Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
BMC Plant Biol ; 19(1): 309, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299898

RESUMO

BACKGROUND: Ethylene promotes fruit ripening whereas 1-methylcyclopropene (1-MCP), a non-toxic antagonist of ethylene, delays fruit ripening via the inhibition of ethylene receptor. However, unsuitable 1-MCP treatment can cause fruit ripening disorders. RESULTS: In this study, we show that short-term 1-MCP treatment (400 nL•L- 1, 2 h) significantly delays papaya fruit ripening with normal ripening characteristics. However, long-term 1-MCP treatment (400 nL•L- 1, 16 h) causes a "rubbery" texture of fruit. The comparative transcriptome analysis showed that a total of 5529 genes were differently expressed during fruit ripening compared to freshly harvested fruits. Comprehensive functional enrichment analysis showed that the metabolic pathways of carbon metabolism, plant hormone signal transduction, biosynthesis of amino acids, and starch and sucrose metabolism are involved in fruit ripening. 1-MCP treatment significantly affected fruit transcript levels. A total of 3595 and 5998 differently expressed genes (DEGs) were identified between short-term 1-MCP, long-term 1-MCP treatment and the control, respectively. DEGs are mostly enriched in the similar pathway involved in fruit ripening. A large number of DEGs were also identified between long-term and short-term 1-MCP treatment, with most of the DEGs being enriched in carbon metabolism, starch and sucrose metabolism, plant hormone signal transduction, and biosynthesis of amino acids. The 1-MCP treatments accelerated the lignin accumulation and delayed cellulose degradation during fruit ripening. Considering the rubbery phenotype, we inferred that the cell wall metabolism and hormone signal pathways are closely related to papaya fruit ripening disorder. The RNA-Seq output was confirmed using RT-qPCR by 28 selected genes that were involved in cell wall metabolism and hormone signal pathways. CONCLUSIONS: These results showed that long-term 1-MCP treatment severely inhibited ethylene signaling and the cell wall metabolism pathways, which may result in the failure of cell wall degradation and fruit softening. Our results reveal multiple ripening-associated events during papaya fruit ripening and provide a foundation for understanding the molecular mechanisms underlying 1-MCP treatment on fruit ripening and the regulatory networks.


Assuntos
Carica/genética , Ciclopropanos/farmacologia , Etilenos/antagonistas & inibidores , Reguladores de Crescimento de Planta/antagonistas & inibidores , Proteínas de Plantas/metabolismo , Transcriptoma , Carica/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética
2.
J Agric Food Chem ; 67(22): 6143-6149, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31083983

RESUMO

Strigolactones (SLs) are one of the plant hormones that control several important agronomic traits, such as shoot branching, leaf senescence, and stress tolerance. Manipulation of the SL biosynthesis can increase the crop yield. We previously reported that a triazole derivative, TIS108, inhibits SL biosynthesis. In this study, we synthesized a number of novel TIS108 derivatives. Structure-activity relationship studies revealed that 4-(2-phenoxyethoxy)-1-phenyl-2-(1 H-1,2,4-triazol-1-yl)butan-1-one (KK5) inhibits the level of 4-deoxyorobanchol in roots more strongly than TIS108. We further found that KK5-treated Arabidopsis showed increased branching phenotype with the upregulated gene expression of AtMAX3 and AtMAX4. These results indicate that KK5 is a specific SL biosynthesis inhibitor in rice and Arabidopsis.


Assuntos
Reguladores de Crescimento de Planta/antagonistas & inibidores , Terpenos/antagonistas & inibidores , Triazóis/química , Triazóis/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/efeitos dos fármacos , Oryza/genética , Oryza/metabolismo , Reguladores de Crescimento de Planta/biossíntese , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Terpenos/metabolismo , Triazóis/síntese química
3.
J Plant Physiol ; 236: 117-123, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30974405

RESUMO

Adventitious rooting, a critical process in the vegetative propagation of many ornamentals, can be affected by both light intensity and light quality. We investigated the use of spectral light quality to improve adventitious rooting of Chrysanthemum morifolium cuttings by applying different combinations of blue, red and far-red light. Additionally, unrooted cuttings were treated before planting with two auxin transport inhibitors (TIBA and NPA) to study the effect of light quality on auxin biosynthesis and/or transport. Results showed that lowering the R:FR ratio (decreasing the phytochrome photostationary state, PSS) improved rooting significantly and decreased the inhibiting effect of the auxin transport inhibitor NPA. An extra decrease of PSS by adding blue light to a red + far-red spectrum further enhanced rooting. In contrast, adding blue light to solely red light decreased rooting, an effect which was more pronounced in combination with the auxin transport inhibitors TIBA and NPA. Our results show that phytochrome plays a role in adventitious root formation through the action of auxin, but that also blue light receptors interact in this process.


Assuntos
Chrysanthemum/efeitos da radiação , Raízes de Plantas/crescimento & desenvolvimento , Chrysanthemum/crescimento & desenvolvimento , Ácidos Indolacéticos/antagonistas & inibidores , Ácidos Indolacéticos/metabolismo , Luz , Fitocromo/metabolismo , Reguladores de Crescimento de Planta/antagonistas & inibidores , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Reprodução Assexuada
4.
N Biotechnol ; 48: 44-52, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-29953966

RESUMO

The plant hormone auxin is a key player in the regulation of plant growth and development. Despite numerous studies devoted to understanding its role in a wide spectrum of physiological processes, full appreciation of its function is linked to a comprehensive determination of its spatio-temporal distribution, which plays a crucial role in its mode of action. Conjugation of fluorescent tracers to plant hormones enables sensitive and specific visualization of their subcellular and tissue-specific localization and transport in planta, which represents a powerful tool for plant physiology. However, to date, only a few fluorescently labeled auxins have been developed. We report the synthesis of four novel fluorescently labeled derivatives of indole-3-acetic acid (IAA) in the form of a conjugate with a nitrobenzoxadiazole (NBD) fluorophore together with validation of their biological activity. These compounds, unlike other previously reported auxins fluorescently labeled at N1 position (nitrogen of the indole ring), do not possess auxin activity but rather show dose-dependent inhibition of auxin-induced effects, such as primary root growth inhibition, root hair growth and the auxin reporter DR5::GUS expression. Moreover, the study demonstrates the importance of the character of the linker and optimal choice of the labeling site in the preparation of fluorescently labeled auxins as important variables influencing their biological activity and fluorescent properties.


Assuntos
Corantes Fluorescentes/química , Ácidos Indolacéticos/antagonistas & inibidores , Ácidos Indolacéticos/farmacologia , Reguladores de Crescimento de Planta/antagonistas & inibidores , Reguladores de Crescimento de Planta/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Corantes Fluorescentes/síntese química , Ácidos Indolacéticos/química , Estrutura Molecular , Reguladores de Crescimento de Planta/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Espectrometria de Fluorescência , Espectrofotometria
5.
Plant J ; 93(2): 270-285, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29160608

RESUMO

Fruits stored at low temperature can exhibit different types of chilling injury. In apple, one of the most serious physiological disorders is superficial scald, which is characterized by discoloration and brown necrotic patches on the fruit exocarp. Although this phenomenon is widely ascribed to the oxidation of α-farnesene, its physiology is not yet fully understood. To elucidate the mechanism of superficial scald development and possible means of prevention, we performed an integrated metabolite screen, including an analysis of volatiles, phenols and lipids, together with a large-scale transcriptome study. We also determined that prevention of superficial scald, through the use of an ethylene action inhibitor, is associated with the triggering of cold acclimation-related processes. Specifically, the inhibition of ethylene perception stimulated the production of antioxidant compounds to scavenge reactive oxygen species, the synthesis of fatty acids to stabilize plastid and vacuole membranes against cold temperature, and the accumulation of the sorbitol, which can act as a cryoprotectant. The pattern of sorbitol accumulation was consistent with the expression profile of a sorbitol 6-phosphate dehydrogenase, MdS6PDH, the overexpression of which in transgenic Arabidopsis thaliana plants confirmed its involvement in the cold acclimation and freezing tolerance.


Assuntos
Ciclopropanos/metabolismo , Etilenos/antagonistas & inibidores , Malus/fisiologia , Doenças das Plantas/imunologia , Reguladores de Crescimento de Planta/antagonistas & inibidores , Transcriptoma , Aclimatação , Temperatura Baixa , Resistência à Doença , Etilenos/metabolismo , Frutas/genética , Frutas/imunologia , Frutas/metabolismo , L-Iditol 2-Desidrogenase/genética , Malus/genética , Malus/imunologia , Modelos Biológicos , Reguladores de Crescimento de Planta/metabolismo , Plantas Geneticamente Modificadas , Metabolismo Secundário , Análise de Sequência de RNA , Sorbitol/metabolismo
6.
Plant Cell Environ ; 40(12): 3002-3017, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28857271

RESUMO

In response to flooding/waterlogging, plants develop various anatomical changes including the formation of lysigenous aerenchyma for the delivery of oxygen to roots. Under hypoxia, plants produce high levels of nitric oxide (NO) but the role of this molecule in plant-adaptive response to hypoxia is not known. Here, we investigated whether ethylene-induced aerenchyma requires hypoxia-induced NO. Under hypoxic conditions, wheat roots produced NO apparently via nitrate reductase and scavenging of NO led to a marked reduction in aerenchyma formation. Interestingly, we found that hypoxically induced NO is important for induction of the ethylene biosynthetic genes encoding ACC synthase and ACC oxidase. Hypoxia-induced NO accelerated production of reactive oxygen species, lipid peroxidation, and protein tyrosine nitration. Other events related to cell death such as increased conductivity, increased cellulase activity, DNA fragmentation, and cytoplasmic streaming occurred under hypoxia, and opposing effects were observed by scavenging NO. The NO scavenger cPTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt) and ethylene biosynthetic inhibitor CoCl2 both led to reduced induction of genes involved in signal transduction such as phospholipase C, G protein alpha subunit, calcium-dependent protein kinase family genes CDPK, CDPK2, CDPK 4, Ca-CAMK, inositol 1,4,5-trisphosphate 5-phosphatase 1, and protein kinase suggesting that hypoxically induced NO is essential for the development of aerenchyma.


Assuntos
Etilenos/antagonistas & inibidores , Nitrato Redutase/metabolismo , Óxido Nítrico/metabolismo , Reguladores de Crescimento de Planta/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Triticum/fisiologia , Benzoatos/farmacologia , Cobalto/farmacologia , Imidazóis/farmacologia , Nitrato Redutase/genética , Nitritos/metabolismo , Oxigênio/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Triticum/efeitos dos fármacos , Triticum/genética , Triticum/crescimento & desenvolvimento
7.
Proc Natl Acad Sci U S A ; 114(24): 6388-6393, 2017 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-28559313

RESUMO

The phytohormone jasmonic acid (JA) is vital in plant defense and development. Although biosynthesis of JA and activation of JA-responsive gene expression by the bioactive form JA-isoleucine have been well-studied, knowledge on JA metabolism is incomplete. In particular, the enzyme that hydroxylates JA to 12-OH-JA, an inactive form of JA that accumulates after wounding and pathogen attack, is unknown. Here, we report the identification of four paralogous 2-oxoglutarate/Fe(II)-dependent oxygenases in Arabidopsis thaliana as JA hydroxylases and show that they down-regulate JA-dependent responses. Because they are induced by JA we named them JASMONATE-INDUCED OXYGENASES (JOXs). Concurrent mutation of the four genes in a quadruple Arabidopsis mutant resulted in increased defense gene expression and increased resistance to the necrotrophic fungus Botrytis cinerea and the caterpillar Mamestra brassicae In addition, root and shoot growth of the plants was inhibited. Metabolite analysis of leaves showed that loss of function of the four JOX enzymes resulted in overaccumulation of JA and in reduced turnover of JA into 12-OH-JA. Transformation of the quadruple mutant with each JOX gene strongly reduced JA levels, demonstrating that all four JOXs inactivate JA in plants. The in vitro catalysis of 12-OH-JA from JA by recombinant enzyme could be confirmed for three JOXs. The identification of the enzymes responsible for hydroxylation of JA reveals a missing step in JA metabolism, which is important for the inactivation of the hormone and subsequent down-regulation of JA-dependent defenses.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Oxigenases/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Imunidade Vegetal , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Ciclopentanos/antagonistas & inibidores , Regulação para Baixo , Genes de Plantas , Hidroxilação , Família Multigênica , Mutação , Oxigenases/genética , Oxilipinas/antagonistas & inibidores , Reguladores de Crescimento de Planta/antagonistas & inibidores , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
8.
Plant Sci ; 261: 1-9, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28554688

RESUMO

Numerous studies have demonstrated the function of salinity or jasmonic acid (JA) in plant growth and senescence. This study evaluated how the combination of salinity and methyl jasmonate (MeJA) (SaM) worked as a novel stress and then regulated plant growth in Arabidopsis. Firstly, we found that compared with MeJA or NaCl treatment alone, SaM would significantly intensified plant growth inhibition and senescence in wild-type (WT) seedlings, and these phenotypes could be partially compromised after SaM stress in JA-insensitive mutants. Meanwhile, genes involved in JA signaling and Senescence Associated Gene 13 (SAG13) were dramatically increased by SaM stress than that by MeJA or NaCl alone in WT. Moreover, a group of secondary metabolite - indolic glucosinolates (IGs) showed obvious over-accumulation after SaM treatment than that after each single one in WT, and the seedlings treated with IGs' metabolites performed similar inhibited growth and chlorotic leaves phenotypes compared with those caused by SaM stress. All these indicated the toxicity of IGs and their metabolites would prevent the growth progress of plants. Therefore, we concluded that SaM worked as a novel stress and intensified plant growth inhibition and senescence, which was dependent on JA-dependent and -independent signaling pathways.


Assuntos
Acetatos/farmacologia , Arabidopsis/fisiologia , Ciclopentanos/metabolismo , Ciclopentanos/farmacologia , Oxilipinas/metabolismo , Oxilipinas/farmacologia , Reguladores de Crescimento de Planta/fisiologia , Plântula/crescimento & desenvolvimento , Transdução de Sinais/fisiologia , Cloreto de Sódio/farmacologia , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Reguladores de Crescimento de Planta/antagonistas & inibidores , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Plântula/efeitos dos fármacos , Plântula/fisiologia
9.
Plant Biol (Stuttg) ; 19(2): 211-216, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27718313

RESUMO

The relationship between the phytohormones, gibberellin (GA) and abscisic acid (ABA) and light and temperature on seed germination is still not well understood. We aimed to investigate the role of the ABA and GA on seed germination of Vellozia caruncularis, V. intermedia and V. alutacea in response to light/dark conditions on different temperature. Seeds were incubated in GA (GA3 or GA4 ) or ABA and their respective biosynthesis inhibitors (paclobutrazol - PAC, and fluridone - FLU) solutions at two contrasting temperatures (25 and 40 °C). Furthermore, endogenous concentrations of active GAs and those of ABA were measured in seeds of V. intermedia and V. alutacea during imbibition/germination. Exogenous ABA inhibited the germination of Vellozia species under all conditions tested. GA, FLU and FLU + GA3 stimulated germination in the dark at 25 °C (GA4 being more effective than GA3 ). PAC reduced seed germination in V. caruncularis and V. alutacea, but did not affect germination of V. intermedia at 40 °C either under light or dark conditions. During imbibition in the dark, levels of active GAs decreased in the seeds of V. intermedia, but were not altered in those of V. alutacea. Incubation at 40 °C decreased ABA levels during imbibition in both V. caruncularis and V. alutacea. We conclude that the seeds of Vellozia species studied here require light or high temperature to germinate and ABA has a major role in the regulation of Vellozia seed germination in response to light and temperature.


Assuntos
Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas , Germinação/efeitos dos fármacos , Giberelinas/farmacologia , Magnoliopsida/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Ácido Abscísico/antagonistas & inibidores , Escuridão , Giberelinas/antagonistas & inibidores , Temperatura Alta , Luz , Magnoliopsida/fisiologia , Magnoliopsida/efeitos da radiação , Reguladores de Crescimento de Planta/antagonistas & inibidores , Piridonas/farmacologia , Sementes/efeitos dos fármacos , Sementes/fisiologia , Sementes/efeitos da radiação , Triazóis/farmacologia
10.
Sci Rep ; 6: 30079, 2016 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-27435109

RESUMO

The objective of this study was to investigate Al(3+)-induced IAA transport, distribution, and the relation of these two processes to Al(3+)-inhibition of root growth in alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or 100 µM AlCl3 and were foliar sprayed with water or 6 mg L(-1) IAA. Aluminium stress resulted in disordered arrangement of cells, deformed cell shapes, altered cell structure, and a shorter length of the meristematic zone in root tips. Aluminium stress significantly decreased the IAA concentration in apical buds and root tips. The distribution of IAA fluorescence signals in root tips was disturbed, and the IAA transportation from shoot base to root tip was inhibited. The highest intensity of fluorescence signals was detected in the apical meristematic zone. Exogenous application of IAA markedly alleviated the Al(3+)-induced inhibition of root growth by increasing IAA accumulation and recovering the damaged cell structure in root tips. In addition, Al(3+) stress up-regulated expression of AUX1 and PIN2 genes. These results indicate that Al(3+)-induced reduction of root growth could be associated with the inhibitions of IAA synthesis in apical buds and IAA transportation in roots, as well as the imbalance of IAA distribution in root tips.


Assuntos
Alumínio/toxicidade , Ácidos Indolacéticos/antagonistas & inibidores , Medicago sativa/efeitos dos fármacos , Medicago sativa/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/antagonistas & inibidores , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Transporte Biológico/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento
11.
J Plant Physiol ; 196-197: 53-9, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-27058428

RESUMO

When grown on a non-penetretable at a surface angle of 45°, Arabidopsis roots form wave-like structures and, in wild type rarely, but in certain mutants the tip root even may form circles. These circles are called coils. The formation of coils depends on the complex interaction of circumnutation, gravitropism and negative thigmotropism where - at least - gravitropism is intimately linked to auxin transport and signaling. The knockout mutant of patatin-related phospholipase-AI-1 (pplaI-1) is an auxin-signaling mutant which forms moderately increased numbers of coils on tilted agar plates. We tested the effects of the auxin efflux transport inhibitor NPA (1-naphthylphtalamic acid) and of the influx transport inhibitor 1-NOA (1-naphthoxyacetic acid) which both further increased root coil formation. The pPLAI-1 inhibitors HELSS (haloenol lactone suicide substrate=E-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one) and ETYA (eicosatetraynoic acid) which are auxin signaling inhibitors also increased coil formation. In addition, far red light treatment increased coil formation. The results point out that a disturbance of auxin transport and signaling is one potential cause for root coils. As we show that the mutant pplaI-1 penetrates horizontal agar plates better than wild type plants root movements may help penetrating the soil.


Assuntos
Arabidopsis/genética , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Hidrolases de Éster Carboxílico/antagonistas & inibidores , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Ácidos Indolacéticos/antagonistas & inibidores , Raios Infravermelhos , Mutação , Reguladores de Crescimento de Planta/antagonistas & inibidores , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Transdução de Sinais
12.
Parasitol Int ; 65(4): 319-22, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27021922

RESUMO

Neospora caninum causes abortion and stillbirth in cattle. Identification of effective drugs against this parasite remains a challenge. Previous studies have suggested that disruption of abscisic acid (ABA)-mediated signaling in apicomplexan parasites such as Toxoplasma gondii offers a new drug target. In this study, the ABA inhibitor, fluridone (FLU), was evaluated for its action against N. caninum. Production of endogenous ABA within N. caninum was confirmed by ultra-performance liquid chromatography-tandem quadruple mass spectrometry. Subsequently, FLU treatment efficacy was assessed using in vitro. Results revealed that FLU inhibited the growth of N. caninum and T. gondii in vitro (IC50 143.1±43.96µM and 330.6±52.38µM, respectively). However, FLU did not affect parasite replication at 24h post-infection, but inhibited egress of N. caninum thereafter. To evaluate the effect of FLU in vivo, N. caninum-infected mice were treated with FLU for 15days. FLU treatment appeared to ameliorate acute neosporosis induced by lethal parasite challenge. Together, our data shows that ABA might control egress in N. caninum. Therefore, FLU has potential as a candidate drug for the treatment of acute neosporosis.


Assuntos
Ácido Abscísico/antagonistas & inibidores , Doenças dos Bovinos/tratamento farmacológico , Coccidiose/tratamento farmacológico , Neospora/efeitos dos fármacos , Reguladores de Crescimento de Planta/antagonistas & inibidores , Complicações na Gravidez/veterinária , Piridonas/farmacologia , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/parasitologia , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Gravidez , Organismos Livres de Patógenos Específicos , Natimorto/veterinária
13.
Sci Rep ; 6: 22073, 2016 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-26902640

RESUMO

Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis.


Assuntos
Ácido Abscísico/biossíntese , Furanos/farmacologia , Germinação/efeitos dos fármacos , Giberelinas/biossíntese , Proteínas de Plantas/genética , Piranos/farmacologia , Sementes/efeitos dos fármacos , Soja/efeitos dos fármacos , Ácido Abscísico/agonistas , Ácido Abscísico/antagonistas & inibidores , Regulação da Expressão Gênica de Plantas , Germinação/genética , Germinação/efeitos da radiação , Giberelinas/agonistas , Giberelinas/antagonistas & inibidores , Luz , Reguladores de Crescimento de Planta/agonistas , Reguladores de Crescimento de Planta/antagonistas & inibidores , Reguladores de Crescimento de Planta/biossíntese , Proteínas de Plantas/metabolismo , Piridonas/farmacologia , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/efeitos da radiação , Transdução de Sinais , Soja/genética , Soja/crescimento & desenvolvimento , Soja/efeitos da radiação , Transcrição Genética , Triazóis/farmacologia
14.
Plant Biol (Stuttg) ; 18(3): 353-61, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26434926

RESUMO

In the last decade, genetic and pharmacological approaches have been used to explore ethylene biosynthesis and perception in order to study the role of ethylene and ethylene/auxin interaction in root architecture development. However, recent findings with pharmacological approaches highlight the non-specificity of commonly used inhibitors. This suggests that caution is required for interpreting these studies and that the use of pharmacological agents is a 'double-edged' tool. On one hand, non-specific effects make interpretation difficult unless other experiments, such as with different mutants or with multiple diversely acting chemicals, are conducted. On the other hand, the non-specificity of inhibitors opens up the possibility of uncovering some ligands or modulators of new receptors such as plant glutamate-like receptors and importance of some metabolic hubs in carbon and nitrogen metabolism such as the pyridoxal phosphate biosynthesis involved in the regulation of the root morphogenetic programme. Identification of such targets is a critical issue to improve the efficiency of absorption of macronutrients in relation to root the morphogenetic programme.


Assuntos
Vias Biossintéticas/efeitos dos fármacos , Etilenos/antagonistas & inibidores , Reguladores de Crescimento de Planta/antagonistas & inibidores , Raízes de Plantas/crescimento & desenvolvimento , Etilenos/biossíntese , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Planta/biossíntese , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Receptores de Glutamato/metabolismo
15.
Plant Sci ; 237: 1-7, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26089146

RESUMO

Chrysanthemums require repeated cycles of short-day (SD) photoperiod for successful anthesis, but their vegetative state is strictly maintained under long-day (LD) or night-break (NB) conditions. We have previously demonstrated that photoperiodic flowering of a wild diploid chrysanthemum (Chrysanthemum seticuspe f. boreale) is controlled by a pair of systemic floral regulators, florigen (CsFTL3) and anti-florigen (CsAFT), produced in the leaves. Here, we report the functional characterisation of a local floral regulator, CsTFL1, a chrysanthemum orthologue of TERMINAL FLOWER 1 gene in Arabidopsis. Constitutive expression of CsTFL1 in C. seticuspe (CsTFL1-ox) resulted in extremely late flowering under SD and prevented up-regulation of floral meristem identity genes in shoot tips and leaves. Bimolecular fluorescence complementation assay showed that both CsTFL1 and CsFTL3 interacted with CsFDL1, a bZIP transcription factor FD homologue, in the nucleus. The transient gene expression assay indicated that CsTFL1 suppresses flowering by directly antagonising the flower inductive activity of the CsFTL3-CsFDL1 complex. Our results suggest that strict maintenance of vegetative state under non-inductive photoperiod is achieved by the coordinated action of both the systemic floral inhibitor and local floral inhibitor CsTFL1, which is constitutively expressed in shoot tips.


Assuntos
Chrysanthemum/genética , Florígeno/antagonistas & inibidores , Flores/genética , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Planta/antagonistas & inibidores , Proteínas Repressoras/genética , Chrysanthemum/crescimento & desenvolvimento , Chrysanthemum/efeitos da radiação , Flores/crescimento & desenvolvimento , Flores/efeitos da radiação , Regulação da Expressão Gênica no Desenvolvimento , Luz , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/efeitos da radiação , Fotoperíodo , Folhas de Planta/genética , Folhas de Planta/efeitos da radiação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/efeitos da radiação , Plantas Geneticamente Modificadas , Proteínas Repressoras/metabolismo , Regulação para Cima
16.
PLoS One ; 10(6): e0131213, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26098557

RESUMO

Sink/source relationships, regulating the mobilization of stored carbohydrates from the vegetative tissues to the grains, are of key importance for grain filling and grain yield. We used different inhibitors of plant hormone action to assess their effects on grain yield and on the expression of hormone-associated genes. Among the tested chemicals, 2-indol-3-yl-4-oxo-4-phenylbutanoic acid (PEO-IAA; antagonist of auxin receptor), nordihydroguaiaretic acid (NDGA; abscisic acid (ABA) biosynthesis inhibitor), and 2-aminoisobutyric acid (AIB; ethylene biosynthesis inhibitor) improved grain yield in a concentration dependent manner. These effects were also dependent on the plant developmental stage. NDGA and AIB treatments induced an increase in photosynthesis in flag leaves concomitant to the increments of starch content in flag leaves and grains. NDGA inhibited the expression of ABA-responsive gene, but did not significantly decrease ABA content. Instead, NDGA significantly decreased jasmonic acid and jasmonic acid-isoleucine. Our results support the notion that the specific inhibition of jasmonic acid and ethylene biosynthesis resulted in grain yield increase in rice.


Assuntos
Oryza/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/fisiologia , Ácido Abscísico/antagonistas & inibidores , Ácidos Aminoisobutíricos/farmacologia , Produção Agrícola/métodos , Ciclopentanos/antagonistas & inibidores , Relação Dose-Resposta a Droga , Etilenos/antagonistas & inibidores , Oryza/química , Oryza/fisiologia , Oxilipinas/antagonistas & inibidores , Fotossíntese/efeitos dos fármacos , Reguladores de Crescimento de Planta/antagonistas & inibidores , Folhas de Planta/química , Proteínas de Plantas/antagonistas & inibidores , Receptores de Superfície Celular/antagonistas & inibidores , Amido/análise
17.
Physiol Plant ; 153(1): 30-42, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24862990

RESUMO

The enormous biological diversity of endophytes, coupled with their potential to enhance the production of bioactive metabolites in plants, has driven research efforts focusing on endophytes. However, limited information is available on the impacts of bacterial endophytes on plant secondary metabolism and signaling pathways involved. This work showed that an endophytic Acinetobacter sp. ALEB16, capable of activating accumulation of plant volatile oils, also induced abscisic acid (ABA) and salicylic acid (SA) production in Atractylodes lancea. Pre-treatment of plantlets with biosynthetic inhibitors of ABA or SA blocked the bacterium-induced volatile production. ABA inhibitors suppressed not only the bacterium-induced volatile accumulation but also the induced ABA and SA generation; nevertheless, SA inhibitors did not significantly inhibit the induced ABA biosynthesis, implying that SA acted downstream of ABA production. These results were confirmed by observations that exogenous ABA and SA reversed the inhibition of bacterium-induced volatile accumulation by inhibitors. Transcriptional activities of genes in sesquiterpenoid biosynthesis also increased significantly with bacterium, ABA and SA treatments. Mevalonate pathway proved to be the main source of isopentenyldiphosphate for bacterium-induced sesquiterpenoids, as assessed in experiments using specific terpene biosynthesis inhibitors. These results suggest that Acinetobacter sp. acts as an endophytic elicitor to stimulate volatile biosynthesis of A. lancea via an ABA/SA-dependent pathway, thereby yielding additional insight into the interconnection between ABA and SA in biosynthesis-related signaling pathways.


Assuntos
Ácido Abscísico/metabolismo , Acinetobacter/fisiologia , Atractylodes/fisiologia , Óleos Voláteis/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Óleos Vegetais/metabolismo , Ácido Salicílico/metabolismo , Transdução de Sinais , Ácido Abscísico/antagonistas & inibidores , Acinetobacter/crescimento & desenvolvimento , Atractylodes/química , Atractylodes/microbiologia , Vias Biossintéticas , Endófitos , Hemiterpenos/metabolismo , Óleos Voláteis/isolamento & purificação , Compostos Organofosforados/metabolismo , Reguladores de Crescimento de Planta/antagonistas & inibidores , Óleos Vegetais/isolamento & purificação , Ácido Salicílico/antagonistas & inibidores , Simbiose
18.
Rev. bras. plantas med ; 16(4): 905-911, oct.-dic. 2014. ilus, graf, tab
Artigo em Português | LILACS | ID: lil-729900

RESUMO

Annona mucosa é uma árvore frutífera da família Annonaceae, produtora de importantes metabólitos secundários de interesse medicinal, como lignanas, acetogeninas e alcaloides. A cultura in vitro de calos representa um importante recurso para a produção contínua de metabólitos, viabilizando a conservação da biodiversidade química e a obtenção controlada de material para estudos biológicos e fitoquímicos. O objetivo deste trabalho foi otimizar a produção de calos friáveis de A. mucosa, avaliando o efeito de diferentes meios nutritivos e fitorreguladores. Segmentos de folha e de hipocótilo de plântulas germinadas in vivo foram utilizados como explantes e inoculados nos meios de cultura MS, WPM e B5 suplementados com picloram (2 - 20µM) isolado ou combinado com as citocininas BAP, KIN ou TDZ (0,2 - 1µM). As culturas foram mantidas a 26±2ºC, no escuro, com subcultivos mensais. A produção de calos foi avaliada por aferição do peso dos calos, após 90 dias. Em todos os tratamentos na presença da auxina picloram, o cultivo de hipocótilos resultou em maior porcentagem de formação de calos, sobretudo no meio de cultura WPM. A associação com TDZ produziu massa calogênica friável altamente proliferativa e ausente de oxidação, alcançando valores superiores àqueles obtidos em trabalhos prévios com a espécie. Os resultados viabilizam o uso do material em suspensões celulares e posterior caracterização fitoquímica para a exploração da produção in vitro de metabólitos da espécie.


The Annona mucosa is a fruit tree of the Annonaceae family that produces a range of secondary metabolites of medicinal interest, such as lignans, acetogenins and alkaloids. The callus culture represents a renewable source of valuable medicinal compounds and controlled supply of material for biological and phytochemical studies. Therefore, this study was carried out to investigate the effects of three nutrient media, different concentrations of picloram and cytokinin types, in order to optimize the biomass yield and friability of calluses of A. mucosa. Leaf and hypocotyl segments from seedlings produced from in vivo seed germination were used as explants, which were inoculated in MS, WPM and B5 culture media supplemented with picloram (2-20µM) only or in addition to the cytokinins BAP, KIN or TDZ (0,2 - 1µM ). Cultures were maintained at 26±2ºC in the dark, with monthly subcultures. After 90 days, biomass production was evaluated. In all treatments, hypocotyl explants provided the highest percentage of callus formation, particularly in WPM. The association with TDZ produced highly proliferative friable callus, with no oxidation, reaching higher values than the previous works with this species. The results enable the use of the calluses produced in cell suspensions and the subsequent phytochemical characterization, in order to explore the in vitro production of metabolites of the species.


Assuntos
Annona/anatomia & histologia , Plantas Medicinais/classificação , Meios de Cultura/análise , Técnicas In Vitro/instrumentação , Reguladores de Crescimento de Planta/antagonistas & inibidores
19.
Plant Cell ; 26(11): 4394-408, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25415975

RESUMO

Seed germination and postgerminative growth are regulated by a delicate hormonal balance. Abscisic acid (ABA) represses Arabidopsis thaliana seed germination and postgerminative growth, while brassinosteroids (BRs) antagonize ABA-mediated inhibition and promote these processes. However, the molecular mechanism underlying BR-repressed ABA signaling remains largely unknown. Here, we show that the Glycogen Synthase Kinase 3-like kinase BRASSINOSTEROID INSENSITIVE2 (BIN2), a critical repressor of BR signaling, positively regulates ABA responses during seed germination and postgerminative growth. Mechanistic investigation revealed that BIN2 physically interacts with ABSCISIC ACID INSENSITIVE5 (ABI5), a bZIP transcription factor. Further genetic analysis demonstrated that the ABA-hypersensitive phenotype of BIN2-overexpressing plants requires ABI5. BIN2 was found to phosphorylate and stabilize ABI5 in the presence of ABA, while application of epibrassinolide (the active form of BRs) inhibited the regulation of ABI5 by BIN2. Consistently, the ABA-induced accumulation of ABI5 was affected in BIN2-related mutants. Moreover, mutations of the BIN2 phosphorylation sites on ABI5 made the mutant protein respond to ABA improperly. Additionally, the expression of several ABI5 regulons was positively modulated by BIN2. These results provide evidence that BIN2 phosphorylates and stabilizes ABI5 to mediate ABA response during seed germination, while BRs repress the BIN2-ABI5 cascade to antagonize ABA-mediated inhibition.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Brassinosteroides/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Proteínas Quinases/metabolismo , Ácido Abscísico/antagonistas & inibidores , Ácido Abscísico/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Mutação , Fosforilação , Reguladores de Crescimento de Planta/antagonistas & inibidores , Reguladores de Crescimento de Planta/metabolismo , Plantas Geneticamente Modificadas , Proteínas Quinases/genética , Sementes/efeitos dos fármacos , Sementes/enzimologia , Sementes/genética , Sementes/fisiologia , Transdução de Sinais/efeitos dos fármacos
20.
Insect Biochem Mol Biol ; 53: 66-72, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25111299

RESUMO

Insect galls are abnormal plant tissues induced by galling insects. The galls are used for food and habitation, and the phytohormone auxin, produced by the insects, may be involved in their formation. We found that the silkworm, a non-galling insect, also produces an active form of auxin, indole-3-acetic acid (IAA), by de novo synthesis from tryptophan (Trp). A detailed metabolic analysis of IAA using IAA synthetic enzymes from silkworms indicated an IAA biosynthetic pathway composed of a three-step conversion: Trp → indole-3-acetaldoxime → indole-3-acetaldehyde (IAAld) → IAA, of which the first step is limiting IAA production. This pathway was shown to also operate in gall-inducing sawfly. Screening of a chemical library identified two compounds that showed strong inhibitory activities on the conversion step IAAld → IAA. The inhibitors can be efficiently used to demonstrate the importance of insect-synthesized auxin in gall formation in the future.


Assuntos
Vias Biossintéticas , Bombyx/metabolismo , Inibidores Enzimáticos , Himenópteros/metabolismo , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Planta/biossíntese , Animais , Ácidos Indolacéticos/antagonistas & inibidores , Ácidos Indolacéticos/isolamento & purificação , Reguladores de Crescimento de Planta/antagonistas & inibidores , Reguladores de Crescimento de Planta/isolamento & purificação , Triptofano/análogos & derivados
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA