Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 346
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Plant Sci ; 302: 110704, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33288017

RESUMO

Arabidopsis thaliana TRY is a negative regulator of trichome differentiation that promotes root hair differentiation. Here, we established that LbTRY, from the recretohalophyte Limonium bicolor, is a typical MYB transcription factor that exhibits transcriptional activation activity and locates in nucleus. By in situ hybridization in L. bicolor, LbTRY may be specifically positioned in salt gland of the expanded leaves. LbTRY expression was the highest in mature leaves and lowest under NaCl treatment. For functional assessment, we heterologously expressed LbTRY in wild-type and try29760 mutant Arabidopsis plants. Epidermal differentiation was remarkably affected in the transgenic wild-type line, as was increased root hair development. Complementation of try29760 with LbTRY under both 35S and LbTRY specific promoter restored the wild-type phenotype. qRT-PCR analysis suggested that AtGL3 and AtZFP5 promote root hair cell fate in lines heterologously producing LbTRY. In addition, four genes (AtRHD6, AtRSL1, AtLRL2, and AtLRL3) involved in root hair initiation and elongation were upregulated in the transgenic lines. Furthermore, LbTRY specifically increased the salt sensitivity of the transgenic lines. The transgenic and complementation lines showed poor germination rates and reduced root lengths, whereas the mutant unexpectedly fared the best under a range of NaCl treatments. Under salt stress, the transgenic seedlings accumulated more MDA and Na+ and less proline and soluble sugar than try29760. Thus, when heterologously expressed in Arabidopsis, LbTRY participates in hair development, similar to other MYB proteins, and specifically reduces salt tolerance by increasing ion accumulation and reducing osmolytes. The expression of salt-tolerance marker genes (SOS1, SOS2, SOS3 and P5CS1) was significant reduced in the transgenic lines. More will be carried by downregulating expression of TRY homologs in crops to improve salt tolerance.


Assuntos
Osmorregulação/genética , Proteínas de Plantas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Plumbaginaceae/genética , Proteínas Proto-Oncogênicas c-myb/fisiologia , Plantas Tolerantes a Sal/genética , Arabidopsis , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Hibridização In Situ , Osmorregulação/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Plumbaginaceae/crescimento & desenvolvimento , Plumbaginaceae/metabolismo , Plumbaginaceae/fisiologia , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo , Tolerância ao Sal , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Plantas Tolerantes a Sal/metabolismo , Plantas Tolerantes a Sal/fisiologia
2.
Plant Sci ; 302: 110668, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33288032

RESUMO

MYB transcription factors are important in abiotic stress responses; however, the detailed mechanisms are unclear. Tamarix hispida contains multiple MYB genes. The present study characterized T. hispida MYB8 (ThMYB8) during salt stress using transgenic T. hispida and Arabidopsis assays. ThMYB8 overexpression and ThMYB8 RNAi analysis demonstrated that ThMYB8 enhanced the salt stress tolerance. Transgenic Arabidopsis ectopic expression of ThMYB8 significantly increased root growth, fresh weight, and seed germination rate compared with that of the wild-type under salt stress. Physiological parameters analysis in T. hispida and Arabidopsis showed that ThMYB8 overexpressing plants had the lowest levels of O2, H2O2, cell death, malondialdehyde, and electrolyte leakage. Overexpression of ThMYB8 regulated Na+ and K+ concentrations in plant tissues while maintaining K+/Na+ homeostasis. Analysis using qRT-PCR and ChIP-PCR identified possible downstream ThMYB8-regulated genes. ThMYB8 regulated the expression of ThCYP450-2 (cytochrome p450-2), Thltk (leucine-rich repeat transmembrane protein kinase), and ThTIP (aquaporin TIP) by binding to the MBSI motif ('CAACTG') in their promoters. The results indicated that ThMYB8 enhanced salt stress tolerance in T. hispida by regulating gene expression related to the activation of stress-associated physiological changes, such as enhanced reactive oxygen species scavenging capability, maintaining K+/Na+ homeostasis, and decreasing the malondialdehyde content and lipid peroxidation cell membranes.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/fisiologia , Proteínas Proto-Oncogênicas c-myb/fisiologia , Plantas Tolerantes a Sal/metabolismo , Tamaricaceae/fisiologia , Árabes , Imunoprecipitação da Cromatina , Perfilação da Expressão Gênica , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Estresse Salino , Plantas Tolerantes a Sal/genética , Análise de Sequência de DNA , Tamaricaceae/genética , Tamaricaceae/metabolismo , Técnicas do Sistema de Duplo-Híbrido
3.
BMC Plant Biol ; 20(1): 560, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33308157

RESUMO

BACKGROUNDS: Pomegranate (Punica granatum L.) is an important commercial fruit tree, with moderate tolerance to salinity. The balance of Cl- and other anions in pomegranate tissues are affected by salinity, however, the accumulation patterns of anions are poorly understood. The chloride channel (CLC) gene family is involved in conducting Cl-, NO3-, HCO3- and I-, but its characteristics have not been reported on pomegranate. RESULTS: In this study, we identified seven PgCLC genes, consisting of four antiporters and three channels, based on the presence of the gating glutamate (E) and the proton glutamate (E). Phylogenetic analysis revealed that seven PgCLCs were divided into two clades, with clade I containing the typical conserved regions GxGIPE (I), GKxGPxxH (II) and PxxGxLF (III), whereas clade II not. Multiple sequence alignment revealed that PgCLC-B had a P [proline, Pro] residue in region I, which was suspected to be a NO3-/H+ exchanger, while PgCLC-C1, PgCLC-C2, PgCLC-D and PgCLC-G contained a S [serine, Ser] residue, with a high affinity to Cl-. We determined the content of Cl-, NO3-, H2PO4-, and SO42- in pomegranate tissues after 18 days of salt treatments (0, 100, 200 and 300 mM NaCl). Compared with control, the Cl- content increased sharply in pomegranate tissues. Salinity inhibited the uptake of NO3- and SO42-, but accelerated H2PO4- uptake. The results of real-time reverse transcription PCR (qRT-PCR) revealed that PgCLC genes had tissue-specific expression patterns. The high expression levels of three antiporters PgCLC-C1, PgCLC-C2 and PgCLC-D in leaves might be contributed to sequestrating Cl- into the vacuoles. However, the low expression levels of PgCLCs in roots might be associated with the exclusion of Cl- from root cells. Also, the up-regulated PgCLC-B in leaves indicated that more NO3- was transported into leaves to mitigate the nitrogen deficiency. CONCLUSIONS: Our findings suggested that the PgCLC genes played important roles in balancing of Cl- and NO3- in pomegranate tissues under salt stress. This study established a theoretical foundation for the further functional characterization of the CLC genes in pomegranate.


Assuntos
Canais de Cloreto/genética , Família Multigênica , Proteínas de Plantas/genética , Romã (Fruta)/fisiologia , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/fisiologia , Sequência de Aminoácidos , Canais de Cloreto/química , Canais de Cloreto/metabolismo , Perfilação da Expressão Gênica , Genoma de Planta , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Romã (Fruta)/genética , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismo , Alinhamento de Sequência
4.
Food Chem ; 333: 127536, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32707417

RESUMO

Some halophyte plants are currently used in gourmet cuisine due to their unique organoleptic properties. Moreover, they exhibit excellent nutritional and functional properties, being rich in polyphenolics and vitamins. These compounds are associated to strong antioxidant activity and enhanced health benefits. This work compared the nutritional properties and antioxidant potential of three species (Mesembryanthemum nodiflorum, Suaeda maritima and Sarcocornia fruticosa) collected in saltmarshes from Portugal and Spain with those of cultivated plants. The latter were generally more succulent and had higher contents of minerals than plants obtained from the wild and contained less fibre. All species assayed are a good source of proteins, fibres and minerals. Additionally, they are good sources of carotenoids and vitamins A, C and B6 and showed good antioxidant potential particularly S. maritima. Chromatographic analysis of the phenolic profile revealed that ferulic and caffeic acids as the most relevant phenolic compounds detected in the halophytes tested.


Assuntos
Valor Nutritivo , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Plantas Tolerantes a Sal/metabolismo , Antioxidantes/metabolismo , Chenopodiaceae/crescimento & desenvolvimento , Chenopodiaceae/metabolismo , Fenóis/metabolismo
5.
Sci Rep ; 10(1): 6583, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313165

RESUMO

Halophytes are increasingly regarded as suitable extractive species and co-products for coastal Integrated Multi-Trophic Aquaculture (IMTA) and studying their lipidome is a valid means towards their economic valorization. Halimione portulacoides (L.) Aellen edible leaves are rich in functional lipids with nutraceutical and pharmaceutical relevance and the present study aimed to investigate the extent to which its lipidome remains unchanged under a range of dissolved inorganic nitrogen (N) and phosphorus (P) concentrations typical of aquaculture effluents. Lipidomics analysis, done by hydrophilic interaction liquid chromatography coupled to high resolution mass spectrometry, identified 175 lipid species in the lipid extract of leaves: 140 phospholipids (PLs) and 35 glycolipids (GLs). Plants irrigated with a saline solution with 20-100 mg DIN-N L-1 and 3-15.5 mg DIP-P L-1 under a 1-week hydraulic retention time displayed a relatively stable lipidome. At lower concentrations (6 mg DIN-N L-1 and 0.8 mg DIP-P L-1), plants exhibited less PLs and GLs per unit of leaves dry weight and the GLs fraction of the lipidome changed significantly. This study reveals the importance of analyzing the lipidomic profile of halophytes under different nutritional regimens in order to establish nutrient-limitation thresholds and assure production conditions that deliver a final product with a consistent lipid profile.


Assuntos
Chenopodiaceae/metabolismo , Lipidômica , Lipídeos/genética , Plantas Tolerantes a Sal/metabolismo , Aquicultura , Chenopodiaceae/genética , Chenopodiaceae/crescimento & desenvolvimento , Glicolipídeos/genética , Glicolipídeos/metabolismo , Humanos , Hidroponia , Fosfolipídeos/genética , Fosfolipídeos/metabolismo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/crescimento & desenvolvimento
6.
Ecotoxicol Environ Saf ; 195: 110486, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32200151

RESUMO

This study aimed at assessing heavy metals (Fe, Mn, Zn, Cu, Cr and Pb) in four perennial halophytes (viz. Heliotropium bacciferum, Halopyrum mucronatum, Ipomoea pes-caprae and Salsola imbricata) growing at two sites on the Karachi coast. Site - II, closer to the Industrial area had higher bioavailability as well as translocation factor (TF) for most of the heavy metals and Na+ where soil sediments had lower pH (approximately 7.5), higher salinity (EC) and organic matter (OM). Site - I which was far from Industrial area had comparatively higher bio-concentration factor (BCF) and lower TF for metal ions and soil pH of 8.1-9. Metal accumulation in plants was both site and species specific. Extractable concentration of shoot Pb in all tested halophytes was above normal of the threshold values (i.e., >0.3 mg kg-1) while Mn (<50 mg kg-1) and Cu (<40 mg kg-1) were within permissible limits. Salsola imbricata had highest Na+ at both sites (site - I = 73; site - II = 98 mg kg-1) with and 10 mg kg-1 extractable shoot Pb at site - I. Ipomea pes-caprae also accumulated shoot Pb higher than normal (site - I = 3.3; site - II = 0.8 mg kg-1) with lowest Na+ content. Heliotropium bacciferum had higher extractable Pb (site - I = 10.5; II = 2.75) with >20 mg kg-1 Na+ in shoot while maintaining > 1 TF for Pb, Cu, Mn and Zn at site - I and all tested metals at site - II. Halopyrum mucronatum had highest shoot Fe (644 mg kg-1), Zn (63 mg kg-1) and Cr (9.2 mg kg-1) at site - II and above threshold values of Pb at both sites (site - I = 8.2; site - II = 2.5 mg kg-1) which makes this species an ideal bio-indicator candidate while other species could be potentially used for Pb phytoremediation.


Assuntos
Bioacumulação , Monitoramento Ambiental/métodos , Metais Pesados/análise , Plantas Tolerantes a Sal/metabolismo , Poluentes do Solo/análise , Solo/química , Biodegradação Ambiental , Disponibilidade Biológica , Ipomoea/crescimento & desenvolvimento , Ipomoea/metabolismo , Metais Pesados/metabolismo , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Poluentes do Solo/metabolismo
7.
Ecotoxicol Environ Saf ; 193: 110345, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32092578

RESUMO

Many areas of the world are affected simultaneously by salinity and heavy metal pollution. Halophytes are considered as useful candidates in remediation of such soils due to their ability to withstand both osmotic stress and ion toxicity deriving from high salt concentrations. Quinoa (Chenopodium quinoa Willd) is a halophyte with a high resistance to abiotic stresses (drought, salinity, frost), but its capacity to cope with heavy metals has not yet been fully investigated. In this pot experiment, we investigated phytoextraction capacity, effects on nutrient levels (P and Fe), and changes in gene expression in response to application of Cr(III) in quinoa plants grown on saline or non-saline soil. Plants were exposed for three weeks to 500 mg kg-1 soil of Cr(NO3)3·9H2O either in the presence or absence of 150 mM NaCl. Results show that plants were able tolerate this soil concentration of Cr(III); the metal was mainly accumulated in roots where it reached the highest concentration (ca. 2.6 mg g-1 DW) in the presence of NaCl. On saline soil, foliar Na concentration was significantly reduced by Cr(III). Phosphorus translocation to leaves was reduced in the presence of Cr(III), while Fe accumulation was enhanced by treatment with NaCl alone. A real-time RT-qPCR analysis was conducted on genes encoding for sulfate, iron, and phosphate transporters, a phytochelatin, a metallothionein, glutathione synthetase, a dehydrin, Hsp70, and enzymes responsible for the biosynthesis of proline (P5CS), glycine betaine (BADH), tocopherols (TAT), and phenolic compounds (PAL). Cr(III), and especially Cr(III)+NaCl, affected transcript levels of most of the investigated genes, indicating that tolerance to Cr is associated with changes in phosphorus and sulfur allocation, and activation of stress-protective molecules. Moderately saline conditions, in most cases, enhanced this response, suggesting that the halophytism of quinoa could contribute to prime the plants to respond to chromium stress.


Assuntos
Chenopodium quinoa/efeitos dos fármacos , Chenopodium quinoa/metabolismo , Cromo/toxicidade , Salinidade , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Transporte Biológico/efeitos dos fármacos , Chenopodium quinoa/genética , Cromo/farmacocinética , Expressão Gênica/efeitos dos fármacos , Íons/metabolismo , Ferro/metabolismo , Chumbo/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Prolina/biossíntese , Plantas Tolerantes a Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismo , Sódio/metabolismo , Cloreto de Sódio/farmacologia , Poluentes do Solo/farmacocinética , Estresse Fisiológico , Enxofre/metabolismo , Tocoferóis/metabolismo
8.
BMC Genomics ; 21(1): 131, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32033524

RESUMO

BACKGROUND: Seashore paspalum (Paspalum vaginatum), a halophytic warm-seasoned perennial grass, is tolerant of many environmental stresses, especially salt stress. To investigate molecular mechanisms underlying salinity tolerance in seashore paspalum, physiological characteristics and global transcription profiles of highly (Supreme) and moderately (Parish) salinity-tolerant cultivars under normal and salt stressed conditions were analyzed. RESULTS: Physiological characterization comparing highly (Supreme) and moderately (Parish) salinity-tolerant cultivars revealed that Supreme's higher salinity tolerance is associated with higher Na+ and Ca2+ accumulation under normal conditions and further increase of Na+ under salt-treated conditions (400 mM NaCl), possibly by vacuolar sequestration. Moreover, K+ retention under salt treatment occurs in both cultivars, suggesting that it may be a conserved mechanism for prevention of Na+ toxicity. We sequenced the transcriptome of the two cultivars under both normal and salt-treated conditions (400 mM NaCl) using RNA-seq. De novo assembly of about 153 million high-quality reads and identification of Open Reading Frames (ORFs) uncovered a total of 82,608 non-redundant unigenes, of which 3250 genes were identified as transcription factors (TFs). Gene Ontology (GO) annotation revealed the presence of genes involved in diverse cellular processes in seashore paspalum's transcriptome. Differential expression analysis identified a total of 828 and 2222 genes that are responsive to high salinity for Supreme and Parish, respectively. "Oxidation-reduction process" and "nucleic acid binding" are significantly enriched GOs among differentially expressed genes in both cultivars under salt treatment. Interestingly, compared to Parish, a number of salt stress induced transcription factors are enriched and show higher abundance in Supreme under normal conditions, possibly due to enhanced Ca2+ signaling transduction out of Na+ accumulation, which may be another contributor to Supreme's higher salinity tolerance. CONCLUSION: Physiological and transcriptome analyses of seashore paspalum reveal major molecular underpinnings contributing to plant response to salt stress in this halophytic warm-seasoned perennial grass. The data obtained provide valuable molecular resources for functional studies and developing strategies to engineer plant salinity tolerance.


Assuntos
Paspalum/genética , Tolerância ao Sal/genética , Cálcio/metabolismo , Perfilação da Expressão Gênica , Genes de Plantas , Paspalum/metabolismo , Bombas de Próton/genética , Bombas de Próton/metabolismo , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismo , Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Ecotoxicol Environ Saf ; 191: 110230, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31982682

RESUMO

The potential for the phytoremediation of halophytes has been widely recognized. However, the effects of salt on Cd accumulation characteristics in different halophytic species, which may also be related to their salt tolerance, are still unclear. This study investigated the effects of salinity on Cd accumulation and distribution in two distinct halophytes, Suaeda glauca (euhalophyte) and Limonium aureum (recretohalophyte). Seedlings of the two species were treated with 0, 3, and 6 mg kg-1 soil Cd in combination with or without 0.3% NaCl in a pot experiment. The amount of Cd within the rhizosphere and plant tissues, plant biomass, and the subcellular distribution and chemical forms of Cd were examined. Results showed that the addition of NaCl significantly increased Cd bioavailability at high Cd levels due to the rhizosphere acidification effect. Meanwhile, salinity differently impacted plant biomass allocation, and enhanced Cd uptake and translocation in both studied halophytes. Excess Cd was excreted from the leaf surface, possibly by salt glands of L. aureum, with the salinity facilitating this process. Majority of the Cd was found within the cell walls and vacuolar compartments of two species. However, S. glauca plants had higher proportions of inactive Cd (extracted by 2% HAc and 0.6 M HCl) and lower proportions of active Cd (extracted by 80% ethanol and water), as opposed to L. aureum, which would better inform S. glauca's higher Cd accumulation. Based on these results, S. glauca seems more applicable for phytomanagement of Cd-contaminated saline soils due to its higher capacity for Cd enrichment and tolerance amplified by NaCl.


Assuntos
Cádmio/farmacocinética , Chenopodiaceae/metabolismo , Plumbaginaceae/metabolismo , Plantas Tolerantes a Sal/metabolismo , Poluentes do Solo/farmacocinética , Biodegradação Ambiental , Biomassa , Folhas de Planta/metabolismo , Rizosfera , Salinidade
10.
Plant Cell Environ ; 43(1): 159-173, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31600831

RESUMO

Choline may affect salt tolerance by regulating lipid and glycine betaine (GB) metabolism. This study was conducted to determine whether alteration of lipid profiles and GB metabolism may contribute to choline regulation and genotypic variations in salt tolerance in a halophytic grass, seashore paspalum (Paspalum vaginatum). Plants of Adalayd and Sea Isle 2000 were subjected to salt stress (200-mM NaCl) with or without foliar application of choline chloride (1 mM). Genotypic variations in salt tolerance and promotive effects of choline application on salt tolerance were associated with both the up-regulation of lipid metabolism and GB synthesis. The genotypic variations in salt tolerance associated with lipid metabolism were reflected by the differential accumulation of phosphatidylcholine and phosphatidylethanolamine between Adalayd and Sea Isle 2000. Choline-induced salt tolerance was associated with of the increase in digalactosyl diacylglycerol (DGDG) content including DGDG (36:4 and 36:6) in both cultivars of seashore paspalum and enhanced synthesis of phosphatidylinositol (34:2, 36:5, and 36:2) and phosphatidic acid (34:2, 34:1, and 36:5), as well as increases in the ratio of digalactosyl diacylglycerol: monogalactosyl diacylglycerol (DGDG:MGDG) in salt-tolerant Sea Isle 2000. Choline regulation of salt tolerance may be due to the alteration in lipid metabolism in this halophytic grass species.


Assuntos
Betaína/metabolismo , Colina/farmacologia , Metabolismo dos Lipídeos/fisiologia , Paspalum/metabolismo , Tolerância ao Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Paspalum/genética , Desenvolvimento Vegetal , Folhas de Planta/genética , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Estresse Salino , Tolerância ao Sal/genética , Espectrometria de Massas em Tandem
11.
Plant Mol Biol ; 102(1-2): 1-17, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31655970

RESUMO

KEY MESSAGE: HbMBF1a was isolated and characterized in H. brevisubulatum, and overexpressed HbMBF1a could enhance the salt tolerance and ABA insensitivity in Arabidopsis thaliana. The transcript levels of stress-responsive genes were significantly increased in the transgenic lines under salt and ABA conditions. Salinity is an abiotic stress that considerably affects plant growth, yield, and distribution. Hordeum brevisubulatum is a halophyte that evolved to become highly tolerant to salinity. Multiprotein bridging factor 1 (MBF1) is a transcriptional coactivator and an important regulator of stress tolerance. In this study, we isolated and characterized HbMBF1a based on the transcriptome data of H. brevisubulatum grown under saline conditions. We overexpressed HbMBF1a in Arabidopsis thaliana and compared the phenotypes of the transgenic lines and the wild-type in response to stresses. The results indicated that HbMBF1a expression was induced by salt and ABA treatments during the middle and late stages. The overexpression of HbMBF1a in A. thaliana resulted in enhanced salt tolerance and ABA insensitivity. More specifically, the enhanced salt tolerance manifested as the increased seed germination and seedling growth and development. Similarly, under ABA treatments, the cotyledon greening rate and seedling root length were higher in the HbMBF1a-overexpressing lines, suggesting the transgenic plants were better adapted to high exogenous ABA levels. Furthermore, the transcript levels of stress-responsive genes were significantly increased in the transgenic lines under salt and ABA conditions. Thus, HbMBF1a is a positive regulator of salt and ABA responses, and the corresponding gene may be useful for producing transgenic plants that are salt tolerant and/or ABA insensitive, with few adverse effects. This study involved a comprehensive analysis of HbMBF1a. The results may provide the basis and insight for the application of MBF1 family genes for developing stress-tolerant crops.


Assuntos
Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Hordeum/genética , Hordeum/metabolismo , Plantas Geneticamente Modificadas/genética , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/genética , Transativadores/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cotilédone/metabolismo , Genes de Plantas/genética , Germinação , Fenótipo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/fisiologia , Plantas Tolerantes a Sal/metabolismo , Sais/farmacologia , Plântula/crescimento & desenvolvimento , Análise de Sequência de DNA , Estresse Fisiológico/genética , Transativadores/classificação , Transativadores/metabolismo , Transcriptoma , Transformação Genética
12.
Antonie Van Leeuwenhoek ; 113(2): 279-291, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31584108

RESUMO

Halophytic plants growing in harsh desert environments are rich reservoirs of unique endophytic microorganisms. Here, healthy fresh plants of the families Tamaricaceae and Amarantaceae at three saline locations in Iran were investigated for their bioactive endophytic fungi. Among a vast number of isolates, eight isolates were identified as Humicola fuscoatra (Sordariomycetes, Pezizomycotina, Ascomycota) by microscopy and representative DNA sequences of the 5.8S rDNA (ITS) and partial ß-tubulin (TUB2). Those isolates were halotolerant, and highly bioactive, so that their intra- and extra-cellular metabolites possessed in vitro antifungal, antibacterial and antiproliferative activities, against a number of fungal and bacterial plant pathogens including the fungi Arthrobotrys conoides, Pyrenophora graminea, Pyricularia grisea and the bacteria Agrobacterium tumefaciens, Pseudomonas syringae and Xanthomonas oryzae. Chemical analyses of metabolites from the endophytes using HNMR, CNMR, NOESY, COSY, HMBC, HSQC, DEPT, TOCSY and EI MASS techniques identified 3,8-dihydroxy-1-methyl-9,10-anthracenedione (aloesaponarin II; an anthraquinone derivative), 1,8,9-anthracenetriol structure (chrysarobin; an anthranol derivative) and 2,4-di-tert-butylthiophenol in fungal extracts. To the best of our knowledge, this is the first report of endophytic association of halotolerant H. fuscoatra isolates with Tamaricaceae and Amarantaceae, and their bioactivity against plant pathogens. Also, the capability of chrysarobin and aloesaponarin II production is new to the fungal kingdom. These findings may find application in agriculture, pharmacology, and biotechnology.


Assuntos
Amaranthaceae/metabolismo , Ascomicetos/metabolismo , Tamaricaceae/microbiologia , Amaranthaceae/genética , Amaranthaceae/fisiologia , Antracenos/metabolismo , Antralina/metabolismo , Antraquinonas/metabolismo , Ascomicetos/genética , Ascomicetos/fisiologia , DNA Bacteriano/genética , DNA Ribossômico/genética , Plantas Tolerantes a Sal/metabolismo , Plantas Tolerantes a Sal/microbiologia , Tamaricaceae/metabolismo
13.
BMC Genomics ; 20(1): 990, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31847807

RESUMO

BACKGROUND: Salinity has obvious effects on plant growth and crop productivity. The salinity-responsive mechanisms have been well-studied in differentiated organs (e.g., leaves, roots and stems), but not in unorganized cells such as callus. High-throughput quantitative proteomics approaches have been used to investigate callus development, somatic embryogenesis, organogenesis, and stress response in numbers of plant species. However, they have not been applied to callus from monocotyledonous halophyte alkaligrass (Puccinellia tenuifora). RESULTS: The alkaligrass callus growth, viability and membrane integrity were perturbed by 50 mM and 150 mM NaCl treatments. Callus cells accumulated the proline, soluble sugar and glycine betaine for the maintenance of osmotic homeostasis. Importantly, the activities of ROS scavenging enzymes (e.g., SOD, APX, POD, GPX, MDHAR and GR) and antioxidants (e.g., ASA, DHA and GSH) were induced by salinity. The abundance patterns of 55 salt-responsive proteins indicate that salt signal transduction, cytoskeleton, ROS scavenging, energy supply, gene expression, protein synthesis and processing, as well as other basic metabolic processes were altered in callus to cope with the stress. CONCLUSIONS: The undifferentiated callus exhibited unique salinity-responsive mechanisms for ROS scavenging and energy supply. Activation of the POD pathway and AsA-GSH cycle was universal in callus and differentiated organs, but salinity-induced SOD pathway and salinity-reduced CAT pathway in callus were different from those in leaves and roots. To cope with salinity, callus mainly relied on glycolysis, but not the TCA cycle, for energy supply.


Assuntos
Poaceae/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino , Antioxidantes/metabolismo , Metabolismo Energético/efeitos dos fármacos , Osmorregulação/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Poaceae/efeitos dos fármacos , Poaceae/enzimologia , Poaceae/crescimento & desenvolvimento , Mapeamento de Interação de Proteínas , Proteômica , Salinidade , Plantas Tolerantes a Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/enzimologia , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Plantas Tolerantes a Sal/metabolismo , Cloreto de Sódio/toxicidade
14.
BMC Plant Biol ; 19(1): 469, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690290

RESUMO

BACKGROUND: Soybean (Glycine max (L.)) is one the most important oil-yielding cash crops. However, the soybean production has been seriously restricted by salinization. It is therefore crucial to identify salt tolerance-related genes and reveal molecular mechanisms underlying salt tolerance in soybean crops. A better understanding of how plants resist salt stress provides insights in improving existing soybean varieties as well as cultivating novel salt tolerant varieties. In this study, the biological function of GmNHX1, a NHX-like gene, and the molecular basis underlying GmNHX1-mediated salt stress resistance have been revealed. RESULTS: We found that the transcription level of GmNHX1 was up-regulated under salt stress condition in soybean, reaching its peak at 24 h after salt treatment. By employing the virus-induced gene silencing technique (VIGS), we also found that soybean plants became more susceptible to salt stress after silencing GmNHX1 than wild-type and more silenced plants wilted than wild-type under salt treatment. Furthermore, Arabidopsis thaliana expressing GmNHX1 grew taller and generated more rosette leaves under salt stress condition compared to wild-type. Exogenous expression of GmNHX1 resulted in an increase of Na+ transportation to leaves along with a reduction of Na+ absorption in roots, and the consequent maintenance of a high K+/Na+ ratio under salt stress condition. GmNHX1-GFP-transformed onion bulb endothelium cells showed fluorescent pattern in which GFP fluorescence signals enriched in vacuolar membranes. Using the non-invasive micro-test technique (NMT), we found that the Na+ efflux rate of both wild-type and transformed plants after salt treatment were significantly higher than that of before salt treatment. Additionally, the Na+ efflux rate of transformed plants after salt treatment were significantly higher than that of wild-type. Meanwhile, the transcription levels of three osmotic stress-related genes, SKOR, SOS1 and AKT1 were all up-regulated in GmNHX1-expressing plants under salt stress condition. CONCLUSION: Vacuolar membrane-localized GmNHX1 enhances plant salt tolerance through maintaining a high K+/Na+ ratio along with inducing the expression of SKOR, SOS1 and AKT1. Our findings provide molecular insights on the roles of GmNHX1 and similar sodium/hydrogen exchangers in regulating salt tolerance.


Assuntos
Proteínas de Plantas/metabolismo , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Soja/metabolismo , Arabidopsis/genética , Inativação Gênica , Proteínas de Plantas/genética , Potássio/metabolismo , Plantas Tolerantes a Sal/genética , Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/genética , Soja/genética , Estresse Fisiológico/genética , Regulação para Cima , Vacúolos/metabolismo
15.
Plant Physiol Biochem ; 143: 83-93, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31491703

RESUMO

Ethylene insensitive 3 (EIN3), a key transcription factor in ethylene signal transduction, play important roles in plant stress signaling pathways. In this study, we isolated and characterized an EIN3-like gene from cotton (Gossypium hirsutum), designated as GhEIN3. GhEIN3 is highly expressed in vegetative tissues, and its expression is induced by 1-aminocyclopropane-1-carboxylic acid (ACC) and NaCl. Ectopic expression of GhEIN3 in Arabidopsis elevated plants' response to ethylene, which exhibit smaller leaves, more root hairs, shorter roots and hypocotyls. The germination rate, survival rate and root length of GhEIN3 transgenic plants were significantly improved compared to wild type under salt stress. GhEIN3 transgenic plants accumulated less H2O2 and malondialdehyde (MDA), while higher superoxide dismutase (SOD) and peroxidase (POD) activities were detected under salt stress. In addition, expression of several genes related to reactive oxygen species (ROS) pathway and ABA signaling pathway was increased in the GhEIN3 transgenic plants under salt stress. In contrast, virus-induced gene silencing (VIGS) of GhEIN3 in cotton enhanced the sensitivity of transgenic plants to salt stress, accumulating higher H2O2 and MDA and lower SOD and POD activities compared to control plants. Collectively, our results revealed that GhEIN3 might be involved in the regulation of plant response to salt stress by regulating ABA and ROS pathway during plant growth and development.


Assuntos
Gossypium/efeitos dos fármacos , Gossypium/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Gossypium/genética , Malondialdeído/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismo , Cloreto de Sódio/farmacologia
16.
PLoS One ; 14(9): e0222940, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31545841

RESUMO

Transcription factors are key regulatory elements that affect gene expression in response to specific signals, including environmental stresses such as salinity. Halophytes are specialized plants that have the ability to complete their life cycle in saline environments. In this study we have identified and characterized the evolutionary relationships of putative transcription factors (TF) in an obligate succulent halophyte, Suaeda fruticosa, that are involved in conferring salt tolerance. Using RNA-seq data we have analyzed the expression patterns of certain TF families, predicted protein-protein interactions, and analyzed evolutionary trajectories to elucidate their possible roles in salt tolerance. We have detected the top differentially expressed (DE) transcription factor families (MYB, CAMTA, MADS-box and bZIP) that show the most pronounced response to salinity. The majority of DE genes in the four aforementioned TF families cluster together on TF phylogenetic trees, which suggests common evolutionary origins and trajectories. This research represents the first comprehensive TF study of a leaf succulent halophyte including their evolutionary relationships with TFs in other halophyte and salt-senstive plants. These findings provide a foundation for understanding the function of salt-responsive transcription factors in salt tolerance and associated gene regulation in plants.


Assuntos
Chenopodiaceae/genética , Proteínas de Plantas/genética , Plantas Tolerantes a Sal/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Chenopodiaceae/metabolismo , Evolução Molecular , Etiquetas de Sequências Expressas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Filogenia , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Plantas Tolerantes a Sal/metabolismo , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/classificação , Fatores de Transcrição/metabolismo
17.
Plant Physiol Biochem ; 143: 212-223, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31518852

RESUMO

In this study, we reported on an ASR gene (TtASR) related to salt/drought tolerance from the edible halophyte Tetragonia tetragonoides (Pall.) Kuntze (Aizoaceae). A phylogenetic analysis revealed that TtASR was evolutionarily close to other two halophytic glycine-rich ASR members, SbASR-1 (from Salicornia brachiate) and SlASR (from Suaeda liaotungensis), with a typical abscisic acid (ABA)/water-deficit stress (WDS) domain at C-terminal. Quantitative RT-PCR analyses showed that TtASR was expressed in all tested different organs of the T. tetragonoides plant and that expression levels were apparently induced after salt, osmotic stress, and ABA treatments in T. tetragonoides seedlings. An induction of TtASR improved the growth performance of yeast and bacteria more than the control under high salinity, osmotic stress, and oxidative stress. TtASR was not a nuclear-specific protein in plant, and the transcriptional activation assay also demonstrated that TtASR could not activate reporter gene's expression in yeast. TtASR overexpressed Arabidopsis plants exhibited higher tolerance for salt/drought and oxidative stresses and lower ROS accumulation than wild type (WT) plants, accompanied by increased CAT, SOD activities, higher proline content, and lower MDA content in vivo. The results indicated that the TtASR was involved in plant responses to salt and drought, probably by mediating water homeostasis or by acting as ROS scavengers, and that it decreased the membrane damage and improved cellular osmotic adjustment that respond to abiotic stresses in microorganisms and plants.


Assuntos
Aizoaceae/metabolismo , Glicina/química , Proteínas de Plantas/metabolismo , Ácido Abscísico/metabolismo , Aizoaceae/efeitos dos fármacos , Aizoaceae/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Prolina/metabolismo , Tolerância ao Sal , Plantas Tolerantes a Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/metabolismo , Plantas Tolerantes a Sal/fisiologia , Plântula/efeitos dos fármacos , Plântula/metabolismo , Plântula/fisiologia , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos
18.
Plant Cell Physiol ; 60(11): 2423-2435, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31292634

RESUMO

Control of K+ and Na+ transport plays a central role in plant adaptation to salinity. In the halophyte Hordeum maritimum, we have characterized a transporter gene, named HmHKT2;1, whose homolog HvHKT2;1 in cultivated barley, Hordeum vulgare, was known to give rise to increased salt tolerance when overexpressed. The encoded protein is strictly identical in two H. maritimum ecotypes, from two biotopes (Tunisian sebkhas) affected by different levels of salinity. These two ecotypes were found to display distinctive responses to salt stress in terms of biomass production, Na+ contents, K+ contents and K+ absorption efficiency. Electrophysiological analysis of HmHKT2;1 in Xenopus oocytes revealed distinctive properties when compared with HvHKT2;1 and other transporters from the same group, especially a much higher affinity for both Na+ and K+, and an Na+-K+ symporter behavior in a very broad range of Na+ and K+ concentrations, due to reduced K+ blockage of the transport pathway. Domain swapping experiments identified the region including the fifth transmembrane segment and the adjacent extracellular loop as playing a major role in the determination of the affinity for Na+ and the level of K+ blockage in these HKT2;1 transporters. The analysis (quantitative reverse transcription-PCR; qRT-PCR) of HmHKT2;1 expression in the two ecotypes submitted to saline conditions revealed that the levels of HmHKT2;1 transcripts were maintained constant in the most salt-tolerant ecotype whereas they decreased in the less tolerant one. Both the unique functional properties of HmHKT2;1 and the regulation of the expression of the encoding gene could contribute to H. maritimum adaptation to salinity.


Assuntos
Hordeum/metabolismo , Proteínas de Plantas/metabolismo , Animais , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Hordeum/genética , Proteínas de Plantas/genética , Potássio/metabolismo , Plantas Tolerantes a Sal/metabolismo , Sódio/metabolismo , Xenopus
19.
Physiol Plant ; 167(1): 2-4, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31268563

RESUMO

Generating salt-tolerant plants that can cope with increasing soil salinity is a major goal of crop-breeding programs worldwide. Together with genetic approaches, research efforts are focusing on finding chemical modulators of salt tolerance. The exogenous application of 5-aminolevulinic acid (ALA) has been shown to improve salt tolerance in diverse crop species, but its mechanism of action is not properly understood. Wu et al. (2019) report that ALA treatment enhances reactive oxygen species (ROS) production in the roots of salt-stressed strawberry plants. Activation of several key ion transporters downstream to the ROS signal helps to sequester the toxic Na+ ions in the roots and protects the shoots against salt stress.


Assuntos
Ácido Aminolevulínico/metabolismo , Fragaria/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fragaria/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Tolerância ao Sal , Plantas Tolerantes a Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/metabolismo , Cloreto de Sódio/farmacologia
20.
Ecotoxicol Environ Saf ; 182: 109382, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31255867

RESUMO

Polycyclic aromatic hydrocarbons (PAH) have become a threat for the conservation of wetlands worldwide. The halophyte Spartina densiflora has shown to be potentially useful for soil phenanthrene phytoremediation, but no studies on bacteria-assisted hydrocarbon phytoremediation have been carried out with this halophyte. In this work, three phenanthrene-degrading endophytic bacteria were isolated from S. densiflora tissues and used for plant inoculation. Bacterial bioaugmentation treatments slightly improved S. densiflora growth, photosynthetic and fluorescence parameters. But endophyte-inoculated S. densiflora showed lower soil phenanthrene dissipation rates than non-inoculated S. densiflora (30% below) or even bulk soil (23% less). Our work demonstrates that endophytic inoculation on S. densiflora under greenhouse conditions with the selected PAH-degrading strains did not significantly increase inherent phenanthrene soil dissipation capacity of the halophyte. It would therefore be advisable to provide effective follow-up of bacterial colonization, survival and metabolic activity during phenanthrene soil phytoremediation.


Assuntos
Bactérias/metabolismo , Fenantrenos/análise , Poaceae/metabolismo , Plantas Tolerantes a Sal/metabolismo , Poluentes do Solo/análise , Solo/química , Biodegradação Ambiental , Endófitos/metabolismo , Fotossíntese , Poaceae/microbiologia , Plantas Tolerantes a Sal/microbiologia , Microbiologia do Solo , Áreas Alagadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...