to predict single nucleotide and structural variants that were unique among the three individual genomes. Some of the variant predictions spanned protein-coding genes and their promoters, and some were in the neighbourhood of annotated interspersed repetitive elements, indicating that the highly inbred homozygous plants remained genetically dynamic. This is the first bioinformatic comparative genomics study of a single highly inbred plant line. For this project, we developed a polymorphism prediction method with optimized precision parameters, which allowed the effective detection of small nucleotide variants (SNVs). This methodology could significantly improve bioinformatic pipelines for comparative genomics and thus has great practical potential in genomic metadata handling.


Assuntos
Cucumis sativus/genética , Genoma de Planta/genética , Mapeamento Cromossômico/métodos , Biologia Computacional/métodos , Genômica/métodos , Anotação de Sequência Molecular/métodos , Polimorfismo Genético/genética , Regiões Promotoras Genéticas/genética
18.
Int J Mol Sci ; 20(21)2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31731414

RESUMO

Chitinases, a subgroup of pathogenesis-related proteins, are responsible for catalyzing the hydrolysis of chitin. Accumulating reports indicate that chitinases play a key role in plant defense against chitin-containing pathogens and are therefore good targets for defense response studies. Here, we undertook an integrated bioinformatic and expression analysis of the cucumber chitinases gene family to identify its role in defense against Fusarium oxysporum f. sp. cucumerinum. A total of 28 putative chitinase genes were identified in the cucumber genome and classified into five classes based on their conserved catalytic and binding domains. The expansion of the chitinase gene family was due mainly to tandem duplication events. The expression pattern of chitinase genes was organ-specific and 14 genes were differentially expressed in response to F. oxysporum challenge of fusarium wilt-susceptible and resistant lines. Furthermore, a class I chitinase, CsChi23, was constitutively expressed at high levels in the resistant line and may play a crucial role in building a basal defense and activating a rapid immune response against F. oxysporum. Whole-genome re-sequencing of both lines provided clues for the diverse expression patterns observed. Collectively, these results provide useful genetic resource and offer insights into the role of chitinases in cucumber-F. oxysporum interaction.


Assuntos
Quitinases , Cucumis sativus , Fusarium/crescimento & desenvolvimento , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Doenças das Plantas , Proteínas de Plantas , Quitinases/biossíntese , Quitinases/genética , Cucumis sativus/enzimologia , Cucumis sativus/genética , Cucumis sativus/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética
19.
Plant Physiol Biochem ; 145: 107-113, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31677541

RESUMO

Hexose transporters play many important roles in plant development. However, the role of hexose transporter in secondary cell wall growth has not been reported before. Here, we report that the hexose transporter gene CsHT3 is mainly expressed in cells with secondary cell walls in cucumber. Spatiotemporal expression analysis revealed that the transcript of CsHT3 mainly accumulates in the stem, petiole, tendril, and peduncle, all of which contain high cellulose levels. Immunolocalization results show that CsHT3 is localized at the sclereids in young peduncles, shifts to the phloem fiber cells during peduncle development, and then shifts again to the companion cells when the development of secondary cell walls is almost completed. Carboxyfluoresce unloading experiment indicated that carbohydrate unloading in the phloem follows an apoplastic pathway. Overexpression of CsHT3 in cucumber plant can improve the cellulose content and cell wall thickness of phloem fiber cells in the peduncle. The expression of cellulose synthase genes were increased in the CsHT3 overexpression plants. These results indicated that CsHT3 may play an important role in cellulose synthesis through promoting the expression of cellulose synthase genes.


Assuntos
Cucumis sativus , Frutas , Regulação da Expressão Gênica de Plantas , Proteínas de Transporte de Monossacarídeos , Proteínas de Plantas , Parede Celular , Celulose/genética , Celulose/metabolismo , Cucumis sativus/genética , Cucumis sativus/metabolismo , Frutas/química , Frutas/genética , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Floema , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
20.
J Plant Res ; 132(6): 813-823, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31654247

RESUMO

The southern root-knot nematode (RKN), Meloidogyne incognita (Kofoid & White) Chitwood, is one of most destructive species of plant parasitic nematodes, causing significant economic losses to numerous crops including cucumber (Cucumis sativus L. 2n = 14). No commercial cultivar is currently available with resistance to RKN, severely hindering the genetic improvement of RKN resistance in cucumber. An introgression line, IL10-1, derived from the interspecific hybridization between the wild species Cucumis hystrix Chakr. (2n = 24, HH) and cucumber, was identified with resistance to RKN. In this study, an ultrahigh-density genetic linkage bin-map, composed of high-quality single-nucleotide polymorphisms (SNPs), was constructed based on low-coverage sequences of the F2:6 recombinant inbred lines derived from the cross between inbred line IL10-1 and cultivar 'Beijingjietou' CC3 (hereinafter referred to as CC3). Three QTLs were identified accounting for 13.36% (qRKN1-1), 9.07% and 9.58% (qRKN5-1 and qRKN5-2) of the resistance variation, respectively. Finally, four genes with nonsynonymous SNPs from chromosome 5 were speculated to be the candidate RKN-resistant related genes, with annotation involved in disease resistance. Though several gaps still exist on the bin-map, our results could potentially be used in breeding programs and establish an understanding of the associated mechanisms underlying RKN resistance in cucumber.


Assuntos
Cucumis sativus/genética , Genes de Plantas , Doenças das Plantas/genética , Tylenchoidea/fisiologia , Animais , Cucumis sativus/parasitologia , Resistência à Doença/genética , Hibridização Genética , Doenças das Plantas/parasitologia , Locos de Características Quantitativas , Análise de Sequência de DNA
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