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1.
Plant Sci ; 311: 111012, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34482915

RESUMO

Agrochemicals are commonly used in agriculture to protect crops and ensure yields. Several of them are mobile within the plant and, being perceived as xenobiotics regardless of their protective/curative roles, they induce a reprogramming of secondary metabolism linked to the detoxification processes even in the absence of phenotype symptoms. Moreover, it is well documented that plants are able to shape the microbial population at the rhizosphere and to significantly affect the processes occurring therein thanks to the root exudation of different metabolites. Here we show that plant metabolic response to foliarly-applied pesticides is much broader than what previously thought and includes diverse and compound-specific hidden processes. Among others, stress-related metabolism and phytohormones profile underwent a considerable reorganization. Moreover, a distinctive microbial rearrangement of the rhizosphere was recorded following foliar application of pesticides. Such effects have unavoidably energetic and metabolic costs for the plant paving the way to both positive and negative aspects. The understanding of these effects is crucial for an increasingly sustainable use of pesticides in agriculture.


Assuntos
Agroquímicos/metabolismo , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/microbiologia , Microbiota/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Xenobióticos/metabolismo , Produtos Agrícolas/metabolismo , Produtos Agrícolas/microbiologia , Herbicidas/metabolismo , Itália , Microbiota/fisiologia , Metabolismo Secundário , Tiazóis/metabolismo , Triazóis/metabolismo
2.
BMC Plant Biol ; 21(1): 429, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34548030

RESUMO

BACKGROUND: Surveillance of potential pathogens is a key feature of plant innate immunity. For non-self-recognition plants rely on the perception of pathogen-derived molecules. Early post-perception events activate signaling cascades, leading to the synthesis of defense-related proteins and specialized metabolites, thereby providing a broad-spectrum antimicrobial coverage. This study was concerned with tracking changes in the tomato plant metabolome following perception of the flagellum-derived elicitors (Flg22 and FlgII-28). RESULTS: Following an untargeted metabolomics workflow, the metabolic profiles of a Solanum lycopersicum cultivar were monitored over a time range of 16-32 h post-treatment. Liquid chromatography was used to resolve the complex mixture of metabolites and mass spectrometry for the detection of differences associated with the elicitor treatments. Stringent data processing and multivariate statistical tools were applied to the complex dataset to extract relevant metabolite features associated with the elicitor treatments. Following perception of Flg22 and FlgII-28, both elicitors triggered an oxidative burst, albeit with different kinetic responses. Signatory biomarkers were annotated from diverse metabolite classes which included amino acid derivatives, lipid species, steroidal glycoalkaloids, hydroxybenzoic acids, hydroxycinnamic acids and derivatives, as well as flavonoids. CONCLUSIONS: An untargeted metabolomics approach adequately captured the subtle and nuanced perturbations associated with elicitor-linked plant defense responses. The shared and unique features characterizing the metabolite profiles suggest a divergence of signal transduction events following perception of Flg22 vs. FlgII-28, leading to a differential reorganization of downstream metabolic pathways.


Assuntos
Resistência à Doença/genética , Resistência à Doença/imunologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Pseudomonas syringae/patogenicidade , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Produtos Agrícolas/microbiologia , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/microbiologia , Metabolômica
3.
Int J Mol Sci ; 22(15)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34361121

RESUMO

The first line of plant defence responses against pathogens can be induced by the bacterial flg22 and can be dependent on various external and internal factors. Here, we firstly studied the effects of daytime and ethylene (ET) using Never ripe (Nr) mutants in the local and systemic defence responses of intact tomato plants after flg22 treatments. Flg22 was applied in the afternoon and at night and rapid reactions were detected. The production of hydrogen peroxide and nitric oxide was induced by flg22 locally, while superoxide was induced systemically, in wild type plants in the light period, but all remained lower at night and in Nr leaves. Flg22 elevated, locally, the ET, jasmonic acid (JA) and salicylic acid (SA) levels in the light period; these levels did not change significantly at night. Expression of Pathogenesis-related 1 (PR1), Ethylene response factor 1 (ERF1) and Defensin (DEF) showed also daytime- and ET-dependent changes. Enhanced ERF1 and DEF expression and stomatal closure were also observable in systemic leaves of wild type plants in the light. These data demonstrate that early biotic signalling in flg22-treated leaves and distal ones is an ET-dependent process and it is also determined by the time of day and inhibited in the early night phase.


Assuntos
Ritmo Circadiano , Etilenos/farmacologia , Lycopersicon esculentum/imunologia , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Transdução de Sinais
4.
J Plant Physiol ; 264: 153483, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34371311

RESUMO

Tomato plants are susceptible to drought stress, but the mechanism involved in this process still remains poorly understood. In the present study, we demonstrated that SlNAC6, a nuclear-localized protein induced by exogenous abscisic acid (ABA) or polyethylene glycol (PEG) stress treatment, plays a positive role in tomato plant response to PEG stress. Down-regulation of SlNAC6 (SlNAC6-RNAi) resulted in a semidwarf phenotype, and the SlNAC6-RNAi lines showed reduced tolerance to PEG stress, exhibiting a higher water loss rate and degree of oxidative damage, as well as lower values of proline content and antioxidant enzyme activity, when compared with those in wild type (WT). In contrast, overexpression of SlNAC6 (SlNAC6-OE) leads to a significant delay of growth, and the SlNAC6-OE lines showed greatly enhanced tolerance to PEG stress concomitant with a lower water loss rate and degree of oxidative damage, as well as higher values of proline content and antioxidant enzyme activity. Further study showed that the transcription level of ABA signaling-related genes and the ABA content are respectively decreased or increased in SlNAC6-RNAi and SlNAC6-OE seedlings, as verified by multiple physiological parameters, such as stomatal conductance, water loss rate, seed germination, and root length. Moreover, overexpression of SlNAC6 can accelerate tomato fruit ripening. Collectively, this study demonstrates SlNAC6 exerts important roles in tomato development, drought stress response, and fruit ripening processes, some of them perhaps partly through modulating an ABA-mediated pathway, which implies SlNAC6 may hold the potential applications in improving agronomic traits of tomato or other Solanaceae crops.


Assuntos
Lycopersicon esculentum/metabolismo , Proteínas de Plantas/fisiologia , Fatores de Transcrição/fisiologia , Desidratação , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/fisiologia , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reprodução , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360893

RESUMO

Flowering is a morphogenetic process in which angiosperms shift from vegetative growth to reproductive growth. Flowering time has a strong influence on fruit growth, which is closely related to productivity. Therefore, research on crop flowering time is particularly important. To better understand the flowering period of the tomato, we performed transcriptome sequencing of early flower buds and flowers during the extension period in the later-flowering "Moneymaker" material and the earlier-flowering "20965" homozygous inbred line, and we analyzed the obtained data. At least 43.92 million clean reads were obtained from 12 datasets, and the similarity with the tomato internal reference genome was 92.86-94.57%. Based on gene expression and background annotations, 49 candidate genes related to flowering time and flower development were initially screened, among which the greatest number belong to the photoperiod pathway. According to the expression pattern of candidate genes, the cause of early flowering of "20965" is predicted. The modes of action of the differentially expressed genes were classified, and the results show that they are closely related to hormone regulation and participated in a variety of life activities in crops. The candidate genes we screened and the analysis of their expression patterns provide a basis for future functional verification, helping to explore the molecular mechanism of tomato flowering time more comprehensively.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/genética , Flores/crescimento & desenvolvimento , Flores/genética , Genes de Plantas , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/genética , Transcriptoma , Produtos Agrícolas/metabolismo , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Estudos de Associação Genética/métodos , Lycopersicon esculentum/metabolismo , Fotoperíodo , Proteínas de Plantas/genética , RNA-Seq/métodos , Transdução de Sinais/genética
6.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445561

RESUMO

Among numerous contaminants, the ubiquitous occurrence of nonsteroidal anti-inflammatory drugs (NSAIDs) in the environment and their plausible harmful impact on nontarget organisms have made them one of the most important areas of concern in recent years. Crop plants can also potentially be exposed to NSAIDs, since the concentration of these pharmaceuticals is constantly rising in the surface water and soil. Our goal was to evaluate the stress response of two crop plants, maize and tomato, to treatment with selected NSAIDs, naproxen and diclofenac. The focus of the research was on the growth response, photosynthetic efficiency, selected oxidative stress factors (such as the H2O2 level and the rate of lipid peroxidation) as well as the total phenolic content, which represents the non-enzymatic protectants against oxidative stress. The results indicate that susceptibility to the NSAIDs that were tested is dependent on the plant species. A higher sensitivity of tomato manifested in growth inhibition, a decrease in the content of the photosynthetic pigments and a reduction in the maximum quantum efficiency of PSII and the activity of PSII, which was estimated using the Fv/Fm and Fv/F0 ratios. Based on the growth results, it was also possible to reveal that diclofenac had a more toxic effect on tomato. In contrast to tomato, in maize, neither the content of the photosynthetic pigments nor growth appeared to be affected by DFC and NPX. However, both drugs significantly decreased in maize Fv and Fm, which are particularly sensitive to stress. A higher H2O2 concentration accompanied, in most cases, increasing lipid peroxidation, indicating that oxidative stress occurred in response to the selected NSAIDs in the plant species that were studied. The higher phenolic content of the plants after NSAIDs treatment may, in turn, indicate the activation of defense mechanisms in response to the oxidative stress that is triggered by these drugs.


Assuntos
Diclofenaco/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Lycopersicon esculentum/efeitos dos fármacos , Naproxeno/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/farmacologia , Peróxido de Hidrogênio/farmacologia , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Oxidantes/farmacologia , Fenóis/farmacologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
7.
Phytochemistry ; 191: 112912, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34450419

RESUMO

The esterification of carotenoids has been associated with high-level accumulation, greater stability and potentially improved dietary bioavailability. Engineering the formation of ketocarotenoids into tomato fruit has resulted in the esterification of these non-endogenous metabolites. A genotype of tomato was created that contains; (i) the mutant pale yellow petal (pyp)1-1 allele, which is responsible for the absence of carotenoid esters in tomato flowers and (ii) the heterologous enzymes for ketocarotenoid formation. Analysis of the resulting progeny showed altered quantitative and qualitative differences in esterified carotenoids. For example, in ripe fruit tissues, in the presence of the pyp mutant allele, non-endogenous ketocarotenoid esters were absent while their free forms accumulated. These data demonstrate the involvement of the PYP gene product in the esterification of diverse xanthophylls.


Assuntos
Lycopersicon esculentum , Aciltransferases/metabolismo , Esterificação , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/metabolismo , Plastídeos/metabolismo , Xantofilas/metabolismo
8.
BMC Plant Biol ; 21(1): 358, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348650

RESUMO

BACKGROUND: The South America pinworm, Tuta absoluta, is a destructive pest of tomato that causes important losses worldwide. Breeding of resistant/tolerant tomato cultivars could be an effective strategy for T. absoluta management but, despite the economic importance of tomato, very limited information is available about its response to this treat. To elucidate the defense mechanisms to herbivore feeding a comparative analysis was performed between a tolerant and susceptible cultivated tomato at both morphological and transcriptome level to highlight constitutive leaf barriers, molecular and biochemical mechanisms to counter the effect of T. absoluta attack. RESULTS: The tolerant genotype showed an enhanced constitutive barrier possibly as result of the higher density of trichomes and increased inducible reactions upon mild infestation thanks to the activation/repression of key transcription factors regulating genes involved in cuticle formation and cell wall strength as well as of antinutritive enzymes, and genes involved in the production of chemical toxins and bioactive secondary metabolites. CONCLUSIONS: Overall, our findings suggest that tomato resilience to the South America pinworm is achieved by a combined strategy between constitutive and induced defense system. A well-orchestrated modulation of plant transcription regulation could ensure a trade-off between defense needs and fitness costs. Our finding can be further exploited for developing T. absoluta tolerant cultivars, acting as important component of integrated pest management strategy for more sustainable production.


Assuntos
Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Doenças das Plantas/genética , Folhas de Planta/genética , Transcriptoma , Animais , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Interações Hospedeiro-Parasita , Larva/fisiologia , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Mariposas/fisiologia , Doenças das Plantas/parasitologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA-Seq/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/metabolismo , Tricomas/parasitologia
9.
Molecules ; 26(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34361654

RESUMO

Growing attention to environmental protection leads food industries to adopt a model of "circular economy" applying safe and sustainable technologies to recover, recycle and valorize by-products. Therefore, by-products become raw material for other industries. Tomato processing industry produces significant amounts of by-products, consisting of skins and seeds. Tomato skin is very rich in lycopene, and from its seeds, high nutritional oil can be extracted. Alternative use of the two fractions not only could cut disposal costs but also allow one to extract bioactive compounds and an oil with a high nutritional value. This review focused on the recent advance in extraction of lycopene, whose beneficial effects on health are widely recognized.


Assuntos
Antioxidantes/isolamento & purificação , Manipulação de Alimentos/métodos , Licopeno/isolamento & purificação , Lycopersicon esculentum , Lycopersicon esculentum/química , Lycopersicon esculentum/metabolismo
10.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445707

RESUMO

The gram-negative bacterial genus Liberibacter includes economically important pathogens, such as 'Candidatus Liberibacter asiaticus' that cause citrus greening disease (or Huanglongbing, HLB) and 'Ca. Liberibacter solanacearum' (Lso) that cause zebra chip disease in potato. Liberibacter pathogens are fastidious bacteria transmitted by psyllids. Pathogen manipulation of the host' and vector's immune system for successful colonization is hypothesized to be achieved by Sec translocon-dependent effectors (SDE). In previous work, we identified hypothetical protein effector 1 (HPE1), an SDE from Lso, that acts as a suppressor of the plant's effector-triggered immunity (ETI)-like response. In this study, using a yeast two-hybrid system, we identify binding interactions between tomato RAD23 proteins and HPE1. We further show that HPE1 interacts with RAD23 in both nuclear and cytoplasmic compartments in planta. Immunoblot assays show that HPE1 is not ubiquitinated in the plant cell, but rather the expression of HPE1 induced the accumulation of other ubiquitinated proteins. A similar accumulation of ubiquitinated proteins is also observed in Lso infected tomato plants. Finally, earlier colonization and symptom development following Lso haplotype B infection are observed in HPE1 overexpressing plants compared to wild-type plants. Overall, our results suggest that HPE1 plays a role in virulence in Lso pathogenesis, possibly by perturbing the ubiquitin-proteasome system via direct interaction with the ubiquitin-like domain of RAD23 proteins.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Liberibacter/metabolismo , Lycopersicon esculentum/metabolismo , DNA Bacteriano , Liberibacter/enzimologia , Liberibacter/patogenicidade , Análise de Sequência com Séries de Oligonucleotídeos , Doenças das Plantas/microbiologia , Rhizobiaceae/fisiologia , Canais de Translocação SEC/metabolismo , Solanum tuberosum/microbiologia , Proteínas Ubiquitinadas
11.
Environ Pollut ; 289: 117912, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34365243

RESUMO

The innovative and sustainable technologies are highly needed to decrease serious environmental problems from current agriculture. Herein, the green and biosafe copper-based nano-agriculture was described for tomato production. Prepared Cu nanoclusters (NCs) showed small size (3.0 ± 0.5 nm) and high bioavailability. At low concentration (1 mg kg-1) in soil, Cu NCs improved the activities of antioxidant enzymes (superoxide dismutase, catalase and peroxidase) in the tomato plants, which could help to slow down leaf aging, increase photosynthesis and carbohydrates content by 19.4 % and 14.9 %, respectively. Cu NCs promoted the roots' growth, especially increasing the root tip' number, which might contribute to the increase in absorption of macronutrients (K, Mg and P) and micronutrients (B, Mn, Cu and Zn). The Cu NCs (1 mg kg-1) promoted tomato growth and increased the tomato fruit yields by 12.2 % compared to the control. Moreover, the tomato fruit qualities had been improved meanwhile the accumulation of Cu in fruits was not observed. These findings indicate that the Cu NCs have potential to be safely applied for tomato production.


Assuntos
Lycopersicon esculentum , Catalase/metabolismo , Cobre , Lycopersicon esculentum/metabolismo , Fotossíntese , Raízes de Plantas/metabolismo
12.
Plant Physiol Biochem ; 167: 91-100, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34340026

RESUMO

The relationship between photosynthesis, pigment accumulation, and the expression of key light-regulated genes in Solanum lycopersicum hp-1, hp-2 and hp-1.2 photomorphogenetic mutants under conditions of high-intensity light (2000 µm (photons) m-2s-1) was studied. The hp-2 mutant (LA3006) and the hp-1 mutants (LA4012 and LA3538) are deficient in DET1 (De-etiolated 1 and DDB1 (DNA DAMAGE-BINDING PROTEIN 1), respectively, which are components of the CDD complex (COP10, DDB1, DET1). HP mutants are superproducers of various pigments and are sensitive to light. We have shown that HIL (high-intensity light) causes a decrease in PSII activity after 24 and 72 h of irradiation, which was partially restored after 72 h in the WT. The photosynthetic rate noticeably decreased only in LA4012 and LA3538 after 24 h of irradiation. After 72 h, the photosynthetic rate decreased in all mutants, with the exception of hp-1.2 LA0279, but the decrease was most noticeable in LA4012, yet significant changes in the respiration rate were absent. The LA0279 mutant was more capable of accumulating anthocyanin in the cells of the subepidermal parenchyma and chlorenchyma, as well as in the cells at the base of large multicellular glandular trichomes and in the mesophyll. Another important difference was the accumulation of increased amounts of antheraxanthin and phenolic compounds in the leaves of LA0279 after 72 h of HIL irradiation. Unlike LA4012, LA3006, LA0279, and LA3538 sowed a significant increase in the expression levels of CHS, HY5, and FLS genes after 24 h, which may be one of the reasons for the higher adaptive potential of those three mutants. In addition to that in LA3538, strong light-induced stress led to an increased level of flavonol synthase (FLS) expression in the LA3006, LA0279, and LA4012 mutants. We hypothesize that the photosynthetic apparatus (PA) of the LA0279 mutant, which is deficient in the DET1 and DDB1 genes, is most adapted to prolonged HIL. Most likely, the resistance of PA mutants to HIL is due to a variety of factors, which, in addition to the redistribution of carotenoids, may include morphological features associated with the accumulation of anthocyanin in the epidermis, subepidermal layer, mesophyll and trichomes of leaves and with an increase in leaf thickness.


Assuntos
Lycopersicon esculentum , Carotenoides/metabolismo , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Fotossíntese/genética , Pigmentação , Folhas de Planta/metabolismo
13.
Plant Physiol Biochem ; 167: 309-320, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34392044

RESUMO

Photosynthesis is a fundamental biosynthetic process in plants that can enhance carbon absorption and increase crop productivity. Heat stress severely inhibits photosynthetic efficiency. Melatonin is a bio-stimulator capable of regulating diverse abiotic stress tolerances. However, the underlying mechanisms of melatonin-mediated photosynthesis in plants exposed to heat stress largely remain elucidated. Our results revealed that melatonin treatment (100 µM) in tomato seedlings increased the endogenous melatonin levels and photosynthetic pigment content along with upregulated of their biosynthesis gene expression under high-temperature stress (42 °C for 24 h), whereas heat stress significantly decreased the values of gas exchange parameters. Under heat stress, melatonin boosted CO2 assimilation, i.e., Vc,max (maximum rate of ribulose-1,5-bisphosphate carboxylase, Rubisco), and Jmax (electron transport of Rubisco generation) and also enhanced the Rubisco and FBPase activities, which resulted in upregulated photosynthetic related gene expression. In addition, heat stress greatly reduced the photochemical chemistry of photosystem II (PSII) and photosystem I (PSI), particularly the maximum quantum efficiency of PSII (Fv/Fm) and PSI (Pm). Conversely, melatonin supplementation increased the chlorophyll a fluorescence parameters led to amplifying the electron transport efficiency. Moreover, heat stress decreased the actual PSII efficiency (ΦPSII), electron transport rate (ETR) and photochemical quenching coefficient (qP), while increasing nonphotochemical quenching (NPQ); however, melatonin reversed these values, which helps to fostering the dissipation of excess excitation energy. Taken together, our results provide a concrete insight into the efficacy of melatonin-mediated photosynthesis performance in a high-temperature regime.


Assuntos
Lycopersicon esculentum , Melatonina , Clorofila , Clorofila A , Lycopersicon esculentum/metabolismo , Fotossíntese , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/metabolismo , Plântula/metabolismo , Temperatura
14.
Plant Physiol Biochem ; 167: 337-348, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34392046

RESUMO

Plants do not always have the genetic capacity to tolerate high levels of arsenic (As), which may not only arrest their growth but pose potential health risks through dietary bioaccumulation. Meanwhile, the interplay between the tomato plants and As-NO-driven molecular cell dynamics is obscure. Accordingly, seedlings were treated with As (10 mg/L) alone or in combination with 100 µM sodium nitroprusside (SNP, NO donor) and 200 µM 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO, NO scavenger). Sodium nitroprusside immobilized As in the roots and reduced the shoot translocation by up-regulating the transcriptional expression of the PCS, GSH1, MT2, and ABC1. SNP further restored the growth retardation through modulating the chlorophyll and proline metabolism, increasing NO accumulation and stomatal conductance along with clear crosstalk between the antioxidant activity as well as glyoxalase I and II leading to endogenous H2O2 and MG reduction. Higher PCs and glutathione accumulation helped protect photosynthetic apparatus; however, cPTIO reversed the protective effects of SNP, confirming the role of NO in the As toxicity alleviation.


Assuntos
Arsênio , Lycopersicon esculentum , Antioxidantes , Arsênio/toxicidade , Peróxido de Hidrogênio , Lycopersicon esculentum/metabolismo , Óxido Nítrico , Nitroprussiato/farmacologia , Oxirredução , Estresse Oxidativo , Fitoquelatinas/metabolismo
15.
J Sci Food Agric ; 101(14): 6134-6142, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34402534

RESUMO

BACKGROUND: Fresh-cut vegetables are subjected to multiple stressing agents including: (i) slicing, which induces cellular decompartmentalization; (ii) low refrigeration temperatures, responsible for chilling injury in the most sensitive products (e.g. tomatoes), and (iii) storage time because tissue senescence and aging can occur and reduce the shelf-life. In tomato slices, one of the most important issues is the membrane, which is responsible for several disorders related to the alteration of physiological processes, including ethylene biosynthesis. RESULTS: Electrolyte leakage and the content of thiobarbituric acid reactive substances in sliced tomatoes increased over time at two storage temperatures (4 °C and 15 °C) compared with intact fruit for the commercial variety (cultivar) Jama used as reference. However, in the tomato Italian landrace Canestrino, electrolyte leakage in sliced fruits increased after 120 h of storage compared to intact tomatoes, while the thiobarbituric acid reactive substance content increased rapidly over time at both storage temperatures. In the packages, higher ethylene content and carbon dioxide concentrations were detected in sliced tomatoes compared with intact fruits for both genotypes. In the most sensitive genotype for slicing (Jama), phospholipase C activity increased in tomato slices after 24 h of storage, but phospholipase D reached a higher value only at 168 h after processing at 4 °C of storage. CONCLUSIONS: The results evidence that the main damage in slices of full ripe tomatoes is more related to cutting, rather than chilling injury due to storage temperatures, with differences related to the genotype. Slicing enhanced membrane catabolism, ethylene production, and enzyme activity of phospholipases with a significant genotype effect. © 2021 Society of Chemical Industry.


Assuntos
Membrana Celular/química , Manipulação de Alimentos/métodos , Lycopersicon esculentum/química , Membrana Celular/genética , Membrana Celular/metabolismo , Etilenos/metabolismo , Armazenamento de Alimentos , Frutas/química , Frutas/genética , Frutas/metabolismo , Genótipo , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Temperatura
16.
Int J Mol Sci ; 22(14)2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34299293

RESUMO

Brassinosteroids (BRs) are growth-promoting phytohormones that can efficiently function by exogenous application at micromolar concentrations or by endogenous fine-tuning of BR-related gene expression, thus, precisely controlling BR signal strength is a key factor in exploring the agricultural potential of BRs. BRASSINOSTEROID INSENSITIVE1 (BRI1), a BR receptor, is the rate-limiting enzyme in BR signal transduction, and the phosphorylation of each phosphorylation site of SlBRI1 has a distinct effect on BR signal strength and botanic characteristics. We recently demonstrated that modifying the phosphorylation sites of tomato SlBRI1 could improve the agronomic traits of tomato to different extents; however, the associated agronomic potential of SlBRI1 phosphorylation sites in tomato has not been fully exploited. In this research, the biological functions of the phosphorylation site threonine-825 (Thr-825) of SlBRI1 in tomato were investigated. Phenotypic analysis showed that, compared with a tomato line harboring SlBRI1, transgenic tomato lines expressing SlBRI1 with a nonphosphorylated Thr-825 (T825A) exhibited a larger plant size due to a larger cell size and higher yield, including a greater plant height, thicker stems, longer internodal lengths, greater plant expansion, a heavier fruit weight, and larger fruits. Molecular analyses further indicated that the autophosphorylation level of SlBRI1, BR signaling, and gibberellic acid (GA) signaling were elevated when SlBRI1 was dephosphorylated at Thr-825. Taken together, the results demonstrated that dephosphorylation of Thr-825 can enhance the functions of SlBRI1 in BR signaling, which subsequently activates and cooperates with GA signaling to stimulate cell elongation and then leads to larger plants and higher yields per plant. These results also highlight the agricultural potential of SlBRI1 phosphorylation sites for breeding high-yielding tomato varieties through precise control of BR signaling.


Assuntos
Brassinosteroides/metabolismo , Lycopersicon esculentum/genética , Proteínas Serina-Treonina Quinases/genética , Tamanho Celular , Frutas/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Fosforilação , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/genética , Treonina/metabolismo
17.
Plant Biol (Stuttg) ; 23(5): 797-805, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34263973

RESUMO

Melatonin (Mel) and hydrogen sulphide (H2 S) have emerged as potential regulators of plant metabolism during abiotic stress. Presence of excess NaCl in the soil is one of the main causes of reduced crop productivity worldwide. The present investigation examines the role of exogenous Mel and endogenous H2 S in tomato seedlings grown under NaCl stress. Effect of 30 µm Mel on endogenous synthesis of H2 S was examined in roots of NaCl-stressed (200 mm) tomato seedlings. Also, the impact of treatments on the oxidative stress markers, transport of K+ and Na+ , and activity of H+ -ATPase and antioxidant enzymes was assessed. Results show that NaCl-stressed seedlings supplemented with 30 µm Mel had increased levels of endogenous H2 S through enhanced L-cysteine desulfhydrase activity. Mel in association with H2 S overcame the deleterious effect of NaCl and induced retention of K+ that maintained a higher K+ /Na+ ratio. Use of plasma membrane inhibitors and an H2 S scavenger revealed that Mel-induced regulation of K+ /Na+ homeostasis in NaCl-stressed seedling roots operates through endogenous H2 S signalling. Synergistic effects of Mel and H2 S also reduced the generation of ROS and oxidative destruction through the enhanced activity of antioxidant enzymes. Thus, it is suggested that the protective function of Mel against NaCl stress operates through an endogenous H2 S-dependent pathway, wherein H+ -ATPase-energized secondary active transport regulates K+ /Na+ homeostasis.


Assuntos
Sulfeto de Hidrogênio , Lycopersicon esculentum , Melatonina , Antioxidantes , Lycopersicon esculentum/metabolismo , Melatonina/farmacologia , Raízes de Plantas/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Plântula/metabolismo , Cloreto de Sódio/farmacologia
18.
J Plant Physiol ; 263: 153461, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34217837

RESUMO

Plant defence responses can be triggered by the application of elicitors for example chitosan (ß-1,4-linked glucosamine; CHT). It is well-known that CHT induces rapid, local production of reactive oxygen species (ROS) and nitric oxide (NO) resulting in fast stomatal closure. Systemic defence responses are based primarily on phytohormones such as ethylene (ET) and salicylic acid (SA), moreover on the expression of hormone-mediated defence genes and proteins. At the same time, these responses can be dependent also on external factors, such as light but its role was less-investigated. Based on our result in intact tomato plants (Solanum lycopersicum L.), CHT treatment not only induced significant ET emission and stomatal closure locally but also promoted significant production of superoxide which was also detectable in the distal, systemic leaves. However, these changes in ET and superoxide accumulation were detected only in wild type (WT) plants kept in light and were inhibited under darkness as well as in ET receptor Never ripe (Nr) mutants suggesting pivotal importance of ET and light in inducing resistance both locally and systemically upon CHT. Interestingly, CHT-induced NO production was mostly independent of ET or light. At the same time, expression of Pathogenesis-related 3 (PR3) was increased locally in both genotypes in the light and in WT leaves under darkness. This was also observed in distal leaves of WT plants. The CHT-induced endoplasmic reticulum (ER) stress, as well as unfolded protein response (UPR) were examined for the first time, via analysis of the lumenal binding protein (BiP). Whereas local expression of BiP was not dependent on the availability of light or ET, systemically it was mediated by ET.


Assuntos
Quitosana/metabolismo , Escuridão , Etilenos/metabolismo , Lycopersicon esculentum/metabolismo , Imunidade Vegetal/genética , Imunidade Vegetal/fisiologia , Estômatos de Plantas/metabolismo , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Variação Genética , Genótipo , Lycopersicon esculentum/genética , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo
19.
J Plant Physiol ; 263: 153460, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34217838

RESUMO

Ethylene is a gaseous hormone with a well-established role in the regulation of plant growth and development. However, its role in the modulation of carbon assimilation and central metabolism remains unclear. Here, we investigated the morphophysiological and biochemical responses of tomato plants (Solanum lycopersicum) following the application of ethylene in the form of ethephon (CEPA - 2-chloroethylphosphonic acid), forcing the classical triple response phenotype. CEPA-treated plants were characterized by growth inhibition, as revealed by significant reductions in both shoot and root dry weights, coupled with a reduced number of leaves and lower specific leaf area. Growth inhibition was associated with a reduction in carbon assimilation due to both lower photosynthesis rates and stomatal conductance, coupled with impairments in carbohydrate turnover. Furthermore, exogenous ethylene led to the accumulation of cell wall compounds (i.e., cellulose and lignin) and phenolics, indicating that exposure to exogenous ethylene also led to changes in specialized metabolism. Collectively, our findings demonstrate that exogenous ethylene disrupts plant growth and leaf structure by affecting both central and specialized metabolism, especially that involved in carbohydrate turnover and cell wall biosynthesis, ultimately leading to metabolic responses that mimic stress situations.


Assuntos
Etilenos/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Fotossíntese/fisiologia , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Parede Celular/química , Parede Celular/metabolismo , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
20.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201240

RESUMO

Infectious viroid clones consist of dimeric cDNAs used to generate transcripts which mimic the longer-than-unit replication intermediates. These transcripts can be either generated in vitro or produced in vivo by agro-inoculation. We have designed a new plasmid, which allows both inoculation methods, and we have compared them by infecting Solanum lycopersicum and Solanum melongena with clones of Citrus exocortis virod (CEVd), Tomato chlorotic dwarf viroid (TCDVd), and Potato spindle tuber viroid (PSTVd). Our results showed more uniform and severe symptoms in agro-inoculated plants. Viroid accumulation and the proportion of circular and linear forms were different depending on the host and the inoculation method and did not correlate with the symptoms, which correlated with an increase in PR1 induction, accumulation of the defensive signal molecules salicylic (SA) and gentisic (GA) acids, and ribosomal stress in tomato plants. The alteration in ribosome biogenesis was evidenced by both the upregulation of the tomato ribosomal stress marker SlNAC082 and the impairment in 18S rRNA processing, pointing out ribosomal stress as a novel signature of the pathogenesis of nuclear-replicating viroids. In conclusion, this updated binary vector has turned out to be an efficient and reproducible method that will facilitate the studies of viroid-host interactions.


Assuntos
Lycopersicon esculentum/virologia , Doenças das Plantas/virologia , Plasmídeos/administração & dosagem , RNA Viral/genética , Ribossomos/metabolismo , Viroides/classificação , Viroides/isolamento & purificação , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Doenças das Plantas/genética , Plasmídeos/genética , Ribossomos/genética , Viroides/patogenicidade
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