RESUMO
The plant cuticle is an important protective barrier on the plant surface, constructed mainly by polymerized cutin matrix and a complex wax mixture. Although the pathway of plant cuticle biosynthesis has been clarified, knowledge of the transcriptional regulation network underlying fruit cuticle formation remains limited. In the present work, we discovered that tomato fruits of the NAC transcription factor SlNOR-like1 knockout mutants (nor-like1) produced by CRISPR/Cas9 [clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9] displayed reduced cutin deposition and cuticle thickness, with a microcracking phenotype, while wax accumulation was promoted. Further research revealed that SlNOR-like1 promotes cutin deposition by binding to the promoters of glycerol-3-phosphate acyltransferase6 (SlGPAT6; a key gene for cutin monomer formation) and CUTIN DEFICIENT2 (SlCD2; a positive regulator of cutin production) to activate their expression. Meanwhile, SlNOR-like1 inhibits wax accumulation, acting as a transcriptional repressor by targeting wax biosynthesis, and transport-related genes 3-ketoacyl-CoA synthase1 (SlKCS1), ECERIFERUM 1-2 (SlCER1-2), SlWAX2, and glycosylphosphatidylinositol-anchored lipid transfer protein 1-like (SlLTPG1-like). In conclusion, SlNOR-like1 executes a dual regulatory effect on tomato fruit cuticle development. Our results provide a new model for the transcriptional regulation of fruit cuticle formation.
Assuntos
Solanum lycopersicum , Fatores de Transcrição , Fatores de Transcrição/metabolismo , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Fenótipo , Ceras/metabolismoRESUMO
Chloroplasts play a crucial role in plant growth and fruit quality. However, the molecular mechanisms of chloroplast development are still poorly understood in fruits. In this study, we investigated the role of the transcription factor SlBEL2 (BEL1-LIKE HOMEODOMAIN 2) in fruit of Solanum lycopersicum (tomato). Phenotypic analysis of SlBEL2 overexpression (OE-SlBEL2) and SlBEL2 knockout (KO-SlBEL2) plants revealed that SlBEL2 has the function of inhibiting green shoulder formation in tomato fruits by affecting the development of fruit chloroplasts. Transcriptome profiling revealed that the expression of chloroplast-related genes such as SlGLK2 and SlLHCB1 changed significantly in the fruit of OE-SlBEL2 and KO-SlBEL2 plants. Further analysis showed that SlBEL2 could not only bind to the promoter of SlGLK2 to inhibit its transcription, but also interacted with the SlGLK2 protein to inhibit the transcriptional activity of SlGLK2 and its downstream target genes. SlGLK2 knockout (KO-SlGLK2) plants exhibited a complete absence of the green shoulder, which was consistent with the fruit phenotype of OE-SlBEL2 plants. SlBEL2 showed an expression gradient in fruits, in contrast with that reported for SlGLK2. In conclusion, our study reveals that SlBEL2 affects the formation of green shoulder in tomato fruits by negatively regulating the gradient expression of SlGLK2, thus providing new insights into the molecular mechanism of fruit green shoulder formation.
Assuntos
Solanum lycopersicum , Solanum lycopersicum/metabolismo , Frutas/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Plantas/metabolismo , Ombro , Regulação da Expressão Gênica de PlantasRESUMO
Rumination is closely linked to the onset and maintenance of major depressive disorder (MDD). Prior neuroimaging studies have identified the association between self-reported rumination trait and the functional coupling among a network of brain regions using resting-state functional magnetic resonance imaging (MRI). However, little is known about the underlying neural circuitry mechanism during active rumination in MDD. Degree centrality (DC) is a simple metric to denote network integration, which is critical for higher-order psychological processes such as rumination. During an MRI scan, individuals with MDD (N = 45) and healthy controls (HC, N = 46) completed a rumination state task. We examined the interaction effect between the group (MDD vs. HC) and condition (rumination vs. distraction) on vertex-wise DC. We further characterized the identified brain region's functional involvement with Neurosynth and BrainMap. Network-wise seed-based functional connectivity (FC) analysis was also conducted for the identified region of interest. Finally, exploratory correlation analysis was conducted between the identified region of interest's network FCs and self-reported in-scanner affect levels. We found that a left superior frontal gyrus (SFG) region, generally overlapped with the frontal eye field, showed a significant interaction effect. Further analysis revealed its involvement with executive functions. FCs between this region, the frontoparietal, and the dorsal attention network (DAN) also showed significant interaction effects. Furthermore, its FC to DAN during distraction showed a marginally significant negative association with in-scanner affect level at the baseline. Our results implicated an essential role of the left SFG in the rumination's underlying neural circuitry mechanism in MDD and provided novel evidence for the conceptualization of rumination in terms of impaired executive control.
Assuntos
Transtorno Depressivo Maior , Humanos , Encéfalo/diagnóstico por imagem , Córtex Pré-Frontal , Função Executiva , Lobo Frontal , Imageamento por Ressonância Magnética , Mapeamento EncefálicoRESUMO
BACKGROUND: The effect of neuroinflammatory cytokines on cognitive deficits in patients with major depressive disorder (MDD) can be altered by selective serotonin reuptake inhibitors (SSRIs). This study aimed to examine serum interleukin-8 (IL-8) levels, cognitive function, and their associations in MDD patients with SSRIs. METHODS: Thirty SSRI-treated MDD patients and 101 healthy controls were recruited for this study. We examined cognitive performance using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum IL-8 levels using the Human Inflammatory Cytokine Cytometric Bead Array in both cases and controls. RESULTS: The RBANS test scores were significantly lower in MDD patients with SSRIs than in healthy controls after controlling for covariates (all p < 0.001). Serum levels of IL-8 were higher in MDD patients with SSRIs than in healthy controls after adjusting for covariates (F = 3.82, p = 0.05). Serum IL-8 levels were positively correlated with sub-scores of delayed memory (r = 0.37, p = 0.04) and visuospatial/constructional (r = 0.43, p = 0.02) in MDD patients with SSRIs but not in in healthy controls (delayed memory score: r = -0.12, p = 0.24; visuospatial/constructional score: r = 0.02, p = 0.81). CONCLUSIONS: Our findings suggested that increased serum IL-8 level might not only be involved in the MDD psychopathology or the use of SSRIs but also correspond to improving MDD delayed memory and visuospatial/constructional function.
Assuntos
Disfunção Cognitiva , Transtorno Depressivo Maior , Humanos , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Interleucina-8 , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Cognição , CitocinasRESUMO
Fruit ripening in tomato (Solanum lycopersicum) is the result of selective expression of ripening-related genes, which are regulated by transcription factors (TFs). The NAC (NAM, ATAF1/2, and CUC2) TF family is one of the largest families of plant-specific TFs and members are involved in a variety of plant physiological activities, including fruit ripening. Fruit ripening-associated NAC TFs studied in tomato to date include NAC-NOR (non-ripening), SlNOR-like1 (non-ripening like1), SlNAC1, and SlNAC4. Considering the large number of NAC genes in the tomato genome, there is little information about the possible roles of other NAC members in fruit ripening, and research on their target genes is lacking. In this study, we characterize SlNAM1, a NAC TF, which positively regulates the initiation of tomato fruit ripening via its regulation of ethylene biosynthesis. The onset of fruit ripening in slnam1-deficient mutants created by CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9) technology was delayed, whereas fruit ripening in OE-SlNAM1 lines was accelerated compared with the wild type. The results of RNA-sequencing (RNA-seq) and promoter analysis suggested that SlNAM1 directly binds to the promoters of two key ethylene biosynthesis genes (1-aminocyclopropane-1-carboxylate synthase: SlACS2 and SlACS4) and activates their expression. This hypothesis was confirmed by electrophoretic mobility shift assays and dual-luciferase reporter assay. Our findings provide insights into the mechanisms of ethylene production and enrich understanding of the tomato fruit ripening regulatory network.
Assuntos
Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Solanum lycopersicum/genética , Frutas/genética , Frutas/fisiologia , Liases/genética , Liases/metabolismo , Solanum lycopersicum/fisiologia , Proteínas de Plantas/genética , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
A biocompatible Y(III)-based metal-organic framework [Y4(TATB)2]·(DMF)3.5·(H2O) (ZJU-16, H3TATB= 4,4',4''-(1,3,5-triazine-2,4,6-triyl) tribenzoic acid) was synthesized, and it was adopted to load Mn2+ for chemodynamic therapy. Meanwhile, ibuprofen sodium (IBUNa), an anti-inflammatory drug, was introduced to increase the amount of Mn2+ (about 5.66 wt %) due to the low loading capacity of Mn2+. Mn&IBUNa@ZJU-16 which was loaded by Mn2+ and IBUNa exhibited significant effects of chemodynamic therapy and excellent inhibition of the 4T1 tumor cell growth, implying its long-term prospects in chemodynamic therapy and its possibility in bimodal cancer therapy.
Assuntos
Antineoplásicos/farmacologia , Materiais Biocompatíveis/farmacologia , Neoplasias da Mama/tratamento farmacológico , Estruturas Metalorgânicas/farmacologia , Ítrio/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Estruturas Metalorgânicas/síntese química , Estruturas Metalorgânicas/química , Camundongos , Células Tumorais Cultivadas , Ítrio/químicaRESUMO
Cognitive deficits are a core feature of major depressive disorder (MDD). However, there are no previous studies that directly compare cognitive performance between first-episode drug-naive depressive patients (FDDP) and medicated depressive patients (MDP). Therefore, the aim of this study was to investigate whether there were the differences in cognitive functions between FDDP and MDP. Sixty-two FDDP, 111 MDP and 90 healthy controls were enrolled in a Chinese population. Cognitive functions were assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). There were the differences in the RBANS total score (F = 26.55, p < 0.001), subscales of immediate memory (F = 3.95, p = 0.02), language (F = 54.11, p < 0.001) and delayed memory (F = 11.19, p = 0.001) among the three groups after controlling for gender, education, smoking and body mass index (BMI). These differences in the RBANS total score, subscales of language and delayed memory passed the Bonferroni corrections (all, p < 0.05). Compared to healthy controls, FDDP and MDP had poorer cognitive performance including the RBANS total score, and subscales of language and delayed memory (all, p < 0.05) after controlling for the variables. FDDP experienced greater language deficits than MDP (p < 0.05) after controlling for the variables. Education was correlated with the language score in FDDP (r = 0.61, p < 0.001). Multivariate regression analysis indicated that education was an independent contributor to the language score in FDDP (ß = 3.11, t = 5.48, p < 0.001). Our findings indicated that FDDP had poorer language performance than MDP. Moreover, education could influence the language performance in FDDP.
Assuntos
Cognição , Disfunção Cognitiva/complicações , Transtorno Depressivo Maior/complicações , Transtorno Depressivo Maior/psicologia , Adolescente , Adulto , Idoso , Povo Asiático/psicologia , Estudos de Casos e Controles , Disfunção Cognitiva/psicologia , Transtorno Depressivo Maior/tratamento farmacológico , Escolaridade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Adulto JovemRESUMO
BACKGROUND: Elevated phospholipase A2 (PLA2) activity is reported to be involved in the development of schizophrenia. Further study revealed an association between PLA2 groups XIIA (PLA2G12A) polymorphism and patients with schizophrenia in a northeast Chinese Han population. OBJECTIVE: This study will further examine whether PLA2G12A rs3087494 polymorphism is associated with patients with schizophrenia in a southern Chinese Han population. METHODS: This polymorphism was genotyped in 438 patients with schizophrenia (diagnosed according to Diagnostic and Statistical Manual of Mental Disorders-IV) and 876 healthy controls using a case-control design. Demographic and clinical data were collected in all subjects. RESULTS: The allele and genotype frequencies of PLA2G12A rs3087494 polymorphism significantly differed between groups (both, p < .001). These differences still were significant by adjusting for sex and age. However, there was no difference in age at onset among 3 genotype groups in patients with schizophrenia by adjusting for the variables (F = 0.22, p = .80). Stepwise multivariate regression analysis showed that this polymorphism was not associated with age at onset in patients with schizophrenia (ß = .008, t = .07, p = .94). CONCLUSIONS: Our results indicated that even though PLA2G12A rs3087494 polymorphism did not influence age at onset in patients with schizophrenia, it may play an important role in the susceptibility to schizophrenia in a southern Chinese Han population.
Assuntos
Predisposição Genética para Doença/genética , Fosfolipases A2/genética , Polimorfismo de Nucleotídeo Único/genética , Esquizofrenia/genética , Adolescente , Adulto , Distribuição de Qui-Quadrado , China , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: Cognitive deficits have been identified as one of core clinical symptoms of major depressive disorder (MDD). Accumulating evidence indicated that triglycerides (TG) might be associated with MDD and cognitive decline. OBJECTIVE: This study examined whether patients with MDD had poorer cognitive functions than healthy controls, and further investigate whether TG levels were involved in MDD, and its cognitive impairments in a Han Chinese population. METHOD: 115 patients with MDD and 119 healthy controls were enrolled. Cognitive functions were assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and serum TG levels were examined using enzymatic colorimetry. RESULTS: TG levels were higher in patients with MDD than healthy controls after controlling for the variables. Cognitive test scores were lower in patients with MDD than healthy controls except for visuospatial/constructional index after controlling for the variables. TG levels were negatively correlated with visuospatial/constructional score, delayed memory score and RBANS total score of MDD. Further multivariate regression analysis showed that TG levels were negatively associated with visuospatial/constructional score, attention score, delayed memory score and RBANS total score of MDD. CONCLUSIONS: Our findings supported that serum TG levels might be involved in MDD, and play an important role in cognitive impairments of MDD, especially in delayed memory. Moreover, patients with MDD experienced greater cognitive impairments than healthy controls except for visuospatial/constructional index.
Assuntos
Disfunção Cognitiva/sangue , Transtorno Depressivo Maior/sangue , Triglicerídeos/sangue , Adulto , Atenção , Disfunção Cognitiva/psicologia , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Repressão PsicológicaRESUMO
BACKGROUND: To explore and compare the values of 3.0T magnetic resonance imaging (MRI) T2 mapping in evaluating the degree of acetabular cartilage degeneration in hip replacement surgery. METHODS: A total of 26 elderly patients with femoral neck fractures who were scanned in 3.0T MRI T2 mapping quantification technique were included. Basing on MRI images, the degree of acetabular cartilage degeneration was classified into Grade 0, 1, 2, 3 and 4, according to the International Cartilage Repair Society (ICRS) scores. In addition, 8 healthy volunteers were included for control group. RESULTS: By comparison with health population, T2 relaxation values in the anterior, superior, and posterior regions of acetabular cartilage in patients with femoral neck fracture were obviously increased (P < 0.001). Among the patients with femoral neck fractures, there were 16 hip joint with Grade 1-2 (mild degeneration subgroup) and 10 hip joints with Grade 3-4 (severe degeneration subgroup), accounting for 61.54% and 38.46%, respectively. Additionally, T2 relaxation values in the anterior and superior bands of articular cartilage were positively related to the MRI-based grading (P < 0.05); while there was no significant difference of T2 relaxation values in the posterior areas of articular cartilage between severe degeneration subgroup and mild degeneration subgroup (P > 0.05). Importantly, acetabular cartilage degeneration can be detected through signal changes of T2 mapping pseudo-color images. CONCLUSION: 3.0T MRI T2 mapping technology can be used to determine the degree of acetabular cartilage degeneration, which can effectively monitor the disease course.
Assuntos
Acetábulo , Artroplastia de Quadril , Cartilagem Articular , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Feminino , Acetábulo/diagnóstico por imagem , Acetábulo/patologia , Idoso , Cartilagem Articular/diagnóstico por imagem , Cartilagem Articular/patologia , Artroplastia de Quadril/métodos , Pessoa de Meia-Idade , Fraturas do Colo Femoral/diagnóstico por imagem , Fraturas do Colo Femoral/cirurgia , Idoso de 80 Anos ou mais , Doenças das Cartilagens/diagnóstico por imagem , Doenças das Cartilagens/patologia , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Accumulating evidence suggests that the inflammatory cytokine interleukin-6 (IL-6) contributes to the pathophysiology of psychiatric disorders. However, there was no study concerning the relationship between IL-6 concentrations and clinical features in the chronic phase of early-onset schizophrenia (EOS). AIM: To investigate the relationship between serum IL-6 concentration and the clinical features of EOS. METHODS: We measured serum IL-6 Levels from 74 patients with chronic schizophrenia, including 33 with age at onset < 21 years (EOS group) and 41 with onset ≥ 21 years in [adult-onset schizophrenia (AOS) group], and from 41 healthy controls. Symptom severities were evaluated using the Positive and Negative Syndrome Scale (PANSS). RESULTS: Serum IL-6 concentrations were higher in both EOS and AOS groups than healthy controls (F = 22.32, P < 0.01), but did not differ significantly between EOS and AOS groups (P > 0.05) after controlling for age, body mass index, and other covariates. Negative symptom scores were higher in the EOS group than the AOS group (F = 6.199, P = 0.015). Serum IL-6 concentrations in the EOS group were negatively correlated with both total PANSS-negative symptom score (r = -0.389, P = 0.032) and avolition/asociality subscore (r = -0.387, P = 0.026). CONCLUSION: Patients with EOS may have more severe negative symptoms than those with adult-onset schizophrenia during the chronic phase of the illness. IL-6 signaling may regulate negative symptoms and its avolition/asociality subsymptoms among the early-onset chronic schizophrenic patients.
RESUMO
Comparative analysis of primate genomes within a phylogenetic context is essential for understanding the evolution of human genetic architecture and primate diversity. We present such a study of 50 primate species spanning 38 genera and 14 families, including 27 genomes first reported here, with many from previously less well represented groups, the New World monkeys and the Strepsirrhini. Our analyses reveal heterogeneous rates of genomic rearrangement and gene evolution across primate lineages. Thousands of genes under positive selection in different lineages play roles in the nervous, skeletal, and digestive systems and may have contributed to primate innovations and adaptations. Our study reveals that many key genomic innovations occurred in the Simiiformes ancestral node and may have had an impact on the adaptive radiation of the Simiiformes and human evolution.
Assuntos
Evolução Molecular , Primatas , Animais , Humanos , Genoma , Genômica , Filogenia , Primatas/anatomia & histologia , Primatas/classificação , Primatas/genética , Rearranjo Gênico , Encéfalo/anatomia & histologiaRESUMO
This paper presents a new technique to generate microwave signal using an electro-absorption modulator (EAM) integrated with a distributed feedback (DFB) laser subject to optical injection. Experiments show that the frequency of the generated microwave can be tuned by changing the wavelength of the external laser or adjusting the bias voltage of the EAM. The frequency response of the EAM is studied and found to be unsmooth due to packaging parasitic effects and four-wave mixing effect occurring in the active layer of the DFB laser. It is also demonstrated that an EA modulator integrated in between two DFB lasers can be used instead of the EML under optical injection. This integrated chip can be used to realize a monolithically integrated tunable microwave source.
Assuntos
Lasers , Micro-Ondas , Óptica e Fotônica , Absorção , Eletrônica , Desenho de Equipamento , Tecnologia de Fibra Óptica , Luz , Fibras Ópticas , Processamento de Sinais Assistido por ComputadorRESUMO
BACKGROUND: Cognitive deficits are common in patients with bipolar disorder (BD). Abnormal high density lipoprotein (HDL) levels have been implicated in cognitive deficits associated with ageing and neurodegenerative disorders. The present study aimed to investigate serum HDL levels, cognitive deficits and their association in patients with BD. METHODS: Thirty-seven patients with BD and 37 gender- and age-matched healthy controls (HCs) were recruited in a case-control study. Cognition was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and serum HDL levels were measured using enzymatic colourimetry. RESULTS: There was no difference in serum HDL levels between patients with BD and HCs after adjusting for gender, age, education and body mass index (BMI). Cognitive test scores in patients with BD were significantly lower than those in HCs except for the visuospatial/constructional index after adjusting for confounding variables. Serum HDL levels were positively correlated with RBANS total score and language score in patients with BD. Stepwise multiple regression analysis showed that serum HDL levels were significantly correlated with RBANS total score and subscale scores on immediate memory and language in patients with BD after adjusting for confounding factors. CONCLUSIONS: Our findings suggest that patients with BD had poorer cognitive performance than HCs except for the visuospatial/constructional domain, and decreased serum HDL levels were correlated with cognitive deficits, especially in immediate memory and language domains in patients with BD.
RESUMO
Recently, we have found that the accumulation of ripening inhibitor (RIN) protein increased gradually during tomato fruit ripening. Here, the recombinant protein was expressed in Escherichia coli and affinity-purified. The DNA binding activity of renatured RIN protein was tested by electrophoretic mobility shift assay. The results indicated that an optimal expression and purification system was suitable for obtaining active RIN with DNA binding activity.
Assuntos
DNA de Plantas/genética , DNA de Plantas/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Solanum lycopersicum/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/isolamento & purificação , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/isolamento & purificação , Proteínas de Domínio MADS/metabolismo , Fases de Leitura Aberta , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/isolamento & purificação , Fatores de Transcrição/isolamento & purificaçãoRESUMO
OBJECTIVE: Our study examined the relationship between variant stereociliary bundles of cochlear outer hair cells (OHCs) and auditory function to analyze assessment criteria for rotated stereociliary bundles in the guinea pig cochlea. METHODS: Auditory brainstem response and distortion product otoacoustic emission (DPOAE) were recorded on 100 guinea pigs. Variant hair cells were identified and counted by scanning electron and light microscopy. RESULTS: The most common variation observed was rotation of stereociliary bundles in the first-row OHCs (OHC1), with most 13.3% variant OHC1 rotated 90 degrees and a few 2.5% rotated 180 degrees. Occasionally, the length and angle of the 2 arms of an OHC deviated from the norm. The auditory brainstem response threshold of affected animals increased only slightly, 20- to 30-dB sound pressure level. More importantly, amplitude of DPOAE increased significantly (40.5 dB sound pressure level). CONCLUSION: Our study suggests that rotation of stereociliary bundles in the cochlear OHC was found to be prevalent in 28% of the animals. We established the assessment criteria for rotated stereociliary bundles that were more than 10% OHC1 rotated. This hair bundle seemed to be rotated by 90 degrees from the normal orientation and was accompanied with changes of auditory function. Increased amplitude of DPOAE is associated with the variation of rotated OHC that might result in hearing loss.
Assuntos
Cóclea/fisiologia , Células Ciliadas Auditivas Externas/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Antibacterianos/toxicidade , Cílios/efeitos dos fármacos , Cílios/fisiologia , Cóclea/efeitos dos fármacos , Cóclea/ultraestrutura , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Gentamicinas/toxicidade , Cobaias , Células Ciliadas Auditivas Externas/efeitos dos fármacos , Células Ciliadas Auditivas Externas/ultraestrutura , Microscopia Eletrônica de Varredura , Emissões Otoacústicas Espontâneas/efeitos dos fármacos , Emissões Otoacústicas Espontâneas/fisiologiaRESUMO
Recently, ETHYLENE OVERPRODUCER 1 (ETO1) had been cloned and identified as a negative post-transcriptional regulator in the ethylene biosynthesis in Arabidopsis. However, little was known about the role of ETO1 in other species, especially in tomato, which was an ideal model for studying the biosynthesis of ethylene during tomato fruit ripening. In this study, a tomato ETHYLENE OVERPRODUCER 1-LIKE 1 (LeEOL1) was cloned. The LeEOL1 cDNA was 3,515 bp long and carried an ORF that putatively encoded a polypeptide of 886 amino acids with a predicted molecular mass of 95 kDa. It shared 74% identity in amino acid sequence with Arabidopsis EOL1 and had one BTB (Broad-complex, Tramtrack, Bric-à-brac) domain and two TPR (tetratricopeptide repeat) domains, which were also conserved domains in AtEOL1. RT-PCR analysis of the temporal expression of LeEOL1 showed that its transcript decreased companied with increase of ethylene production in tomato ripening. The level of LeEOL1 transcripts in wild type tomato fruit at mature green stage did not distinctively change when treated with exogenous ethylene.
Assuntos
DNA de Plantas/genética , Etilenos/biossíntese , Genes de Plantas , Proteínas de Plantas/genética , Solanum lycopersicum/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Sequência Conservada , DNA Complementar , Solanum lycopersicum/química , Dados de Sequência Molecular , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Virus-induced gene silencing (VIGS) is an attractive reverse-genetics tool for studying gene function in plants. We showed that silencing of a phytoene desaturase (PDS) gene is maintained throughout TRV-PDS-inoculated tomato plants as well as in their flowers and fruit and is enhanced by low temperature (15 degrees C) and low humidity (30%). RT-PCR analysis of the PDS gene revealed a dramatic reduction in the level of PDS mRNA in leaves, flowers and fruits. Silencing of PDS results in the accumulation of phytoene, the desaturase substrate. In addition, the content of chlorophyll a, chlorophyll b and total chlorophyll in the leaves of PDS-silenced plants was reduced by more than 90%. We also silenced the LeEIN2 gene by infecting seedlings, and this suppressed fruit ripenning. We conclude that this VIGS approach should facilitate large-scale functional analysis of genes involved in the development and ripening of tomato.
Assuntos
Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Umidade , Vírus de Plantas/fisiologia , Solanum lycopersicum/genética , Solanum lycopersicum/virologia , Carotenoides/metabolismo , Flores/anatomia & histologia , Frutas/anatomia & histologia , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Inativação Gênica/efeitos da radiação , Vetores Genéticos , Solanum lycopersicum/enzimologia , Oxirredutases/deficiência , Oxirredutases/genética , Fenótipo , Fotodegradação , Folhas de Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/genéticaRESUMO
Ethylene is crucial in climacteric fruit ripening. The ethylene signal pathway regulates several physiological alterations such as softening, carotenoid accumulation and sugar level reduction, and production of volatile compounds. All these physiological processes are controlled by numerous genes and their expression simultaneously changes at the onset of ripening. Ethylene insensitive 2 (EIN2) is a key component for ethylene signal transduction, and its mutation causes ethylene insensitivity. In tomato, silencing SlEIN2 resulted in a non-ripening phenotype and low ethylene production. RNA sequencing of SlEIN2-silenced and wild type tomato, and differential gene expression analyses, indicated that silencing SlEIN2 caused changes in more than 4,000 genes, including those related to photosynthesis, defense, and secondary metabolism. The relative expression level of 28 genes covering ripening-associated transcription factors, ethylene biosynthesis, ethylene signal pathway, chlorophyll binding proteins, lycopene and aroma biosynthesis, and defense pathway, showed that SlEIN2 influences ripening inhibitor (RIN) in a feedback loop, thus controlling the expression of several other genes. SlEIN2 regulates many aspects of fruit ripening, and is a key factor in the ethylene signal transduction pathway. Silencing SlEIN2 ultimately results in lycopene biosynthesis inhibition, which is the reason why tomato does not turn red, and this gene also affects the expression of several defense-associated genes. Although SlEIN2-silenced and green wild type fruits are similar in appearance, their metabolism is significantly different at the molecular level.
Assuntos
Etilenos/química , Frutas/fisiologia , Proteínas de Plantas/metabolismo , Transdução de Sinais , Solanum lycopersicum/genética , Transcriptoma , Agrobacterium tumefaciens , Carotenoides/química , Clorofila/química , Clonagem Molecular , Frutas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Genes de Plantas , Vetores Genéticos , Licopeno , Solanum lycopersicum/fisiologia , Fenótipo , Fotossíntese , Proteínas de Plantas/genética , Regiões Promotoras Genéticas , Análise de Sequência de RNA , Fatores de Transcrição/metabolismoRESUMO
Ripening is an important stage of fruit development. To screen the genes associated with pigment formation in tomato fruit, a suppression subtractive hybridization (SSH) cDNA library was constructed by using tomato fruit in the green ripe and break ripe stages, and 129 differential genes were obtained. Using redness as a screening marker, virus-induced gene silencing (VIGS) of the differential genes was performed with a sprout vacuum-infiltration system (SVI). The results showed that silencing the SlNAP7 gene affected the chloroplast development of tomato leaves, manifesting as a photo-bleaching phenotype, and silenced fruit significantly affected the accumulation of lycopene, manifested as a yellow phenotype. In our study, we found that silencing the SlNAP7 gene downregulates the expression of the POR and PORA genes and destroys the normal development of the chloroplast. The expression of related genes included in the lycopene biosynthesis pathway was not significantly changed, but lycopene accumulation was significantly reduced in tomato fruit. Perhaps it was caused by the destruction of the chromoplast, which leads to the oxidation of lycopene. The results show that the SlNAP7 gene influences chloroplast development and lycopene accumulation in tomato.