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1.
Environ Monit Assess ; 194(2): 86, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35018533

RESUMO

This study aimed to investigate the acute and chronic hazard quotients of chlorpyrifos and diazinon for tomatoes in preharvest and postharvest conditions, and to evaluate the relationship between the main variables, including temperature and contact time and pesticide dissipation at different conditions using response surface methodology for the first time. The qualification analyses were conducted by a gas chromatography-tandem mass spectrometry. The Monte Carlo simulation technique was utilized to evaluate the variability and uncertainty and achieve more accurate results in the health risk assessment process. A quadratic model and the second-order polynomial analysis were employed to investigate the mutual effect of time and temperature on removing diazinon and chlorpyrifos. Based on findings, the chronic hazard quotient values of chlorpyrifos and diazinon residues ranged from 0.43 - 1.33 to 0.13 - 2.27 for boiling, 0.65 - 1.49 to 3.05 - 7.15 for room condition, and 0.63 - 1.92 to 3.28 - 7.47 for refrigerator condition, respectively. According to the Monte Carlo simulation, the hazard quotient and estimated daily intake values were more affected by the consumption rate, pesticide concentration, and body weight. The results of response surface methodology showed that the effect of temperature variations on the dissipation of both pesticides was more than that of contact time variations.


Assuntos
Clorpirifos , Lycopersicon esculentum , Resíduos de Praguicidas , Clorpirifos/análise , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Resíduos de Praguicidas/análise
2.
Braz J Biol ; 82: e255753, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35019067

RESUMO

The leaf miner, Tuta absoluta is continue to be a serious threat to solanaceous plants, especially tomato plant worldwide. Tomato crop in Saudi Arabia has been recently affected by T. absoluta, which is difficult to control due to its unique biological features, such as high fecundity and its potential to develop resistance to chemical pesticides. In this article, the suitability and effectiveness of the predatory mite, Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae), an indigenous species usually found in tomato greenhouses of northcentral Saudi Arabia, has been evaluated on eggs and 1st instar larvae of T. absoluta in the laboratory. All experiments were conducted in an incubator at three constant temperatures of 22, 27 and 32°C ± 1°C, 50 ± 4% R.H. and L12:D12 h photoperiod. Adult females and males of N. cucumeris were able to feed and sustain oviposition on eggs and 1st instar larvae of T. absoluta, and could be an effective biocontrol agent against T. absoluta. The N. cucumeris had a clear preference for eggs compared to 1st instar larvae of T. absoluta. The results showed the obvious effect of the temperature on the consumption rate of the predatory mite. The maximum daily consumption rate occurred during the oviposition period, when the females of the predatory mite consumed an average of 4.26 eggs and 2.44 1st instar larvae of T. absoluta. In general, total fecundity was high with T. absoluta eggs as a food source when temperature increased from 22 to 32°C. The highest fecundity rate (42.92 and 20.97 eggs /female) was recorded at 32°C, while the lowest one (26.77 and 10.12 eggs / female) was recorded at 22°C, when N. cucumeris female fed on eggs and 1st instar larvae of T. absoluta, respectively. The results of this study indicated that the predatory mite, N. cucumeris can be considered a promising potential candidate for controlling the leaf miner T. absoluta, and further research is required to assess its effectiveness under greenhouse conditions.


Assuntos
Lepidópteros , Lycopersicon esculentum , Ácaros , Animais , Feminino , Larva , Masculino , Oviposição , Controle Biológico de Vetores , Comportamento Predatório
3.
Trop Anim Health Prod ; 54(1): 37, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34997366

RESUMO

This study investigated the ameliorative effect of dietary tomato powder (TP) on performance and blood characteristics of broilers under heat stress condition. A total of 240 (21 days old), unsexed Marshall broiler chicks were allotted to four dietary treatments having 6 replicates of 10 birds each in a completely randomized design (CRD). The birds were exposed to ambient temperature of 33 °C between 8:00am and 5:00 pm and relative humidity of 81.5% for 2 h per day, throughout the 21-day feeding trial. Data was analyzed using one-way analysis of variance and polynomial contrast (linear (L) and quadratic (Q)) applied using IBM SPSS version 20. The experimental diets 1 (control), 2, 3, and 4 contained 0%, 2.5%, 5%, and 7.5% TP, respectively. Results showed that live weight, weight gain, feed intake, and feed conversion ratio increased (L.Q: P < 0.05) while mortality rate reduced (P < 0.05) following increasing dietary inclusion of TP. Birds fed diets containing 0, 2.5, and 5.0% TP had similar feed cost per weight gain which was lower (L: P < 0.001: Q: P < 0.05) than those of birds fed diet containing 7.5% TP. Most hematological parameters and serum enzymes measured were not affected (P > 0.05) by inclusion of TP. Birds fed diets containing 5.0 and 7.5% TP had similar serum cholesterol (L.Q: P < 0.05) and triglyceride (L:P < 0.001:.Q:P < 0.05) concentration which is lower than those of control. It was concluded that tomato powder (especially at 5% inclusion) in the diet of heat-stressed broiler chickens is beneficial for improved growth, health, and production cost with no adverse effect.


Assuntos
Galinhas , Lycopersicon esculentum , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais , Resposta ao Choque Térmico , Pós
4.
BMC Plant Biol ; 22(1): 13, 2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-34979927

RESUMO

BACKGROUND: Leaves, which are the most important organs of plants, can not only fix carbon sources through photosynthesis, but also absorb nutrients through transpiration. Leaf development directly determines the growth, flowering and fruiting of plants. There are many factors that affect leaf development, such as the growth environment, gene expression, and hormone synthesis. In this study, tomatoes were used to study the role of the transcription factor Solanum lycopersicum salt-related MYB1-like (SlSRM1-like) in the development of tomato leaves. RESULTS: Loss-of-function of the SlSRM1-like gene mediated by clustered, regularly interspaced, short palindromic repeat (CRISPR)/CRISPR-associated 9 (Cas9) resulted in abnormal tomato leaf morphology, including thinner leaves, wrinkled edges, raised veins, disordered edge veins, and left and right asymmetry. An analysis of the transcription levels of genes related to leaf development revealed that the expression of these genes was significantly altered in the SlSRM1-like mutants (SlSRM1-like-Ms). Moreover, the SlSRM1-like gene was expressed at higher transcription levels in young tissues than in old tissues, and its expression was also induced in response to auxin. In addition, the transcription levels of genes related to the auxin pathway, which regulates tomato growth and development, were severely affected in the SlSRM1-like-Ms. Therefore, it is hypothesized that the SlSRM1-like gene functions in the regulation of tomato leaf development through the auxin-related pathway. CONCLUSIONS: In this study, we successfully knocked out the SlSRM1-like gene in the tomato variety Ailsa Craig using CRISPR technology and found that knockout of the SlSRM1-like gene resulted in abnormal development of tomato leaves. Further research indicated that SlSRM1-like regulated tomato leaf development through auxin-related pathways. The results provide an important reference for the functional study of other SRM1-like genes in plants and provide new insights into the regulation of leaf development in tomato and other plants.


Assuntos
Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Sistemas CRISPR-Cas , Lycopersicon esculentum , Mutagênese , Folhas de Planta/genética , Proteínas de Plantas/metabolismo
5.
Planta ; 255(2): 31, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34982240

RESUMO

MAIN CONCLUSION: Cultivar-biased regulation of HSFB4a and HSFA7 mediates heat stress tolerance/sensitivity in tomato. Reduced HSFB4a repressor levels and enhanced HSFA7 activator levels govern thermo-tolerance in tolerant cultivars. Heat shock factors (HSFs) are at the core of heat stress (HS) response in plants. However, the contribution of HSFs governing the inherent thermo-tolerance mechanism in tomato from sub-tropical hot climates is poorly understood. With the above aim, comparative expression profiles of the HSF family in a HS-tolerant (CLN1621L) and -sensitive cultivars (CA4 and Pusa Ruby) of tomato under HS revealed cultivar-biased regulation of an activator (HSFA7) and a repressor (HSFB4a) class HSF. HSFA7 exhibited strong upregulation while HSFB4a showed downregulation in tolerant tomato cultivar upon HS. Functional characterization of HSFA7 and HSFB4a in a tolerant-sensitive cultivar pair by virus-induced gene silencing (VIGS)-based silencing and transient overexpression established them as a positive and a negative regulator of HS tolerance, respectively. Promoter:GUS reporter assays and promoter sequence analyses suggest heat-mediated transcriptional control of both the HSF genes in the contrasting cultivars. Moreover, degradome data highlighted HSFB4a is a probable target of microRNA Sly-miR4200. Transient in-planta Sly-MIR4200-effector:HSFB4a-reporter assays showed miRNA-dependent target down-regulation. Chelation of miRNA by short-tandem-target-mimic of Sly-miR4200 increased target abundance, highlighting a link between Sly-miR4200 and HSFB4a. This miRNA has induced several folds upon HS in the tolerant cultivar where HSFB4a levels are reduced, thus exhibiting the inverse miR:target expression. Thus, we speculate that the alleviation of HSFB4a and increased HSFA7 levels govern thermo-tolerance in the tolerant cultivar by regulating downstream heat stress-responsive genes.


Assuntos
Resposta ao Choque Térmico , Lycopersicon esculentum , Proteínas de Plantas , Termotolerância , Fatores de Transcrição , Regulação da Expressão Gênica de Plantas , Temperatura Alta , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
6.
Arch Microbiol ; 204(1): 116, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34985603

RESUMO

This study investigated the effect of foliar application of extract and culture of Nostoc calcicola and Nostoc linckia on the Fusarium oxysporum f. sp. lycopersici (FOL) that infects tomatoes (Solanum lycopersicum) plant in vitro and in vivo. Cyanobacterial isolates were isolated from saline soils at El-Hamoul and Seidy Salem locations Kafr Elsheikh, Egypt, and identified to be N. calcicola and N. linckia Bioactive compounds of extract were analyzed by Gas chromatography-mass spectrometry (GC-MS). Dry weight, carotene, chlorophyll content, and total phenolic compounds of isolates were measured. Plant height, dry weight, fruit number, and fruit weight of tomatoes were estimated. GC/MS analysis showed 49 and 35 bioactive compounds in extracts of N. calcicola and N. linckia, respectively. N. calcicola possesses the highest values of chlorophyll a, carotenoid, and total phenol contents in dry weight compared with N. linckia. After 100 days of tomato growth, the results showed the highest yield of tomato fruits with the application of N. calcicola and N. linckia compared with the untreated plants and the plants which were infected with Fusarium, suggesting that N. calcicola and N. linckia can serve as a new bioagent for biological control of the soil fungus Fusarium oxysporum f. sp. lycopersici (FOL).


Assuntos
Fusarium , Lycopersicon esculentum , Nostoc , Clorofila A , Doenças das Plantas
7.
J Sci Food Agric ; 102(2): 531-539, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34143503

RESUMO

BACKGROUND: Chilling injury (CI) is a physiological disorder that results in a limitation for cold storage (CS) of many fruits and vegetables. The low temperature-induced changes in the properties and composition of cell membranes are involved in the response to chilling temperature and in the mechanism of CI and tolerance. RESULTS: We compared the changes in the lipid composition by gas chromatography-mass spectrometry before, immediately after CS, as well as during a 3-day subsequent period, of tomato fruits with different chilling-sensitivity: Micro-Tom (tolerant) and Minitomato (susceptible). The changes in linolenic acid content, double bond index and digalactosyldiacylglycerol/monogalactosyldiacylglycerol ratio (DGDG/MGDG) showed membrane fluidity adjustment, depending on the temperature. By a database search, we identified 18 membrane-bound fatty acid desaturase (FAD) genes and five DGDG synthases (DGD) genes that phylogenetically clustered into four and two subfamilies, respectively. The FAD and DGD genes were differentially expressed in response to CS, as determined by quantitative reverse transcriptase-polymerase chain reaction analysis. CONCLUSION: The data strongly suggest that reversion of CS-induced changes during the recovery period is important for the proper function of the membrane and tolerance to postharvest CI in tomato fruit. © 2021 Society of Chemical Industry.


Assuntos
Frutas/química , Galactolipídeos/química , Lycopersicon esculentum/química , Temperatura Baixa , Manipulação de Alimentos , Armazenamento de Alimentos , Cromatografia Gasosa-Espectrometria de Massas
8.
Food Microbiol ; 102: 103925, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809951

RESUMO

Antibacterial activity against Escherichia coli O157:H7 and Staphylococcus aureus of five typical plant-derived compounds [gallic acid (G.A), citral (Cit), thymol (Thy), salicylic acid (S.A), lauric acid (L.A)] were investigated by determining the minimum inhibitory concentration (MIC) and the fractional inhibitory concentration index (FICI). The results showed that only a combination of Thy and G.A (TGA), with a concentration of 0.1 and 1.25 mg/mL, respectively, had a synergistic effect (FICI = 0.5) on both E. coli O157:H7 and S. aureus. The amount of Thy and G.A in mixture were four-fold lower than the MICs of the individuals shown to cause the equivalent antimicrobial activity in trypticase soy broth (TSB). The microbial reduction obtained in TSB with addition of TGA were significantly higher (P < 0.05) than the reduction shown for the broth supplemented with the separated phenolics. TGA caused the changes of morphology and membrane integrity of bacteria. Additionally, the application of TGA on fresh-cut tomatoes are investigated. Fresh-cut tomatoes inoculated with E. coli O157:H7and S. aureus were washed for 2min, 5min, 10min at 4 °C, 25 °C, 40 °C in 0.3% NaOCl, or water containing TGA at various concentrations. Overall, the reduction of TGA achieved against S. aureus is higher than E. coli O157:H7. Same concentrations of combined antimicrobials at a temperature of 40 °C further increased the degree of microbial inactivation, with an additional 0.89-1.51 log CFU/g reduction compared to that at 25 °C. Moreover, 1/2MICThy+1/2MICG.A at 25 °C for 10min or 40 °C for 5min were generally acceptable with sensorial scores higher than 7. Our results showed that TGA could work synergistically on the inactivation of the tested bacteria and may be used as an alternative disinfectant of fresh produce.


Assuntos
Anti-Infecciosos , Escherichia coli O157 , Ácido Gálico , Lycopersicon esculentum , Staphylococcus aureus , Timol , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Escherichia coli O157/efeitos dos fármacos , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Ácido Gálico/farmacologia , Lycopersicon esculentum/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Timol/farmacologia
9.
Food Chem ; 371: 131161, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34583171

RESUMO

High hydrostatic pressure (HHP) processing has become a commercial success in fruit and vegetable processing. Herein, the effects of HHP and high-temperature short-time (HTST) processing on metabolic profiling in tomato juice was evaluated by UPLC-MS/MS, HPLC, and GC-MS; a total of 425 metabolites, 14 carotenoids, and 56 volatile compounds were identified in tomato juice. HHP processing affects the composition of the juice less than HTST processing, considering 4 and 33 differential metabolites discriminated after HHP and HTST processing, respectively. The total lycopene and carotenoid contents in tomato juice increased after HHP processing, while the ß-carotene and lycopene contents decreased after HTST processing. Further, more volatile compounds and higher contents of aldehydes that contribute to green aroma and lower contents of alcohols were observed after HHP and HTST processing, respectively. These findings provide a comprehensive understanding of the advantages of HHP processing on metabolite profiles in tomato juice.


Assuntos
Lycopersicon esculentum , Compostos Orgânicos Voláteis , Cromatografia Líquida , Frutas , Pressão Hidrostática , Espectrometria de Massas em Tandem , Temperatura
10.
Food Chem ; 371: 131162, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34600368

RESUMO

The effects of combined treatment (PAL-U) of plasma-activated liquid (PAL) including plasma-activated water (PAW) and plasma-activated buffer solution (PABS) and ultrasound (U) for the degradation of chlorothalonil fungicide on tomato fruit was investigated. Distilled water and buffer solution were activated by radiofrequency plasma jet for durations of 1, 3, 5, and 10 min to obtain PAL1 to PAL10. Fruits were immersed in PAL for 15 min and also in distilled water with sonication for 15 min for individual treatments, and in PAL with sonication for 15 min for combined treatments. The maximum chlorothalonil fungicide residues were reduced by 89.28 and 80.23% for PAW10-U and PABS10-U, respectively. HPLC-MS characterization revealed chlorothalonil degradation pathway and formation of 2,4,5-trichloroisophthalonitrile, 2,4-dichloroisophthalonitrile, 4-chloroisophthalonitrile, isophthalonitrile and phenylacetonitrile as degradation products. Treatments also showed no negative effects on tomato quality. Therefore, PAL and PAL-U treatments could serve as effective methods for degrading pesticides on tomatoes.


Assuntos
Fungicidas Industriais , Lycopersicon esculentum , Resíduos de Praguicidas , Fungicidas Industriais/análise , Nitrilas/análise , Resíduos de Praguicidas/análise
11.
Methods Mol Biol ; 2316: 23-28, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34845681

RESUMO

The characterization of the elusive disease agent of the potato spindle tuber disease, potato spindle tuber viroid (PSTVd), was aided by the ability to obtain large amounts of infected tomato tissue in a simple bioassay where PSTVd was easily mechanically transmissible to an alternate herbaceous host in which it thrived and produced dramatic symptoms in a relatively short period (Diener, Viroids. Handbook of plant virus infections: comparative diagnosis. Elsevier/North-Holland, Amsterdam, pp 913-934, 1981; Diener, Virology 45:411-428, 1971; Raymer and O'Brien, Am Pot J, 39:401-408, 1962). Reactions in the primary, or secondary, herbaceous indicator host can range from asymptomatic to severe depending upon the viroid strain, host species, and environmental conditions and can provide evidence of a viroid infection, but do not permit identification of the viroid in question. Further characterization by molecular hybridization, RT-PCR, and sequence analysis is used to determine the etiology of the disease agent. In this chapter, methods are described for mechanical inoculation of viroids to herbaceous hosts to determine the viroid nature of diseases and the experimental host range of the viroid or to shorten the time required for obtaining relatively large amounts of viroid for subsequent purification and characterization.


Assuntos
Vírus de Plantas , Viroides , Bioensaio , Lycopersicon esculentum , Doenças das Plantas , Vírus de Plantas/genética , Plantas/virologia , RNA Viral/genética , Solanum tuberosum , Viroides/genética
12.
Methods Mol Biol ; 2316: 89-96, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34845688

RESUMO

A simplified dot-blot hybridization protocol for Potato spindle tuber viroid (PSTVd) detection in Solanaceae species is described here. The protocol uses an RNA DIG-labeled probe and a simplified extraction procedure that avoids the use of hazardous chemicals. PSTVd was detected in composite tomato leaf samples in a ratio of up to 1:15 of PSTVd-infected to non-infected tissue and in composite potato tuber samples in a ratio up to 1:5 of PSTVd-infected to non-infected tissue. In Brugmansia spp., PSTVd was detected solely in the standard sample extract preparation. The method is suitable for a reliable, large-scale sample screening especially where cost is a limiting factor.


Assuntos
Solanum tuberosum , Viroides , Lycopersicon esculentum , Hibridização de Ácido Nucleico , Doenças das Plantas , Sondas RNA , RNA Viral/genética , Viroides/genética
13.
Plant Physiol Biochem ; 170: 316-324, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34954566

RESUMO

Essential macronutrient potassium (K) and environmental signal light regulate a number of vital plant biological processes related to growth, development, and stress response. Recent research has shown connections between the perception of light and the regulation of K in plants. Photoreceptors-mediated wavelength-specific light perception activates signaling cascades which mediate stomatal movement by altering K+influx/efflux via K+ channels in the guard cells. The quality, intensity, and duration of light affect the regulation of K nutrition and crop quality. Blue/red illumination or red combined blue light treatment increases the expression levels of K transporter genes, K uptake and accumulation, leading to increased lycopene synthesis and improved fruit color in tomato. Despite the commonalities of light and K in multiple functions, our understanding of light regulation of K and associated physiological and molecular processes is fragmentary. In this review, we take a look at the light-controlled K uptake and utilization in plants and propose working models to show potential mechanisms. We discuss major light signaling components, their possible involvement in K nutrition, stomatal movement and crop quality by linking the perception of light signal and subsequent regulation of K. We also pose some outstanding questions to guide future research. Our analysis suggests that the enhancement of K utilization efficiency by manipulation of light quality and light signaling components can be a promising strategy for K management in crop production.


Assuntos
Lycopersicon esculentum , Potássio , Transporte Biológico , Lycopersicon esculentum/metabolismo , Plantas/metabolismo , Potássio/metabolismo , Canais de Potássio
14.
J Plant Physiol ; 268: 153581, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34915351

RESUMO

The upcoming climate change presents a great challenge for plant growth and development being extremes temperatures among the major environmental limitations to crop productivity. Understanding the repercussions of these extreme temperatures is of high importance to elaborate future strategies to confront crop damages. Tomato plants (Solanum lycopersicum L.) are one of the most cultivated crops and their fruits are consumed worldwide standing out for their organoleptic characteristics and nutritional value. Tomato plants are sensitive to temperatures below 12 °C and above 32 °C. In this study, Micro-Tom cultivar was used to evaluate the effects of extreme temperatures on the plant of tomato and the fruit productivity and quality from the stressed plants, either exposed to cold (4 °C for three nights per week) or heat (32 °C during the day, seven days per week) treatments. Total productivity and the percentage of ripe fruits per plant were evaluated together with foliar stress markers and the contents of photosynthetic pigments and tocochromanols. Fruit quality was also assessed determining lycopene contents, total soluble solids, total acidity and ascorbate contents. High temperatures altered multiple physiological parameters indicating a moderate stress, particularly decreasing fruit yield. As a response to this stress, plants enhanced their antioxidant contents both at leaf and fruit level. Low temperatures did not negatively affect the physiology of plants with similar yields as compared to controls, suggesting chilling acclimation. Both high and low temperatures, but most particularly the former, increased total soluble solids contents indicating that temperature control may be used as a strategy to modulate fruit quality.


Assuntos
Resposta ao Choque Frio , Frutas , Resposta ao Choque Térmico , Lycopersicon esculentum , Temperatura Baixa , Frutas/química , Temperatura Alta , Licopeno , Lycopersicon esculentum/fisiologia
15.
Plant Sci ; 314: 111118, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34895547

RESUMO

Seedling quality greatly affects the subsequent survival, quality and yield of tomatoes. To explore the response of tomato seedlings on vertical light, we investigated the continuous trends of chlorophyll fluorescence parameters in six vertical light intensities and Pearson's correlation analysis of them. The results showed that the dark fluorescence parameters of Fm, Fv/Fm highly correlated with the photosynthetic photon flux density (PPFD) while NPQ, Y(NPQ), Y(NO) were highly correlated with the day of light processing (DLP). With increasing PPFD, the Fv/Fm decreased, the residual sum of curves increased and the scaling factor (S) was decreased. The photoinhibition phenomenon was relieved to different degrees on DLP 4. L4 (243.17 ± 4.37 µmol m-2 s-1) was the fastest light adaptation, L5 (295.34 ± 5.42 µmol m-2 s-1) was the second. ΦPSII accumulation was greatest in L4 and second in L5. Both L4 and L5 seedling health index and dry weight were significantly higher than L1 (53.20 ± 1.55 µmol m-2 s-1). L4 had the highest Chl a/b and total soluble sugar. It can be concluded that L4 was the best vertical PPFD with the highest light-adaption. The larger the PPFD, the greater the curve deviation, the greater the degree of data discretization, and the higher the photoinhibition. The more appropriate the light intensity is, the faster the seedlings light-adapted are. Therefore, the rapid and proper adjustment of light intensity is the key to obtain high quality tomato seedlings.


Assuntos
Adaptação Ocular/fisiologia , Clorofila/metabolismo , Produtos Agrícolas/fisiologia , Lycopersicon esculentum/fisiologia , Folhas de Planta/fisiologia , Plântula/fisiologia , Fluorescência
16.
Plant Sci ; 314: 111120, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34895549

RESUMO

Little is known about how different plant-based diets influence the insect herbivores' oral secretion (OS) composition and eventually the plant defense responses. We analyzed the OS composition of the generalist Lepidopteran insect, Helicoverpa armigera feeding on the host plant tomato (OSH), non-host plant capsicum (OSNH), and artificial diet (OSAD) using Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry. Higher numbers and levels of alkaloids and terpenoids were observed in OSH and OSNH, respectively while OSAD was rich in phospholipids. Interestingly, treatment of H. armigera OSAD, OSH and OSNH on wounded tomato leaves showed differential expression of (i) genes involved in JA and SA biosynthesis and their responsive genes, and (ii) biosynthetic pathway genes of chlorogenic acid (CGA) and trehalose, which exhibited increased accumulation along with several other plant defensive metabolites. Specifically, high levels of CGA were detected after OSH and OSNH treatments in tomato leaves. There was higher expression of the genes involved in phenylpropanoid biosynthesis, which may lead to the increased accumulation of CGA and related metabolites. In the insect bioassay, CGA significantly inhibited H. armigera larval growth. Our results underline the differential accumulation of plant and insect OS metabolites and identified potential plant metabolite(s) affecting insect growth and development.


Assuntos
Secreções Corporais/química , Dieta , Herbivoria/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Lepidópteros/fisiologia , Lycopersicon esculentum/parasitologia , Defesa das Plantas contra Herbivoria/fisiologia , Animais
17.
Methods Mol Biol ; 2360: 235-252, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34495519

RESUMO

Expressing insecticidal double-stranded RNA (dsRNA) molecules in plant plastids is a novel approach for in planta production of dsRNA that has enormous potential for developing improved plant-mediated RNA interference (RNAi) strategies for insect pest control. In this chapter, we describe the design of a transformation vector containing an expression cassette which can be used to stably transform plastids of tomato plants for production and accumulation of dsRNA . Such dsRNA can trigger the mechanisms of RNAi in pest insects and selectively suppress the expression of target genes, resulting in lethality. We also describe a protocol for detection of full-length dsRNA molecules in plastids using an RT-PCR-based method.


Assuntos
Biolística , Lycopersicon esculentum , Animais , Insetos/genética , Lycopersicon esculentum/genética , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA de Plantas/genética
18.
Methods Mol Biol ; 2360: 317-345, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34495524

RESUMO

RNA interference (RNAi) is a natural mechanism of gene regulation, highly conserved in eukaryotes. Since the elucidation of the gene silencing mechanism, RNAi became an important tool used in insect reverse genetics. The demonstration of effective target-gene silencing by ingestion of double-stranded RNA (dsRNA) produced by transgenic plants indicated the RNAi potential to be used in insect pest management, particularly in agriculture. However, the efficiency of gene silencing by RNAi in insects may vary according to the target taxa, and lepidopteran species have been shown to be quite recalcitrant to RNAi. Developing transgenic plants is a time-consuming and labor-intensive process, so alternative oral delivery systems are required to develop and optimize RNAi settings, such as selecting an efficient target gene, and dsRNA design, length, and stability, among other features. We have developed delivery systems to evaluate dsRNAs to silence genes from two important lepidopteran crop pests of tomato (Solanum lycopersicum) and sugarcane (Saccharum × officinarum): Tuta absoluta (Meyrick), the South American Tomato Pinworm, and Diatraea saccharalis (Fabricius), the Sugarcane Borer, respectively. The protocol described here can be used in similar species and includes (a) direct oral delivery by droplets containing dsRNA; (b) oral delivery by tomato leaflets that absorbed dsRNA solution; (c) delivery by Escherichia coli expressing dsRNA; and (d) delivery by transgenic plants expressing dsRNA.


Assuntos
RNA de Cadeia Dupla/genética , Agricultura , Animais , Inativação Gênica , Insetos/genética , Lycopersicon esculentum/genética , Mariposas/genética , Plantas Geneticamente Modificadas/genética , Interferência de RNA
19.
New Phytol ; 233(1): 458-478, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34655240

RESUMO

The molecular mechanisms of quantitative resistance (QR) to fungal pathogens and their relationships with growth pathways are poorly understood. We identified tomato TRK1 (TPK1b Related Kinase1) and determined its functions in tomato QR and plant growth. TRK1 is a receptor-like cytoplasmic kinase that complexes with tomato LysM Receptor Kinase (SlLYK1). SlLYK1 and TRK1 are required for chitin-induced fungal resistance, accumulation of reactive oxygen species, and expression of immune response genes. Notably, TRK1 and SlLYK1 regulate SlMYC2, a major transcriptional regulator of jasmonic acid (JA) responses and fungal resistance, at transcriptional and post-transcriptional levels. Further, TRK1 is also required for maintenance of proper meristem growth, as revealed by the ectopic meristematic activity, enhanced branching, and altered floral structures in TRK1 RNAi plants. Consistently, TRK1 interacts with SlCLV1 and SlWUS, and TRK1 RNAi plants show increased expression of SlCLV3 and SlWUS in shoot apices. Interestingly, TRK1 suppresses chitin-induced gene expression in meristems but promotes expression of the same genes in leaves. SlCLV1 and TRK1 perform contrasting functions in defense but similar functions in plant growth. Overall, through molecular and biochemical interactions with critical regulators, TRK1 links upstream defense and growth signals to downstream factor in fungal resistance and growth homeostasis response regulators.


Assuntos
Lycopersicon esculentum , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Meristema/metabolismo , Doenças das Plantas , Imunidade Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
20.
Plant Physiol Biochem ; 171: 49-65, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34971955

RESUMO

The mechanism of the combined action of potassium (K) and melatonin (Mel) in modulating tolerance to cadmium (Cd) stress in plants is not well understood. The present study reveals the synergistic role of K and Mel in enhancing physiological and biochemical mechanisms of Cd stress tolerance in tomato seedlings. The present findings reveal that seedlings subjected to Cd toxicity exhibited disturbed nutrients balance [nitrogen (N) and potassium (K)], chlorophyll (Chl) biosynthesis [reduced δ-aminolevulinic acid (δ-ALA) content and δ-aminolevulinic acid dehydratase (δ-ALAD) activity], pathway of carbon fixation [reduced fructose-1,6-bisphosphatase (FBPase) and sedoheptulose-1,7- bisphosphatase (SBPase) activity] and photosynthesis process in tomato seedlings. However, exogenous application of K and Mel alone as well as together improved physiological and biochemical mechanisms in tomato seedlings, but their combined application proved best by efficiently improving nutrient uptake, photosynthetic pigments biosynthesis (increased Chl a and b, and Total Chl), carbon flow in Calvin cycle, activity of Rubisco, carbonic anhydrase activity, and accumulation of total soluble carbohydrates content in seedlings under Cd toxicity. Furthermore, the combined treatment of K and Mel suppressed overproduction of reactive oxygen species (hydrogen peroxide and superoxide), Chl degradation [reduced chlorophyllase (Chlase) activity] and methylglyoxal content in Cd-stressed tomato seedlings by upregulating glyoxalase (increased glyoxalase I and glyoxalase II activity) and antioxidant systems (increased ascorbate-glutathione metabolism). Thus, the present study provides stronger evidence that the co-application of K and Mel exhibited synergistic roles in mitigating the toxic effect of Cd stress by increasing glyoxalase and antioxidant systems and also by improving photosynthetic efficiency in tomato seedlings.


Assuntos
Lycopersicon esculentum , Melatonina , Antioxidantes/metabolismo , Cádmio/toxicidade , Carbono , Frutose , Frutose-Bifosfatase , Heptoses , Lycopersicon esculentum/metabolismo , Fotossíntese , Potássio , Plântula/metabolismo
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