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1.
J Agric Food Chem ; 67(38): 10563-10576, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31487171

RESUMO

Sulfur (S) metabolism plays a vital role in Cd detoxification, but the collaboration between melatonin biosynthesis and S metabolism under Cd stress remains unaddressed. Using exogenous melatonin, melatonin-deficient tomato plants with a silenced caffeic acid O-methyltransferase (COMT) gene, and COMT-overexpressing plants with cosuppression of sulfate transporter (SUT)1 and SUT2 genes, we found that melatonin deficiency decreased S accumulation and aggravated Cd phytotoxicity, whereas exogenous melatonin or overexpression of COMT increased S uptake and assimilation, resulting in an improved plant growth and Cd tolerance. Melatonin deficiency promoted Cd translocation from root to shoot, but COMT overexpression caused the opposite effect. COMT overexpression failed to compensate the functional hierarchy of S when its uptake was inhibited by cosilencing of transporter SUT1 and SUT2. Our study provides genetic evidence that melatonin-mediated tolerance to Cd is closely associated with the efficient regulation of S metabolism, redox homeostasis, and Cd translocation in tomato plants.


Assuntos
Cádmio/metabolismo , Lycopersicon esculentum/metabolismo , Melatonina/metabolismo , Enxofre/metabolismo , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Oxirredução , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteína O-Metiltransferase/genética , Proteína O-Metiltransferase/metabolismo
2.
BMC Plant Biol ; 19(1): 354, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31412779

RESUMO

BACKGROUND: High temperature is a major environmental stress that limits plant growth and agriculture productivity. Mitogen-activated protein kinases (MAPKs) are highly conserved serine and threonine protein kinases that participate in response to diverse environmental stresses in plants. A total of 16 putative SlMAPK genes are identified in tomato, and SlMAPK3 is one of the most extensively studied SlMAPKs. However, the role of SlMAPK3 in response to heat stress is not clearly understood in tomato plants. In this study, we performed functional analysis of SlMAPK3 for its possible role in response to heat stress. RESULTS: qRT-PCR analyses revealed that SlMAPK3 relative expression was depressed by heat stress. Here, wild-type (WT) tomato plants and CRISPR/Cas9-mediated slmapk3 mutant lines (L8 and L13) were used to investigate the function of SlMAPK3 in response to heat stress. Compared with WT plants, slmapk3 mutants exhibited less severe wilting and less membrane damage, showed lower reactive oxygen species (ROS) contents, and presented higher both activities and transcript levels of antioxidant enzymes, as well as elevated expressions of genes encoding heat stress transcription factors (HSFs) and heat shock proteins (HSPs). CONCLUSIONS: CRISPR/Cas9-mediated slmapk3 mutants exhibited more tolerance to heat stress than WT plants, suggesting that SlMAPK3 was a negative regulator of thermotolerance. Moreover, antioxidant enzymes and HSPs/HSFs genes expression were involved in SlMAPK3-mediated heat stress response in tomato plants.


Assuntos
Resposta ao Choque Térmico/genética , Lycopersicon esculentum/genética , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/metabolismo , Técnicas de Inativação de Genes , Homeostase , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/metabolismo
3.
J Chem Ecol ; 45(8): 693-707, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31367970

RESUMO

Crop domestication and selective breeding have altered plant defense mechanisms, influencing insect-plant interactions. A reduction in plant resistance/tolerance against herbivory is generally expected in domesticated species, however, limited efforts have been made to compare inducibility of plant defenses between wild and domesticated genotypes. In the present study, the inducibility of several plant defense mechanisms (e.g. defensive chemicals, trichomes, plant volatiles) were investigated, and the performance and preference of the herbivore Helicoverpa zea were measured in three different tomato genotypes; a) wild tomato, Solanum pimpinellifolium L. (accession LA 2093), b) cherry tomato, S. lycopersicum L. var. cerasiforme (accession Matts Wild Cherry), and c) cultivated tomato, S. lycopersicum L. var. Better Boy). Enhanced inducibility of defensive chemicals, trichomes, and plant volatiles in the cultivated tomato, and a higher level of constitutive plant resistance against herbivory in the wild genotype was observed. When comparing the responses of damaged vs. undamaged leaves, the percent reduction in larval growth was higher on damaged leaves from cultivated tomato, suggesting a higher induced resistance compared to other two genotypes. While all tomato genotypes exhibited increased volatile organic compound (VOCs) emissions in response to herbivory, the cultivated variety responded with generally higher levels of VOCs. Differences in VOC patterns may have influenced the ovipositional preferences, as H. zea female moths significantly preferred laying eggs on the cultivated versus the wild tomato genotypes. Selection of traits during domestication and selective breeding could alter allocation of resources, where plants selected for higher yield performance would allocate resources to defense only when attacked.


Assuntos
Lycopersicon esculentum/química , Mariposas/fisiologia , Solanum/química , Animais , Comportamento Animal/efeitos dos fármacos , Catecol Oxidase/metabolismo , Feminino , Genótipo , Herbivoria , Larva/fisiologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Oviposição/efeitos dos fármacos , Fenóis/análise , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/análise , Análise de Componente Principal , Inibidores de Proteases/química , Solanum/genética , Solanum/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia
4.
Genome Biol ; 20(1): 156, 2019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31387610

RESUMO

BACKGROUND: Methylation of nucleotides, notably in the forms of 5-methylcytosine (5mC) in DNA and N6-methyladenosine (m6A) in mRNA, carries important information for gene regulation. 5mC has been elucidated to participate in the regulation of fruit ripening, whereas the function of m6A in this process and the interplay between 5mC and m6A remain uncharacterized. RESULTS: Here, we show that mRNA m6A methylation exhibits dynamic changes similar to DNA methylation during tomato fruit ripening. RNA methylome analysis reveals that m6A methylation is a prevalent modification in the mRNA of tomato fruit, and the m6A sites are enriched around the stop codons and within the 3' untranslated regions. In the fruit of the ripening-deficient epimutant Colorless non-ripening (Cnr) which harbors DNA hypermethylation, over 1100 transcripts display increased m6A levels, while only 134 transcripts show decreased m6A enrichment, suggesting a global increase in m6A. The m6A deposition is generally negatively correlated with transcript abundance. Further analysis demonstrates that the overall increase in m6A methylation in Cnr mutant fruit is associated with the decreased expression of RNA demethylase gene SlALKBH2, which is regulated by DNA methylation. Interestingly, SlALKBH2 has the ability to bind the transcript of SlDML2, a DNA demethylase gene required for tomato fruit ripening, and modulates its stability via m6A demethylation. Mutation of SlALKBH2 decreases the abundance of SlDML2 mRNA and delays fruit ripening. CONCLUSIONS: Our study identifies a novel layer of gene regulation for key ripening genes and establishes an essential molecular link between DNA methylation and mRNA m6A methylation during fruit ripening.


Assuntos
Adenosina/análogos & derivados , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , RNA Mensageiro/metabolismo , Adenosina/metabolismo , Metilação de DNA , Retículo Endoplasmático/enzimologia , Frutas/genética , Frutas/metabolismo , Regulação Enzimológica da Expressão Gênica , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/metabolismo , Metilação , Mutação , Motivos de Nucleotídeos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estabilidade de RNA , RNA Mensageiro/química
5.
BMC Plant Biol ; 19(1): 373, 2019 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-31445524

RESUMO

BACKGROUND: The ability of severed rootstocks and shoots to re-establish vascular connections is used to generate grafted plants that combine desirable traits from both scions and rootstocks. Clarifying the mechanisms of graft healing is essential for its further application. We performed RNA sequencing of internodes near the cut position, making a distinction between separated or grafted tissues above and below the cut, in order to obtain a genetic description of graft union formation. RESULTS: Using weighted gene co-expression analysis, variable transcripts were clustered into 10 distinct co-expression networks (modules) based on expression profiles, and genes with the most "hubness" ("hub" genes show the most connections in a network) within each module were predicted. A large proportion of modules were related to Position, and represent asymmetric expression networks from different pathways. Expression of genes involved in auxin and sugar transport and signaling, and brassinosteroid biosynthesis was increased above the cut, while stress response genes were up-regulated below the cut. Some modules were related to graft union formation, among which oxidative detoxification genes were co-expressed along with both wounding response and cell wall organization genes. CONCLUSIONS: The present work provides a comprehensive understanding of graft healing-related gene networks in tomato. Also, the candidate pathways and hub genes identified here will be valuable for future studies of grafting in tomato.


Assuntos
Lycopersicon esculentum/fisiologia , Regeneração/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Lycopersicon esculentum/genética , Raízes de Plantas/fisiologia , Transdução de Sinais
6.
BMC Plant Biol ; 19(1): 323, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31319801

RESUMO

BACKGROUND: Exogenous 5-aminolevulinic acid (ALA) positively regulates plants chlorophyll synthesis and protects them against environmental stresses, although the protection mechanism is not fully clear. Here, we explored the effects of ALA on chlorophyll synthesis in tomato plants, which are sensitive to low temperature. We also examined the roles of the glutathione S-transferase (GSTU43) gene, which is involved in ALA-induced tolerance to oxidation stress and regulation of chlorophyll synthesis under low temperature. RESULTS: Exogenous ALA alleviated low temperature caused chlorophyll synthesis obstacle of uroporphyrinogen III (UROIII) conversion to protoporphyrin IX (Proto IX), and enhanced the production of chlorophyll and its precursors, including endogenous ALA, Proto IX, Mg-protoporphyrin IX (Mg-proto IX), and protochlorophyll (Pchl), under low temperature in tomato leaves. However, ALA did not regulate chlorophyll synthesis at the level of transcription. Notably, ALA up-regulated the GSTU43 gene and protein expression and increased GST activity. Silencing of GSTU43 with virus-induced gene silencing reduced the activities of GST, superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase, and increased the membrane lipid peroxidation; while fed with ALA significant increased all these antioxidase activities and antioxidant contents, and alleviated the membrane damage. CONCLUSIONS: ALA triggered GST activity encoded by GSTU43, and increased tomato tolerance to low temperature-induced oxidative stress, perhaps with the assistance of ascorbate- and/or a glutathione-regenerating cycles, and actively regulated the plant redox homeostasis. This latter effect reduced the degree of membrane lipid peroxidation, which was essential for the coordinated synthesis of chlorophyll.


Assuntos
Ácido Aminolevulínico/metabolismo , Clorofila/metabolismo , Genes de Plantas/fisiologia , Glutationa Transferase/metabolismo , Lycopersicon esculentum/genética , Proteínas de Plantas/metabolismo , Ácido Aminolevulínico/farmacologia , Resposta ao Choque Frio , Glutationa Transferase/genética , Homeostase/efeitos dos fármacos , Peroxidação de Lipídeos , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/fisiologia , Oxirredução/efeitos dos fármacos , Proteínas de Plantas/genética
7.
Gene ; 714: 143985, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31330236

RESUMO

In all eukaryotes, the response to heat stress (HS) is dependent on the activity of HS transcription factors (Hsfs). Plants contain a large number of Hsfs, however, only members of the HsfA1 subfamily are considered as master regulators of stress response and thermotolerance. In Solanum lycopersicum, among the four HsfA1 members, only HsfA1a has been proposed to possess a master regulator function. We performed a comparative analysis of HsfA1a, HsfA1b, HsfA1c and HsfA1e at different levels of regulation and function. HsfA1a is constitutively expressed under control and stress conditions, while the other members are induced in specific tissues and stages of HS response. Despite that all members are localized in the nucleus when expressed in protoplasts, only HsfA1a shows a wide range of basal activity on several HS-induced genes. In contrast, HsfA1b, HsfA1c, and HsfA1e show only high activity for specific subsets of genes. Domain swapping mutants between HsfA1a and HsfA1c revealed that the variation in that transcriptional transactivation activity is due to differences in the DNA binding domain (DBD). Specifically, we identified a conserved arginine (R107) residue in the turn of ß3 and ß4 sheet in the C-terminus of the DBD of HsfA1a that is highly conserved in plant HsfA1 proteins, but is replaced by leucine and cysteine in tomato HsfA1c and HsfA1e, respectively. Although not directly involved in DNA interaction, R107 contributes to DNA binding and consequently the activity of HsfA1a. Thus, we demonstrate that this variation in DBD in part explains the functional diversification of tomato HsfA1 members.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Fatores de Transcrição de Choque Térmico/genética , Lycopersicon esculentum/genética , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Choque Térmico/genética , Resposta ao Choque Térmico/genética , Temperatura Alta , Domínios Proteicos/genética , Protoplastos/fisiologia , Temperatura Ambiente , Termotolerância/genética , Transcrição Genética/genética , Ativação Transcricional/genética
8.
BMC Evol Biol ; 19(1): 141, 2019 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296160

RESUMO

BACKGROUND: The LysM receptor-like kinases (LysM-RLKs) are important to both plant defense and symbiosis. Previous studies described three clades of LysM-RLKs: LysM-I/LYKs (10+ exons per gene and containing conserved kinase residues), LysM-II/LYRs (1-5 exons per gene, lacking conserved kinase residues), and LysM-III (two exons per gene, with a kinase unlike other LysM-RLK kinases and restricted to legumes). LysM-II gene products are presumably not functional as conventional receptor kinases, but several are known to operate in complexes with other LysM-RLKs. One aim of our study was to take advantage of recently mapped wild tomato transcriptomes to evaluate the evolutionary history of LysM-RLKs within and between species. The second aim was to place these results into a broader phylogenetic context by integrating them into a sequence analysis of LysM-RLKs from other functionally well-characterized model plant species. Furthermore, we sought to assess whether the Group III LysM-RLKs were restricted to the legumes or found more broadly across Angiosperms. RESULTS: Purifying selection was found to be the prevailing form of natural selection within species at LysM-RLKs. No signatures of balancing selection were found in species-wide samples of two wild tomato species. Most genes showed a greater extent of purifying selection in their intracellular domains, with the exception of SlLYK3 which showed strong purifying selection in both the extracellular and intracellular domains in wild tomato species. The phylogenetic analysis did not reveal a clustering of microbe/functional specificity to groups of closely related proteins. We also discovered new putative LysM-III genes in a range of Rosid species, including Eucalyptus grandis. CONCLUSIONS: The LysM-III genes likely originated before the divergence of E. grandis from other Rosids via a fusion of a Group II LysM triplet and a kinase from another RLK family. SlLYK3 emerges as an especially interesting candidate for further study due to the high protein sequence conservation within species, its position in a clade of LysM-RLKs with distinct LysM domains, and its close evolutionary relationship with LYK3 from Arabidopsis thaliana.


Assuntos
Evolução Molecular , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/genética , Proteínas Serina-Treonina Quinases/genética , Sequência de Aminoácidos , Filogenia , Domínios Proteicos , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Seleção Genética , Transcriptoma
9.
Plant Mol Biol ; 100(6): 647-658, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31154655

RESUMO

KEY MESSAGE: Found a trans-splicing of PHYTOENE SYNTHASE 1 alters tomato fruit color by map-based cloning, functional complementation and RACE providing an insight into fruit color development. Color is an important fruit quality trait and a major determinant of the economic value of tomato (Solanum lycopersicum). Fruit color inheritance in a yellow-fruited cherry tomato (cv. No. 22), named yellow-fruited tomato 2 (yft2), was shown to be controlled by a single recessive gene, YFT2. The YFT2 gene was mapped in a 95.7 kb region on chromosome 3, and the candidate gene, PHYTOENE SYNTHASE 1 (PSY1), was confirmed by functional complementation analysis. Constitutive over expression of PSY1 in yft2 increased the accumulation of carotenoids and resulted in a red fruit color, while no causal mutation was detected in the YFT2 allele of yft2, compared with red-fruited SL1995 cherry tomato or cultivated variety (cv. M82). Expression of YFT2 3' region in yft2 was significantly lower than in SL1995, and further studies revealed a difference in YFT2 post-transcriptional processing in yft2 compared with SL1995 and cv. M82, resulting in a longer YFT2 transcript. The alternatively trans-spliced allele of YFT2 in yft2 is predicted to encode a novel LT-YFT2 protein of 432 amino acid (AA) residues, compared to the 412 AA YFT2 protein of SL1995. The trans-spliced event also resulted in significantly down regulated expression of YFT2 in yft2 tomato, and the YFT2 allele suppressed expression of the downstream genes involved in the carotenoid biosynthesis pathway and carotenoids synthesis by a mechanism of the feed-forward regulation. In conclusion, we found that trans-splicing of YFT2 alters tomato fruit color, providing new insights into fruit color development.


Assuntos
Lycopersicon esculentum/metabolismo , Pigmentação/genética , Proteínas de Plantas/metabolismo , Processamento Alternativo , Carotenoides/metabolismo , Mapeamento Cromossômico , Clonagem Molecular , Cor , DNA Complementar/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Genes Recessivos , Teste de Complementação Genética , Genótipo , Lycopersicon esculentum/genética , Mutação , Proteínas de Plantas/genética , Trans-Splicing
10.
BMC Plant Biol ; 19(1): 265, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221088

RESUMO

BACKGROUND: Chloroplast biogenesis, a complex process in higher plants, is the key to photoautotrophic growth in plants. White virescent (wv) mutants have been used to unfold the molecular mechanisms underlying the regulation of chloroplast development and chloroplast gene expression in plants. However, most of genes controlling white virescent phenotype still remain unknown. RESULTS: In this study, we identified a temperature- and light intensity-sensitive mutant, named as wv. The content of chlorophyll was dramatically decreased in the immature leaves of wv mutant under the conditions of low temperature and high-light intensity. TEM observation showed that the chloroplasts in the young leaves of wv mutant lacked an organized thylakoid membrane, whereas crescent-shaped chloroplasts with well-developed stromal and stacked grana thylakoids in the mature leaves were developed. Immunoblot analyses suggested that proteins of photosynthetic complexes were decreased substantially in wv mutants. Based on map-based cloning and transgenic analysis, we determined that the wv phenotype was caused by single base mutation in the first intron of WV gene, which encoded a thioredoxin protein with 365 amino acids. qRT-PCR analysis revealed that the expression of WV gene was significantly down-regulated in wv mutant. In addition, knockdown of WV gene through RNAi also resulted in white virescent young leaves, suggesting that the mutation possibly blocks the differentiation of chloroplasts through inhibiting the expression of WV gene. Furthermore, the expression of WV peaked in apical buds and gradually decreased along with the developmental stage, which was consistent with the wv mutant phenotype. Expression analysis of chloroplast-encoded genes by qRT-PCR showed that the wv mutation affected the expression pattern of chloroplast-encoded PEP dependent genes. CONCLUSION: Our results suggested that wv mutant was sensitive to low temperature and light intensity. WV gene was essential for chloroplast differentiation. A single base mutation in the first intron resulted in down-regulation of WV gene expression, which inhibited the expression of chloroplast-encoded genes, thereby blocking chloroplast formation and chlorophyll synthesis.


Assuntos
Cloroplastos/genética , Lycopersicon esculentum/genética , Tiorredoxinas/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Temperatura Baixa , Genes de Plantas , Luz , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/efeitos da radiação , Mutação , Fenótipo , Fotossíntese/genética , Alinhamento de Sequência , Tiorredoxinas/fisiologia
11.
Food Chem ; 293: 263-270, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151610

RESUMO

Gray mold caused by Botrytis cinerea is the most important disease in postharvest tomato fruit. Inducing resistance to fungal pathogens in the harvested fruit and vegetable is a promising approach to control postharvest losses. In the present study, the effect of l-glutamate on induction of resistance to B. cinerea and the underlying mechanisms were investigated. The results indicated that l-glutamate at 100 ppm was effective in reducing the gray mold of tomatoes after inoculation of the pathogen. Gene expressions of nine glutamate receptors, four pathogenesis-related proteins and the content of amino acids were affected by l-glutamate treatment. Furthermore, the metabolites of l-glutamate, including GABA, Met, Lys and Arg, could also induce significant resistance against B. cinerea in tomato fruit. Our findings suggested that l-glutamate treatment may represent a promising method for managing postharvest decay of tomato fruit.


Assuntos
Aminoácidos/metabolismo , Botrytis/efeitos dos fármacos , Ácido Glutâmico/farmacologia , Lycopersicon esculentum/imunologia , Micoses/prevenção & controle , Doenças das Plantas/prevenção & controle , Receptores de Glutamato/metabolismo , Resistência à Doença , Frutas/química , Lycopersicon esculentum/genética , Lycopersicon esculentum/microbiologia , Micoses/microbiologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Regulação para Cima/efeitos dos fármacos
12.
J Sci Food Agric ; 99(14): 6139-6154, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31152450

RESUMO

BACKGROUND: Tomato is an important food item and a cocktail of phytonutrients. In the current study, metabolites from a non-pathogenic fungal species Penicillium oxalicum have been exploited to obtain nutritionally augmented tomato fruits from the plants to better withstand against Alternaria alternata infection. RESULTS: Initially, bioactivity-guided assay and chromatographic analyses identified the bioactive metabolites of P. oxalicum [benzenedicarboxylic acid (BDA) and benzimidazole]. Then, ≥3 times elevated quantities of vitamins and other nutritional elements (protein, fat, fibers, and carbohydrates) were achieved by the foliar application of BDA. The maximum increase (625.81%) was recorded in riboflavin contents; however, thiamine showed the second highest enhancement (542.86%). Plant metabolites analysis revealed that jasmonic acid contents were boosted 121.53% to significantly enhance guaiacyl lignin defenses along with the reduction in coumarin contents. The protein profile analysis explored three most actively responding protein species toward BDA applications, (i) palmitoyltransferase protein Q9FLM3; (ii) serine/threonine-protein kinase O48814; and (iii) E3 ubiquitin-protein ligase Q9FJQ8. The O48814 improved plant defenses; whereas, Q9FJQ8 protein was negatively regulating cysteine-type endopeptidase activity and assisted plant to resist schedule alterations. Tomato cultivar with more active innate metabolism was found to be more responsive toward BDA. Furthermore, the bioactive compounds were enriched by using the two-step extraction method of ethyl acetate and chloroform, respectively. CONCLUSION: Penicillium oxalicum a non-pathogenic fungal species, produced BDA, induced nutritional contents in tomato and protected it against Alternaria alternata. The current study is the first report on the bioactivity of BDA and benzimidazole concerning the nutritional enhancement and plant defense improvement. © 2019 Society of Chemical Industry.


Assuntos
Alternaria/fisiologia , Ácidos Dicarboxílicos/farmacologia , Lycopersicon esculentum/microbiologia , Penicillium/metabolismo , Doenças das Plantas/prevenção & controle , Proteínas de Plantas/genética , Proteínas Serina-Treonina Quinases/genética , Ubiquitina-Proteína Ligases/genética , Inoculantes Agrícolas/química , Inoculantes Agrícolas/metabolismo , Ácidos Dicarboxílicos/metabolismo , Frutas/química , Frutas/genética , Frutas/metabolismo , Frutas/microbiologia , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Valor Nutritivo , Penicillium/química , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
13.
BMC Plant Biol ; 19(1): 233, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159738

RESUMO

BACKGROUND: Auxin conjugates are hydrolyzed to release free auxin to ensure defined cellular auxin levels or gradients within tissues for proper development or response to environmental signals. The auxin concentration in the abscission zone (AZ) is thought to play an important role in mediating the abscission lag phase. RESULTS: In this study, the full cDNA sequences of seven tomato ILR1-like SlILL genes were identified and characterized, All SlILLs were found to have auxin conjugate hydrolysis activity. The effects of different auxin conjugates on abscission identified IAA-Ile as a candidate to determine the auxin conjugate and auxin conjugate hydrolysis functions in abscission. Treatment of pedicel explants with IAA-Ile for different times showed that application before 6 h could effectively delay abscission. IAA-Ile pre-incubation for 2 h was sufficient to inhibit abscission. These results showed that there is not sufficient auxin conjugates in the AZ to inhibit abscission, and the optimal time to inhibit abscission by the application of exogenous auxin conjugates is before 6 h. Treatment with cycloheximide (CHX, a protein biosynthesis inhibitor) indicated that de novo synthesis of auxin conjugate hydrolases is also required to delay abscission. During abscission, SlILL1, 5, and 6 showed abscission-related gene expression patterns, and SlILL1, 3, 5, 6, and 7 showed increasing expression trends, which collectively might contribute to delay abscission. Silencing the expression of SlILL1, 3, 5, 6, and 7 using virus-induced gene silencing showed that SlILL1, 5, and 6 are major mediators of abscission in tomato. CONCLUSIONS: In the process of abscission, auxin inhibition is concentration dependent, and the concentration of auxin in the AZ was regulated by hydrolyzed auxin conjugates. SlILR1, 5, and 6 play a key role in flower pedicel abscission.


Assuntos
Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Hidrolases/metabolismo , Ácidos Indolacéticos/metabolismo , Lycopersicon esculentum/genética , Inibidores da Síntese de Proteínas/farmacologia , Cicloeximida/farmacologia , Flores/genética , Lycopersicon esculentum/enzimologia
14.
Plant Cell Rep ; 38(9): 1151-1163, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31152194

RESUMO

KEY MESSAGE: Piriformospora indica confers salt tolerance in tomato seedlings by increasing the uptake of nutrients such as N, P and Ca, improving K+/Na+ homoeostasis by regulating the expression of NHXs, SOS1 and CNGC15 genes, maintaining water status by regulating the expression of aquaporins. Piriformospora indica, an endophytic basidiomycete, has been shown to increase the growth and improve the plants tolerance to stressful conditions, especially salinity, by establishing the arbuscular mycorrhiza-like symbiotic relationship in various plant hosts. In the present research, the effect of NaCl treatment (150 mM) and P. indica inoculation on growth, accumulation of nutrients, the transcription level of genes involved in ionic homeostasis (NHXs, SOS1 and CNGC15) and regulating water status (PIP1;2, PIP2;4, TIP1;1 and TIP2;2) in roots and leaves of tomato seedlings were investigated. The P. indica improved the uptake of N, P, Ca and K, and reduced Na accumulation, and had no significant effect on Cl accumulation in roots and leaves. The endophytic fungus also increased in K+/Na+ ratio in roots and leaves of tomato by regulating the expression of NHX isoforms and upregulating SOS1 and CNGC15 expression. Salinity stress increased the transcription of PIP2;4 gene and reduced the transcription of PIP1;2, TIP1;1 and TIP2;2 genes compared to the control treatment. However, P. indica inoculation upregulated the expression of PIP1;2 and PIP2;4 genes versus non-inoculated plants but did not have a significant effect on TIP1;1 and TIP2;2 expression. These results conclude that the positive effects of P. indica on nutrients accumulation, ionic homeostasis and water status lead to the increased salinity tolerance and the improved plant growth under NaCl treatment.


Assuntos
Basidiomycota/fisiologia , Lycopersicon esculentum/microbiologia , Nutrientes/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Água/metabolismo , Homeostase , Lycopersicon esculentum/genética , Lycopersicon esculentum/fisiologia , Salinidade , Tolerância ao Sal , Estresse Fisiológico , Simbiose
15.
BMC Plant Biol ; 19(1): 256, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31196007

RESUMO

BACKGROUND: Appropriate brassinosteroid (BR) signal strength caused by exogenous application or endogenous regulation of BR-related genes can increase crop yield. However, precise control of BR signals is difficult and can cause unstable effects and failure to reach full potential. Phosphorylated BRASSINOSTEROID INSENSITIVE1 (BRI1), the rate-limiting receptor in BR signalling, transduces BR signals, and we recently demonstrated that modifying BRI1 phosphorylation sites alters BR signal strength and botanical characteristics in Arabidopsis. However, the functions of such phosphorylation sites in agronomic characteristics of crops remain unclear. RESULTS: In this work, we investigated the roles of tomato SlBRI1 threonine-1050 (Thr-1050). SlBRI1 mutant cu3-abs1 plants expressing SlBRI1 with a non-phosphorylatable Thr-1050 (T1050A), with a wild-type SlBRI1 transformant used as a control, were examined. The results showed enhanced autophosphorylation of SlBRI1 and BR signal strength for cu3-abs1 harbouring T1050A, which promoted yield through increased plant expansion, leaf area, fruit weight and fruit number per cluster but reduced nutrient contents, including ascorbic acid and soluble sugar levels. Moreover, plant height, stem diameter, and internodal distance were similar between the transgenic plants. CONCLUSION: Our results reveal the biological role of Thr-1050 in tomato and provide a molecular basis for establishing high-yield crops by precisely controlling BR signal strength via phosphorylation site modification.


Assuntos
Brassinosteroides/metabolismo , Frutas/crescimento & desenvolvimento , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Plantas/fisiologia , Proteínas Quinases/fisiologia , Transdução de Sinais , Lycopersicon esculentum/genética , Mutação , Fosforilação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Quinases/genética , Proteínas Quinases/metabolismo
16.
Planta ; 250(2): 643-655, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31144110

RESUMO

MAIN CONCLUSION: Trehalose increased drought tolerance of tomato plants, accompanied by reduced water loss and closed stomata, which was associated with the upregulated ABA signaling-related genes expression, but not in ABA accumulation. Drought is one of the principal abiotic stresses that negatively influence the growth of plant and yield. Trehalose has great agronomic potential to improve the stress tolerance of plants. However, little information is available on the role of ABA and its signaling components in trehalose-induced drought tolerance. The aim of this study is to elucidate the potential mechanism by which trehalose regulates ABA in response to drought stress. In this study, 6-week-old tomato (Solanum lycopersicum cv. Ailsa Craig) plants were treated with 0 or 15.0 mM trehalose solution. Results showed that trehalose treatment significantly enhanced drought tolerance of tomato plants, accompanied by encouraged stomatal closure and protected chloroplast ultrastructure. Compared with controls, trehalose-treated plants showed lower hydrogen peroxide content and higher antioxidant enzymes activities, which contributed to alleviate oxidative damage caused by drought. Moreover, trehalose treatment decreased ABA content, which was followed by the downregulation of ABA biosynthesis genes expression and the upregulation of ABA catabolism genes expression. In contrast, exogenous trehalose upregulated transcript levels of ABA signaling-related genes, including SlPYL1/3/4/5/6/7/9, SlSnRK2.3/4, SlAREB1/2, and SlDREB1. These results suggested that trehalose treatment enhanced drought tolerance of tomato plants, and it's ABA signaling rather than ABA metabolism that was involved in trehalose-induced drought tolerance in tomato plants. These findings provide evidence for the physiological role of trehalose and bring about a new understanding of the possible relationship between trehalose and ABA.


Assuntos
Ácido Abscísico/metabolismo , Lycopersicon esculentum/fisiologia , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/metabolismo , Transdução de Sinais , Trealose/farmacologia , Cloroplastos/fisiologia , Cloroplastos/ultraestrutura , Secas , Lycopersicon esculentum/genética , Lycopersicon esculentum/ultraestrutura , Fenótipo , Proteínas de Plantas/genética , Estômatos de Plantas/genética , Estômatos de Plantas/fisiologia , Estômatos de Plantas/ultraestrutura , Estresse Fisiológico
17.
Nat Genet ; 51(6): 1044-1051, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31086351

RESUMO

Modern tomatoes have narrow genetic diversity limiting their improvement potential. We present a tomato pan-genome constructed using genome sequences of 725 phylogenetically and geographically representative accessions, revealing 4,873 genes absent from the reference genome. Presence/absence variation analyses reveal substantial gene loss and intense negative selection of genes and promoters during tomato domestication and improvement. Lost or negatively selected genes are enriched for important traits, especially disease resistance. We identify a rare allele in the TomLoxC promoter selected against during domestication. Quantitative trait locus mapping and analysis of transgenic plants reveal a role for TomLoxC in apocarotenoid production, which contributes to desirable tomato flavor. In orange-stage fruit, accessions harboring both the rare and common TomLoxC alleles (heterozygotes) have higher TomLoxC expression than those homozygous for either and are resurgent in modern tomatoes. The tomato pan-genome adds depth and completeness to the reference genome, and is useful for future biological discovery and breeding.


Assuntos
Alelos , Frutas/genética , Estudos de Associação Genética , Genoma de Planta , Genômica , Lycopersicon esculentum/genética , Característica Quantitativa Herdável , Biologia Computacional/métodos , Domesticação , Genômica/métodos , Humanos , Fases de Leitura Aberta , Melhoramento Vegetal , Regiões Promotoras Genéticas , Seleção Genética
18.
J Agric Food Chem ; 67(24): 6725-6735, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31117506

RESUMO

Jasmonic acid (JA)- and ethylene-mediated signaling pathways are reported to have synergistic effects on inhibiting gray mold. The present study aimed to explain the role of ethylene perception in methyl jasmonate (MeJA)-mediated immune responses. Results showed that exogenous MeJA enhanced disease resistance, accompanied by the induction of endogenous JA biosynthesis and ethylene production, which led to the activation of the phenolic metabolism pathway. Blocking ethylene perception using 1-methylcyclopropene (1-MCP) either before or after MeJA treatment could differently weaken the disease responses induced by MeJA, including suppressing the induction of ethylene production and JA contents and reducing activities of lipoxygenase and allene oxide synthase compared to MeJA treatment alone. Consequently, MeJA-induced elevations in the total phenolic content and the activities of phenylalanine ammonia-lyase, cinnamate 4-hydroxylase, 4-coumarate:coenzyme A ligase, and peroxidase were impaired by 1-MCP. These results suggested that ethylene perception participated in MeJA-mediated immune responses in tomato fruit.


Assuntos
Acetatos/imunologia , Botrytis/fisiologia , Ciclopentanos/imunologia , Etilenos/imunologia , Lycopersicon esculentum/imunologia , Oxilipinas/imunologia , Doenças das Plantas/imunologia , Reguladores de Crescimento de Planta/imunologia , Resistência à Doença , Frutas/imunologia , Frutas/microbiologia , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/microbiologia , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Transcinamato 4-Mono-Oxigenase/genética , Transcinamato 4-Mono-Oxigenase/imunologia
19.
Exp Appl Acarol ; 77(4): 555-570, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31055676

RESUMO

The tomato red spider mite, Tetranychus evansi Baker & Pritchard, is one of the main pests of the tomato crop in several countries, mainly in Africa, where it can reduce tomato yield by up to 90%. The biotic potential of this mite is high and its control is difficult because of low efficiency of chemicals used and the rapid development of resistance to acaricides. We used the two-sex life table to evaluate the effect of two wild tomato genotypes (PI134417 and PI134418) and five tomato varieties widely grown in Benin (Kekefo, Akikon, TLCV15, Tounvi, and TOML4) on demographic characteristics of T. evansi under laboratory conditions. Tetranychus evansi did not develop on the genotypes PI134417 and PI134418, indicating their resistance to this mite. Developmental time of immature stages and female longevity were significantly higher on TLCV15 and Kekefo. Fecundity, net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) of T. evansi on the African varieties were not statistically different among varieties. Generation time (T) was shorter on TOML4 than on TLCV15 and Tounvi. Thus, efforts should be made to prospect varieties with resistance characteristics or to develop other control means, to reduce the use of pesticides to control T. evansi in Africa.


Assuntos
Lycopersicon esculentum/genética , Tetranychidae/fisiologia , Animais , Benin , Feminino , Fertilidade , Cadeia Alimentar , Genótipo , Larva/crescimento & desenvolvimento , Larva/fisiologia , Tábuas de Vida , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Óvulo/fisiologia , Reprodução , Tetranychidae/crescimento & desenvolvimento
20.
Chemosphere ; 230: 628-639, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31128509

RESUMO

The current study evaluated the synergistic role of Plant growth promoting rhizobacteria (PGPR), Pseudomonas aeruginosa and Burkholderia gladioli on different physiological, biochemical and molecular activities of 10-days old Solanum lycopersicum seedlings under Cd stress. Cd toxicity altered the levels of phenolic compounds (total phenols (30.2%), flavonoids (92.7%), anthocyanin (59.5%), polyphenols (368.7%)), osmolytes (total osmolytes (10.3%), total carbohydrates (94%), reducing sugars (64.5%), trehalose (112.5%), glycine betaine (59%), proline (54.8%), and free amino acids (63%)), and organic acids in S. lycopersicum seedlings. Inoculation of P. aeruginosa and B. gladioli alleviated Cd-induced toxicity, which was manifested through enhanced phenolic compound levels and osmolytes. Additionally, the levels of low molecular weight organic acids (fumaric acid, malic acid, succinic acid, and citric acid) were also elevated. The expression of genes encoding enzymes for phenols and organic acid metabolism were also studied to be modulated that included CHS (chalcone synthase; 138.4%), PAL (phenylalanine ammonia lyase; 206.7%), CS (citrate synthase; 61.3%), SUCLG1 (succinyl Co-A ligase; 33.6%), SDH (succinate dehydrogenase; 23.2%), FH (fumarate hydratase; 12.4%), and MS (malate synthase; 41.2%) and found to be upregulated in seedlings inoculated independently with P. aeruginosa and B. gladioli. The results provide insights into the role of micro-organisms in alleviating Cd-induced physiological damage by altering levels of different metabolites.


Assuntos
Burkholderia gladioli/crescimento & desenvolvimento , Cádmio/toxicidade , Lycopersicon esculentum/metabolismo , Polifenóis/metabolismo , Pseudomonas aeruginosa/crescimento & desenvolvimento , Poluentes do Solo/toxicidade , Perfilação da Expressão Gênica , Genes de Plantas , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/genética , Lycopersicon esculentum/microbiologia , Desenvolvimento Vegetal/efeitos dos fármacos , Desenvolvimento Vegetal/genética , Rizosfera , Transcriptoma/efeitos dos fármacos
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