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1.
Ecotoxicol Environ Saf ; 203: 111054, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888616

RESUMO

Quinclorac (3,7-dichloroquinoline-8-carboxylic acid, QNC) is a highly selective auxin herbicide that is typically applied to paddy rice fields. Its residue is a serious problem in crop rotations. In this study, Oryza sativa L. seedlings was used as a model plant to explore its biochemical response to abiotic stress caused by QNC and nZVI coexposure, as well as the interactions between QNC and nZVI treatments. Exposure to 5 and 10 mg/L QNC reduced the fresh biomass by 26.6% and 33.9%, respectively, compared to the control. The presence of 50 and 250 mg/L nZVI alleviated the QNC toxicity, but the nZVI toxicity was aggravated by the coexist of QNC. Root length was enhanced upon exposure to low or medium doses of both QNC and nZVI, whereas root length was inhibited under high-dose coexposure. Both nZVI and QNC, either alone or in combination, significantly inhibited the biosynthesis of chlorophyll, and the inhibition rate increased with elevated nZVI and QNC concentration. It was indicated that nZVI or QNC can affect the plant photosynthesis, and there was a significant interaction between the two treatments. Effects of QNC on the antioxidant response of Oryza sativa L. differed in the shoots and roots; generally, the introduction of 50 and 250 mg/L nZVI alleviated the oxidative stress (POD in shoots, SOD and MDA in roots) induced by QNC. However, 750 mg/kg nZVI seriously damaged Oryza sativa L. seedlings, which likely resulted from active iron deficiency. QNC could be removed from the culture solution by nZVI; as a result, nZVI suppressed QNC uptake by 20%-30%.


Assuntos
Antioxidantes/metabolismo , Ferro/toxicidade , Nanopartículas/toxicidade , Oryza/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Quinolinas/toxicidade , Poluentes do Solo/toxicidade , Transporte Biológico , Biomassa , Clorofila/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
2.
Ecotoxicol Environ Saf ; 203: 110999, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888604

RESUMO

Aluminium (Al) is a key element that plays a major role in inhibiting plant growth and productivity under acidic soils. While lipids may be involved in plant tolerance/sensitivity to Al, the role of monogalactosyldiacylglycerol (MGDG) in Al response remains unknown. In this study, Arabidopsis MGDG synthase (AtMGD) mutants (mgd1, mgd2 and mgd3) and wild-type (Col-0) plants were treated with AlCl3; the effect of aluminium on root growth, aluminium distribution, plasma membrane integrity, lipid peroxidation, hydrogen peroxide content and membrane lipid compositions were analysed. Under Al stress, mgd mutants exhibited a more severe root growth inhibition, plasma membrane integrity damage and lipid peroxidation compared to Col-0. Al accumulation in root tips showed no difference between Col-0 and mutants under Al stress. Lipid analysis demonstrated that under Al treatment the MGDG content in all plants and MGDG/DGDG (digalactosyldiacylglycerol) remarkably reduced, especially in mutants impairing the stability and permeability of the plasma membrane. These results indicate that the Arabidopsis mgd mutants are hypersensitive to Al stress due to the reduction in MGDG content, and this is of great significance in the discovery of effective measures for plants to inhibit aluminium toxicity.


Assuntos
Alumínio/toxicidade , Arabidopsis/efeitos dos fármacos , Galactolipídeos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Poluentes do Solo/toxicidade , Alumínio/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Galactolipídeos/genética , Galactosiltransferases/genética , Galactosiltransferases/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lipídeos de Membrana/metabolismo , Mutação , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Poluentes do Solo/metabolismo
3.
PLoS One ; 15(8): e0237448, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790800

RESUMO

We established that Endosidin2 (ES2) affected the trafficking routes of both newly synthesized and endocytic pools of PIN-FORMED2 (PIN2) in Arabidopsis root epidermal cells. PIN2 populations accumulated in separated patches, which gradually merged into large and compact ES2 aggregates (ES2As). FM4-64 endocytic tracer labeled ES2As as well. Both PIN2 pools also appeared in vacuoles. Accelerated endocytosis of PIN2, its aggregation in the cytoplasm, and redirection of PIN2 flows to vacuoles led to a substantial reduction of the abundance of this protein in the plasma membrane. Whereas PIN-FORMED3 and PIN-FORMED4 also aggregated in the cytoplasm, SYT1 was not sensitive to ES2 treatment and did not appear either in the cytoplasmic aggregates or vacuoles. Ultrastructural analysis revealed that ES2 affects the Golgi apparatus so that stacks acquired cup-shape and even circular shape surrounded by several vesicles. Abnormally shaped Golgi stacks, stack remnants, multi-lamellar structures, separated Golgi cisterna rings, tubular structures, and vesicles formed discrete clusters.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Endocitose/efeitos dos fármacos , Limoninas/farmacologia , Proteínas de Membrana Transportadoras/metabolismo , Parede Celular/metabolismo , Citoplasma/metabolismo , Complexo de Golgi/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Transporte Proteico/efeitos dos fármacos , Sinaptotagmina I/metabolismo
4.
Ecotoxicol Environ Saf ; 202: 110904, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800239

RESUMO

Cation diffusion facilitators (CDFs) play central roles in metal homeostasis and tolerance in plants, but the specific functions of Camellia sinensis CDF-encoding genes and the underlying mechanisms remain unknown. Previously, transcriptome sequencing results in our lab indicated that the expression of CsMTP8.2 in tea plant shoots was down-regulated exposed to excessive amount of Mn2+ conditions. To elucidate the possible mechanisms involved, we systematically identified 13 C. sinensis CsMTP genes from three subfamilies and characterized their phylogeny, structures, and the features of the encoded proteins. The transcription of CsMTP genes was differentially regulated in C. sinensis shoots and roots in responses to high concentrations of Mn, Zn, Fe, and Al. Differences in the cis-acting regulatory elements in the CsMTP8.1 and CsMTP8.2 promoters suggested the expression of these two genes may be differentially regulated. Transient expression analysis indicated that CsMTP8.2 was localized to the plasma membrane in tobacco and onion epidermal cells. Moreover, when heterologously expressed in yeast, CsMTP8.2 conferred tolerance to Ni and Mn but not to Zn. Additionally, heterologous expression of CsMTP8.2 in Arabidopsis thaliana revealed that CsMTP8.2 positively regulated the response to manganese toxicity by decreasing the accumulation of Mn in plants. However, there was no difference in the accumulation of other metals, including Cu, Fe, and Zn. These results suggest that CsMTP8.2 is a Mn-specific transporter that contributes to the efflux of excess Mn2+ from plant cells.


Assuntos
Camellia sinensis/genética , Manganês/toxicidade , Poluentes do Solo/toxicidade , Arabidopsis/metabolismo , Membrana Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Manganês/metabolismo , Filogenia , Células Vegetais/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Saccharomyces cerevisiae/metabolismo , Chá
5.
PLoS One ; 15(8): e0237194, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760135

RESUMO

We aimed to profile the metabolism of soybean roots that were infected with soybean cyst nematodes and treated with Bacillus simplex to identify metabolic differences that may explain nematode resistance. Compared with control soybean roots, B. simplex-treated soybean roots contained lower levels of glucose, fructose, sucrose, and trehalose, which reduced the nematodes' food source. Furthermore, treatment with B. simplex led to higher levels of melibiose, gluconic acid, lactic acid, phytosphingosine, and noradrenaline in soybean roots, which promoted nematocidal activity. The levels of oxoproline, maltose, and galactose were lowered after B. simplex treatment, which improved disease resistance. Collectively, this study provides insight into the metabolic alterations induced by B. simplex treatment, which affects the interactions with soybean cyst nematodes.


Assuntos
Bacillus/patogenicidade , Resistência à Doença , Metaboloma , Nematoides/patogenicidade , Soja/parasitologia , Animais , Metabolismo dos Carboidratos , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/parasitologia , Soja/metabolismo , Soja/microbiologia
6.
PLoS One ; 15(7): e0236943, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735612

RESUMO

Halophyte Lobularia maritima LmSAP encodes an A20AN1 zinc-finger stress-associated protein which expression is up-regulated by abiotic stresses and heavy metals in transgenic tobacco. To deepen our understanding of LmSAP function, we isolated a 1,147 bp genomic fragment upstream of LmSAP coding sequence designated as PrLmSAP. In silico analyses of PrLmSAP revealed the presence of consensus CAAT and TATA boxes and cis-regulatory elements required for abiotic stress, phytohormones, pathogen, and wound responses, and also for tissue-specific expression. The PrLmSAP sequence was fused to the ß-glucuronidase (gusA) reporter gene and transferred to rice. Histochemical GUS staining showed a pattern of tissue-specific expression in transgenic rice, with staining observed in roots, coleoptiles, leaves, stems and floral organs but not in seeds or in the root elongation zone. Wounding strongly stimulated GUS accumulation in leaves and stems. Interestingly, we observed a high stimulation of the promoter activity when rice seedlings were exposed to NaCl, PEG, ABA, MeJA, GA, cold, and heavy metals (Al3+, Cd2+, Cu2+ and Zn2+). These results suggest that the LmSAP promoter can be a convenient tool for stress-inducible gene expression and is a potential candidate for crop genetic engineering.


Assuntos
Regulação da Expressão Gênica de Plantas/genética , Regiões Promotoras Genéticas , Plantas Tolerantes a Sal/genética , Estresse Fisiológico/genética , Dedos de Zinco/genética , Produtos Agrícolas/genética , Engenharia Genética , Glucuronidase/metabolismo , Metais Pesados/metabolismo , Especificidade de Órgãos , Oryza/genética , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Caules de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tabaco/genética
7.
PLoS One ; 15(7): e0234448, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735565

RESUMO

Soybean root rot is a typical soil-borne disease that severely affects the yield of soybean. Funneliformis mosseae is one of the arbuscular mycorrhizal fungi(AMF) dominant strains in soybean continuous cropping soil. The aim of this study was to providing an experimental basis for the study of the molecular mechanism underlying the alleviation of the obstacles associated with the continuous cropping of soybean by AMF. In this study, F. mosseae was inoculated in soil planted with soybean infected with Fusarium oxysporum. The results showed that the incidence of soybean root rot was significantly reduced after inoculation with F. mosseae. In F. mosseae-treated samples, the significantly upregulated genes encoded transmembrane protein in fungal cell membrane. The significantly downregulated genes encoded some proteins, which took part in composition of essential component of fungal cell wall; hydrolyse cellulose and hemicellulose. The DEGs in each treatment were enriched in antigen processing and presentation, carbon fixation in photosynthetic organisms, glycolysis/gluconeogenesis, the MAPK signalling pathway, protein processing in the endoplasmic reticulum and RNA degradation. Inoculation with F. mosseae could in a variety of ways to promote the growth, development of soybean and improve disease resistance. Such as help fungal build barriers to the disease resistance of host plant and enhance their pathogenicity; damaging the structure of the pathogen; protect plant tissues and so on. This study provides an experimental basis for further research on the molecular mechanism underlying the alleviation of challenges associated with the continuous cropping of soybean by AMF.


Assuntos
Fusarium/genética , Micorrizas/genética , Transcriptoma/genética , Fusarium/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação Fúngica da Expressão Gênica/genética , Micorrizas/patogenicidade , Fotossíntese , Raízes de Plantas/metabolismo , Solo , Microbiologia do Solo , Soja/crescimento & desenvolvimento
8.
Ecotoxicol Environ Saf ; 202: 110958, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800230

RESUMO

Phytoremediation is an effective way to repair heavy metal contaminated soil and rhizosphere microorganisms play an important role in plant regulation. Nevertheless, little information is known about the variation of microbial metabolic activities and community structure in rhizosphere during phytoremediation. In this study, the rhizosphere soil microbial metabolic activities and community structure of Trifolium repensL. during Cd-contaminated soil phytoremediation, were analyzed by Biolog EcoPlate™ and high-throughput sequencing. The uptake in the roots of Trifolium repensL. grown in 5.68 and 24.23 mg/kg Cd contaminated soil was 33.51 and 84.69 mg/kg respectively, causing the acid-soluble Cd fractions decreased 7.3% and 5.4%. Phytoremediation significantly influenced microbial community and Trifolium repensL. planting significantly increased the rhizosphere microbial population, diversity, the relative abundance of plant growth promoting bacteria (Kaistobacter and Flavisolibacter), and the utilization of difficultly metabolized compounds. The correlation analysis among substrate utilization and microbial communities revealed that the relative abundance increased microorganisms possessed stronger carbon utilization capacity, which was beneficial to regulate the stability of plant-microbial system. Collectively, the results of this study provide fundamental insights into the microbial metabolic activities and community structure during heavy metal contaminated soil phytoremediation, which may aid in the bioregulation of phytoremediation.


Assuntos
Cádmio/toxicidade , Microbiota/efeitos dos fármacos , Rizosfera , Microbiologia do Solo , Poluentes do Solo/toxicidade , Solo/química , Trifolium/efeitos dos fármacos , Biodegradação Ambiental , Cádmio/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Poluentes do Solo/metabolismo , Trifolium/crescimento & desenvolvimento , Trifolium/metabolismo , Trifolium/microbiologia
9.
Ecotoxicol Environ Saf ; 202: 110885, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32650140

RESUMO

Silicon (Si) is a metalloid which is gaining worldwide attention of plant scientists due to its ameliorating impact on plants' growth and development. The beneficial response of Si is observed predominantly under numerous abiotic and biotic stress conditions. However, under favorable conditions, most of the plant can grow without it. Therefore, Si has yet not been fully accepted as essential element rather it is being considered as quasi-essential for plants' growth. Si is also known to enhance resilience in plants by reducing the plant's stress. Besides its second most abundance on the earth crust, most of the soils lack plant available form of Si i.e. silicic acid. In this regard, understanding the role of Si in plant metabolism, its uptake from roots and transport to aerial tissues along with its ionomics and proteomics under different circumstances is of great concern. Plants have evolved a well-optimized Si-transport system including various transporter proteins like Low silicon1 (Lsi1), Low silicon2 (Lsi2), Low silicon3 (Lsi3) and Low silicon6 (Lsi6) at specific sub-cellular locations along with the expression profiling that creates precisely coordinated network among these transporters, which also facilitate uptake and accumulation of Si. Though, an ample amount of information is available pertinent to the solute specificity, active sites, transcriptional and post-transcriptional regulation of these transporter genes. Similarly, the information regarding transporters involved in Si accumulation in different organelles is also available particularly in silica cells occurred in poales. But in this review, we have attempted to compile studies related to plants vis à vis Si, its role in abiotic and biotic stress, its uptake in various parts of plants via different types of Si-transporters, expression pattern, localization and the solute specificity. Besides these, this review will also provide the compiled knowledge about the genetic variation among crop plants vis à vis enhanced Si uptake and related benefits.


Assuntos
Plantas/metabolismo , Silício/metabolismo , Transporte Biológico , Proteínas de Transporte/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Raízes de Plantas/metabolismo , Solo
10.
Ecotoxicol Environ Saf ; 203: 110964, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678754

RESUMO

Soil salinization is the most common abiotic stress limiting agricultural productivity worldwide. Recent research has suggested that the application of silicon (Si) has beneficial effects against salt stress in sorghum (Sorghum bicolor L. Moench) and sunflower (Helianthus annuus L.) by regulating the antioxidant system, mineral nutrients, and other important mechanisms. However, whether these effects can be achieved through foliar application of Si, or whether Si application affects Si-accumulating (e.g., sorghum), and intermediate-Si-accumulating (e.g., sunflower) plant species differently, remains unclear. This study investigated different methods of Si application in attenuating the detrimental effects of salt stress, based on the biological responses of two distinct species of Si accumulators, under greenhouse conditions. Two pot experiments were designed as a factorial (2 × 4), randomized complete blocks design (RCBD) with control and salt-stress groups (0 and 100 mmol.L-1 NaCl), and four Si-treatment groups: control (no Si), foliar application (28.6 mmol.L-1), root application (2 mmol.L-1), and combined foliar and root applications. Our results showed that the harmful effects of salt stress were attenuated by Si treatments in both plant species, which decreased Na+ uptake and lipid peroxidation, and increased Si and K+ uptake, relative leaf water content, antioxidant enzyme activities, leaf area, and shoot dry matter. These results were more prominent when Si was applied via nutrient solution in the sorghum plants, and the combined foliar and root applications of Si in sunflower plants. In addition, foliar application of Si alone is an efficient alternative in attenuating the effects of salinity in both plant species when Si is not available in the growth medium. These results suggest that the Si application method plays an important role in Na+ detoxification by modifying the antioxidative defense mechanism, which could actively mediate some important physiological and biochemical processes and helps to increase the shoot dry matter production in sorghum and sunflower plants under salt stress.


Assuntos
Antioxidantes/metabolismo , Helianthus/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Salino , Silício/farmacologia , Sorghum/efeitos dos fármacos , Grão Comestível/efeitos dos fármacos , Grão Comestível/metabolismo , Helianthus/metabolismo , Componentes Aéreos da Planta/efeitos dos fármacos , Componentes Aéreos da Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Distribuição Aleatória , Salinidade , Solo/química , Sorghum/metabolismo
11.
Ecotoxicol Environ Saf ; 203: 110978, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678757

RESUMO

In this study, hydroponic experiments were conducted to elucidate mechanism(s) that are associated with differential effects of low (5 µM) and high (25 µM) dose of cadmium (Cd) stress in tomato. Furthermore, emphasis has also been focused on any involvement of endogenous hydrogen sulfide (H2S) in differential behaviour of low and high doses of Cd stress. At low dose of Cd, root growth i.e. root fresh weight, length and fitness did not significantly alter when compared to the control seedlings. Though at low dose of Cd, cellular accumulation of Cd was slightly increased but this was accompanied by higher endogenous H2S and phytochelatins, L-cysteine desulfhydrase (DES) activity, activities of glutathione biosynthetic and AsA-GSH cycle enzymes, and maintained redox status of ascorbate and glutathione. However, addition of hypotaurine (HT, a scavenger of H2S) resulted in greater toxicity, even at low dose of Cd, and these responses resembled with higher dose of Cd stress such as greater decline in root growth, endogenous H2S and phytochelatins, activities of DES, glutathione biosynthesis and AsA-GSH cycle enzymes, disturbed redox status of ascorbate and glutathione which collectively led to higher oxidative stress in tomato roots. Moreover, addition of HT with higher dose of Cd also further enhanced its toxicity. Collectively, the results showed that differential behaviour of low and high dose of Cd stress is mediated by differential regulation of biochemical attributes in which endogenous H2S has a crucial role.


Assuntos
Cádmio/toxicidade , Sulfeto de Hidrogênio/metabolismo , Lycopersicon esculentum/efeitos dos fármacos , Fitoquelatinas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Ácido Ascórbico/metabolismo , Glutationa/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
12.
PLoS One ; 15(7): e0236565, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730299

RESUMO

Flavonoids are key components of licorice plant that directly affect its medicinal quality. Importantly, the MYB family of transcription factors serves to regulate the synthesis of flavonoids in plants. The MYB transcription factors represent one of the largest families of transcription factors in plants and play important roles in the process of plant growth and development. MYB gene expression is induced by a number of plant hormones, including the lipid-based hormone jasmonate (JA). Methyl jasmonate (MeJA) is an endogenous plant growth regulator that can induce the JA signaling pathway, which functions to regulate the synthesis of secondary metabolites, including flavonoids. In this study, MeJA was added to licorice cell suspensions, and RNA-seq analysis was performed to identify the differentially expressed genes. As a result, the MYB transcription factors GlMYB4 and GlMYB88 were demonstrated to respond significantly to MeJA induction. Subsequently, the GlMYB4 and GlMYB88 protein were shown to localize to the cell nucleus, and it was verified that GlMYB4 and GlMYB88 could positively regulate the synthesis of flavonoids in licorice cells. Overall, this research helps illustrate the molecular regulation of licorice flavonoid biosynthesis induced by MeJA.


Assuntos
Acetatos/farmacologia , Ciclopentanos/farmacologia , Flavonoides/biossíntese , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glycyrrhiza uralensis/metabolismo , Oxilipinas/farmacologia , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Flavonoides/química , Glycyrrhiza uralensis/química , Glycyrrhiza uralensis/crescimento & desenvolvimento , Filogenia , Folhas de Planta/metabolismo , Proteínas de Plantas/classificação , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Caules de Planta/metabolismo , Fatores de Transcrição/classificação , Fatores de Transcrição/genética
13.
Chemosphere ; 259: 127410, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32615455

RESUMO

Arsenic (As) can be present naturally in groundwater from peanut fields, constituting a serious problem, as roots can accumulate and mobilize the metalloid to their edible parts. Understanding the redox changes in the legume exposed to As may help to detect potential risks to human health and recognize tolerance mechanisms. Thirty-days old peanut plants inoculated with Bradyrhizobium sp. strains (SEMIA6144 or C-145) were exposed to a realistic arsenate concentration, in order to unravel the redox response and characterize the oxidative stress indexes. Thus, root anatomy, reactive oxygen species detection by fluorescence microscopy and, ROS histochemical staining along with the NADPH oxidase activity were analyzed. Besides, photosynthetic pigments and damage to lipids and proteins were determined as oxidative stress indicators. Results showed that at 3 µM AsV, the cross-section areas of peanut roots were augmented; NADPH oxidase activity was significantly increased and O2˙¯and H2O2 accumulated in leaves and roots. Likewise, an increase in the lipid peroxidation and protein carbonyls was also observed throughout the plant regardless the inoculated strain, while chlorophylls and carotenes were increased only in those inoculated with Bradyrhizobium sp. C-145. Interestingly, the oxidative burst, mainly induced by the NADPH oxidase activity, and the consequent oxidative stress was strain-dependent and organ-differential. Additionally, As modifies the root anatomy, acting as a possibly first defense mechanism against the metalloid entry. All these findings allowed us to conclude that the redox response of peanut is conditioned by the rhizobial strain, which contributes to the importance of effectively formulating bioinoculants for this crop.


Assuntos
Arachis/microbiologia , Arsênico/toxicidade , Bradyrhizobium/fisiologia , Estresse Oxidativo/fisiologia , Arachis/efeitos dos fármacos , Arachis/metabolismo , Arachis/fisiologia , Arseniatos , Arsênico/metabolismo , Bradyrhizobium/efeitos dos fármacos , Bradyrhizobium/metabolismo , Clorofila/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , Oxirredução , Raízes de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Simbiose/efeitos dos fármacos
14.
PLoS One ; 15(7): e0234550, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32663226

RESUMO

Chickpea has a profound nutritional and economic value in vegetarian society. Continuous decline in chickpea productivity is attributed to insufficient genetic variability and different environmental stresses. Chickpea like several other legumes is highly susceptible to terminal drought stress. Multiple genes control drought tolerance and ASR gene plays a key role in regulating different plant stresses. The present study describes the molecular characterization and functional role of Abscissic acid and stress ripening (ASR) gene from chickpea (Cicer arietinum) and the gene sequence identified was submitted to NCBI Genbank (MK937569). Molecular analysis using MUSCLE software proved that the ASR nucleotide sequences in different legumes show variations at various positions though ASR genes are conserved in chickpea with only few variations. Sequence similarity of ASR gene to chickpea putative ABA/WDS induced protein mRNA clearly indicated its potential involvement in drought tolerance. Physiological screening and qRT-PCR results demonstrated increased ASR gene expression under drought stress possibly enabled genotypes to perform better under stress. Conserved domain search, protein structure analysis, prediction and validation, network analysis using Phyre2, Swiss-PDB viewer, ProSA and STRING analysis established the role of hypothetical ASR protein NP_001351739.1 in mediating drought responses. NP_001351739.1 might have enhanced the ASR gene activity as a transcription factor regulating drought stress tolerance in chickpea. This study could be useful in identification of new ASR genes that play a major role in drought tolerance and also develop functional markers for chickpea improvement.


Assuntos
Cicer/genética , Regulação da Expressão Gênica de Plantas/genética , Estresse Fisiológico/genética , Ácido Abscísico/farmacologia , Adaptação Fisiológica/genética , Sequência de Bases/genética , Cicer/crescimento & desenvolvimento , Secas , Perfilação da Expressão Gênica/métodos , Genótipo , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Fatores de Transcrição/metabolismo
15.
PLoS One ; 15(7): e0236530, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706831

RESUMO

Apple trees grafted on different rootstock types, including vigorous rootstock (VR), dwarfing interstock (DIR), and dwarfing self-rootstock (DSR), are widely planted in production, but the molecular determinants of tree branch architecture growth regulation induced by rootstocks are still not well known. In this study, the branch growth phenotypes of three combinations of 'Fuji' apple trees grafted on different rootstocks (VR: Malus baccata; DIR: Malus baccata/T337; DSR: T337) were investigated. The VR trees presented the biggest branch architecture. The results showed that the sugar content, sugar metabolism-related enzyme activities, and hormone content all presented obvious differences in the tender leaves and buds of apple trees grafted on these rootstocks. Transcriptomic profiles of the tender leaves adjacent to the top buds allowed us to identify genes that were potentially involved in signaling pathways that mediate the regulatory mechanisms underlying growth differences. In total, 3610 differentially expressed genes (DEGs) were identified through pairwise comparisons. The screened data suggested that sugar metabolism-related genes and complex hormone regulatory networks involved the auxin (IAA), cytokinin (CK), abscisic acid (ABA) and gibberellic acid (GA) pathways, as well as several transcription factors, participated in the complicated growth induction process. Overall, this study provides a framework for analysis of the molecular mechanisms underlying differential tree branch growth of apple trees grafted on different rootstocks.


Assuntos
Regulação da Expressão Gênica de Plantas , Malus/genética , Transdução de Sinais/genética , Açúcares/metabolismo , Ácido Abscísico/análise , Ácido Abscísico/metabolismo , Cromatografia Líquida de Alta Pressão , Citocininas/análise , Citocininas/metabolismo , Flores/genética , Flores/metabolismo , Giberelinas/análise , Giberelinas/metabolismo , Ácidos Indolacéticos/análise , Ácidos Indolacéticos/metabolismo , Malus/crescimento & desenvolvimento , Fenótipo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Caules de Planta/genética , Caules de Planta/fisiologia , RNA de Plantas/genética , RNA de Plantas/metabolismo , Açúcares/análise , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , alfa-Glucosidases/genética , alfa-Glucosidases/metabolismo
16.
PLoS One ; 15(7): e0236376, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32722723

RESUMO

Grafting is a well-established agricultural practice in cherry production for clonal propagation, altered plant vigor and architecture, increased tolerance to biotic and abiotic stresses, precocity, and higher yield. Mobile molecules, such as water, hormones, nutrients, DNAs, RNAs, and proteins play essential roles in rootstock-scion interactions. Small RNAs (sRNAs) are 19 to 30-nucleotides (nt) RNA molecules that are a group of mobile signals in plants. Rootstock-to-scion transfer of transgene-derived small interfering RNAs enabled virus resistance in nontransgenic sweet cherry scion. To determine whether there was long-distance scion-to-rootstock transfer of endogenous sRNAs, we compared sRNAs profiles in bud tissues of an ungrafted 'Gisela 6' rootstock, two sweet cherry 'Emperor Francis' scions as well as their 'Gisela 6' rootstocks. Over two million sRNAs were detected in each sweet cherry scion, where 21-nt sRNA (56.1% and 55.8%) being the most abundant, followed by 24-nt sRNAs (13.1% and 12.5%). Furthermore, we identified over three thousand sRNAs that were potentially transferred from the sweet cherry scions to their corresponding rootstocks. In contrast to the sRNAs in scions, among the transferred sRNAs in rootstocks, the most abundant were 24-nt sRNAs (46.3% and 34.8%) followed by 21-nt sRNAs (14.6% and 19.3%). In other words, 21-nt sRNAs had the least transferred proportion out of the total sRNAs in sources (scions) while 24-nt had the largest proportion. The transferred sRNAs were from 574 cherry transcripts, of which 350 had a match from the Arabidopsis thaliana standard protein set. The finding that "DNA or RNA binding activity" was enriched in the transcripts producing transferred sRNAs indicated that they may affect the biological processes of the rootstocks at different regulatory levels. Overall, the profiles of the transported sRNAs and their annotations revealed in this study facilitate a better understanding of the role of the long-distance transported sRNAs in sweet cherry rootstock-scion interactions as well as in branch-to-branch interactions in a tree.


Assuntos
Raízes de Plantas/genética , Prunus avium/genética , Pequeno RNA não Traduzido/metabolismo , Arabidopsis/genética , Redes Reguladoras de Genes/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Prunus avium/crescimento & desenvolvimento , Pequeno RNA não Traduzido/química , Pequeno RNA não Traduzido/isolamento & purificação
17.
PLoS One ; 15(7): e0235975, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649704

RESUMO

Rice cultivar "Weiyou916" (Oryza sativa L. ssp. Indica) were cultured with control (10 mM NO3-) and nitrate deficient solution (0 mM NO3-) for four weeks. Nitrogen (N) deficiency significantly decreased the content of N and P, dry weight (DW) of the shoots and roots, but increased the ratio of root to shoot in O. sativa. N deficiency decreased the photosynthesis rate and the maximum quantum yield of primary photochemistry (Fv/Fm), however, increased the intercellular CO2 concentration and primary fluorescence (Fo). N deficiency significantly increased the production of H2O2 and membrane lipid peroxidation revealed as increased MDA content in O. sativa leaves. N deficiency significantly increased the contents of starch, sucrose, fructose, and malate, but did not change that of glucose and total soluble protein in O. sativa leaves. The accumulated carbohydrates and H2O2 might further accelerate biosynthesis of lignin in O. sativa leaves under N limitation. A total of 1635 genes showed differential expression in response to N deficiency revealed by Illumina sequencing. Gene Ontology (GO) analysis showed that 195 DEGs were found to highly enrich in nine GO terms. Most of DEGs involved in photosynthesis, biosynthesis of ethylene and gibberellins were downregulated, whereas most of DEGs involved in cellular transport, lignin biosynthesis and flavonoid metabolism were upregulated by N deficiency in O. sativa leaves. Results of real-time quantitative PCR (RT-qPCR) further verified the RNA-Seq data. For the first time, DEGs involved oxygen-evolving complex, phosphorus response and lignin biosynthesis were identified in rice leaves. Our RNA-Seq data provided a global view of transcriptomic profile of principal processes implicated in the adaptation of N deficiency in O. sativa and shed light on the candidate direction in rice breeding for green and sustainable agriculture.


Assuntos
Flavonoides/metabolismo , Lignina/metabolismo , Nitratos/metabolismo , Oryza/genética , Fotossíntese , Carboidratos/análise , Clorofila A/química , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Oryza/metabolismo , Oxirredução , Folhas de Planta/genética , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , RNA de Plantas/química , RNA de Plantas/metabolismo , Análise de Sequência de RNA
18.
Chemosphere ; 260: 127541, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32688311

RESUMO

The present study explores the effect of ethylene diamine disuccinic acid (EDDS) and gibberellic acid (GA) application on the phytoextraction of copper and zinc ions by Lolium perenne. When Cu was individually applied, accumulation diminished over time with little translocation from roots to shoots. In contrast, Zn accumulation and damage to roots rapidly increased over 3 days with increase in Zn translocation to shoots. Co-application of Zn to Cu amended treatments enhanced Cu concentration in shoots. For the CuEDDS application, EDDS significantly increased Cu accumulation and the damage to root increased over time, while gibberellic acid applied with Cu and Zn generally lowered metal uptake and decreased cell membrane damage. The application of EDDS and GA-EDDS, by themselves or with Cu and Zn, lowered transpiration and increased translocation, while GA increased transpiration but decreased translocation. EDDS application typically increased metal ion uptake by causing more cell damage, while GA typically lowered the damage and decreased metal uptake even though the transpiration increased over time and plant growth occurred. Furthermore, the behaviour of metal uptake changed over time and, for some treatments, the short-term and long-term response differed greatly. These results show that EDDS can be successfully used in phytoextraction of both Cu and Zn ions by Lolium perenne while GA can resist damage and protect against plant stress.


Assuntos
Biodegradação Ambiental , Etilenodiaminas/química , Giberelinas/química , Lolium/metabolismo , Poluentes do Solo/metabolismo , Transporte Biológico , Cobre/metabolismo , Etilenos , Íons/metabolismo , Raízes de Plantas/metabolismo , Succinatos/metabolismo , Zinco/metabolismo
19.
PLoS One ; 15(7): e0235556, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614916

RESUMO

To gain a better insight into the selenium nanoparticle (nSe) benefits/toxicity, this experiment was carried out to address the behavior of bitter melon seedlings to nSe (0, 1, 4, 10, 30, and 50 mgL-1) or bulk form (selenate). Low doses of nSe increased biomass accumulation, while concentrations of 10 mgL-1 and above were associated with stem bending, impaired root meristem, and severe toxicity. Responses to nSe were distinct from that of bulk in that the nano-type exhibited a higher efficiency to stimulate growth and organogenesis than the bulk. The bulk form displayed higher phytotoxicity than the nano-type counterpart. According to the MSAP-based analysis, nSe mediated substantial variation in DNA cytosine methylation, reflecting the epigenetic modification. By increasing the concentration of nSe, the expression of the WRKY1 transcription factor linearly up-regulated (mean = 7.9-fold). Transcriptions of phenylalanine ammonia-lyase (PAL) and 4-Coumarate: CoA-ligase (4CL) genes were also induced. The nSe treatments at low concentrations enhanced the activity of leaf nitrate reductase (mean = 52%) in contrast with the treatment at toxic concentrations. The toxic concentration of nSe increased leaf proline concentration by 80%. The nSe supplement also stimulated the activities of peroxidase (mean = 35%) and catalase (mean = 10%) enzymes. The nSe-treated seedlings exhibited higher PAL activity (mean = 39%) and soluble phenols (mean = 50%). The nSe toxicity was associated with a disrupted differentiation of xylem conducting tissue. The callus formation and performance of the explants originated from the nSe-treated seedlings had a different trend than that of the control. This experiment provides new insights into the nSe-associated advantage/ cytotoxicity and further highlights the necessity of designing convincing studies to introduce novel methods for plant cell/tissue cultures and agriculture.


Assuntos
Metilação de DNA/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Momordica charantia/metabolismo , Nanopartículas/toxicidade , Selênio/química , Citosina/metabolismo , Momordica charantia/efeitos dos fármacos , Momordica charantia/crescimento & desenvolvimento , Nanopartículas/química , Nitrato Redutase/genética , Nitrato Redutase/metabolismo , Fenóis/metabolismo , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Prolina/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima/efeitos dos fármacos
20.
J Vis Exp ; (159)2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32478741

RESUMO

In this article, we give hands-on instructions to obtain translatome data from different Arabidopsis thaliana root cell types via the translating ribosome affinity purification (TRAP) method and consecutive optimized low-input library preparation. As starting material, we employ plant lines that express GFP-tagged ribosomal protein RPL18 in a cell type-specific manner by use of adequate promoters. Prior to immunopurification and RNA extraction, the tissue is snap frozen, which preserves tissue integrity and simultaneously allows execution of time series studies with high temporal resolution. Notably, cell wall structures remain intact, which is a major drawback in alternative procedures such as fluorescence-activated cell sorting-based approaches that rely on tissue protoplasting to isolate distinct cell populations. Additionally, no tissue fixation is necessary as in laser capture microdissection-based techniques, which allows high-quality RNA to be obtained. However, sampling from subpopulations of cells and only isolating polysome-associated RNA severely limits RNA yields. It is, therefore, necessary to apply sufficiently sensitive library preparation methods for successful data acquisition by RNA-seq. TRAP offers an ideal tool for plant research as many developmental processes involve cell wall-related and mechanical signaling pathways. The use of promoters to target specific cell populations is bridging the gap between organ and single-cell level that in turn suffer from little resolution or very high costs. Here, we apply TRAP to study cell-cell communication in lateral root formation.


Assuntos
Arabidopsis/metabolismo , Cromatografia de Afinidade/métodos , Raízes de Plantas/metabolismo , Biossíntese de Proteínas , Ribossomos/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Biblioteca Gênica , Proteínas de Fluorescência Verde/metabolismo , Plantas Geneticamente Modificadas , Polirribossomos/genética , RNA Mensageiro/genética , RNA de Plantas/metabolismo , Ribossomos/genética , Esterilização , Transgenes
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