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BACKGROUND: Pruning is an important cultivation management option that has important effects on peach yield and quality. However, the effects of pruning on the overall genetic and metabolic changes in peach leaves and fruits are poorly understood. RESULTS: The transcriptomic and metabolomic profiles of leaves and fruits from trees subjected to pruning and unpruning treatments were measured. A total of 20,633 genes and 622 metabolites were detected. Compared with those in the control, 1,127 differentially expressed genes (DEGs) and 77 differentially expressed metabolites (DEMs) were identified in leaves from pruned and unpruned trees (pdLvsupdL), whereas 423 DEGs and 29 DEMs were identified in fruits from the pairwise comparison pdFvsupdF. The content of three auxin analogues was upregulated in the leaves of pruned trees, the content of all flavonoids detected in the leaves decreased, and the expression of almost all genes involved in the flavonoid biosynthesis pathway decreased. The phenolic acid and amino acid metabolites detected in fruits from pruned trees were downregulated, and all terpenoids were upregulated. The correlation analysis revealed that DEGs and DEMs in leaves were enriched in tryptophan metabolism, auxin signal transduction, and flavonoid biosynthesis. DEGs and DEMs in fruits were enriched in flavonoid and phenylpropanoid biosynthesis, as well as L-glutamic acid biosynthesis. CONCLUSIONS: Pruning has different effects on the leaves and fruits of peach trees, affecting mainly the secondary metabolism and hormone signalling pathways in leaves and amino acid biosynthesis in fruits.
Assuntos
Frutas , Perfilação da Expressão Gênica , Metabolômica , Folhas de Planta , Prunus persica , Folhas de Planta/metabolismo , Folhas de Planta/genética , Prunus persica/genética , Prunus persica/metabolismo , Prunus persica/crescimento & desenvolvimento , Frutas/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Metaboloma , Transcriptoma , Flavonoides/metabolismo , Ácidos Indolacéticos/metabolismoRESUMO
MAIN CONCLUSION: Overexpression of MdLBD3 in Arabidopsis reduced sensitivity to salt and drought stresses and was instrumental in promoting early flowering. Salt and drought stresses have serious effects on plant growth. LATERAL ORGAN BOUNDARY DOMAIN (LBD) proteins are a plant-specific transcription factors (TFs) family and play important roles in plants in resisting to abiotic stress. However, about the function of LBDs in apple and other woody plants is little known. In this study, protein sequences of the LBD family TFs in apples were identified which contained conserved LOB domains. The qRT-PCR analysis showed that the MdLBD3 gene was widely expressed in various tissues and organs. The subcellular localization assay showed that the MdLBD3 protein was localized in the nucleus. Ectopic expression of MdLBD3 in Arabidopsis positively regulated its salt and drought resistance, and promoted early flowering. Collectively, these results showed that MdLBD3 improved the abiotic stress resistance, plant growth and development. Overall, this study provided a new gene for breeding that can increase the abiotic stress tolerance in apple.
Assuntos
Arabidopsis , Malus , Fatores de Transcrição , Secas , Melhoramento Vegetal , Estresse Salino , Clonagem MolecularRESUMO
ABA is a crucial phytohormone for development and stress responses in plants. Snf1-related protein kinase 1.1 (SnRK1.1) is involved in the ABA response. However, the molecular mechanism underlying the SnRK1.1 response to ABA is largely unknown. Here, it was found that overexpression of the apple MdSnRK1.1 gene enhanced ABA sensitivity in both transgenic apple calli and Arabidopsis seedlings. Subsequently, a yeast two-hybrid screen demonstrated that MdCAIP1 (C2-domain ABA Insensitive Protein1) interacted with MdSnRK1.1. Their interaction was further confirmed by pull-down and co-immunoprecipitation assays. Expression of the MdCAIP1 gene was positively induced by ABA. Its overexpression enhanced ABA sensitivity in transgenic apple calli. Furthermore, it was found that MdSnRK1.1 phosphorylated the MdCAIP1 protein in vivo and promoted its degradation in vitro and in vivo. As a result, MdSnRK1.1 inhibited MdCAIP1-mediated ABA sensitivity, and MdCAIP1 partially reduced MdSnRK1.1-mediated ABA sensitivity. Our findings indicate that MdSnRK1.1 plays an important role in the ABA response, partially by controlling the stability of the MdCAIP1 protein.
Assuntos
Ácido Abscísico/farmacologia , Malus/metabolismo , Proteínas de Plantas/metabolismo , Proteínas Quinases/metabolismo , Sequência de Aminoácidos , Malus/genética , Fosforilação/efeitos dos fármacos , Filogenia , Proteínas de Plantas/química , Plantas Geneticamente Modificadas , Ligação Proteica/efeitos dos fármacos , Domínios Proteicos , Estabilidade Proteica/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismoRESUMO
Sugars induce anthocyanin biosynthesis in plants. As a conserved energy sensor, SnRK1 (SNF1-related kinase 1) is involved in sucrose-induced anthocyanin accumulation. However, the exact molecular mechanism by which SnRK1 regulates the biosynthesis of anthocyanins and proanthocyanidins (PAs) in response to sucrose in plants is not clear. In this study, it was found that MdSnRK1.1 interacted with MdJAZ18 protein which acts as a repressor in the jasmonate (JA) signaling pathway. MdSnRK1.1 then phosphorylated MdJAZ18 to facilitate its 26S proteasome-mediated degradation, which released MdbHLH3 thereby activating the expression of the regulatory and structural genes, thus finally promoting the biosynthesis of anthocyanins and PAs. Taken together, these results demonstrate the involvement of MdSnRK1.1 in sucrose-induced accumulation of anthocyanins and PAs. For the first time, our findings shed light on the molecular mechanism by which the crosstalk of sucrose and JA signaling regulates flavonoid biosynthesis.
Assuntos
Antocianinas/biossíntese , Malus/metabolismo , Proteínas de Plantas/metabolismo , Proantocianidinas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Antocianinas/metabolismo , Clonagem Molecular , Fosforilação , Proteínas de Plantas/genética , Proteínas Serina-Treonina Quinases/genética , SacaroseRESUMO
KEY MESSAGE: Here, we report the decrease of JA-sensitivity and enhancement of tolerance to salt and PEG stresses in Arabidopsis overexpressing apple MdJAZ2. As signalling molecules, jasmonates (JAs) play significant roles in plant development and stress responses. JAZ proteins are the targets of the SCFCOI1 complex and act as the negative regulators in JA signalling pathway. However, there are no reports regarding the biological function of apple JAZ genes. In this study, one JAZ gene, MdJAZ2 from apple, was functionally characterized in detail. The expression of MdJAZ2 was up-regulated by MeJA and wounding treatments. MdJAZ2-GFP fusion protein was observed in nucleus in transient expression assay. Yeast two-hybrid and bimolecular fluorescence complementation assays revealed that MdJAZ2 could form homo- and heteromers, and also interact with F-box protein MdCOI1. Overexpression of MdJAZ2 conferred impaired JA-sensitivity in transgenic Arabidopsis, including JA-mediated root growth inhibition, susceptibility to the bacterial pathogen Pst DC3000, and the expression of JA response genes. Additionally, MdJAZ2 overexpression also improved tolerance to NaCl and PEG treatments in transgenic Arabidopsis. Together, our findings suggest that apple MdJAZ2 was not only involved in the JA response but also played roles in stress tolerance.
Assuntos
Adaptação Fisiológica/genética , Arabidopsis/fisiologia , Ciclopentanos/farmacologia , Genes de Plantas , Malus/genética , Oxilipinas/farmacologia , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Adaptação Fisiológica/efeitos dos fármacos , Sequência de Aminoácidos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Secas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Ligação Proteica/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismoRESUMO
Anthocyanin and proanthocyanidin (PA) are important secondary metabolites and beneficial to human health. Their biosynthesis is induced by jasmonate (JA) treatment and regulated by MYB transcription factors (TFs). However, which and how MYB TFs regulate this process is largely unknown in apple. In this study, MdMYB9 and MdMYB11 which were induced by methyl jasmonate (MeJA) were functionally characterized. Overexpression of MdMYB9 or MdMYB11 promoted not only anthocyanin but also PA accumulation in apple calluses, and the accumulation was further enhanced by MeJA. Subsequently, yeast two-hybrid, pull-down and bimolecular fluorescence complementation assays showed that both MYB proteins interact with MdbHLH3. Moreover, Jasmonate ZIM-domain (MdJAZ) proteins interact with MdbHLH3. Furthermore, chromatin immunoprecipitation-quantitative PCR and yeast one-hybrid assays demonstrated that both MdMYB9 and MdMYB11 bind to the promoters of ANS, ANR and LAR, whereas MdbHLH3 is recruited to the promoters of MdMYB9 and MdMYB11 and regulates their transcription. In addition, transient expression assays indicated that overexpression of MdJAZ2 inhibits the recruitment of MdbHLH3 to the promoters of MdMYB9 and MdMYB11. Our findings provide new insight into the mechanism of how MeJA regulates anthocyanin and PA accumulation in apple.
Assuntos
Antocianinas/biossíntese , Ciclopentanos/farmacologia , Malus/metabolismo , Oxilipinas/farmacologia , Proteínas de Plantas/metabolismo , Proantocianidinas/biossíntese , Acetatos/farmacologia , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genética , Flavonoides/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Malus/efeitos dos fármacos , Malus/genética , Modelos Biológicos , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Ligação Proteica/efeitos dos fármacosRESUMO
Introduction: Peach (Prunus persica) has a high nutritional and economic value. However, its overgrowth can lead to yield loss. Regulating the growth of peach trees is challenging. The small auxin-up RNA (SAUR) gene family is the largest family of auxin-responsive genes, which play important roles in plant growth and development. However, members of this gene family are rarely reported in peach. Methods: In this study, we measured leaf area, chlorophyll and lignin content to detect the role of PpSAUR5 on growth through transgenic Arabidopsis. Results: PpSAUR5 responds to auxin and gibberellin, promoting and inhibiting the synthesis of gibberellin and auxin, respectively. The heterologous transformation of PpSAUR5 in Arabidopsis led to enhanced growth of leaves and siliques, lightening of leaf color, decrease in chlorophyll content, increase in lignin content, abnormalities in the floral organs, and distortion of the inflorescence axis. Transcriptome data analysis of PpSAUR5 overexpression and wild-type lines revealed 854 differentially expressed genes (DEGs). GO and KEGG analyses showed that the DEGs were primarily involved in biological processes, such as cellular processes, metabolic processes, response to stimuli, and catalytic activity. These genes were mainly enriched in pathways, such as phenylalanine biosynthesis, phytohormone signaling, and MAPK signaling. Discussion: In summary, these results suggested that PpSAUR5 might regulate tree vigor by modulating the synthesis of auxin and gibberellin. Future studies can use PpSAUR5 as a candidate gene to elucidate the potential regulatory mechanisms underlying peach tree vigor.
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Abscisic acid (ABA), as a plant hormone, plays a positive role in leaf chlorosis; however, the underlying molecular mechanism is less known. Our findings provide ABA treatment reduced the chlorophyll accumulation in apple, and Malus × domestica Sucrose Non-fermenting 1-Related Protein Kinase 1.1 (MdSnRK1.1) participates in the process. MdSnRK1.1 interacts with MdGLK1, a GOLDEN2-like transcription factor that orchestrates development of the chloroplast. Furthermore, MdSnRK1.1 affects MdGLK1 protein stability through phosphorylation. We found that Ser468 of MdGLK1 is target site of MdSnRK1.1 phosphorylation. MdSnRK1.1-mediated phosphorylation was critical for MdGLK1 binding to the target gene MdHEMA1 promoters. Collectively, our results demonstrate that ABA activates MdSnRK1.1 to degrade MdGLK1 and inhibit the accumulation of chlorophyll. These findings extend our understanding on how MdSnRK1.1 balances normal growth and hormone response.
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Introduction: Walnut blight is a serious bacterial disease that affects the yield and quality of walnuts. Pantoea agglomerans is one of the main causative agents of walnut blight. However, there have been few studies on the response of walnuts to P. agglomerans infection. Methods: In this study, the soluble sugar, photosynthesis, antioxidant enzyme activities, and secondary metabolites were measured, and the transcriptomic analysis was performed to determine the response of walnut tissue cultures to P. agglomerans infection. Results: After pathogen inoculation, the soluble sugar content decreased, and photosynthesis was inhibited. Antioxidant enzyme (superoxide dismutase and peroxidase) activities and secondary metabolites (phenol and flavonoid) contents increased, especially in the early stages of inoculation. Transcriptomic analysis revealed that the phenylpropanoid biosynthesis pathway is induced after infection, and pathogen infection promotes ABA and ethylene signal transduction and inhibits auxin signaling. In addition, SA and JA-related gene expression was altered after inoculation with P. agglomerans, and the FLS- and calcium-mediated disease resistance signaling pathways were activated. Furthermore, our results suggested an involvement of the R-protein RPM-mediated disease resistance pathway in the response of walnuts to bacterial infections. Discussion: Our findings indicated that phenylpropanoid biosynthesis, hormone signal transduction, and plant-pathogen interaction have key roles in pathogenic inoculation, which provide insights into the molecular mechanisms in the response of walnuts to P. agglomerans infection.
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Nitrate is the major nitrogen sources for higher plants. In addition to serving not only as a nutrient, it is also a signaling molecule that regulates plant growth and development. Although membrane-bound nitrate transporter/peptide transporters (NRT/PTR) have been extensively studied and shown to regulate nitrate uptake and movement, little is known about how these factors are regulated by the external nitrogen environment. Red flesh apple, the coloration of which is determined by the transcription factor MdMYB10, had higher nitrate uptake efficiency than non-red flesh apple. Nitrate assimilation and utilization were increased in red flesh apple cultivar, and comparative transcriptome analysis showed that the expression of genes encoding the NRT2s was increased in red flesh apple. In vitro and in vivo experiments showed that MdMYB10 directly bound to the MdNRT2.4-1 promoter to transcriptionally activate its expression, resulting in enhanced nitrate uptake. MdMYB10 also controlled nitrate reallocation from old leaves to new leaves through MdNRT2.4-1. Overall, our findings provide novel insights into the mechanism by which MdMYB10 controls nitrate uptake and reallocation in apple, which facilitates adaptation to low nitrogen environment.
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MdMYB9 is a positive regulator in the biosynthesis of anthocyanin and proanthocyanidin in apple. However, its posttranslational regulation is unclear. Here, we demonstrated that the BTB protein MdBT2 had a negative role in the biosynthesis of anthocyanin and proanthocyanidin. MdBT2 interacted with MdMYB9 and negatively regulated the abundance of MdMYB9 protein through the 26S proteasome system. The degradation of MdMYB9 by MdBT2 reduced the expression of MdMYB9-mediated anthocyanin and proanthocyanidin-related genes and reduced the accumulation of anthocyanin and proanthocyanidin, which functioned in an MdCUL3-independent pathway. Our results indicated that MdBT2 negatively regulated the stability of MdMYB9, which provides new insight into the homeostasis of anthocyanin and proanthocyanidin in apple.
Assuntos
Antocianinas/metabolismo , Regulação da Expressão Gênica de Plantas , Malus/genética , Proteínas de Plantas/genética , Proantocianidinas/metabolismo , Fatores de Transcrição/genética , Homeostase , Malus/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismoRESUMO
In higher plants, jasmonate ZIM-domain (JAZ) proteins negatively regulate the biosynthesis of anthocyanins by interacting with bHLH transcription factors. However, it is largely unknown if and how other regulators are involved in this process. In this study, the apple MdJAZ2 protein was characterized in regards to its function in the negative regulation of anthocyanin accumulation and peel coloration. MdJAZ2 was used as a bait to screen a cDNA library using the yeast two-hybrid method. The hypersensitive induced reaction (HIR) proteins, MdHIR2 and MdHIR4, were obtained from this yeast two-hybrid. The ZIM domain of MdJAZ2 and the PHB domain of the MdHIR proteins are necessary for their interactions. The interactions were further verified using an in vitro pull-down assay. Subsequently, immunoblotting assays demonstrated that MdHIR4 enhanced the stability of the MdJAZ2-GUS protein. Finally, a viral vector-based transformation method showed that MdHIR4 inhibited anthocyanin accumulation and fruit coloration in apple by modulating the expression of genes associated with anthocyanin biosynthesis.
Assuntos
Antocianinas/biossíntese , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Malus/genética , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Proteínas Repressoras/genética , Sequência de Aminoácidos , Antocianinas/genética , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Biblioteca Gênica , Malus/crescimento & desenvolvimento , Malus/metabolismo , Pigmentação/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Proteólise , Proteínas Repressoras/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Técnicas do Sistema de Duplo-HíbridoRESUMO
Polycomb-group (PcG) protein MULTICOPY SUPPRESSOR OF IRA1 (MSI1) protein is an evolutionarily conserved developmental suppressor and plays a crucial role in regulating epigenetic modulations. However, the potential role and function of MSI1 in fleshy fruits remain unknown. In this study, SlMSI1 was cloned and transformed into tomato to explore its function. The quantitative real-time PCR results showed that SlMSI1 was highly expressed in flowers and fruits and that its transcript and protein levels were significantly decreased in fruits after the breaker stage. Additionally, SlMSI1-overexpressing transgenic tomatoes displayed abnormal non-ripening fruit formation, whereas its suppression promoted fruit ripening in transgenic tomatoes. Quantitative real-time PCR assays also showed that RIN and its regulons were decreased in SlMSI1 overexpression transgenic tomato fruits. Furthermore, RNA-seq analysis demonstrated that SlMSI1 inhibits fruit ripening by negatively regulating a large set of fruit-ripening genes in addition to RIN and its regulons. Finally, genetic manipulation of SlMSI1 and RIN successfully prolonged the fruit shelf life by regulating the fruit-ripening genes in tomato. Our findings reveal a novel regulatory function of SlMSI1 in fruit ripening and provide a new regulator that may be useful for genetic engineering and modification of fruit shelf life.
Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte/fisiologia , Frutas/fisiologia , Proteínas Nucleares/genética , Proteínas Nucleares/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Solanum lycopersicum/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiologia , Etilenos/química , Flores/fisiologia , Frutas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Solanum lycopersicum/genética , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Proteínas do Grupo Polycomb/genética , Proteínas do Grupo Polycomb/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologiaRESUMO
The abundance of anthocyanins and proanthocyanins in apples is tightly regulated by three classes of regulatory factors, MYB, bHLH and WD40 proteins, only some of which have been previously identified. In this study, we identified an apple WD40 protein (MdTTG1) that promotes the accumulation of anthocyanins. The biosynthetic genes required downstream in the flavonoid pathway were up-regulated when MdTTG1 was over-expressed in Arabidopsis. Consistent with its role as a transcriptional regulator, an MdTTG1-GFP fusion protein was observed only in the nucleus. We assayed the expression patterns of this gene in different organs and found that they were positively correlated with anthocyanin accumulation in the apple. Yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated that MdTTG1 interacted with bHLH transcription factors (TFs) but not MYB protein, whereas bHLH was known to interact with MYB in apples. However, based on a ChIP assay, MdTTG1 does not appear to bind to the promoter of the anthocyanin biosynthetic genes MdDFR and MdUFGT. Taken together, these results suggest that the apple WD40 protein MdTTG1 interacts with bHLH but not MYB proteins to regulate anthocyanin accumulation.
Assuntos
Antocianinas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Malus/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Antocianinas/análise , Arabidopsis/genética , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Flores/genética , Flores/metabolismo , Flores/fisiologia , Frutas/genética , Frutas/metabolismo , Frutas/fisiologia , Malus/genética , Malus/fisiologia , Pigmentação , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Caules de Planta/genética , Caules de Planta/metabolismo , Caules de Planta/fisiologia , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Proteínas Recombinantes de Fusão , Sementes/genética , Sementes/metabolismo , Sementes/fisiologia , Fatores de Transcrição/genética , Técnicas do Sistema de Duplo-HíbridoRESUMO
Vacuolar H(+)-translocating inorganic pyrophosphatase (VHP, EC 3.6.1.1) is an electrogenic proton pump, which is related to growth as well as abiotic stress tolerance in plants. In this study, a VHP gene MdVHP1 was isolated from apple. The alignment of nucleotide and amino acid sequences showed that it encoded a type I VHP protein. It expressed in vegetative and reproductive organs, and its expression was induced by salt, PEG-mediated osmotic stress, cold and heat in apple in vitro shoot cultures. MdVHP1 expression showed a similar pattern in different apple tissues, but different change dynamics in response to abiotic stresses, compared with MdVHP2 (another MdVHP gene in apple). MdVHP1 overexpression enhanced tolerance to salt, PEG-mimic drought, cold and heat in transgenic apple calluses, which was related to an increased accumulation of proline and decreased MDA content compared with control calluses. In addition, MdVHP1 overexpression confers improved tolerance to salt and drought in transgenic tomato, along with an increased ion accumulation, high RWC and low solute potential compared with wild type. These results indicate that MdVHP1 is an important regulator for plant tolerance to abiotic stresses by modulating internal stores of ions and solutes.