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1.
BMC Plant Biol ; 19(1): 369, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31438855

RESUMO

BACKGROUND: Cucumis melo is a suitable study material for investigation of fruit ripening owing to its climacteric nature. Long non-coding RNAs have been linked to many important biological processes, such as fruit ripening, flowering time regulation, and abiotic stress responses in plants. However, knowledge of the regulatory roles of lncRNAs underlying the ripening process in C. melo are largely unknown. In this study the complete transcriptome of Cucumis melo L. cv. Hetao fruit at four developmental stages was sequenced and analyzed. The potential role of lncRNAs was predicted based on the function of differentially expressed target genes and correlated genes. RESULTS: In total, 3857 lncRNAs were assembled and annotated, of which 1601 were differentially expressed between developmental stages. The target genes of these lncRNAs and the regulatory relationship (cis- or trans-acting) were predicted. The target genes were enriched with GO terms for biological process, such as response to auxin stimulus and hormone biosynthetic process. Enriched KEGG pathways included plant hormone signal transduction and carotenoid biosynthesis. Co-expression network construction showed that LNC_002345 and LNC_000154, which were highly expressed, might co-regulate with mutiple genes associated with auxin signal transduction and acted in the same pathways. We identified lncRNAs (LNC_000987, LNC_000693, LNC_001323, LNC_003610, LNC_001263 and LNC_003380) that were correlated with fruit ripening and the climacteric, and may participate in the regulation of ethylene biosynthesis and metabolism and the ABA signaling pathway. A number of crucial transcription factors, such as ERFs, WRKY70, NAC56, and NAC72, may also play important roles in the regulation of fruit ripening in C. melo. CONCLUSIONS: Our results predict the regulatory functions of the lncRNAs during melon fruit development and ripening, and 142 highly expressed lncRNAs (average FPKM > 100) were identified. These lncRNAs participate in the regulation of auxin signal transduction, ethylene, sucrose biosynthesis and metabolism, the ABA signaling pathway, and transcription factors, thus regulating fruit development and ripening.


Assuntos
Cucumis melo/genética , Frutas/genética , RNA Longo não Codificante/fisiologia , RNA de Plantas/fisiologia , Mapeamento Cromossômico , Climatério , Cucumis melo/crescimento & desenvolvimento , Frutas/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Genoma de Planta , Fenótipo , Reguladores de Crescimento de Planta/metabolismo , Análise de Sequência de RNA , Transdução de Sinais , Transcriptoma
2.
Plant Sci ; 286: 17-27, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300138

RESUMO

The plant-specific gibberellic acid (GA)-stimulated transcript gene family is critical for plant growth and development. There are 10 family members in rice (Oryza sativa), known as OsGASRs. However, few have been functionally characterized. Here, we investigated the function of OsGASR9 in rice. OsGASR9 transcripts were detected in various tissues, with the lowest and highest levels in leaves and panicles, respectively. Greater mRNA levels accumulated in young, compared with in old, panicles and spikelets. OsGASR9 localized to the plasma membrane, cytoplasm and nucleus. Transgenic RNA interference-derived lines in the Zhonghua 11 background exhibited reduced plant height, grain size and yield compared with the wild-type. The two osgasr9 mutants in the Nipponbare background showed similar phenotypes. Conversely, the overexpression of OsGASR9 in the two backgrounds increased plant height and grain size. A significantly increased grain yield per plant was also observed in the overexpression lines having a Nipponbare background. Furthermore, by measuring the GA-induced lengths of the second leaf sheaths and α-amylase activity levels of seeds, we concluded that OsGASR9 is a positive regulator of responses to GA in rice. Thus, OsGASR9 may regulate plant height, grain size and yield through the GA pathway and could have an application value in breeding.


Assuntos
Giberelinas/metabolismo , Oryza/genética , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Família Multigênica , Oryza/crescimento & desenvolvimento , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Interferência de RNA
3.
Plant Sci ; 286: 37-48, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300140

RESUMO

In this work, a non-metallicolous and a metallicolous population of S. paradoxa were exposed to copper excess and fungal elicitation, and investigated for phytohormone production and cytological alterations. Under the stress applied separately and in combination, S. paradoxa plants varied phytohormone concentration in a population-specific way, suggesting a different signalling in response to biotic and abiotic stimuli according to the environment of origin. Generally, the stress responses consisted in increased levels of salicylic acid, auxin, and gibberellin in the non-metallicolous population, and of jasmonic and abscisic acid in the metallicolous one. Interestingly, the metallicolous population increased the level of such phytohormones following exposure to the fungal elicitor only in the presence of copper. This alternative hormonal signalling could derive from the incompatibility between the ordinary ROS-mediated response to pathogens and the acquired mechanisms that prevent oxidative stress in the population from the metal-rich soil. Furthermore, stress-induced autophagic phenomena were more evident in the non-metallicolous plants than in the metallicolous ones, suggesting that the adaptation to the metalliferous environment has also affected autophagy intensity and signalling in response to copper excess and fungal elicitation.


Assuntos
Cobre/efeitos adversos , Fungos/fisiologia , Reguladores de Crescimento de Planta/metabolismo , Silene/efeitos dos fármacos , Silene/microbiologia , Poluentes do Solo/efeitos adversos , Adaptação Fisiológica , Doenças das Plantas/microbiologia , Silene/crescimento & desenvolvimento , Silene/metabolismo
4.
Plant Mol Biol ; 101(1-2): 203-220, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31297725

RESUMO

KEY MESSAGE: Here, a functional characterization of a wheat MSR has been presented: this protein makes a contribution to the plant's tolerance of abiotic stress, acting through its catalytic capacity and its modulation of ROS and ABA pathways. The molecular mechanism and function of certain members of the methionine sulfoxide reductase (MSR) gene family have been defined, however, these analyses have not included the wheat equivalents. The wheat MSR gene TaMSRA4.1 is inducible by salinity and drought stress and in this study, we demonstrate that its activity is restricted to the Met-S-SO enantiomer, and its subcellular localization is in the chloroplast. Furthermore, constitutive expression of TaMSRA4.1 enhanced the salinity and drought tolerance of wheat and Arabidopsis thaliana. In these plants constitutively expressing TaMSRA4.1, the accumulation of reactive oxygen species (ROS) was found to be influenced through the modulation of genes encoding proteins involved in ROS signaling, generation and scavenging, while the level of endogenous abscisic acid (ABA), and the sensitivity of stomatal guard cells to exogenous ABA, was increased. A yeast two-hybrid screen, bimolecular fluorescence complementation and co-immunoprecipitation assays demonstrated that heme oxygenase 1 (HO1) interacted with TaMSRA4.1, and that this interaction depended on a TaHO1 C-terminal domain. In plants subjected to salinity or drought stress, TaMSRA4.1 reversed the oxidation of TaHO1, activating ROS and ABA signaling pathways, but not in the absence of HO1. The aforementioned properties advocate TaMSRA4.1 as a candidate for plant genetic enhancement.


Assuntos
Heme Oxigenase-1/metabolismo , Metionina Sulfóxido Redutases/metabolismo , Transdução de Sinais , Estresse Fisiológico , Triticum/enzimologia , Ácido Abscísico/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/fisiologia , Secas , Perfilação da Expressão Gênica , Heme Oxigenase-1/genética , Metionina Sulfóxido Redutases/genética , Oxirredução , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Salinidade , Tolerância ao Sal , Plântula/enzimologia , Plântula/genética , Plântula/fisiologia , Triticum/genética , Triticum/fisiologia , Técnicas do Sistema de Duplo-Híbrido
5.
Biol Res ; 52(1): 39, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31358053

RESUMO

In the growth condition(s) of plants, numerous secondary metabolites (SMs) are produced by them to serve variety of cellular functions essential for physiological processes, and recent increasing evidences have implicated stress and defense response signaling in their production. The type and concentration(s) of secondary molecule(s) produced by a plant are determined by the species, genotype, physiology, developmental stage and environmental factors during growth. This suggests the physiological adaptive responses employed by various plant taxonomic groups in coping with the stress and defensive stimuli. The past recent decades had witnessed renewed interest to study abiotic factors that influence secondary metabolism during in vitro and in vivo growth of plants. Application of molecular biology tools and techniques are facilitating understanding the signaling processes and pathways involved in the SMs production at subcellular, cellular, organ and whole plant systems during in vivo and in vitro growth, with application in metabolic engineering of biosynthetic pathways intermediates.


Assuntos
Reguladores de Crescimento de Planta/metabolismo , Fenômenos Fisiológicos Vegetais , Metabolismo Secundário/fisiologia , Estresse Fisiológico/fisiologia , Técnicas de Cultura de Células , Regulação da Expressão Gênica de Plantas/fisiologia , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Plantas/metabolismo , Transdução de Sinais
6.
BMC Plant Biol ; 19(1): 317, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307384

RESUMO

BACKGROUND: Anthocyanins, which are colored pigments, have long been used as food and pharmaceutical ingredients due to their potential health benefits, but the intermediate signals through which environmental or developmental cues regulate anthocyanin biosynthesis remains poorly understood. Fleshy fruits have become a good system for studying the regulation of anthocyanin biosynthesis, and exploring the mechanism underlying pigment metabolism is valuable for controlling fruit ripening. RESULTS: The present study revealed that ABA accumulated during Lycium fruit ripening, and this accumulation was positively correlated with the anthocyanin contents and the LbNCED1 transcript levels. The application of exogenous ABA and of the ABA biosynthesis inhibitor fluridon increased and decreased the content of anthocyanins in Lycium fruit, respectively. This is the first report to show that ABA promotes the accumulation of anthocyanins in Lycium fruits. The variations in the anthocyanin content were consistent with the variations in the expression of the genes encoding the MYB-bHLH-WD40 transcription factor complex or anthocyanin biosynthesis-related enzymes. Virus-induced LbNCED1 gene silencing significantly slowed fruit coloration and decreased both anthocyanin and ABA accumulation during Lycium fruit ripening. An qRT-PCR analysis showed that LbNCED1 gene silencing clearly reduced the transcript levels of both structural and regulatory genes in the flavonoid biosynthetic pathway. CONCLUSIONS: Based on the results, a model of ABA-mediated development-dependent anthocyanin biosynthesis and fruit coloration during Lycium fruit maturation was proposed. In this model, the developmental cues transcriptionally activates LbNCED1 and thus enhances accumulation of the phytohormone ABA, and the accumulated ABA stimulates transcription of the MYB-bHLH-WD40 transcription factor complex to upregulate the expression of structural genes in the flavonoid biosynthetic pathway and thereby promoting anthocyanin production and fruit coloration. Our results provide a valuable strategy that could be used in practice to regulate the ripening and quality of fresh fruit in medicinal and edible plants by modifying the phytohormone ABA.


Assuntos
Ácido Abscísico/metabolismo , Antocianinas/biossíntese , Frutas/metabolismo , Lycium/metabolismo , Pigmentação , Reguladores de Crescimento de Planta/metabolismo , Dioxigenases/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Genes de Plantas , Lycium/genética , Lycium/crescimento & desenvolvimento , Proteínas de Plantas/genética , Transdução de Sinais
7.
BMC Plant Biol ; 19(1): 306, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296169

RESUMO

BACKGROUND: Phosphorus (P) deficiency in soil is a worldwide issue and a major constraint on the production of sorghum, which is an important staple food, forage and energy crop. The depletion of P reserves and the increasing price of P fertilizer make fertilizer application impractical, especially in developing countries. Therefore, identifying sorghum accessions with low-P tolerance and understanding the underlying molecular basis for this tolerance will facilitate the breeding of P-efficient plants, thereby resolving the P crisis in sorghum farming. However, knowledge in these areas is very limited. RESULTS: The 29 sorghum accessions used in this study demonstrated great variability in their tolerance to low-P stress. The internal P content in the shoot was correlated with P tolerance. A low-P-tolerant accession and a low-P-sensitive accession were chosen for RNA-seq analysis to identify potential underlying molecular mechanisms. A total of 2089 candidate genes related to P starvation tolerance were revealed and found to be enriched in 11 pathways. Gene Ontology (GO) enrichment analyses showed that the candidate genes were associated with oxidoreductase activity. In addition, further study showed that malate affected the length of the primary root and the number of tips in sorghum suffering from low-P stress. CONCLUSIONS: Our results show that acquisition of P from soil contributes to low-P tolerance in different sorghum accessions; however, the underlying molecular mechanism is complicated. Plant hormone (including auxin, ethylene, jasmonic acid, salicylic acid and abscisic acid) signal transduction related genes and many transcriptional factors were found to be involved in low-P tolerance in sorghum. The identified accessions will be useful for breeding new sorghum varieties with enhanced P starvation tolerance.


Assuntos
Fósforo/deficiência , Reguladores de Crescimento de Planta/metabolismo , Transdução de Sinais/genética , Sorghum/genética , Grão Comestível/genética , Grão Comestível/fisiologia , Perfilação da Expressão Gênica , Solo/química , Sorghum/fisiologia
8.
Chemosphere ; 233: 905-912, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31340418

RESUMO

We investigated the interconnected roles of reactive oxygen species (ROS) generated upon seed exposure to glyphosate and/or gibberellic acid (GA3), and the possible interaction between the herbicide and the plant hormone during germination of sorghum seeds. GA3 decreased antioxidant enzyme activity in embryos, and the over accumulation of hydrogen peroxide (H2O2) in 1000 mM GA3-treated seeds resulted in the lowest germinability among treatments. The deleterious effects of glyphosate on germination rate, in contrast, were not related to H2O2 accumulation, but to its interference with the mitochondrial electron transport chain. However, interactions among glyphosate, GA3 and H2O2 during seed germination were observed. Similar to paclobutrazol, glyphosate appears to interfere with the de novo synthesis of gibberellin, which modulates seed germination through oxidative metabolism. Seeds experiencing increased oxidative status due to GA3 (100 mM) or H2O2 (50 mM) applications had the effects of glyphosate on germination rate reversed. Since decreased ATP synthesis is a secondary effect of glyphosate, increased H2O2 concentrations in embryos must facilitate germination by decreasing the energy required by ATP-demanding metabolism. Our results showed that glyphosate affect seed germination of sorghum, and that the herbicide interacts with oxidative and gibberellin metabolisms.


Assuntos
Germinação/efeitos dos fármacos , Giberelinas/metabolismo , Glicina/análogos & derivados , Herbicidas/farmacologia , Peróxido de Hidrogênio/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Sorghum/metabolismo , Antioxidantes/metabolismo , Grão Comestível/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Glicina/farmacologia , Sementes/efeitos dos fármacos
9.
Chemosphere ; 233: 954-965, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31340423

RESUMO

Heavy metals such as cadmium and zinc constitute major pollutants in coastal areas and frequently accumulate in salt marshes. The wetland halophyte plant species Kosteletzkya pentacarpos is a promising species for phytostabilization of contaminated areas. In order to assess the role of the antisenescing phytohormone cytokinin in heavy metal resistance in this species, seedlings were exposed for two weeks to Cd (10 µM), Zn (100 µM) or Cd + Zn (10 µM + 100 µM) in the presence or absence of 50 mM NaCl and half of the plants were sprayed every two days with the cytokinin trans-zeatine riboside (10 µM). Zinc reduced the endogenous cytokinin concentration. Exogenous cytokinin increased plant growth, stomatal conductance, net photosynthesis and total ascorbate and reduced oxidative stress estimated by malondialdehyde in Zn-treated plants maintained in the absence of NaCl. Heavy metal induced an increase in the senescing hormone ethylene which was reduced by cytokinin treatment. Plants exposed to the mixed treatment (Cd + Zn) exhibited a specific hormonal status in relation to accumulation of abscisic acid and depletion of salicylic acid. Non-protein thiols (glutathione and phytochelatins) accumulated in response to Cd and Cd + Zn. It is concluded that toxic doses of Cd and Zn have different impacts on the plant behavior and that the simultaneous presence of the two elements induces a specific physiological constraint at the plant level. Salinity helps the plant to cope with heavy metal toxicities and the plant hormone cytokinin assumes key function in Zn resistance but its efficiency is lower in the presence of NaCl.


Assuntos
Cádmio/toxicidade , Citocininas/metabolismo , Hibiscus/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Cloreto de Sódio/farmacologia , Zinco/toxicidade , Ácido Abscísico/análise , Glutationa/metabolismo , Hibiscus/crescimento & desenvolvimento , Fotossíntese/efeitos dos fármacos , Fitoquelatinas/metabolismo , Desenvolvimento Vegetal/efeitos dos fármacos , Ácido Salicílico/análise , Salinidade , Plântula/fisiologia , Poluentes Químicos da Água/toxicidade , Áreas Alagadas
10.
BMC Plant Biol ; 19(1): 264, 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31215396

RESUMO

BACKGROUND: Brassica napus L. has little or no primary dormancy, but exhibits great variation in secondary dormancy. Secondary dormancy potential in oilseed rape can lead to the emergence of volunteer plants that cause genetic contamination, reduced quality and biosafety issues. However, the mechanisms underlying secondary dormancy are poorly understood. In this study, cultivars Huaiyou-WSD-H2 (H) and Huaiyou-SSD-V1 (V), which exhibit low (approximately 5%) and high (approximately 95%) secondary dormancy rate, respectively, were identified. Four samples, before (Hb and Vb) and after (Ha and Va) secondary dormancy induction by polyethylene glycol (PEG), were collected to identify the candidate genes involved in secondary dormancy via comparative transcriptome profile analysis. RESULTS: A total of 998 differentially expressed genes (DEGs), which are mainly involved in secondary metabolism, transcriptional regulation, protein modification and signaling pathways, were then detected. Among these DEGs, the expression levels of those involved in the sulfur-rich indole glucosinolate (GLS)-linked auxin biosynthesis pathway were markedly upregulated in the dormant seeds (Va), which were validated by qRT-PCR and subsequently confirmed via detection of altered concentrations of indole-3-acetic acid (IAA), IAA conjugates and precursors. Furthermore, exogenous IAA applications to cultivar H enhanced secondary dormancy. CONCLUSION: This study first (to our knowledge) elucidated that indole GLS-linked auxin biosynthesis is enhanced during secondary dormancy induced by PEG, which provides valuable information concerning secondary dormancy and expands the current understanding of the role of auxin in rapeseed.


Assuntos
Brassica napus/metabolismo , Ácidos Indolacéticos/metabolismo , Dormência de Plantas , Reguladores de Crescimento de Planta/metabolismo , Brassica napus/genética , Brassica napus/fisiologia , Perfilação da Expressão Gênica , Genes de Plantas/genética , Genes de Plantas/fisiologia , Glucosinolatos/metabolismo , Indóis/metabolismo , Redes e Vias Metabólicas , Dormência de Plantas/genética , Dormência de Plantas/fisiologia , Metabolismo Secundário/genética , Metabolismo Secundário/fisiologia
11.
World J Microbiol Biotechnol ; 35(6): 90, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31147784

RESUMO

The ability of plant growth promoting rhizobacteria (PGPR) for imparting abiotic stress tolerance to plants has been widely explored in recent years; however, the diversity and potential of these microbes have not been maximally exploited. In this study, we characterized four bacterial strains, namely, Pseudomonas aeruginosa PM389, Pseudomonas aeruginosa ZNP1, Bacillus endophyticus J13 and Bacillus tequilensis J12, for potential plant growth promoting (PGP) traits under osmotic-stress, induced by 25% polyethylene glycol (PEG) in the growth medium. Growth curve analysis was performed in LB medium with or without PEG, in order to understand the growth patterns of these bacteria under osmotic-stress. All strains were able to grow and proliferate under osmotic-stress, although their growth rate was slower than that under non-stressed conditions (LB without PEG). Bacterial secretions were analyzed for the presence of exopolysaccharides and phytohormones and it was observed that all four strains released these compounds into the media, both, under stressed and non-stressed conditions. In the Pseudomonas strains, osmotic stress caused a decrease in the levels of auxin (IAA) and cytokinin (tZ), but an increase in the levels of gibberellic acid. The Bacillus strains on the other hand showed a stress-induced increase in the levels of all three phytohormones. P. aeruginosa ZNP1 and B. endophyticus J13 exhibited increased EPS production under osmotic-stress. While osmotic stress caused a decrease in the levels of EPS in P. aeruginosa PM389, B. tequilensis J12 showed no change in EPS quantities released into the media under osmotic stress when compared to non-stressed conditions. Upon inoculating Arabidopsis thaliana seedlings with these strains individually, it was observed that all four strains were able to ameliorate the adverse effects of osmotic-stress (induced by 25% PEG in MS-Agar medium) in the plants, as evidenced by their enhanced fresh weight, dry weight and plant water content, as opposed to osmotic-stressed, non-inoculated plants.


Assuntos
Arabidopsis/microbiologia , Fenômenos Fisiológicos Bacterianos , Secas , Pressão Osmótica , Desenvolvimento Vegetal , Reguladores de Crescimento de Planta/metabolismo , Polissacarídeos Bacterianos/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Bacillus/crescimento & desenvolvimento , Bacillus/fisiologia , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Citocininas/metabolismo , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Raízes de Plantas/microbiologia , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/fisiologia , Rizosfera , Plântula/crescimento & desenvolvimento , Microbiologia do Solo , Estresse Fisiológico/fisiologia
12.
BMC Plant Biol ; 19(1): 272, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31226952

RESUMO

BACKGROUND: Cyclophilins (CYPs), belonging to the peptidyl prolyl cis/trans isomerase (PPIase) superfamily, play important roles during plant responses to biotic and abiotic stresses. RESULTS: Here, a total of 79 CYPs were identified in the genome of Gossypium hirsutum. Of which, 65 GhCYPs only contained one cyclophilin type PPIase domain, others 14 GhCYPs contain additional domains. A number of cis-acting elements related to phytohormone signaling were predicated in the upstream of GhCYPs ORF. The expression analysis revealed that GhCYPs were induced in response to cold, hot, salt, PEG and Verticillium dahliae infection. In addition, the functional importance of GhCYP-3 in Verticillium wilt resistance was also presented in this study. GhCYP-3 showed both cytoplasmic and nuclear localization. Overexpression of GhCYP-3 in Arabidopsis significantly improved Verticillium wilt resistance of the plants. Recombinant GhCYP-3 displayed PPIase activity and evident inhibitory effects on V. dahliae in vitro. Moreover, the extracts from GhCYP-3 transgenic Arabidopsis displayed significantly inhibit activity to conidia germinating and hyphal growth of V. dahliae. CONCLUSIONS: Our study identified the family members of cotton CYP genes using bioinformatics tools. Differential expression patterns of GhCYPs under various abiotic stress and V. dahliae infection conditions provide a comprehensive understanding of the biological functions of candidate genes. Moreover, GhCYP-3 involved in the resistance of cotton to V. dahliae infection presumably through antifungal activity.


Assuntos
Ciclofilinas/genética , Resistência à Doença/genética , Gossypium/genética , Doenças das Plantas/microbiologia , Verticillium , Sequência de Aminoácidos , Arabidopsis/genética , Clonagem Molecular , Sequência Conservada , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Humanos , Doenças das Plantas/genética , Reguladores de Crescimento de Planta/metabolismo , Alinhamento de Sequência , Estresse Fisiológico , Transcriptoma
13.
Plant Sci ; 285: 132-140, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203877

RESUMO

Xanthomonas campestris pv. campestris (Xcc)- responsive soluble and cell wall-bound hydroxycinnamic acids (HAs) and flavonoids accumulation in relation to hormonal changes in two Brassica napus cultivars contrasting disease susceptibility were interpreted with regard to the disease resistance. At 14-day post inoculation with Xcc, disease resistance in cv. Capitol was distinguished by an accumulation of specific (HAs) and flavonoids particularly in cell-wall bound form, and was characterized by higher endogenous jasmonic acid (JA) resulting in a decrease of JA-based balance with other hormones, as well as enhanced expression of JA signaling that was concurrently based on upregulation of PAP1 (production of anthocyanin pigment 1), MYB transcription factor, and phenylpropanoid biosynthetic genes. Fourier transform infrared spectra confirmed higher amounts of esterified phenolic acids in cv. Capitol. These results indicate that enhanced JA levels and signaling in resistant cultivar was associated with a higher accumulation of HAs and flavonoids, particularly in the cell wall-bound form, and vice versa in the susceptible cultivar (cv. Mosa) with enhanced SA-, ABA-, and CK- levels and signaling. Thus the JA-mediated phenolic metabolites accumulation is an important feature for the management and breeding program to develop disease-resistant B. napus cultivar.


Assuntos
Brassica napus/imunologia , Parede Celular/metabolismo , Ácidos Cumáricos/metabolismo , Ciclopentanos/metabolismo , Resistência à Doença , Oxilipinas/metabolismo , Fenóis/metabolismo , Reguladores de Crescimento de Planta/fisiologia , Xanthomonas campestris , Brassica napus/metabolismo , Brassica napus/microbiologia , Brassica napus/fisiologia , Parede Celular/fisiologia , Resistência à Doença/fisiologia , Suscetibilidade a Doenças/microbiologia , Suscetibilidade a Doenças/fisiopatologia , Flavonoides/metabolismo , Peroxidação de Lipídeos , Microscopia Eletrônica de Varredura , Peptídeo Hidrolases/metabolismo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/microbiologia , Folhas de Planta/ultraestrutura , Espécies Reativas de Oxigênio/metabolismo
14.
Plant Sci ; 285: 200-213, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203885

RESUMO

NONRACE-SPECIFIC DISEASE RESISTANCE (NDR1) is a widely characterized gene that plays a key role in defense against multiple bacterial, fungal, oomycete and nematode plant pathogens. NDR1 is required for activation of resistance by multiple NB and LRR-containing (NLR) protein immune sensors and contributes to basal defense. The role of NDR1 in positively regulating salicylic acid (SA)-mediated plant defense responses is well documented. However, ndr1-1 plants flower earlier and show accelerated development in comparison to wild type (WT) Arabidopsis plants, indicating that NDR1 is a negative regulator of flowering and growth. Exogenous application of gibberellic acid (GA) further accelerates the early flowering phenotype in ndr1-1 plants, while the GA biosynthesis inhibitor paclobutrazol attenuated the early flowering phenotype of ndr1-1, but not to WT levels, suggesting partial resistance to paclobutrazol and enhanced GA response in ndr1-1 plants. Mass spectroscopy analyses confirmed that ndr1-1 plants have 30-40% higher levels of GA3 and GA4, while expression of various GA metabolic genes and major flowering regulatory genes is also altered in the ndr1-1 mutant. Taken together this study provides evidence of crosstalk between the ndr1-1-mediated defense and GA-regulated developmental programs in plants.


Assuntos
Arabidopsis/genética , Flores/crescimento & desenvolvimento , Giberelinas/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Proteínas de Arabidopsis/fisiologia , Resistência à Doença/genética , Resistência à Doença/fisiologia , Giberelinas/metabolismo , Mutação/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Ácido Salicílico/metabolismo , Fatores de Transcrição/fisiologia , Transcriptoma , Verticillium
15.
Plant Sci ; 285: 79-90, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203896

RESUMO

Inactivation of abscisic acid (ABA) in vitro may be catalyzed either by ABA 8'-hydroxylase (ABA8'OH) or by ABA uridine diphosphate glucosyltransferase (ABAUGT), which conjugates ABA with glucose. However, the involvement of these enzymes in the control of ABA content in vivo, especially ABAUGT, has not been fully elucidated. In pea seeds, both PsABAUGT1 and PsABA8'OH1 contribute to the reduction of ABA content during seed maturation and imbibition; however, during the first hours of imbibition, a high expression of only PsABAUGT1 was observed. Imbibition of seeds with H2O2 increased the ABA content despite the oxygen availability and altered the expression of metabolic genes. The expression of the biosynthetic gene 9-cis-epoxycarotene dioxygenase (PsNCED2) was increased, while that of PsABAUGT1 was decreased in each H2O2 experiment despite O2 availability. Under hypoxia, only seeds imbibed with H2O2 germinated, while under nonlimiting oxygen conditions, the germination rate was not altered by H2O2. Under hypoxia, the germination rate of H2O2-imbibed seeds seemed to not depend on the absolute ABA content and rather on the balance between ABA and gibberellins (GA), as H2O2 increased the expression of GA synthesis genes. Overexpression of PsABAUGT1 in Arabidopsis decreases seed ABA content, accelerates germination and reduces seed sensitivity to exogenously applied ABA, confirming the ability of PsABAUGT1 to inactivate ABA. Thus, PsABAUGT1 is a new player in the regulation of ABA content in maturating and imbibed pea seeds, both under standard conditions and in response to H2O2.


Assuntos
Ácido Abscísico/metabolismo , Genes de Plantas/fisiologia , Germinação , Peróxido de Hidrogênio/metabolismo , Ervilhas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/fisiologia , Sementes/metabolismo , Arabidopsis , Homeostase , Ervilhas/crescimento & desenvolvimento , Ervilhas/fisiologia , Plantas Geneticamente Modificadas , Sementes/crescimento & desenvolvimento
16.
J Plant Physiol ; 239: 10-17, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177026

RESUMO

Auxin is one of the crucial plant hormones which stimulates and controls cell and plant growth. The effects of auxin IBA (indole-3-butyric acid) during 10-days on maize plants growth in controlled conditions (hydroponic, 16-h photoperiod, 70% humidity, 25/20 °C temperature), depended on its concentration in the substrate. A high concentration (10-7 M) of IBA inhibited root growth, evoked the development of apoplasmic barriers (Casparian bands and suberin lamellae) closer to the root apex, and elevated the amount of lignin in roots. A low concentration (10-11 M) of IBA stimulated root growth but affected neither the development of apoplasmic barriers, nor the amount of lignin. Auxin in a 10-8 M concentration influenced the root growth to a minimal extent compare to the control, and it was the non-effective concentration. Plant cell walls as cell structures ensure cell enlargement and plant growth, and have to react to auxin stimulus by modification of their components. We found the most significant changes in the composition of the PF III fraction (lignocellulosic complex) of the cell wall. The presence of auxin in the substrate affected all three components of this fraction - Klason lignin and both the by acid (2 M TFA) non-hydrolysable and the hydrolysable parts of this complex. The ratio of the non-hydrolysable part to the Klason lignin increased from 1.3 to 3.3 with increasing auxin concentrations in the substrate. This may be related to the deposition of polysaccharides and lignin in the cell wall, which help maintain the specific tensile stress of, and turgor pressure on, the cell walls.


Assuntos
Indóis/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Zea mays/efeitos dos fármacos , Zea mays/fisiologia , Parede Celular/efeitos dos fármacos , Parede Celular/fisiologia , Relação Dose-Resposta a Droga , Ácidos Indolacéticos/administração & dosagem , Ácidos Indolacéticos/farmacologia , Indóis/administração & dosagem , Lipídeos/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Xilema/efeitos dos fármacos , Xilema/fisiologia
17.
J Plant Physiol ; 239: 52-60, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31185317

RESUMO

The contents of eight phytohormones and the expression levels of genes encoding enzymes related to abscisic acid (ABA) biosynthesis and deactivation/degradation and transcription factors (TFs) related to fruit ripening were studied in the non-climacteric strawberry fruit (Fragaria × ananassa Duch., cv. 'Seolhyang') at six developmental stages. The hormones tested were ABA, indole-3-acetic acid (IAA), gibberellic acid 4 (GA4), jasmonic acid (JA), methyljasmonate (MJ), jasmonoyl isoleucine (JA-Ile), salicylic acid (SA), and ethylene (ET). The developmental and ripening stages studied were small green (S1, 11 days post-anthesis, DPA), green (S2, 20 DPA), breaker (S3, 24 DPA), pink (S4, 27 DPA), red (S5, 31 DPA), and fully red (S6, 40 DPA). IAA and GA4 contents were highest at S1 and gradually decreased after this stage. ABA content was low at S1-S3 and then increased rapidly until peaking at S6. By contrast, MJ content showed no significant changes over time, while SA content gradually increased. JA, JA-Ile, and ET contents were either insufficient for quantification or undetectable. Expression of the ABA biosynthesis genes FaNCED1 and FaABA2 increased during fruit ripening, whereas expression of the ABA deactivation/degradation genes FaUGT75C1 and FaCYP707A1 was high early in development, when ABA content was low, and then decreased. Among four ripening-related TF genes, FaMYB1, FaMYB5, FaMYB10, and FaASR, only the expression of FaMYB10 seemed to be closely related to strawberry fruit ripening. Our study supports the idea that ABA and FaMYB10 appear to be the key hormone and TF regulating strawberry ripening.


Assuntos
Ácido Abscísico/genética , Fragaria/genética , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Ácido Abscísico/metabolismo , Fragaria/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo
18.
Syst Appl Microbiol ; 42(4): 517-525, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31176475

RESUMO

Plant roots are inhabited by a large diversity of microbes, some of which are beneficial for the growth of plants and known as plant growth promoting rhizobacteria (PGPR). In this work, we designed a multispecies inoculum of PGPRs containing Rhizobium phaseoli, Sinorhizobium americanum and Azospirillum brasilense nitrogen-fixing strains and other plant-growth promoting bacteria such as Bacillus amyloliquefaciens and Methylobacterium extorquens. We evaluated the effect of this group of bacteria on the growth of one-month-old maize plants. The multispecies inoculum exerted a beneficial effect on maize plants that was greater than that obtained with single-bacteria. Using the same multispecies inoculant, acetylene reduction was recorded in 5-day-old roots indicating active nitrogen fixation by bacteria in maize. Azospirillum nitrogen fixation was lower than that obtained with the multispecies inoculum. We focused on the analysis of R. phaseoli gene expression in presence of other PGPRs. Many R. phaseoli up- regulated genes in roots in the presence of other bacteria are hypothetical, showing our poor knowledge of bacteria-bacteria interactions. Other genes indicated bacterial nutrient competition and R. phaseoli stress. Differentially expressed transcriptional regulators were identified that may be key in bacteria-bacteria interaction regulation. Additionally, gene expression was analyzed from Azospirillum but not from sinorhizobia and methylobacteria due to the low number of transcripts obtained from maize roots. The metatranscriptomic analysis from maize roots showed expression of Azospirillum nif genes in the presence of PGPR bacteria. Our hypothesis is that other bacteria stimulate Azospirillum capacity to fix nitrogen and this should be further explored.


Assuntos
Bactérias/genética , Interações Microbianas , Fixação de Nitrogênio/genética , Reguladores de Crescimento de Planta/genética , Zea mays/microbiologia , Bactérias/metabolismo , Proteínas de Bactérias/genética , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Microbiota , Reguladores de Crescimento de Planta/metabolismo , Reguladores de Crescimento de Planta/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
19.
Microbiol Res ; 223-225: 120-128, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31178044

RESUMO

Plant growth-promoting bacteria have been highlighted by their potential for application in plant production, allowing the reduction of the use of fertilizers and pesticides, which is due to the ability to stimulate the growth of plants by nitrogen-fixation and production of phytohormones, such as indole-3-acetic acid (IAA). The objective of this study was to verify the potential of plant growth promotion of 25 wild isolates from the Agricultural Microbiology Culture Collection of the Federal University of Lavras (CCMA-UFLA) through the evaluation of the biological nitrogen-fixation capacity and the production of IAA. In addition, the growth of three selected strains inoculated on roots of strawberry seedlings in greenhouse conditions was evaluated. The experiment was conducted in a completely randomized design (CRD), with an 8 × 2 factorial schemes involving eight combinations of bacteria: alone, in pairs and threes, plus the control without inoculation. Two fertilizer levels were used (0% and 50% of nitrogen), totaling 16 treatments with eight replicates each. After 75 days, variables such as root length, root dry weight, aerial part length, aerial part dry weight, leaf number, total dry mass and ultrastructural analysis of the inoculated and uninoculated roots, were evaluated. The results showed that the strawberry crop responded positively to inoculation with the three bacteria combined Azospirillum brasilense (Ab-V5) + Burkholderia cepacia (CCMA 0056) + Enterobacter cloacae (CCMA 1285) compared to the uninoculated controls. More expressive responses in terms of plant growth were observed in relation to the combined inoculation of the three bacterial strains plus fertilizer application with 50% of nitrogen.


Assuntos
Fenômenos Fisiológicos Bacterianos , Fragaria/crescimento & desenvolvimento , Fragaria/microbiologia , Fixação de Nitrogênio , Desenvolvimento Vegetal , Azospirillum brasilense/fisiologia , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biomassa , Burkholderia cepacia/fisiologia , Enterobacter cloacae , Ácidos Indolacéticos/metabolismo , Nitrogênio , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Plântula
20.
BMC Plant Biol ; 19(1): 262, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208336

RESUMO

BACKGROUND: Stored potato (Solanum tuberosum L.) tubers are sensitive to wet conditions that can cause rotting in long-term storage. To study the effect of water on the tuber surface during storage, microarray analysis, RNA-Seq profiling, qRT-PCR and phytohormone measurements were performed to study gene expression and hormone content in wet tubers incubated at two temperatures: 4 °C and 15 °C. The growth of the plants was also observed in a greenhouse after the incubation of tubers in wet conditions. RESULTS: Wet conditions induced a low-oxygen response, suggesting reduced oxygen availability in wet tubers at both temperatures when compared to that in the corresponding dry samples. Wet conditions induced genes coding for heat shock proteins, as well as proteins involved in fermentative energy production and defense against reactive oxygen species (ROS), which are transcripts that have been previously associated with low-oxygen stress in hypoxic or anoxic conditions. Wet treatment also induced senescence-related gene expression and genes involved in cell wall loosening, but downregulated genes encoding protease inhibitors and proteins involved in chloroplast functions and in the biosynthesis of secondary metabolites. Many genes involved in the production of phytohormones and signaling were also affected by wet conditions, suggesting altered regulation of growth by wet conditions. Hormone measurements after incubation showed increased salicylic acid (SA), abscisic acid (ABA) and auxin (IAA) concentrations as well as reduced production of jasmonate 12-oxo-phytodienoic acid (OPDA) in wet tubers. After incubation in wet conditions, the tubers produced fewer stems and more roots compared to controls incubated in dry conditions. CONCLUSIONS: In wet conditions, tubers invest in ROS protection and defense against the abiotic stress caused by reduced oxygen due to excessive water. Changes in ABA, SA and IAA that are antagonistic to jasmonates affect growth and defenses, causing induction of root growth and rendering tubers susceptible to necrotrophic pathogens. Water on the tuber surface may function as a signal for growth, similar to germination of seeds.


Assuntos
Armazenamento de Alimentos , Reguladores de Crescimento de Planta/metabolismo , Tubérculos/metabolismo , Solanum tuberosum/metabolismo , Metabolismo dos Carboidratos , Parede Celular/metabolismo , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo , Tubérculos/crescimento & desenvolvimento , Metabolismo Secundário , Solanum tuberosum/crescimento & desenvolvimento , Transcriptoma , Água
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