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1.
Plant Physiol Biochem ; 151: 486-499, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32302942

RESUMO

Involvement of nitrate reductase (NR) and nitric oxide synthase (NOS)-like enzyme in 24-epibrassinolide (EB)-triggered nitric oxide (NO) synthesis to improve iron deficiency (ID) tolerance in strawberry plants was studied. EB was sprayed to strawberry plants every two days for two weeks. Then, the EB-treated plants were pre-treated with inhibitors of NR, tungstate, or NOS, L-NAME for 3 h. During the first three weeks, Fe was supplied as 100 µM EDTA-Fe or FeSO4 to Fe-sufficient or Fe-deficient plants, respectively. Thereafter, plants were subjected for further three weeks to control (100 µM EDTA-Fe) and Fe deficiency (ID; without Fe). ID reduced biomass, chlorophyll, and chlorophyll fluorescence, while increased oxidative stress parameters, ascorbate (AsA), glutathione (GSH), endogenous NO, and the activities of NR, NOS, and antioxidant enzymes. Pre-treatments with EB and EB + SNP improved ID tolerance of strawberry by improving leaf Fe2+, plant growth, and antioxidant enzyme activities, and causing a further elevation in AsA, GSH, NO, NR and NOS. L-NAME application reversed NOS activity, but it did not eliminate NO, however, tungstate application reversed both NR activity and NO synthesis in plants exposed to ID + EB, suggesting that NR is the main contributor of EB-induced NO synthesis to improve ID tolerance in strawberry plants.


Assuntos
Fragaria , Ferro , Nitrato Redutase , Óxido Nítrico , Regulação para Cima , Ácido Ascórbico/metabolismo , Brassinosteroides/farmacologia , Fragaria/efeitos dos fármacos , Fragaria/enzimologia , Fragaria/genética , Regulação da Expressão Gênica de Plantas , Glutationa/metabolismo , Ferro/deficiência , Nitrato Redutase/metabolismo , Óxido Nítrico/biossíntese , Esteroides Heterocíclicos/farmacologia
2.
Plant Dis ; 104(5): 1298-1304, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32196417

RESUMO

Tomato gray mold caused by Botrytis cinerea is one of the main diseases of tomato and significantly impacts the yield and quality of tomato fruit. The overuse of chemical fungicides has resulted in the development of fungicide-resistant strains. Biological control is becoming an alternative method for the control of plant diseases to replace or decrease the application of traditional synthetic chemical fungicides and genus Trichoderma is widely used as a biological agent for controlling tomato gray mold. Brassinolide (BR) is a plant-growth-promoting steroid. To enhance the efficiency and stability of Trichoderma activity against B. cinerea, an optimal combination of Trichoderma atroviride CCTCCSBW0199 and BR that controls B. cinerea infection in tomato was identified. Strain CCTCCSBW0199 was found to have antagonistic activity against B. cinerea both in vitro and in vivo. In addition, a fermented culture of chlamydospores and metabolites, or metabolites only of strain CCTCCSBW0199 also reduced growth of B. cinerea. BR reduced growth of B. cinerea and had no effect on the sporulation and growth of Trichoderma spp. An application of metabolites of a Trichoderma sp. + BR reduced gray mold on tomato leaves by approximately 70.0%. Furthermore, the activities of induced defense response-related enzyme, such as peroxidase, superoxide dismutase, catalase, and phenylalanine ammonia-lyase were increased in tomato plants treated with a Trichoderma sp. + BR. Our data suggested that applying a mix of metabolites of T. atroviride CCTCCSBW0199 + BR was effective at reducing gray mold of tomato and may lay a theoretical foundation for the development of novel biofungicides.


Assuntos
Infecções , Lycopersicon esculentum , Trichoderma , Botrytis , Brassinosteroides , Humanos , Esteroides Heterocíclicos
3.
Chemosphere ; 244: 125579, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050351

RESUMO

Although Solanum nigrum L. is a phytoremediator for different metals, its growth and physiology are still compromised by toxic levels of zinc (Zn). Thus, the development of eco-friendly strategies to enhance its tolerance, maintaining remediation potential is of special interest. This study evaluated the potential of 24-epibrassinolide (24-EBL) to boost S. nigrum defence against Zn towards a better growth rate and remediation potential. After 24 days of exposure, the results revealed that Zn-mediated inhibitory effects on biomass and biometry were efficiently mitigated upon application of 24-EBL, without affecting Zn accumulation. The evaluation of oxidative stress markers reported that Zn excess stimulated the accumulation of superoxide anion (O2.-), but reduced hydrogen peroxide (H2O2) levels, while not altering lipid peroxidation (LP). This was accompanied by an up-regulation of the antioxidant system, especially proline, superoxide dismutase (SOD) and ascorbate peroxidase (APX) in both organs, and ascorbate in roots of Zn-exposed plants. Foliar application of 24-EBL, however, induced distinctive effects, lowering proline levels in both organs, as well as APX activity in shoots and SOD in roots, whilst stimulating GSH and total thiols in both organs, as well as SOD and APX activity, in shoots and in roots, respectively. Probably due to a better antioxidant efficiency, levels of O2.- and H2O2 in pre-treated plants remained identical to the control, while LP further decreased in shoots. Overall, our results indicate a protective effect of 24-EBL on S. nigrum response to excess Zn, contributing for a better tolerance and growth rate, without disturbing its phytoremediation potential.


Assuntos
Brassinosteroides/metabolismo , Poluentes do Solo/toxicidade , Solanum nigrum/fisiologia , Esteroides Heterocíclicos/metabolismo , Zinco/toxicidade , Antioxidantes/farmacologia , Ascorbato Peroxidases/metabolismo , Ácido Ascórbico/farmacologia , Biodegradação Ambiental , Catalase/metabolismo , Peróxido de Hidrogênio/farmacologia , Peroxidação de Lipídeos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Raízes de Plantas/metabolismo , Superóxido Dismutase/metabolismo , Zinco/análise
4.
Food Chem ; 315: 126275, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32004982

RESUMO

The effects of individual epi-brassinolide (eBL) and NaCl, as well as their combination on contents of main phytochemicals and antioxidant capacity of Chinese kale sprouts were investigated. Our results showed that the application of 100 nM eBL decreased the contents of individual and total glucosinolates, while treatments of 160 mM NaCl both alone and combined with 100 nM eBL enhanced the glucosinolates accumulation by promoting the expression of genes involved in glucosinolate biosynthesis in Chinese kale sprouts and the combined treatment led to significantly higher content of most glucosinolate profiles. Moreover, it also elevated the contents of ascorbic acid and total carotenoids, whereas did not influence the total phenolics and antioxidant capacity. These findings indicated that the combined treatment of 100 nM eBL plus 160 mM NaCl could provide a new strategy to improve the main health promoting compounds in Chinese kale sprouts.


Assuntos
Brassica/química , Brassinosteroides/química , Compostos Fitoquímicos/química , Plântula/química , Cloreto de Sódio/química , Esteroides Heterocíclicos/química , Antioxidantes/química , Ácido Ascórbico/química , Carotenoides/química , Glucosinolatos/química , Fenóis/química , Cloreto de Sódio/farmacologia
5.
Ecotoxicol Environ Saf ; 193: 110296, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32092579

RESUMO

Lead (Pb) is a highly toxic heavy metal to plants, animals, and human beings. The use of growth regulators has reversed the effects of heavy metal stress on germination and early plant development. The aim of this study was to evaluate the effect of brassinosteroids on seed germination and seedling growth of Brassica juncea (L.) Czern. & Coss. under Pb stress conditions. Two forms of application of 24-epibrassinolide (EBL) were evaluated, application on seeds in pre-soaking and on germination paper, using EBL concentrations of 0, 10-10, 10-8, and 10-6 M. Germination and seedling growth parameters were evaluated during the germination test. The activity of the enzymes superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase were determined, as well as the lead content in the seeds and seedlings. The EBL applied at the 10-8 M concentration was the most effective in overcoming Pb stress in both forms of application. The antioxidant enzyme defense system was compromised by Pb exposure. However, 10-8 M EBL increased the activity of antioxidant enzymes such as catalase and peroxidase to overcome the toxic effects caused by Pb. In addition, EBL at the concentration of 10-8 M increased Pb content in seedlings without affecting seedling growth.


Assuntos
Brassinosteroides/farmacologia , Germinação/efeitos dos fármacos , Chumbo/toxicidade , Mostardeira/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Plântula/efeitos dos fármacos , Sementes/efeitos dos fármacos , Esteroides Heterocíclicos/farmacologia , Antioxidantes/metabolismo , Relação Dose-Resposta a Droga , Chumbo/metabolismo , Modelos Teóricos , Mostardeira/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
6.
Chemosphere ; 242: 125112, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31669993

RESUMO

This investigation was made to examine the role of indole-3-acetic acid (IAA), gibberellin A3 (GA3), 6-Benzylaminopurine (6-BA), and 24-epibrassinolide (EBL) in improving stress tolerance and phytoremediation of the cadmium (Cd) and uranium (U) by mustard (Brassica juncea L.). The optimum concentrations of IAA, GA3, 6-BA, and EBL were determined based on plant biomass production, metal uptake, translocation, and removal efficiency. The biomass and total chlorophyll content decreased under Cd and U stress. Nevertheless, the application of IAA, GA3, and 6-BA significantly (p < 0.05) increased the growth and total chlorophyll content of mustard. The malondialdehyde (MDA) and H2O2 content of mustard were enhanced under Cd and U stress, but they were significantly (p < 0.05) decreased in plant growth regulators (PGRs) treatments (except for EBL). PGRs treatments increased activities of antioxidant enzymes such as superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, thus reducing the oxidative stress. Furthermore, the shoot uptake of Cd and U of IAA and EBL treatments was significantly (p < 0.05) higher than that of other treatments. IAA and EBL also have more significant effects on the translocation and remediation of Cd and U compared to GA3 and 6-BA. The removal efficiency of Cd and U reached the maximum in the 500 mg L-1 IAA treatment, which was 330.77% and 118.61% greater than that in the control (CK), respectively. These results suggested that PGRs could improve the stress tolerance and efficiency of phytoremediation using B. juncea in Cd- and U- contaminated soils.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Mostardeira/metabolismo , Reguladores de Crescimento de Planta , Poluentes do Solo/metabolismo , Urânio/metabolismo , Antioxidantes , Ascorbato Peroxidases , Brassinosteroides , Cádmio/análise , Catalase , Peróxido de Hidrogênio , Malondialdeído , Peroxidase , Peroxidases , Solo , Poluentes do Solo/análise , Esteroides Heterocíclicos , Superóxido Dismutase
7.
Plant Physiol Biochem ; 146: 420-427, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31805496

RESUMO

The involvement of wheat germ agglutinin (WGA) in the protective action of 24-epibrassinolide (EBR) against drought stress was studied in the seedling roots of two wheat cultivars differing in drought tolerance. Under dehydration conditions, the contents of ABA and WGA were shown to change significantly in the roots of either drought-tolerant cultivar Omskaya 35 or drought-sensitive cultivar Salavat Yulaev. Meanwhile, accumulation of either ABA or WGA started earlier and was two times greater in plants of drought-tolerant cultivar. Since WGA is an excreted protein, it is not surprising that the level of lectin in the roots gradually decreased by the 7th day of treatment due to its exudation into root environment. Pre-sowing treatment with EBR contributed to additional accumulation of lectin as compared to the control variants of either cultivar, while the hormone treatment did not change ABA content. Meanwhile, under conditions of drought, EBR-pretreated seedlings were characterized by lower level of accumulation of ABA and WGA in the roots. EBR application was found to prevent drought-induced inhibition of cell division in the root apical meristem, while WGA excreted into the root environment may contribute significantly to the effect.


Assuntos
Plântula , Triticum , Brassinosteroides , Secas , Raízes de Plantas , Esteroides Heterocíclicos , Aglutininas do Germe de Trigo
8.
Mol Genet Genomics ; 295(2): 343-356, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31745640

RESUMO

Dwarfing is the development trend of pepper breeding. It is of great practical and scientific value to generate new dwarf germplasms, and identify new genes or alleles conferring dwarf traits in pepper. In our previous study, a weakly BR-insensitive dwarf mutant, E29, was obtained by EMS mutagenesis of the pepper inbred line 6421. It can be used as a good parent material for breeding new dwarf varieties. Here, we found that this dwarf phenotype was controlled by a single recessive gene. Whole-genome resequencing, dCAPs analysis, and VIGs validation revealed that this mutation was caused by a nonsynonymous single-nucleotide mutation (C to T) in CaBRI1. An enzyme activity assay, transcriptome sequencing, and BL content determination further revealed that an amino-acid change (Pro1157Ser) in the serine/threonine protein kinase and catalytic (S_TKc) domain of CaBRI1 impaired its kinase activity and caused the transcript levels of two important genes (CaDWF4 and CaROT3) participating in BR biosynthesis to increase dramatically in the E29 mutant, accompanied by significantly increased accumulation of brassinolide (BL). Therefore, we concluded that the novel single-base mutation in CaBRI1 conferred the dwarf phenotype and resulted in brassinosteroid (BR) accumulation in pepper. This study provides a new allelic variant of the height-regulating gene CaBRI1 that has theoretical and practical values for the breeding of the plants suitable for the facility cultivation and mechanized harvesting of pepper varieties.


Assuntos
Brassinosteroides/metabolismo , Capsicum/genética , Reguladores de Crescimento de Planta/genética , Proteínas de Plantas/genética , Alelos , Sequência de Aminoácidos/genética , Capsicum/metabolismo , Domínio Catalítico/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Mutagênese/genética , Mutação/genética , Oryza/genética , Proteínas Quinases/genética , Homologia de Sequência de Aminoácidos , Esteroides Heterocíclicos/metabolismo , Sequenciamento Completo do Genoma
9.
Ecotoxicol Environ Saf ; 187: 109831, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31654868

RESUMO

Lead is one of the most hazardous pollutants to both the environment as well as human beings. As one of the approaches to enhance phytoremediation, brassinosteroids are predicted as a potential candidate phytohormone for assisted phytoremediation. Few studies have focused on the physiological regulations of tall fescue plants (Festuca arundinacea Schreb.), a potential phytoremediation species, for its responses to applications of brassinosteroids under lead stress. Therefore, the objectives of this study were to investigate the effects of foliar application of 24-epibrassinolide, a brassinosteroids analogue, on reactive oxygen species accumulation and antioxidative defense systems of tall fescue when exposed to lead, and ultimately its potential to be used in phytoremediation. When exposed to lead (1000 mg/kg) for 80 d, decreases in shoot and root biomass of tall fescue biomass as well as chlorophyll and carotenoid productions were found. Foliar application of 24-epibrassinolide at three rates and five applications every 7 d improved the biomass of both shoots and roots, and increased the photosynthetic pigments. The improved lead tolerance in tall fescue plants after 24-epibrassinolide applications was associated with reduced H2O2 and O2.- accumulations and increased antioxidative enzyme activities including superoxide dismutase, catalase, and guaiacol peroxidase. Additionally, osmoprotectants increased and lipid peroxidation decreased. Ultimately, foliar applications of 24-epibrassinolide enhanced the lead recovery rate of tall fescue plants, proving its potential role in phytoremediation for soil contaminated with heavy metals such as lead.


Assuntos
Antioxidantes/metabolismo , Brassinosteroides/farmacologia , Festuca/efeitos dos fármacos , Chumbo/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Esteroides Heterocíclicos/farmacologia , Biodegradação Ambiental , Clorofila/metabolismo , Festuca/crescimento & desenvolvimento , Festuca/metabolismo , Chumbo/metabolismo , Peroxidação de Lipídeos , Reguladores de Crescimento de Planta/farmacologia , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade
10.
Nat Commun ; 10(1): 5516, 2019 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-31797871

RESUMO

Arabidopsis PIN2 protein directs transport of the phytohormone auxin from the root tip into the root elongation zone. Variation in hormone transport, which depends on a delicate interplay between PIN2 sorting to and from polar plasma membrane domains, determines root growth. By employing a constitutively degraded version of PIN2, we identify brassinolides as antagonists of PIN2 endocytosis. This response does not require de novo protein synthesis, but involves early events in canonical brassinolide signaling. Brassinolide-controlled adjustments in PIN2 sorting and intracellular distribution governs formation of a lateral PIN2 gradient in gravistimulated roots, coinciding with adjustments in auxin signaling and directional root growth. Strikingly, simulations indicate that PIN2 gradient formation is no prerequisite for root bending but rather dampens asymmetric auxin flow and signaling. Crosstalk between brassinolide signaling and endocytic PIN2 sorting, thus, appears essential for determining the rate of gravity-induced root curvature via attenuation of differential cell elongation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Gravitropismo/fisiologia , Raízes de Plantas/metabolismo , Arabidopsis/efeitos dos fármacos , Transporte Biológico/efeitos dos fármacos , Brassinosteroides/farmacologia , Endocitose/efeitos dos fármacos , Gravitropismo/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Meristema/efeitos dos fármacos , Meristema/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Raízes de Plantas/efeitos dos fármacos , Transdução de Sinais , Esteroides Heterocíclicos/metabolismo , Esteroides Heterocíclicos/farmacologia
11.
BMC Genomics ; 20(1): 810, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694527

RESUMO

BACKGROUND: Brassinosteroids (BRs) have a positive effect on many processes during plant growth and development, and in response to various abiotic stressors. Low-temperature (LT) stress constricts the geographic distribution, growth, and development of wucai (Brassica campestris L. ssp. chinensis var. rosularis Tsen). However, there is little information on the global gene expression of BRs under LT stress in wucai. In this study, the molecular roles of 24-epibrassinolide (EBR) after exogenously application, were explored by RNA sequencing under LT conditions. RESULTS: According to the Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, photosynthesis was significantly enriched after spraying EBR under LT. The transcripts encoding the photosystem II (PSII) oxygen-evolving enhancer protein, photosystem I (PSI) subunit, light-harvesting chlorophyll protein complexes I and II, and ferredoxin were up-regulated after the application of EBR. Transcripts encoding several key enzymes involved in chlorophyll biosynthesis were also up-regulated, accompanied by significant differences in the contents of 5-aminolevulinic acid (ALA), porphobilinogen (PBG), protoporphyrin IX (Proto IX), Mg-protoporphyrin IX (Mg-proto IX), protochlorophyllide (Pchl), and photosynthetic pigments. Notably, transcriptional and physiological analyses revealed that under LT stress, plant responses to EBR involved a major reorientation of photosynthesis, as well as porphyrin and chlorophyll metabolism. CONCLUSION: This study explored the role of EBR as an LT stress tolerance mechanism in wucai. At the transcription level, LT tolerance manifests as an enhancement of photosynthesis, and the amelioration of porphyrin and chlorophyll metabolism.


Assuntos
Brassica/genética , Brassica/metabolismo , Brassinosteroides/farmacologia , Resposta ao Choque Frio/genética , Perfilação da Expressão Gênica , Fotossíntese/efeitos dos fármacos , Brassica/efeitos dos fármacos , Brassica/fisiologia , Esteroides Heterocíclicos/farmacologia
12.
Environ Pollut ; 255(Pt 2): 113256, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31563783

RESUMO

The presence of pesticide residues in fresh fruits and vegetables poses a serious threat to human health. Brassinosteroids (BRs) can reduce pesticide residues in plants, but the underlying mechanisms still remain unclear. Here, we identified a tomato glutaredoxin gene GRXS25 which was induced by 24-epibrassinolide (EBR) and chlorothalonil (CHT) in a way dependent on apoplastic reactive oxygen species (ROS). Silencing of GRXS25 in tomato abolished EBR-induced glutathione S-transferases (GSTs) gene expression and activity, leading to an increased CHT residue. Yeast two-hybrid and bimolecular fluorescence complementation assays showed protein-protein interaction between GRXS25 and a transcription factor TGA2. Electrophoretic mobility shift and chromatin immunoprecipitation assays indicated that TGA2 factor bound to the TGACG-motif in the GST3 promoter. While silencing of TGA2 strongly compromised, overexpression of TGA2 enhanced expression of GST genes and CHT residue metabolism. Our results suggest that BR-induced apoplastic ROS trigger metabolism of pesticide residue in tomato plants through activating TGA2 factor via GRXS25-dependent posttranslational redox modification. Activation of plant detoxification through physiological approaches has potential implication in improving the food safety of agricultural products.


Assuntos
Brassinosteroides/metabolismo , Glutarredoxinas/metabolismo , Lycopersicon esculentum/fisiologia , Nitrilos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lycopersicon esculentum/metabolismo , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Esteroides Heterocíclicos
13.
Plant Cell Physiol ; 60(10): 2282-2292, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31290980

RESUMO

Brassinosteroids (BRs), a group of plant steroid hormones, participate in the regulation of plant growth and developmental processes. BR functions through the BES1/BZR1 family of transcription factors, however, the regulation of the BES1 activity by post-translational modifications remains largely unknown. Here, we present evidence that the SUMO E3 ligase SIZ1 negatively regulates BR signaling pathway. T-DNA insertion mutant siz1-2 shows BL (Brassinolide, the most active BR) hypersensitivity and BRZ (Brassinazole, a BR biosynthesis inhibitor) insensitivity during hypocotyl elongation. In addition, expression of BES1-dependent BR-response genes is hyper-regulated in siz1-2 seedlings. The siz1-2bes1-D double mutant exhibits longer hypocotyl than bes1-D. Moreover, SIZ1 physically interacts with BES1 in vivo and in vitro and mediates the sumoylation of BES1. A K302R substitution in BES1 blocks its sumoylation mediated by SIZ1 in plants, indicating that K302 is the principal site for SUMO conjugation. Consistently, we find that sumoylation inhibits BES1 protein stability and activity. Taken together, our data show that the sumoylation of BES1 via SIZ1 negatively regulates the BR signaling pathway.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Brassinosteroides/metabolismo , Proteínas de Ligação a DNA/metabolismo , Ligases/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Transdução de Sinais , Esteroides Heterocíclicos/metabolismo , Arabidopsis/enzimologia , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Hipocótilo/enzimologia , Hipocótilo/genética , Hipocótilo/fisiologia , Ligases/genética , Plântula/enzimologia , Plântula/genética , Plântula/fisiologia , Sumoilação , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
BMC Plant Biol ; 19(1): 225, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31146677

RESUMO

BACKGROUND: Suboptimal root zone temperature (RZT) causes a remarkable reduction in growth of horticultural crops during winter cultivation under greenhouse production. However, limited information is available on the effects of suboptimal RZT on nitrogen (N) metabolism in cucumber seedlings. The aim of this study is to investigate the effects of 24-Epibrassinolide (EBR) on nitrate and ammonium flux rate, N metabolism, and transcript levels of NRT1 family genes under suboptimal RZT in cucumber seedlings. RESULTS: Suboptimal RZT (LT) negatively affected on cucumber growth and proportionately decreased EBR contents, bleeding rate, root activity, enzyme activities of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT), nitrate (NO3-) influx rate, ammonium (NH4+) efflux rate, and transcript levels of nitrate transporter (NRT1) encoding genes. However, exogenous EBR reduced the harmful effects of suboptimal RZT and increased endogenous EBR contents, bleeding rate, root activity, enzyme activities of NR, NiR, GS, and GOGAT, NH4+ and NO3- flux rates and contents, and N accumulation. EBR-treated seedlings also upregulated the transcript levels of nitrate transporters CsNRT1.1, CsNRT1.2A, CsNRT1.2B, CsNRT1.2C, CsNRT1.3, CsNRT1.4A, CsNRT1.5B, CsNRT1.5C, CsNRT1.9, and CsNRT1.10, and downregulated CsNRT1.5A and CsNRT1.8. LT treatment upregulated the expression level of CsNRT1.5A, while exogenous BZR application downregulated the expression level of NRT1 genes. CONCLUSION: These results indicate that exogenous application of EBR alleviated the harmful effects of suboptimal RZT through changes in N metabolism, NH4+ and NO3- flux rates, and NRT1 gene expression, leading to improved cucumber seedlings growth. Our study provides the first evidence of the role of EBR in the response to suboptimal RZT in cucumber, and can be used to improve vegetable production.


Assuntos
Compostos de Amônio/metabolismo , Brassinosteroides/metabolismo , Cucumis sativus/genética , Nitratos/metabolismo , Proteínas de Plantas/genética , Esteroides Heterocíclicos/metabolismo , Transcrição Genética , Cucumis sativus/metabolismo , Família Multigênica , Nitrogênio/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Temperatura
15.
Environ Sci Pollut Res Int ; 26(22): 23192-23197, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31187379

RESUMO

Soil alkalinity caused by salts, such as sodium bicarbonate (NaHCO3), and the frequently associated waterlogging problems are pervasive in agriculture and have a deleterious impact on crop production. However, various plant growth regulators, including brassinosteroids, are considered to be important against different abiotic stresses experienced by plants due to drought, salinity, and heavy metal stress. We investigated the putative role of 24-epibrassinolide (EBL), an active brassinosteroid, on red rice plants experiencing alkaline stress. Seedlings were pre-treated with 0.01 µM EBL for 30 min and later, exposed to NaHCO3 (25 mM) and were sampled, 5 days after treatments. Results showed that the pre-treatment of seedlings with EBL under non-stress conditions could promote rice plant growth. Growth parameters including dry weight (DW), root and coleoptile lengths were reduced under alkaline stress, whereas EBL application reduced the level of inhibition, as compared with NaHCO3 treatment. Enhanced levels of malondialdehyde content, hydrogen peroxide, and superoxide radicals were significantly diminished by EBL pre-treatment. Moreover, pre-treatment of EBL to alkaline-treated rice seedlings largely stimulated the enzymatic activities of ascorbate peroxidase, catalase, and superoxide dismutase. Thus, the results suggest that pre-application of EBL significantly ameliorates alkaline stress in rice.


Assuntos
Ascorbato Peroxidases/química , Brassinosteroides/farmacologia , Catalase/metabolismo , Oryza/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Plântula/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Ascorbato Peroxidases/metabolismo , Peróxido de Hidrogênio/química , Malondialdeído/química , Plântula/efeitos dos fármacos , Esteroides Heterocíclicos , Superóxido Dismutase/química
16.
J Plant Physiol ; 238: 12-19, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31121523

RESUMO

In this study, the effect of 24-Epibrassinolide (EBL) on antioxidant system in Arabidopsis thaliana were investigated under arsenate [As(V)] stress. The enzyme activity of superoxide dismutase (SOD) and catalase (CAT), total antioxidant status, malondialdehyde (MDA) level and free proline content, as well as the expression levels of SOD isoforms (Cu-ZnSODs, FeSODs and MnSOD), CAT isoforms (CAT1, CAT2 and CAT3), some heat shock proteins (Hsp70-4 and Hsp90-1) and proline biosynthesis (P5CS1 and P5CS2) genes were determined in rosette leaves of eight-week old plants under exposure of 100 and 200 µM As(V) and/or 1 µM EBL treatments for 24 h. Total SOD and CAT enzyme activities increased as a result of 100 µM As(V) + EBL treatments compared to 100 µM As(V) treatment. Total antioxidant and proline levels increased in plants subjected to As(V), and the treatment of EBL together with stress caused further increase. As the MDA level increased in As-treated plants, 100 µM As(V) + EBL treatment decreased MDA level. Transcript levels of CSD1, CSD2, FSD1, FSD2, MSD1 and CAT2 genes increased as a result of combined treatment of EBL and As(V) compared to control and alone stress treatments (except CSD1 gene). Expression level of CSD3, CAT1 and CAT3 genes were downregulated in response to As(V) and/or EBL treatments. EBL application alone and in combination with As(V) elevated the expression level of P5CS1 gene dramatically. Treatment with 100 µM As(V) and EBL increased the transcript level of Hsp70-4 and Hsp90-1 genes in leaves compared to 100 µM As(V) treatment. To our best knowledge, this is the first detailed study to evaluate the improving effect of EBL on antioxidant defense system at biochemical and transcriptional level in A. thaliana plants under As(V) stress.


Assuntos
Arabidopsis/metabolismo , Arsênico/toxicidade , Brassinosteroides/farmacologia , Esteroides Heterocíclicos/farmacologia , Arabidopsis/efeitos dos fármacos , Catalase/metabolismo , Relação Dose-Resposta a Droga , Proteínas de Choque Térmico/metabolismo , Malondialdeído/metabolismo , Prolina/metabolismo , Isoformas de Proteínas , Estresse Fisiológico/efeitos dos fármacos , Superóxido Dismutase/metabolismo
17.
BMC Genomics ; 20(1): 377, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088374

RESUMO

BACKGROUND: Sulforaphane is a natural isothiocyanate available from cruciferous vegetables with multiple characteristics including antioxidant, antitumor and anti-inflammatory effect. Single-molecule real-time (SMRT) sequencing has been used for long-read de novo assembly of plant genome. Here, we investigated the molecular mechanism related to glucosinolates biosynthesis in Chinese kale using combined NGS and SMRT sequencing. RESULTS: SMRT sequencing produced 185,134 unigenes, higher than 129,325 in next-generation sequencing (NGS). NaCl (75 mM), methyl jasmonate (MeJA, 40 µM), selenate (Se, sodium selenite 100 µM), and brassinolide (BR, 1.5 µM) treatment induced 6893, 13,287, 13,659 and 11,041 differentially expressed genes (DEGs) in Chinese kale seedlings comparing with control. These genes were associated with pathways of glucosinolates biosynthesis, including phenylalanine, tyrosine and tryptophan biosynthesis, cysteine and methionine metabolism, and glucosinolate biosynthesis. We found NaCl decreased sulforaphane and glucosinolates (indolic and aliphatic) contents and downregulated expression of cytochrome P45083b1 (CYP83b1), S-alkyl-thiohydroximatelyase or carbon-sulfur lyase (SUR1) and UDP-glycosyltransferase 74B1 (UGT74b1). MeJA increased sulforaphane and glucosinolates contents and upregulated the expression of CYP83b1, SUR1 and UGT74b1; Se increased sulforaphane; BR increased expression of CYP83b1, SUR1 and UGT74b1, and increased glucosinolates contents. The desulfoglucosinolate sulfotransferases ST5a_b_c were decreased by all treatments. CONCLUSIONS: We confirmed that NaCl inhibited the biosynthesis of both indolic and aliphatic glucosinolates, while MeJA and BR increased them. MeJA and BR treatments, conferred the biosynthesis of glucosinolates, and Se and MeJA contributed to sulforaphane in Chinese kale via regulating the expression of CYP83b1, SUR1 and UGT74b1.


Assuntos
Brassica/metabolismo , Perfilação da Expressão Gênica/métodos , Isotiocianatos/metabolismo , Proteínas de Plantas/genética , Acetatos/farmacologia , Brassica/genética , Brassinosteroides/farmacologia , Ciclopentanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Oxilipinas/farmacologia , Ácido Selênico/farmacologia , Análise de Sequência de RNA/métodos , Análise de Célula Única , Cloreto de Sódio/farmacologia , Esteroides Heterocíclicos/farmacologia , Sequenciamento Completo do Exoma/métodos
18.
Food Chem ; 289: 500-511, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30955642

RESUMO

The aim of current investigation was to perform proteomics and physio-chemical studies to dissect the changes in contrasting varieties (S-22 and PKM-1) of Lycopersicon esculentum under low-temperature stress. Plant grown under variable low-temperature stress were analysed for their growth biomarkers, antioxidant enzyme activities, and other physiological parameters, which headed toward the determination of protein species responding to low-temperature and 24-epibrassinolide (EBL) concentrations. The plants grown under temperatures, 20/14, 12/7, and 10/3 °C recorded significantly lower growth biomarkers, SPAD chlorophyll, net photosynthetic rate and carbonic anhydrase activity in S-22 and PKM-1. Moreover, the combined effect of EBL and hydrogen peroxide (H2O2) significantly improved the parameters mentioned above and consecutively upgraded the different antioxidant enzymes (CAT and SOD) with higher accumulation of proline under stress and stress-free environments. Furthermore, proteomics study revealed that the maximum number of differentially expressed proteins were detected in S-22 (EBL + H2O2); while treatment with EBL + H2O2 + low temperature lost expression of 20 proteins. Overall, three proteins (O80577, Q9FJQ8, and Q9SKL2) took a substantial part in the biosynthesis of citrate cycle pathway and enhanced the growth and photosynthetic efficiency of tomato plants under low-temperature stress.


Assuntos
Brassinosteroides/farmacologia , Temperatura Baixa , Peróxido de Hidrogênio/farmacologia , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Plantas/análise , Esteroides Heterocíclicos/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Antioxidantes/análise , Clorofila/análise , Lycopersicon esculentum/química , Lycopersicon esculentum/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Proteômica , Estresse Fisiológico/fisiologia
19.
Environ Sci Pollut Res Int ; 26(17): 17163-17172, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31001773

RESUMO

High temperature poses a severe extortion to productivity of many crops like wheat. Therefore, well documented roles of brassinosteroid (BR) and silicon (Si) in terms of abiotic stress tolerance, the current study was designed to evaluate the response of wheat (Triticum aestivum L. Var. PBW-343) to 24-epibrassinolide (EBL) mediated by silicon grown under high temperature stress. At 10- and 12-day stage after sowing, the seedlings were administered Si (0.8 mM) through the sand, and the plants at 20, 22, or 24 days after sowing (DAS) were given EBL (0.01µM) through foliage. Plants were treated to high-temperature stress (35/28 or 40/35 °C), for 24 h with 12-h photoperiod in plant growth chamber at 25- and 26-day stage of growth. High temperatures cause significant reduction in growth performance and photosynthesis-related attributes at 35 days after sowing. However, antioxidant enzymes and proline content also augmented substantially with increasing temperature. BR and Si enhanced antioxidant activity and proline content, which was earlier increased by the high temperature. It is established that interaction of EBL and Si considerably improved the growth features, photosynthetic efficacy, and several biochemical traits under high-temperature stress through elevated antioxidant system and osmoprotectant.


Assuntos
Brassinosteroides/metabolismo , Silício/metabolismo , Esteroides Heterocíclicos/metabolismo , Temperatura , Triticum/fisiologia , Antioxidantes , Fotossíntese , Prolina/metabolismo , Plântula/metabolismo , Silício/química , Estresse Fisiológico/fisiologia , Superóxido Dismutase/metabolismo , Triticum/crescimento & desenvolvimento
20.
Plant Physiol Biochem ; 137: 84-92, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30769236

RESUMO

This study focused on the idea that the toxic effect of zearalenone (ZEA) and the protective actions of the brassinosteroid - 24-epibrassinolide (EBR) as well as selenium are dependent on its accumulation in chloroplasts to a high degree. These organelles were isolated from the leaves of oxidative stress-sensitive and stress-tolerant wheat cultivars that had been grown from grains that had been incubated in a solution of ZEA (30 µM), Na2SeO4 (Se, 10 µM), EBR (0.1 µM) or in a mixture of ZEA with Se or EBR. Ultra-high performance liquid chromatography techniques indicated that ZEA was adsorbed in higher amounts in the chloroplasts in the sensitive rather than tolerant cultivar. Although the brassinosteroids and Se were also accumulated in the chloroplasts, higher levels were only found in the tolerant cultivar. The application of EBR increased the homocastasterone content, especially in the chloroplasts of the tolerant plant and after the addition of ZEA. The presence of both protectants caused a decrease in the ZEA content in studied organelles and resulted in diminishing of the oxidative stress (i.e. changes in the activity of the antioxidative enzymes). Moreover, a recovery of photosystem II and decrease in the negative impact of ZEN on Hsp90 transcript accumulation was observed in plants.


Assuntos
Brassinosteroides/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Selênio/farmacologia , Esteroides Heterocíclicos/farmacologia , Triticum/efeitos dos fármacos , Zearalenona/toxicidade , Antioxidantes/metabolismo , Brassinosteroides/metabolismo , Brassinosteroides/farmacocinética , Carotenoides/metabolismo , Clorofila A/metabolismo , Cloroplastos/efeitos dos fármacos , Enzimas/metabolismo , Proteínas de Choque Térmico HSP90/genética , Proteínas de Plantas/genética , Selênio/farmacocinética , Esteroides Heterocíclicos/farmacocinética , Triticum/metabolismo , Zearalenona/farmacocinética
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