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1.
Environ Sci Technol ; 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34570468

RESUMO

Rice is known to accumulate arsenic (As) in its grains, posing serious health concerns for billions of people globally. We studied the effect of nanoscale sulfur (NS) on rice seedlings and mature plants under As stress. NS application caused a 40% increase in seedling biomass and a 26% increase in seed yield of mature plants compared to untreated control plants. AsIII exposure caused severe toxicity to rice; however, coexposure of plants to AsIII and NS alleviated As toxicity, and growth was significantly improved. Rice seedlings treated with AsIII + NS produced 159 and 248% more shoot and root biomass, respectively, compared to plants exposed to AsIII alone. Further, AsIII + NS-treated seedlings accumulated 32 and 11% less As in root and shoot tissues, respectively, than the AsIII-alone treatment. Mature plants treated with AsIII + NS produced 76, 110, and 108% more dry shoot biomass, seed number, and seed yield, respectively, and accumulated 69, 38, 18, and 54% less total As in the root, shoot, flag leaves, and grains, respectively, compared to AsIII-alone-treated plants. A similar trend was observed in seedlings treated with AsV and NS. The ability of sulfur (S) to alleviate As toxicity and accumulation is clearly size dependent as NS could effectively reduce bioavailability and accumulation of As in rice via modulating the gene expression activity of As transport, S assimilatory, and glutathione synthesis pathways to facilitate AsIII detoxification. These results have significant environmental implications as NS application in agriculture has the potential to decrease As in the food chain and simultaneously enable crops to grow and produce higher yields on marginal and contaminated lands.

2.
J Agric Food Chem ; 69(35): 10017-10035, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34459588

RESUMO

Seed priming is a cost-effective, practical, environmental, and farmer-friendly method to improve seed germination that can potentially increase the growth and yield of plants. The priming process enhances various physiological and biochemical mechanisms of defense and empowers the seeds or seedlings to overcome different environmental stresses. However, under critical circumstances, plants are hindered from absorbing specific chemical priming reagents owing to their larger size, molecular structure, or lack of carriers. Therefore, nanoscale materials having exceptional physiochemical properties and a large surface/volume ratio are expected to be better absorbed by the seeds/seedlings as priming agents in comparison to bulk chemicals and can trigger enhanced molecular interactions at the cellular level. Further, the flexibility in altering the surface chemical properties of the nanomaterials can facilitate better interaction with the seeds/seedlings while inhibiting the wastage of priming agents. In this review, we have systematically discussed the potentiality of various nanostructured materials as priming agents in alleviating the adverse effects of various abiotic stresses, viz., drought, salinity, high temperature, cold temperature, and heavy metals, by studying the growth parameters and physiological and biochemical response of various crop plants subjected to these stress conditions. Also, we have highlighted the molecular mechanism and activation of genes involved in enabling abiotic stress tolerance in plants after being primed with nanostructured materials.


Assuntos
Plântula , Estresse Fisiológico , Secas , Salinidade , Sementes
3.
Int J Mol Sci ; 22(11)2021 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-34204152

RESUMO

In nature, plants are exposed to an ever-changing environment with increasing frequencies of multiple abiotic stresses. These abiotic stresses act either in combination or sequentially, thereby driving vegetation dynamics and limiting plant growth and productivity worldwide. Plants' responses against these combined and sequential stresses clearly differ from that triggered by an individual stress. Until now, experimental studies were mainly focused on plant responses to individual stress, but have overlooked the complex stress response generated in plants against combined or sequential abiotic stresses, as well as their interaction with each other. However, recent studies have demonstrated that the combined and sequential abiotic stresses overlap with respect to the central nodes of their interacting signaling pathways, and their impact cannot be modelled by swimming in an individual extreme event. Taken together, deciphering the regulatory networks operative between various abiotic stresses in agronomically important crops will contribute towards designing strategies for the development of plants with tolerance to multiple stress combinations. This review provides a brief overview of the recent developments in the interactive effects of combined and sequentially occurring stresses on crop plants. We believe that this study may improve our understanding of the molecular and physiological mechanisms in untangling the combined stress tolerance in plants, and may also provide a promising venue for agronomists, physiologists, as well as molecular biologists.


Assuntos
Produtos Agrícolas/fisiologia , Estresse Fisiológico/fisiologia , Produtos Agrícolas/crescimento & desenvolvimento , Homeostase , Fotossíntese/fisiologia , Espécies Reativas de Oxigênio/metabolismo
4.
Int J Mol Sci ; 22(10)2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34068347

RESUMO

To ensure global food security under the changing climate, there is a strong need for developing 'climate resilient crops' that can thrive and produce better yields under extreme environmental conditions such as drought, salinity, and high temperature. To enhance plant productivity under the adverse conditions, we constitutively overexpressed a bifunctional wax synthase/acyl-CoA:diacylglycerol acyltransferase (WSD1) gene, which plays a critical role in wax ester synthesis in Arabidopsis stem and leaf tissues. The qRT-PCR analysis showed a strong upregulation of WSD1 transcripts by mannitol, NaCl, and abscisic acid (ABA) treatments, particularly in Arabidopsis thaliana shoots. Gas chromatography and electron microscopy analyses of Arabidopsis seedlings overexpressing WSD1 showed higher deposition of epicuticular wax crystals and increased leaf and stem wax loading in WSD1 transgenics compared to wildtype (WT) plants. WSD1 transgenics exhibited enhanced tolerance to ABA, mannitol, drought and salinity, which suggested new physiological roles for WSD1 in stress response aside from its wax synthase activity. Transgenic plants were able to recover from drought and salinity better than the WT plants. Furthermore, transgenics showed reduced cuticular transpirational rates and cuticle permeability, as well as less chlorophyll leaching than the WT. The knowledge from Arabidopsis was translated to the oilseed crop Camelina sativa (L.) Crantz. Similar to Arabidopsis, transgenic Camelina lines overexpressing WSD1 also showed enhanced tolerance to drought stress. Our results clearly show that the manipulation of cuticular waxes will be advantageous for enhancing plant productivity under a changing climate.


Assuntos
Aciltransferases/metabolismo , Arabidopsis/fisiologia , Brassicaceae/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Ceras/metabolismo , Acil Coenzima A/metabolismo , Aciltransferases/genética , Ésteres/metabolismo , Pressão Osmótica , Proteínas de Plantas/genética , Ceras/química
5.
ACS Nano ; 2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-34148346

RESUMO

In agriculture, loss of crop yield to pathogen damage seriously threatens efforts to achieve global food security. In the present work, "organic" elemental sulfur nanoparticles (SNPs) were investigated for management of the fungal pathogen Fusarium oxysporum f. sp. lycopersici on tomatoes. Foliar application and seed treatment with SNPs (30-100 mg/L, 30 and 100 nm) suppressed pathogen infection in tomatoes, in a concentration- and size-dependent fashion in a greenhouse experiment. Foliar application with 1 mg/plant of 30 nm SNPs (30-SNPs) exhibited the best performance for disease suppression, significantly decreasing disease incidence by 47.6% and increasing tomato shoot biomass by 55.6% after 10 weeks application. Importantly, the disease control efficacy with 30-SNPs was 1.43-fold greater than the commercially available fungicide hymexazol. Mechanistically, 30-SNPs activated the salicylic acid-dependent systemic acquired resistance pathway in tomato shoots and roots, with subsequent upregulation of the expression of pathogenesis-related and antioxidase-related genes (upregulated by 11-352%) and enhancement of the activity and content of disease-related biomolecules (enhanced by 5-49%). In addition, transmission electron microscopy imaging shows that SNPs were distributed in the tomato stem and directly inactivated in vivo pathogens. The oxidative stress in tomato shoots and roots, the root plasma membrane damage, and the growth of the pathogen in stem were all significantly decreased by SNPs. The findings highlight the significant potential of SNPs as an eco-friendly and sustainable crop protection strategy.

6.
Nanomaterials (Basel) ; 11(4)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33806035

RESUMO

The present study investigated the role of graphitic carbon nitride (C3N4) in alleviating cadmium (Cd)- and arsenic (As)-induced phytotoxicity to rice (Oryza sativa L.). A high-temperature pyrolysis was used to synthesize the C3N4, which was characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy, and dynamic light scattering. Rice seedlings were exposed to C3N4 at 50 and 250 mg/L in half-strength Hoagland's solution amended with or without 10 mg/L Cd or As for 14 days. Both Cd and As alone resulted in 26-38% and 49-56% decreases in rice root and shoot biomass, respectively. Exposure to 250 mg/L C3N4 alone increased the root and shoot fresh biomass by 17.5% and 25.9%, respectively. Upon coexposure, Cd + C3N4 and As + C3N4 alleviated the heavy metal-induced phytotoxicity and increased the fresh weight by 26-38% and 49-56%, respectively. Further, the addition of C3N4 decreased Cd and As accumulation in the roots by 32% and 25%, respectively, whereas the metal contents in the shoots were 30% lower in the presence of C3N4. Both As and Cd also significantly altered the macronutrient (K, P, Ca, S, and Mg) and micronutrient (Cu, Fe, Zn, and Mn) contents in rice, but these alterations were not evident in plants coexposed to C3N4. Random amplified polymorphic DNA analysis suggests that Cd significantly altered the genomic DNA of rice roots, while no difference was found in shoots. The presence of C3N4 controlled Cd and As uptake in rice by regulating transport-related genes. For example, the relative expression of the Cd transporter OsIRT1 in roots was upregulated by approximately threefold with metal exposure, but C3N4 coamendment lowered the expression. Similar results were evident in the expression of the As transporter OsNIP1;1 in roots. Overall, these findings facilitate the understanding of the underlying mechanisms by which carbon-based nanomaterials alleviate contaminant-induced phyto- and genotoxicity and may provide a new strategy for the reduction of heavy metal contamination in agriculture.

7.
J Hazard Mater ; 400: 123165, 2020 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-32569986

RESUMO

Cadmium pollution has become a serious environmental problem. Iris lactea var. chinensis showed strong Cd tolerance and accumulation ability, which has significant potential to be applied for the phytoremediation of Cd-contaminated soil. However, the lack of molecular information on the mechanism of I. lactea response to Cd limited the improvement of phytoremediation efficiency. In this study, label-free proteomics analysis of Cd response in I. lactea showed that there were 163 and 196 differentially expressed proteins (DEPs) in the shoots and roots, respectively. Bioinformatics analysis indicated the DEPs responding to Cd stress mainly involved in signal transduction, ion transport, redox etc., and participate in the pathway of amino acid biosynthesis, lignin biosynthesis, glycerolipid metabolism and glutathione metabolism. Besides, differential expression of seven DEPs was validated via gene expression analysis. Finally, we found that a Cd-induced mannose-specific lectin (IlMSL) from I. lactea enhanced the Cd sensitivity and increased Cd accumulation in yeast. The results of this study will enhance our understanding of the molecular mechanism of Cd tolerance and accumulation in I. lactea and ultimately provide valuable resources for using Cd tolerant genes for developing efficient strategies for phytoremediation of Cd-contaminated soils or limiting Cd accumulation in food crops.


Assuntos
Iris (Planta) , Poluentes do Solo , Biodegradação Ambiental , Cádmio/toxicidade , Iris , Iris (Planta)/genética , Raízes de Plantas , Proteômica , Poluentes do Solo/toxicidade
9.
J Exp Bot ; 71(2): 569-594, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31328236

RESUMO

Among various abiotic stresses, heat stress is one of the most damaging, threatening plant productivity and survival all over the world. Warmer temperatures due to climatic anomalies above optimum growing temperatures have detrimental impacts on crop yield potential as well as plant distribution patterns. Heat stress affects overall plant metabolism in terms of physiology, biochemistry, and gene expression. Membrane damage, protein degradation, enzyme inactivation, and the accumulation of reactive oxygen species are some of the harmful effects of heat stress that cause injury to various cellular compartments. Although plants are equipped with various defense strategies to counteract these adversities, their defensive means are not sufficient to defend against the ever-rising temperatures. Hence, substantial yield losses have been observed in all crop species under heat stress. Here, we describe the involvement of various plant growth-regulators (PGRs) (hormones, polyamines, osmoprotectants, antioxidants, and other signaling molecules) in thermotolerance, through diverse cellular mechanisms that protect cells under heat stress. Several studies involving the exogenous application of PGRs to heat-stressed plants have demonstrated their role in imparting tolerance, suggesting the strong potential of these molecules in improving the performance of food crops grown under high temperature.


Assuntos
Produtos Agrícolas/fisiologia , Resposta ao Choque Térmico , Reguladores de Crescimento de Plantas/fisiologia , Termotolerância , Mudança Climática , Produtos Agrícolas/crescimento & desenvolvimento , Temperatura Alta
10.
J Exp Bot ; 71(2): 470-479, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31644801

RESUMO

Abiotic stresses, including drought, salinity, temperature, and heavy metals, pose a major challenge for crop production and cause substantial yield reduction worldwide. Breeding tolerant cultivars against these abiotic stresses is the most sustainable and eco-friendly approach to cope with this challenge. Advances in genome editing technologies provide new opportunities for crop improvement by employing precision genome engineering for targeted crop traits. However, the selection of the candidate genes is critical for the success of achieving the desired traits. Broadly speaking, these genes could fall into two major categories, structural and regulatory genes. Structural genes encode proteins that provide stress tolerance directly, whereas regulatory genes act indirectly by controlling the expression of other genes involved in different cellular processes. Additionally, cis-regulatory sequences are also vital for achieving stress tolerance. We propose targeting of these regulatory and/or structural genes along with the cis-regulatory sequences via the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system as a robust, efficient, and practical approach for developing crop varieties resilient to climate change. We also discuss the possibility of creating novel quantitative trait loci for abiotic stress tolerance via the CRISPR/Cas-mediated targeting of promoters. It is hoped that these genome editing tools will not only make a significant contribution towards raising novel plant types having tolerance to multiple abiotic stresses but will also aid in public acceptance of these products in years to come. This article is an attempt to critically evaluate the suitability of available tools and the target genes for obtaining plants with improved tolerance to abiotic stresses.


Assuntos
Sistemas CRISPR-Cas , Produtos Agrícolas/fisiologia , Melhoramento Vegetal , Plantas Geneticamente Modificadas/fisiologia , Estresse Fisiológico , Produtos Agrícolas/genética , Edição de Genes , Plantas Geneticamente Modificadas/genética
11.
J Exp Bot ; 71(2): 507-519, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31270541

RESUMO

Climate change will negatively affect crop production by exacerbating the incidence of disease and decreasing the efficacy of conventional approaches to disease control. Nanotechnology is a promising new strategy for plant disease management that has many advantages over conventional products and approaches, such as better efficacy, reduced input requirements, and lower eco-toxicity. Studies on crop plants using various nanomaterials (NMs) as protective agents have produced promising results. This review focuses on the use of NMs in disease management through three different mechanisms: (i) as antimicrobial agents; (ii) as biostimulants that induce plant innate immunity; and (iii) as carriers for active ingredients such as pesticides, micronutrients, and elicitors. The potential benefits of nanotechnology are considered, together with the role that NMs might play in future disease management and crop adaptation measures.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Produção Agrícola/métodos , Nanoestruturas/uso terapêutico , Doenças das Plantas/prevenção & controle , Imunidade Vegetal/efeitos dos fármacos , Adjuvantes Imunológicos/administração & dosagem , Anti-Infecciosos/administração & dosagem , Mudança Climática , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/microbiologia , Nanoestruturas/administração & dosagem , Nanoestruturas/análise , Nanotecnologia/métodos , Doenças das Plantas/microbiologia
12.
Biotechnol Biofuels ; 11: 335, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30574188

RESUMO

Background: Camelina sativa has attracted much interest as alternative renewable resources for biodiesel, other oil-based industrial products and a source for edible oils. Its unique oil attributes attract research to engineering new varieties of improved oil quantity and quality. The overexpression of enzymes catalyzing the synthesis of the glycerol backbone and the sequential conjugation of fatty acids into this backbone is a promising approach for increasing the levels of triacylglycerol (TAG). In a previous study, we co-expressed the diacylglycerol acyltransferase (DGAT1) and glycerol-3-phosphate dehydrogenase (GPD1), involved in TAG metabolism, in Camelina seeds. Transgenic plants exhibited a higher-percentage seed oil content, a greater seed mass, and overall improved seed and oil yields relative to wild-type plants. To further increase seed oil content in Camelina, we utilized metabolite profiling, in conjunction with transcriptome profiling during seed development to examine potential rate-limiting step(s) in the production of building blocks for TAG biosynthesis. Results: Transcriptomic analysis revealed approximately 2518 and 3136 transcripts differentially regulated at significant levels in DGAT1 and GPD1 transgenics, respectively. These transcripts were found to be involved in various functional categories, including alternative metabolic routes in fatty acid synthesis, TAG assembly, and TAG degradation. We quantified the relative contents of over 240 metabolites. Our results indicate major metabolic switches in transgenic seeds associated with significant changes in the levels of glycerolipids, amino acids, sugars, and organic acids, especially the TCA cycle and glycolysis intermediates. Conclusions: From the transcriptomic and metabolomic analysis of DGAT1, GPD1 and DGAT1 + GPD1 expressing lines of C. sativa, we conclude that TAG production is limited by (1) utilization of fixed carbon from the source tissues supported by the increase in glycolysis pathway metabolites and decreased transcripts levels of transcription factors controlling fatty acids synthesis; (2) TAG accumulation is limited by the activity of lipases/hydrolases that hydrolyze TAG pool supported by the increase in free fatty acids and monoacylglycerols. This comparative transcriptomics and metabolomics approach is useful in understanding the regulation of TAG biosynthesis, identifying bottlenecks, and the corresponding genes controlling these pathways identified as limitations, for generating Camelina varieties with improved seed and oil yields.

13.
Int J Phytoremediation ; 20(11): 1136-1143, 2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30156917

RESUMO

Long- and short-term hydroponic experiments were conducted to study the effect of different concentrations of exogenous glutathione (GSH) on Pb uptake, translocation, and gene expresses in Iris lactea var. chinensis exposed to excess lead (Pb). Exogenous GSH remarkedly promoted Pb uptake and translocation in long-term (14 d) experiment, and the GSH-dose-dependent increases in shoot and root Pb contents existed obviously when GSH concentrations were lower than 800 mg·L-1. The fresh weight in gradual rise in plants was observed with the increase of exogenous GSH concentration. In short-term (24 h) experiment, Pb contents in roots under Pb with L-buthionine sulfoximine (BSO, a known inhibitor of GSH biosynthesis) treatments were significantly lower than that under Pb exposure alone. The transcript levels of three genes (Ilγ-ECS, IlGS, and IlPCS) involved in GSH synthesis and metabolism, showed no significant change in expression pattern except that upregulation after 24 h of treatment with Pb and GSH in comparison with that of the single Pb treatment. Further, the level of IlGS transcript after exposure for 4 h was much higher than that of Ilγ-ECS and IlPCS transcripts. All these results obtained here suggest that exogenous GSH can increase Pb accumulation, detoxification, and translocation to the shoot.


Assuntos
Glutationa , Iris (Planta) , Biodegradação Ambiental , Chumbo , Raízes de Plantas
14.
Environ Sci Pollut Res Int ; 25(25): 25207-25216, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29943252

RESUMO

This study investigated the growth, physiological changes, and the transcript levels of NHX1 gene of Iris halophila in response to low NaCl concentration (50 mM) and high NaCl concentration (150 mM). Our results showed that both 50 and 150 mM NaCl had no obvious negative effects on plant growth; what is more, low NaCl concentration (50 mM) increased root length, root fresh weight, and the ratio of root length to leaf length compared with the control group. The malondialdehyde (MDA) contents in leaves and roots of I. halophila had no obvious difference as compared with control. Proline levels of I. halophila exhibited basically an enhancement under salt stress conditions. Particularly at 4 days, the proline contents in leaves reached 1.85 to 2.31-fold higher and the contents in roots reached 1.27 to 1.62-fold higher than that of control at 50 and 150 mM NaCl, respectively. The contents of the soluble sugar in leaves and roots of I. halophila under 150 mM NaCl at 7 days were 32.4 and 98.7% higher than that of control, respectively. The increase rate of K+ contents with the increasing concentration of salt was less than that of Na+ contents, but K+ contents in the seedlings under NaCl stress was still higher than Na+ contents and the ratio of K+ to Na+ was also greater than 1. The transcript levels of IhNHX1 in leaves of I. halophila at 4 and 7 days under 150 mM NaCl were higher than that of control; however, the transcript levels of IhNHX1 in roots had no significant difference compared with the control under low and high salt stress at 1, 4, and 7 days. Therefore, salt tolerance in I. halophila could be partially due to higher proline, soluble sugar, and K+ accumulation.


Assuntos
Iris (Planta)/fisiologia , Raízes de Plantas/fisiologia , Estresse Salino/genética , Tolerância ao Sal/genética , Trocadores de Sódio-Hidrogênio/genética , Iris (Planta)/genética , Iris (Planta)/crescimento & desenvolvimento , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Potássio/metabolismo , Prolina/metabolismo , RNA de Plantas/metabolismo , Plântula/metabolismo , Sódio/metabolismo , Açúcares/metabolismo
15.
Plant Cell Environ ; 41(5): 877-884, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29663504

RESUMO

Food security and the protection of the environment are urgent issues for global society, particularly with the uncertainties of climate change. Changing climate is predicted to have a wide range of negative impacts on plant physiology metabolism, soil fertility and carbon sequestration, microbial activity and diversity that will limit plant growth and productivity, and ultimately food production. Ensuring global food security and food safety will require an intensive research effort across the food chain, starting with crop production and the nutritional quality of the food products. Much uncertainty remains concerning the resilience of plants, soils, and associated microbes to climate change. Intensive efforts are currently underway to improve crop yields with lower input requirements and enhance the sustainability of yield through improved biotic and abiotic stress tolerance traits. In addition, significant efforts are focused on gaining a better understanding of the root/soil interface and associated microbiomes, as well as enhancing soil properties.


Assuntos
Produtos Agrícolas/fisiologia , Inocuidade dos Alimentos , Abastecimento de Alimentos , Microbiota , Agricultura , Mudança Climática , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/microbiologia , Solo , Microbiologia do Solo
16.
Plant Cell Environ ; 41(5): 1171-1185, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29194659

RESUMO

Members of Stress-Associated Protein (SAP) family in plants have been shown to impart tolerance to multiple abiotic stresses, however, their mode of action in providing tolerance to multiple abiotic stresses is largely unknown. There are 14 SAP genes in Arabidopsis thaliana containing A20, AN1, and Cys2-His2 zinc finger domains. AtSAP13, a member of the SAP family, carries two AN1 zinc finger domains and an additional Cys2-His2 domain. AtSAP13 transcripts showed upregulation in response to Cd, ABA, and salt stresses. AtSAP13 overexpression lines showed strong tolerance to toxic metals (AsIII, Cd, and Zn), drought, and salt stress. Further, transgenic lines accumulated significantly higher amounts of Zn, but less As and Cd accumulation in shoots and roots. AtSAP13 promoter-GUS fusion studies showed GUS expression predominantly in the vascular tissue, hydathodes, and the apical meristem and region of root maturation and elongation as well as the root hairs. At the subcellular level, the AtSAP13-eGFP fusion protein was found to localize in both nucleus and cytoplasm. Through yeast one-hybrid assay, we identified several AP2/EREBP family transcription factors that interacted with the AtSAP13 promoter. AtSAP13 and its homologues will be highly useful for developing climate resilient crops.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Dedos de Zinco CYS2-HIS2 , Regulação da Expressão Gênica de Plantas , Proteínas Nucleares/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Secas , Genes Reporter , Proteínas Nucleares/genética , Plantas Geneticamente Modificadas , Proteínas Recombinantes de Fusão , Tolerância ao Sal , Estresse Fisiológico , Técnicas do Sistema de Duplo-Híbrido , Dedos de Zinco
17.
Plant Biotechnol J ; 16(5): 1034-1045, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28975735

RESUMO

Plant seed oil-based liquid transportation fuels (i.e., biodiesel and green diesel) have tremendous potential as environmentally, economically and technologically feasible alternatives to petroleum-derived fuels. Due to their nutritional and industrial importance, one of the major objectives is to increase the seed yield and oil production of oilseed crops via biotechnological approaches. Camelina sativa, an emerging oilseed crop, has been proposed as an ideal crop for biodiesel and bioproduct applications. Further increase in seed oil yield by increasing the flux of carbon from increased photosynthesis into triacylglycerol (TAG) synthesis will make this crop more profitable. To increase the oil yield, we engineered Camelina by co-expressing the Arabidopsis thaliana (L.) Heynh. diacylglycerol acyltransferase1 (DGAT1) and a yeast cytosolic glycerol-3-phosphate dehydrogenase (GPD1) genes under the control of seed-specific promoters. Plants co-expressing DGAT1 and GPD1 exhibited up to 13% higher seed oil content and up to 52% increase in seed mass compared to wild-type plants. Further, DGAT1- and GDP1-co-expressing lines showed significantly higher seed and oil yields on a dry weight basis than the wild-type controls or plants expressing DGAT1 and GPD1 alone. The oil harvest index (g oil per g total dry matter) for DGTA1- and GPD1-co-expressing lines was almost twofold higher as compared to wild type and the lines expressing DGAT1 and GPD1 alone. Therefore, combining the overexpression of TAG biosynthetic genes, DGAT1 and GPD1, appears to be a positive strategy to achieve a synergistic effect on the flux through the TAG synthesis pathway, and thereby further increase the oil yield.


Assuntos
Proteínas de Arabidopsis/genética , Brassicaceae/metabolismo , Diacilglicerol O-Aciltransferase/metabolismo , Glicerol-3-Fosfato Desidrogenase (NAD+)/genética , Glicerolfosfato Desidrogenase/metabolismo , Óleos Vegetais/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Arabidopsis/enzimologia , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Biocombustíveis , Brassicaceae/genética , Brassicaceae/crescimento & desenvolvimento , Diacilglicerol O-Aciltransferase/genética , Expressão Gênica , Glicerol-3-Fosfato Desidrogenase (NAD+)/metabolismo , Glicerolfosfato Desidrogenase/genética , Metabolismo dos Lipídeos , Engenharia Metabólica , Especificidade de Órgãos , Plantas Geneticamente Modificadas , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
18.
Nanotoxicology ; 11(1): 98-111, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28024451

RESUMO

This study evaluates the bioaccumulation of unweathered (U) and weathered (W) CuO in NP, bulk and ionic form (0-400 mg/kg) by lettuce exposed for 70 d in soil co-contaminated with field incurred chlordane. To evaluate CuO trophic transfer, leaves were fed to crickets (Acheta domestica) for 15 d, followed by insect feeding to lizards (Anolis carolinensis). Upon weathering, the root Cu content of the NP treatment increased 214% (327 ± 59.1 mg/kg) over unaged treatment. Cu root content decreased in bulk and ionic treatments from 70-130 mg/kg to 13-26 mg/kg upon aging in soil. Micro X-ray fluorescence (µ-XRF) analysis of W-NP-exposed roots showed a homogenous distribution of Cu (and Ca) in the tissues. Additionally, micro X-ray absorption near-edge (µ-XANES) analysis of W-NP-exposed roots showed near complete transformation of CuO to Cu (I)-sulfur and oxide complexes in the tissues, whereas in unweathered treatment, most root Cu remained as CuO. The expression level of nine genes involved in Cu transport shows that the mechanisms of CuO NPs (and bulk) response/accumulation are different than ionic Cu. The chlordane accumulation by lettuce upon co-exposure to CuO NPs significantly increased upon weathering. Conversely, bulk and ionic exposures decreased pesticide accumulation by plant upon weathering. The Cu cricket fecal content from U-NP-exposed insects was significantly greater than the bulk or ion treatments, suggesting a higher initial NP accumulation followed by significantly greater elimination during depuration. In the lizard, Cu content in the intestine, body and head did not differ as a function of weathering. This study demonstrates that CuO NPs may undergo transformation processes in soil upon weathering that subsequently impact NPs availability in terrestrial food chains.


Assuntos
Cobre/análise , Nanopartículas/análise , Poluentes do Solo/análise , Solo/química , Animais , Cobre/química , Cobre/metabolismo , Cadeia Alimentar , Gryllidae/química , Gryllidae/efeitos dos fármacos , Gryllidae/metabolismo , Alface/química , Alface/crescimento & desenvolvimento , Alface/metabolismo , Lagartos/metabolismo , Nanopartículas/química , Raízes de Plantas/química , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Poluentes do Solo/química , Poluentes do Solo/metabolismo , Espectrometria por Raios X
19.
Biotechnol Biofuels ; 9: 136, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27382413

RESUMO

BACKGROUND: Camelina sativa is an emerging dedicated oilseed crop designed for biofuel and biodiesel applications as well as a source for edible and general-purpose oils. Such valuable oilseed crop is subjected to plant breeding programs and is suggested for large-scale production of better seed and oil quality. To accomplish this objective and to further enhance its oil content, a better understanding of lipid metabolism at the molecular level in this plant is critical. Here, we applied tissue transcriptomics and lipid composition analysis to identify and profile the genes and gene networks associated with triacylglycerol (TAG) biosynthesis, and to investigate how those genes are interacting to determine the quantity and quality of Camelina oil during seed development. RESULTS: Our Camelina transcriptome data analysis revealed an approximate of 57,854 and 57,973 genes actively expressing in developing seeds (RPKM ≥ 0.1) at 10-15 (Cs-14) and 16-21 (Cs-21) days after flowering (DAF), respectively. Of these, 7932 genes showed temporal and differential gene expression during the seed development (log2 fold change ≥1.5 or ≤-1.5; P ≤ 0.05). The differentially expressed genes (DEGs) were annotated and were found to be involved in distinct functional categories and metabolic pathways. Furthermore, performing quantitative real-time PCR for selected candidate genes associated with TAG biosynthesis validated RNA-seq data. Our results showed strong positive correlations between the expression abundance measured using both qPCR and RNA-Seq technologies. Furthermore, the analysis of fatty-acid content and composition revealed major changes throughout seed development, with the amount of oil accumulate rapidly at early mid seed development stages (from 16-28 DAF onwards), while no important changes were observed in the fatty-acid profile between seeds at 28 DAF and mature seeds. CONCLUSIONS: This study is highly useful for understanding the regulation of TAG biosynthesis and identifying the rate-limiting steps in TAG pathways at seed development stages, providing a precise selection of candidate genes for developing Camelina varieties with improved seed and oil yields.

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