Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.625
Filtrar
1.
Nat Commun ; 11(1): 2912, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32518237

RESUMO

Small RNAs play important roles during plant development by regulating transcript levels of target mRNAs, maintaining genome integrity, and reinforcing DNA methylation. Dicer-like 5 (Dcl5) is proposed to be responsible for precise slicing in many monocots to generate diverse 24-nt phased, secondary small interfering RNAs (phasiRNAs), which are exceptionally abundant in meiotic anthers of diverse flowering plants. The importance and functions of these phasiRNAs remain unclear. Here, we characterized several mutants of dcl5, including alleles generated by the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system and a transposon-disrupted allele. We report that dcl5 mutants have few or no 24-nt phasiRNAs, develop short anthers with defective tapetal cells, and exhibit temperature-sensitive male fertility. We propose that DCL5 and 24-nt phasiRNAs are critical for fertility under growth regimes for optimal yield.


Assuntos
Metilação de DNA , Regulação da Expressão Gênica de Plantas , Infertilidade das Plantas/genética , Proteínas de Plantas/fisiologia , Zea mays/genética , Alelos , Sistemas CRISPR-Cas , Edição de Genes , Mutagênese , Mutação , Proteínas de Plantas/genética , RNA de Plantas/genética , RNA Interferente Pequeno/metabolismo , Temperatura
2.
PLoS Genet ; 16(6): e1008814, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32555650

RESUMO

The circadian clocks in chlorophyte algae have been studied in two model organisms, Chlamydomonas reinhardtii and Ostreococcus tauri. These studies revealed that the chlorophyte clocks include some genes that are homologous to those of the angiosperm circadian clock. However, the genetic network architectures of the chlorophyte clocks are largely unknown, especially in C. reinhardtii. In this study, using C. reinhardtii as a model, we characterized RHYTHM OF CHLOROPLAST (ROC) 75, a clock gene encoding a putative GARP DNA-binding transcription factor similar to the clock proteins LUX ARRHYTHMO (LUX, also called PHYTOCLOCK 1 [PCL1]) and BROTHER OF LUX ARRHYTHMO (BOA, also called NOX) of the angiosperm Arabidopsis thaliana. We observed that ROC75 is a day/subjective day-phase-expressed nuclear-localized protein that associates with some night-phased clock genes and represses their expression. This repression may be essential for the gating of reaccumulation of the other clock-related GARP protein, ROC15, after its light-dependent degradation. The restoration of ROC75 function in an arrhythmic roc75 mutant under constant darkness leads to the resumption of circadian oscillation from the subjective dawn, suggesting that the ROC75 restoration acts as a morning cue for the C. reinhardtii clock. Our study reveals a part of the genetic network of C. reinhardtii clock that could be considerably different from that of A. thaliana.


Assuntos
Chlamydomonas reinhardtii/fisiologia , Relógios Circadianos/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/fisiologia , Fatores de Transcrição/fisiologia , Cloroplastos/fisiologia , Ritmo Circadiano/genética , Redes Reguladoras de Genes/fisiologia , Mutação , Fotoperíodo , Plantas Geneticamente Modificadas
3.
Nat Commun ; 11(1): 2114, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32355217

RESUMO

Most plants associate with beneficial arbuscular mycorrhizal (AM) fungi that facilitate soil nutrient acquisition. Prior to contact, partner recognition triggers reciprocal genetic remodelling to enable colonisation. The plant Dwarf14-Like (D14L) receptor conditions pre-symbiotic perception of AM fungi, and also detects the smoke constituent karrikin. D14L-dependent signalling mechanisms, underpinning AM symbiosis are unknown. Here, we present the identification of a negative regulator from rice, which operates downstream of the D14L receptor, corresponding to the homologue of the Arabidopsis thaliana Suppressor of MAX2-1 (AtSMAX1) that functions in karrikin signalling. We demonstrate that rice SMAX1 is a suppressor of AM symbiosis, negatively regulating fungal colonisation and transcription of crucial signalling components and conserved symbiosis genes. Similarly, rice SMAX1 negatively controls strigolactone biosynthesis, demonstrating an unexpected crosstalk between the strigolactone and karrikin signalling pathways. We conclude that removal of SMAX1, resulting from D14L signalling activation, de-represses essential symbiotic programmes and increases strigolactone hormone production.


Assuntos
Proteínas de Arabidopsis/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Micorrizas/fisiologia , Oryza/microbiologia , Proteínas de Plantas/fisiologia , Simbiose , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Furanos/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação , Compostos Heterocíclicos com 3 Anéis/metabolismo , Homozigoto , Peptídeos e Proteínas de Sinalização Intracelular/genética , Lactonas/metabolismo , Família Multigênica , Oryza/genética , Filogenia , Proteínas de Plantas/genética , Raízes de Plantas/microbiologia , Piranos/metabolismo , RNA-Seq , Transdução de Sinais
4.
PLoS One ; 15(5): e0233375, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32421756

RESUMO

MYB-related transcription factors play important roles in plant development and response to various environmental stresses. In the present study, a novel MYB gene, designated as BnMYB2 (GenBank accession number: MF741319.1), was isolated from Boehmeria nivea using rapid amplification of cDNA ends (RACE) and RT-PCR on a sequence fragment from a ramie transcriptome. BnMYB2 has a 945 bp open reading frame encoding a 314 amino acid protein that contains a DNA-binding domain and shares high sequence identity with MYB proteins from other plant species. The BnMYB2 promoter contains several putative cis-acting elements involved in stress or phytohormone responses. A translational fusion of BnMYB2 with enhanced green fluorescent protein (eGFP) showed nuclear and cytosolic subcellular localization. Real-time PCR results indicated that BnMYB2 expression was induced by Cadmium (Cd) stress. Overexpression of BnMYB2 in Arabidopsis thaliana resulted in a significant increase of Cd tolerance and accumulation. Thus, BnMYB2 positively regulated Cd tolerance and accumulation in Arabidopsis, and could be used to enhance the efficiency of Cd removal with plants.


Assuntos
Boehmeria/genética , Cádmio/metabolismo , Fatores de Transcrição/fisiologia , Arabidopsis/metabolismo , Cádmio/farmacologia , Tolerância a Medicamentos/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/fisiologia , Proteínas Proto-Oncogênicas c-myb/metabolismo , Proteínas Proto-Oncogênicas c-myb/fisiologia , Estresse Fisiológico/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
PLoS One ; 15(5): e0233420, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428039

RESUMO

Stress-associated proteins (SAPs) are favorable targets to improve stress tolerance in plants, owing to their roles in developmental processes and stress responses. However, the role of SAPs and the molecular mechanisms by which they regulate plant stress responses remain poorly understood. Previously, it was reported that LmSAP expression was upregulated by various abiotic stressors in Lobularia maritima, and that transgenic tobacco lines with constitutively expressed LmSAPΔA20 and LmSAPΔA20-ΔAN1 showed dwarf phenotypes due to the deficiency of cell elongation under salt and osmotic stresses. In this study, we examined the function of A20 domain in the GA pathway in response to abiotic stresses. Transient expression of acGFP-LmSAPΔA20 and acGFP-LmSAPΔA20-ΔAN1 in onion epidermal cells demonstrated that these fused proteins were localized in the nucleo-cytoplasm. However, the truncated form acGFP-LmSAPΔAN1 was localized in the nucleus. Moreover, comparison of native and truncated LmSAP showed dramatic structural changes caused by the deletion of the A20 domain, leading to loss of function and localization. Interestingly, overexpression LmSAP and truncated LmSAPΔAN1 led to up-regulation of GA biosynthetic genes and increased total gibberellins (GAs) content, corresponding with accelerated development in transgenic tobacco plants. Moreover, the dwarf phenotype of the transgenic lines that express LmSAPΔA20 and LmSAPΔA20-ΔAN1 under stress conditions was fully restored by the application of exogenous GA3. These findings improve our understanding of the role of LmSAP in regulating GA homeostasis, which is important for regulating plant development under abiotic stress conditions.


Assuntos
Brassicaceae/química , Giberelinas/metabolismo , Proteínas de Choque Térmico/fisiologia , Homeostase , Proteínas de Plantas/fisiologia , Estresse Fisiológico/fisiologia , Regulação da Expressão Gênica de Plantas , Domínios Proteicos/fisiologia
6.
Nat Commun ; 11(1): 1777, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286317

RESUMO

Pseudonectaries, or false nectaries, the glistening structures that resemble nectaries or nectar droplets but do not secrete nectar, show considerable diversity and play important roles in plant-animal interactions. The morphological nature, optical features, molecular underpinnings and ecological functions of pseudonectaries, however, remain largely unclear. Here, we show that pseudonectaries of Nigella damascena (Ranunculaceae) are tiny, regional protrusions covered by tightly arranged, non-secretory polygonal epidermal cells with flat, smooth and reflective surface, and are clearly visible even under ultraviolet light and bee vision. We also show that genes associated with cell division, chloroplast development and wax formation are preferably expressed in pseudonectaries. Specifically, NidaYABBY5, an abaxial gene with ectopic expression in pseudonectaries, is indispensable for pseudonectary development: knockdown of it led to complete losses of pseudonectaries. Notably, when flowers without pseudonectaries were arrayed beside those with pseudonectaries, clear differences were observed in the visiting frequency, probing time and visiting behavior of pollinators (i.e., honey bees), suggesting that pseudonectaries serve as both visual attractants and nectar guides.


Assuntos
Flores/metabolismo , Nigella damascena/metabolismo , Divisão Celular/fisiologia , Ecologia , Flores/fisiologia , Nigella damascena/fisiologia , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Ranunculaceae/metabolismo , Ranunculaceae/fisiologia
7.
Science ; 367(6485): 1482-1485, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32217727

RESUMO

The premature abscission of flowers and fruits limits crop yield under environmental stress. Drought-induced flower drop in tomato plants was found to be regulated by phytosulfokine (PSK), a peptide hormone previously known for its growth-promoting and immune-modulating activities. PSK formation in response to drought stress depends on phytaspase 2, a subtilisin-like protease of the phytaspase subtype that generates the peptide hormone by aspartate-specific processing of the PSK precursor in the tomato flower pedicel. The mature peptide acts in the abscission zone where it induces expression of cell wall hydrolases that execute the abscission process. Our results provide insight into the molecular control of abscission as regulated by proteolytic processing to generate a small plant peptide hormone.


Assuntos
Secas , Flores/fisiologia , Lycopersicon esculentum/fisiologia , Hormônios Peptídicos/fisiologia , Proteínas de Plantas/fisiologia , Estresse Fisiológico , Parede Celular/enzimologia , Etilenos , Frutas/fisiologia , Técnicas de Silenciamento de Genes , Hidrolases/fisiologia , Ácidos Indolacéticos , Peptídeos , Plantas Geneticamente Modificadas/fisiologia , Transdução de Sinais
8.
Artigo em Inglês | MEDLINE | ID: mdl-32200192

RESUMO

The basic region/leucine zipper (bZIP) transcription factors play key roles in regulating diverse biological processes in plants. However, their participation in shoot branching has been rarely reported. Here, we isolated a CmbZIP1 transcription factor gene, a member of the bZIP family, from chrysanthemum. Subcellular localization analysis indicated that CmbZIP1 is a nuclear protein. Tissue-specific expression analysis indicated that CmbZIP1 was principally expressed in apical bud and axillary bud. Expression patterns analysis results showed that CmbZIP1 expression was suppressed in axillary buds in response to decapitation but increased in response to shade. Overexpression of CmbZIP1 in Arabidopsis inhibits its shoot branching. In addition, expression of auxin efflux protein PIN-FORMED 1 (PIN1) and auxin signaling components AUXIN RESISTANT 1/3 (AXR1, AXR3) were significantly up-regulated in overexpressing plants in comparison with wild type plants. Moreover, the transcript expression of BRANCHED 2 (AtBRC2) was also significantly up-regulated in overexpressing plants compared with the wild type. Altogether, these results suggest important and negative roles of CmbZIP1 in shoot branching. Our study extends the understanding of the function of bZIP transcription factors in plants and provides valuable gene resources for improving the architectural traits of ornamental plants.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/fisiologia , Chrysanthemum/crescimento & desenvolvimento , Proteínas de Plantas/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Arabidopsis , Regulação da Expressão Gênica de Plantas , Proteínas Nucleares/fisiologia , Plantas Geneticamente Modificadas
9.
Artigo em Inglês | MEDLINE | ID: mdl-32222679

RESUMO

Brassinazole-resistant (BZR) transcription factors have important roles in the brassinosteroid (BR) signalling pathway and are widely involved in plant growth and abiotic stress processes. However, there are few studies on the functions and regulatory mechanisms of BZR TFs in birch. In this study, 5 BZR genes were identified from birch. The qRT-PCR results showed that the expression levels of most BpBZRs were significantly downregulated and/or upregulated in at least one organ following NaCl and PEG stress or ABA, GA3 and JA treatments. In particular, BpBZR1 expression was changed in all three organs after exposure to NaCl stress at all time points, indicating that this gene may be involved in salt stress. The BpBZR1 transcription factor was shown to have transcriptional activation activity in a yeast two-hybrid assay. Through a transient transformation system, we found that overexpression of BpBZR1 in birch resulted in lower H2O2 and MDA accumulation, higher SOD and POD activities and maintained a higher photosynthetic intensity and a lower chlorophyll degradation rate than those of the control plants under salt stress. These results preliminarily showed that overexpression of the BpBZR1 gene increased the tolerance of birch to salt stress.


Assuntos
Betula/fisiologia , Proteínas de Ligação a DNA/fisiologia , Proteínas de Plantas/fisiologia , Estresse Fisiológico , Fatores de Transcrição/fisiologia , Betula/genética , Regulação da Expressão Gênica de Plantas
10.
Plant Mol Biol ; 102(4-5): 537-551, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31916084

RESUMO

KEY MESSAGE: Silencing of SlCAND1 expression resulted in dwarfish, loss of apical dominance, early flowering, suppression of seed germination, and abnormal root architecture in tomato Cullin-RING E3 ligases (CRLs)-dependent ubiquitin proteasome system mediates degradation of numerous proteins that controls a wide range of developmental and physiological processes in eukaryotes. Cullin-associated Nedd8-dissociated protein 1 (CAND1) acts as an exchange factor allowing substrate recognition part exchange and plays a vital role in reactivating CRLs. The present study reports on the identification of SlCAND1, the only one CAND gene in tomato. SlCAND1 expression is ubiquitous and positively regulated by multiple plant hormones. Silencing of SlCAND1 expression using RNAi strategy resulted in a pleiotropic and gibberellin/auxin-associated phenotypes, including dwarf plant with reduced internode length, loss of apical dominance, early flowering, low seed germination percentage, delayed seed germination speed, short primary root, and increased lateral root proliferation and elongation. Moreover, application of exogenous GA3 or IAA could partly rescue some SlCAND1-silenced phenotypes, and the expression levels of gibberellin/auxin-related genes were altered in SlCAND1-RNAi lines. These facts revealed that SlCAND1 is required for gibberellin/auxin-associated regulatory network in tomato. Although SlCAND1 is crucial for multiple developmental processes during vegetative growth stage, SlCAND1-RNAi lines didn't exhibit visible effect on fruit development and ripening. Meanwhile, we discussed that multiple physiological functions of SlCAND1 in tomato are different to previous report of its ortholog in Arabidopsis. Our study adds a new perspective on the functional roles of CAND1 in plants, and strongly supports the hypothesis that CAND1 and its regulated ubiquitin proteasome system are pivotal for plant vegetative growth but possibly have different roles in diverse plant species.


Assuntos
Flores/fisiologia , Germinação , Lycopersicon esculentum/fisiologia , Proteínas de Plantas/fisiologia , Raízes de Plantas/fisiologia , Arabidopsis/genética , Proteínas Culina , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Lycopersicon esculentum/genética , Fenótipo , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Interferência de RNA , Sementes/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia
11.
Plant Mol Biol ; 102(4-5): 501-515, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31919641

RESUMO

Leaf senescence, which affects plant growth and yield in rice, is an ideal target for crop improvement and remarkable advances have been made to identify the mechanism underlying this process. We have characterized an early senile mutant es5 (early leaf senescence 5) in rice exhibiting leaf yellowing phenotype after the 4-leaf stage. This phenotype was confirmed by the higher accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), the disintegration of chloroplasts, reduction in chlorophyll content and photosynthetic rate and up-regulation of senescence-associated genes (SAGs) like Osh36, OsI57, and OsI85. Positional cloning revealed that the es5 phenotype is the result of one base substitution in ES5, encoding phosphatidylserine synthase (PSS) family protein, which is involved in the base-exchange type reaction to synthesize the minor membrane phospholipid phosphatidylserine. Functional complementation of ES5 in the es5 plants completely restored the wild-type phenotype. Ultra-high-performance liquid chromatography (UHPLC) analysis showed that es5 plants had increased levels of phosphatidylserine (PS) and decreased level of phosphatidylcholine (PC). These results provide evidence about the role of PS in rice leaf senescence.


Assuntos
Oryza/fisiologia , Fosfatidilserinas/biossíntese , Folhas de Planta/fisiologia , Proteínas de Plantas/fisiologia , Clorofila/metabolismo , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Malondialdeído/metabolismo , Mutação , Oryza/genética , Estresse Oxidativo , Fenótipo , Fotossíntese , Pigmentação , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
12.
Plant Mol Biol ; 102(4-5): 553-567, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31989373

RESUMO

KEY MESSAGE: Overexpression of K2-NhaD in transgenic cotton resulted in phenotypes with strong salinity and drought tolerance in greenhouse and field experiments, increased expression of stress-related genes, and improved regulation of metabolic pathways, such as the SOS pathway. Drought and salinity are major abiotic stressors which negatively impact cotton yield under field conditions. Here, a plasma membrane Na+/H+ antiporter gene, K2-NhaD, was introduced into upland cotton R15 using an Agrobacterium tumefaciens-mediated transformation system. Homozygous transgenic lines K9, K17, and K22 were identified by PCR and glyphosate-resistance. TAIL-PCR confirmed that T-DNA carrying the K2-NhaD gene in transgenic lines K9, K17 and K22 was inserted into chromosome 3, 19 and 12 of the cotton genome, respectively. Overexpression of K2-NhaD in transgenic cotton plants grown in greenhouse conditions and subjected to drought and salinity stress resulted in significantly higher relative water content, chlorophyll, soluble sugar, proline levels, and SOD, CAT, and POD activity, relative to non-transgenic plants. The expression of stress-related genes was significantly upregulated, and this resulted in improved regulation of metabolic pathways, such as the salt overly sensitive pathway. K2-NhaD transgenic plants growing under field conditions displayed strong salinity and drought tolerance, especially at high levels of soil salinity and drought. Seed cotton yields in transgenic line were significantly higher than in wild-type plants. In conclusion, the data indicate that K2-NhaD transgenic lines have great potential for the production of stress-tolerant cotton under field conditions.


Assuntos
Gossypium/metabolismo , Proteínas de Plantas/fisiologia , Tolerância ao Sal/genética , Trocadores de Sódio-Hidrogênio/fisiologia , Secas , Gossypium/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/metabolismo , Estresse Fisiológico , Água/metabolismo
13.
J Plant Res ; 133(2): 231-244, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31915951

RESUMO

Plant growth promoting rhizobacteria (PGPR) are a group of bacteria that promote plants growth in the rhizosphere. PGPRs are involved in various mechanisms that reinforce plant development. In this study, we screened for PGPRs that were effective in early growth of Arabidopsis thaliana when added to the media and one Bacillus subtilis strain L1 (Bs L1) was selected for further study. When Bs L1 was placed near the roots, seedlings showed notably stronger growth than that in the control, particularly in biomass and root hair. Quantitative reverse transcription polymerase chain reaction analysis revealed a high level of expression of the high affinity nitrate transporter gene, NRT2.1 in A. thaliana treated with Bs L1. After considering how Bs L1 could promote plant growth, we focused on nitrate, which is essential to plant growth. The nitrate content was lower in A. thaliana treated with Bs L1. However, examination of the activity of nitrate reductase revealed higher activity in plants treated with PGPR than in the control. Bs L1 had pronounced effects in representative crops (wheat and lettuce). These results suggest that Bs L1 promotes the assimilation and use of nitrate and plant growth.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Bacillus subtilis/fisiologia , Alface/crescimento & desenvolvimento , Nitrato Redutase/fisiologia , Triticum/genética , Proteínas de Transporte de Ânions/fisiologia , Arabidopsis/enzimologia , Proteínas de Arabidopsis/fisiologia , Alface/enzimologia , Nitratos/metabolismo , Proteínas de Plantas/fisiologia , Raízes de Plantas/microbiologia , Triticum/enzimologia
14.
Plant Mol Biol ; 102(4-5): 447-462, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31898148

RESUMO

KEY MESSAGE: ZjICE2 works as a positive regulator in abiotic stress responses and ZjICE2 is a valuable genetic resource to improve abiotic stress tolerance in the molecular breeding program of Zoysia japonica. The basic helix-loop-helix (bHLH) family transcription factors (TFs) play an important role in response to biotic or abiotic stresses in plants. However, the functions of bHLH TFs in Zoysia japonica, one of the warm-season turfgrasses, remain poorly understood. Here, we identified ZjICE2 from Z. japonica, a novel MYC-type bHLH transcription factor that was closely related to ICE homologs in the phylogenetic tree, and its expression was regulated by various abiotic stresses. Transient expression of ZjICE2-GFP in onion epidermal cells revealed that ZjICE2 was a nuclear-localized protein. Also, ZjICE2 bound the MYC cis-element in the promoter of dehydration responsive element binding 1 of Z. japonica (ZjDREB1) using yeast one-hybrid assay. A phenotypic analysis showed that overexpression of the ZjICE2 in Arabidopsis enhanced tolerance to cold, drought, and salt stresses. The transgenic Arabidopsis and Z. japonica accumulated more transcripts of cold-responsive DREB/CBFs and their downstream genes than the wild type (WT) after cold treatment. Furthermore, the transgenic plants exhibited an enhanced Reactive oxygen species (ROS) scavenging ability, which resulted in an efficient maintenance of oxidant-antioxidant homeostasis. In addition, overexpression of the ZjICE2 in Z. japonica displayed intensive cold tolerance with increases in chlorophyll contents and photosynthetic efficiency. Our study suggests that ZjICE2 works as a positive regulator in abiotic stress responses and the ICE-DREB/CBFs response pathway involved in cold stress tolerance is also conserved in Z. japonica. These results provide a valuable genetic resource for the molecular breeding program especially for warm-season grasses as well as other leaf crop plants.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/fisiologia , Poaceae/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Temperatura Baixa , Resposta ao Choque Frio , Secas , Filogenia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/fisiologia , Poaceae/genética , Regulon , Tolerância ao Sal , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia , Ativação Transcricional
15.
Physiol Plant ; 168(3): 675-693, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31343748

RESUMO

Potato tuberization is a complicated biological process regulated by multiple phytohormones, in particular cytokinins (CKs). The information available on the molecular mechanisms regulating tuber development by CKs remains largely unclear. Physiological results initially indicated that low 6-benzylaminopurine (BAP) concentration (3 mg l-1 ) advanced the tuberization beginning time and promoted tuber formation. A comparative proteomics approach was applied to investigate the proteome change of tuber development by two-dimensional gel electrophoresis in vitro, subjected to exogenous BAP treatments (0, 3, 6 and 13 mg l-1 ). Quantitative image analysis showed a total of 83 protein spots with significantly altered abundance (>2.5-fold, P < 0.05), and 55 differentially abundant proteins were identified by MALDI-TOF/TOF MS. Among these proteins, 22 proteins exhibited up-regulation with the increase of exogenous BAP concentration, and 31 proteins were upregulated at 3 mg l-1 BAP whereas being downregulated at higher BAP concentrations. These proteins were involved in metabolism and bioenergy, storage, redox homeostasis, cell defense and rescue, transcription and translation, chaperones, signaling and transport. The favorable effects of low BAP concentrations on tuber development were found in various cellular processes, mainly including the stimulation of starch and storage protein accumulation, the enhancement of the glycolysis pathway and ATP synthesis, the cellular homeostasis maintenance, the activation of pathogen defense, the higher efficiency of transcription and translation, as well as the enhanced metabolite transport. However, higher BAP concentration, especially 13 mg l-1 , showed disadvantageous effects. The proposed hypothetical model would explain the interaction of these proteins associated with CK-induced tuber development in vitro.


Assuntos
Citocininas/fisiologia , Proteínas de Plantas/fisiologia , Tubérculos/crescimento & desenvolvimento , Proteoma , Solanum tuberosum/fisiologia , Compostos de Benzil/farmacologia , Regulação da Expressão Gênica de Plantas , Purinas/farmacologia
16.
Environ Sci Pollut Res Int ; 27(2): 1499-1507, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31749010

RESUMO

Freezing-thawing and saline-alkaline are the major abiotic stress for the pasture in most high-latitude areas, which are serious threats to the yield of pasture. In this study, the osmotic adjustment substances, membrane lipid peroxidation, and antioxidant enzymes activities of rye (Secale cereale L., cv. Dongmu-70) seedlings under different treatments: CK (no treatment), SC (Na2CO3 treatment), FT (freezing-thawing treatment), and FT+SC (combined Na2CO3 and freezing-thawing treatments), were investigated. At the freezing stage, the content of MDA and proline, the activity of APX, SOD, and POD increased with the decrease of the temperature in the leaves of rye seedlings in FT and FT+SC treatments and reached the maximum value at - 5 °C. In addition, the content of protein and H2O2, CAT activity reached the maximum value at 0 °C; the damage is larger under low temperature stress at 0 °C and - 5 °C in rye seedling. At the thawing stage, the content of MDA and H2O2 in seedling leaves decreased in FT and FT + SC treatments. These results demonstrated that proline content and antioxidant enzymes activities could play an important role in protecting cytomembrane and scavenging ROS respectively in rye under alkaline salt stress and freezing-thawing stress. The result also indicated rye seedlings were subjected to a freezing-thawing stress which resulted in a reversible (recoverable) injury.


Assuntos
Proteínas de Plantas/fisiologia , Estresse Salino , Secale/fisiologia , Plântula/fisiologia , Antioxidantes , Congelamento , Peróxido de Hidrogênio , Estresse Fisiológico
17.
Prep Biochem Biotechnol ; 50(2): 133-140, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31702437

RESUMO

Watermelon seed is the potential source of value-added proteins, oils, and carbohydrates. The present study evaluates the extraction, and functional properties of watermelon seed protein (WMSP) obtained by ultrasound-assisted extraction (UAE) method from watermelon seed (WMS). The optimization of various operating parameters, such as pH (9), WMS powder to solvent ratio (1:50 w/v), temperature (30 ± 2 °C), ultrasound power (90 W), frequency (25 kHz), and duty cycle (75%) has been carried out. The extraction yield obtained was 87% and the extraction time was lowered down to 9 min from 120 min of conventional batch extraction. It contains all essential amino acids in an adequate amount required for adults as per FAO/WHO guidelines while for 2-5 years old children, the content of valine and isoleucine are above the required range. Methionine and lysine contents are adequate for both children and adults. Functional properties of ultrasonic extracted proteins were found superior to conventionally extracted proteins.highlightsThe UAE method is more efficient for watermelon seed protein extraction.Impact of extraction parameters on the extraction yield was studied.Protein isolate with enhanced functional properties was obtained.Essential amino acid content was determined.


Assuntos
Citrullus/embriologia , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/fisiologia , Sementes/metabolismo , Sonicação , Adulto , Aminoácidos/metabolismo , Carboidratos/análise , Pré-Escolar , Humanos , Temperatura
18.
Physiol Plant ; 168(3): 590-600, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31115057

RESUMO

Nucleoporins are components of the nuclear pore complexes, channels that regulate the transport of macromolecules between the nucleus and cytoplasm. The nucleoporin GLE1 (GLFG lethal1) functions in the export of messenger RNAs containing poly(A) tails from the nucleus into the cytoplasm. Here we investigated a mutant of the model legume Lotus japonicus that was defective in GLE1, which we designated Ljgle1. The growth of Ljgle1 was retarded under symbiotic association with rhizobia, and the nitrogen-fixation activities of the nodules were around one-third of those in the wild-type plant. The growth of Ljgle1 was not substantialy recovered by supplemention of combined nitrogen. Nodules formed on the Ljgle1 were smaller than those on the wild-type and colored faint pink. The numbers of infected cells of nodules on the Ljgle1 were smaller than on the wild-type plant, and the former cells remained undeveloped. Rhizobia in the cells of the Ljgle1 exhibited disordered forms, and the symbiosome membrane was closely attached to the bacterial membrane. These results indicate that GLE1 plays a distinct role in the symbiotic association between legumes and rhizobia.


Assuntos
Lotus/fisiologia , Complexo de Proteínas Formadoras de Poros Nucleares/fisiologia , Proteínas de Plantas/fisiologia , Rhizobium/fisiologia , Simbiose , Lotus/microbiologia , Fixação de Nitrogênio
19.
Mol Plant Microbe Interact ; 33(2): 320-327, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31880983

RESUMO

Legumes survive in nitrogen-limited soil by forming a symbiosis with rhizobial bacteria. During root nodule symbiosis, legumes strictly control the development of their symbiotic organs, the nodules, in a process known as autoregulation of nodulation (AON). The study of hypernodulation mutants has elucidated the molecular basis of AON. Some hypernodulation mutants show an increase in rhizobial infection in addition to developmental alteration. However, the relationship between the AON and the regulation of rhizobial infection has not been clarified. We previously isolated daphne, a nodule inception (nin) allelic mutant, in Lotus japonicus. This mutant displayed dramatically increased rhizobial infection, suggesting the existence of NIN-mediated negative regulation of rhizobial infection. Here, we investigated whether the previously isolated components of AON, especially CLAVATA3/ESR (CLE)-RELATED-ROOT SIGNAL1 (CLE-RS1), CLE-RS2, and their putative receptor HYPERNODULATION AND ABERRANT ROOT FORMATION1 (HAR1), were able to suppress increased infection in the daphne mutant. The constitutive expression of LjCLE-RS1/2 strongly reduced the infection in the daphne mutant in a HAR1-dependent manner. Moreover, reciprocal grafting analysis showed that strong reduction of infection in daphne rootstock constitutively expressing LjCLE-RS1 was canceled by a scion of the har1 or klavier mutant, the genes responsible for encoding putative LjCLE-RS1 receptors. These data indicate that rhizobial infection is also systemically regulated by CLE-HAR1 signaling, a component of AON. In addition, the constitutive expression of NIN in daphne har1 double-mutant roots only partially reduced the rhizobial infection. Our findings indicate that the previously identified NIN-mediated negative regulation of infection involves unknown local signaling, as well as CLE-HAR1 long-distance signaling.


Assuntos
Lotus , Proteínas de Plantas , Rhizobium , Transdução de Sinais , Regulação da Expressão Gênica de Plantas , Humanos , Lotus/genética , Lotus/microbiologia , Proteínas de Plantas/fisiologia , Nodulação , Nódulos Radiculares de Plantas
20.
BMC Plant Biol ; 19(1): 586, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31881835

RESUMO

BACKGROUND: In soft fruits, the differential expression of many genes during development and ripening is responsible for changing their organoleptic properties. In strawberry fruit, although some genes involved in the metabolic regulation of the ripening process have been functionally characterized, some of the most studied genes correspond to transcription factors. High throughput transcriptomics analyses performed in strawberry red receptacle (Fragaria x ananassa) allowed us to identify a ripening-related gene that codes an atypical HLH (FaPRE1) with high sequence homology with the PACLOBUTRAZOL RESISTANCE (PRE) genes. PRE genes are atypical bHLH proteins characterized by the lack of a DNA-binding domain and whose function has been linked to the regulation of cell elongation processes. RESULTS: FaPRE1 sequence analysis indicates that this gene belongs to the subfamily of atypical bHLHs that also includes ILI-1 from rice, SlPRE2 from tomato and AtPRE1 from Arabidopsis, which are involved in transcriptional regulatory processes as repressors, through the blockage by heterodimerization of bHLH transcription factors. FaPRE1 presented a transcriptional model characteristic of a ripening-related gene with receptacle-specific expression, being repressed by auxins and activated by abscisic acid (ABA). However, its expression was not affected by gibberellic acid (GA3). On the other hand, the transitory silencing of FaPRE1 transcription by agroinfiltration in receptacle produced the down-regulation of a group of genes related to the ripening process while inducing the transcription of genes involved in receptacle growth and development. CONCLUSIONS: In summary, this work presents for the first time experimental data that support an important novel function for the atypical HLH FaPRE1 during the strawberry fruit ripening. We hypothesize that FaPRE1 modulates antagonistically the transcription of genes related to both receptacle growth and ripening. Thus, FaPRE1 would repress the expression of receptacle growth promoting genes in the ripened receptacle, while it would activate the expression of those genes related to the receptacle ripening process.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Fragaria/fisiologia , Proteínas de Plantas/fisiologia , Fatores de Transcrição/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fragaria/efeitos dos fármacos , Fragaria/genética , Fragaria/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Proteínas Nucleares/genética , Proteínas Nucleares/fisiologia , Desenvolvimento Vegetal/genética , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Triazóis/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA