RESUMO
Ridomil Gold SL (45.3% a.i. mefenoxam) is a widely used chemical fungicide for the control of oomycetes. However, its impact on fungal communities remains unexplored. Therefore, the goal of this study was to examine the effects of mefenoxam on the temporal dynamics of fungal taxonomic and functional diversities during carrot cultivation under four treatment groups: mefenoxam application with and without Pythium inoculation, and untreated control groups with and without Pythium inoculation. Our in vitro sensitivity assay showed that the maximum recommended concentration of mefenoxam, 0.24 ppm, did not suppress the mycelial growth of P. irregulare. At 100 ppm, mycelial growth was only reduced by 11.4%, indicating that the isolate was resistant to mefenoxam. MiSeq sequencing data revealed transient taxonomic variations among treatments 2 weeks post-treatment. Mortierella dominated the fungal community in the mefenoxam-Pythium combination treatment, as confirmed through PCR using our newly designed Mortierella-specific primers. Conversely, mefenoxam-Pythium combination had adverse effects on Penicillium, Trichoderma, and Fusarium, and decrease the overall alpha diversity. However, these compositional changes gradually reverted to those observed in the control by the 12th week. The predicted ecological functions of fungal communities in all Pythium and mefenoxam treatments shifted, leading to a decrease in symbiotrophs and plant pathogen functional groups. Moreover, the community-level physiological profiling approach, utilizing 96-well Biolog FF microplates, showed discernible variations in the utilization of 95 diverse carbon sources among the treatments. Notably, arbutin, L-arabinose, Tween 80, and succinamic acid demonstrated a strong positive association with Mortierella. Our findings demonstrate that a single application of mefenoxam at its recommended rate triggers substantial taxonomic and functional shifts in the soil fungal community. Considering this impact, the conventional agricultural practice of repeated mefenoxam application is likely to exert considerable shifts on the soil ecosystem that may affect agricultural sustainability.
Assuntos
Alanina/análogos & derivados , Daucus carota , Fungos , Fungicidas Industriais , Pythium , Daucus carota/microbiologia , Pythium/efeitos dos fármacos , Fungos/efeitos dos fármacos , Fungos/genética , Fungos/classificação , Fungicidas Industriais/farmacologia , Microbiologia do Solo , Micobioma/efeitos dos fármacos , Mortierella/efeitos dos fármacos , Mortierella/genéticaRESUMO
Climate change has exacerbated the effects of abiotic stresses on plant growth and productivity. Drought is one of the most important abiotic stress factors that interfere with plant growth and development. Plant selection and breeding as well as genetic engineering methods used to improve crop drought tolerance are expensive and time consuming. Plants use a myriad of adaptative mechanisms to cope with the adverse effects of drought stress including the association with beneficial microorganisms such as plant growth promoting rhizobacteria (PGPR). Inoculation of plant roots with different PGPR species has been shown to promote drought tolerance through a variety of interconnected physiological, biochemical, molecular, nutritional, metabolic, and cellular processes, which include enhanced plant growth, root elongation, phytohormone production or inhibition, and production of volatile organic compounds. Therefore, plant colonization by PGPR is an eco-friendly agricultural method to improve plant growth and productivity. Notably, the processes regulated and enhanced by PGPR can promote plant growth as well as enhance drought tolerance. This review addresses the current knowledge on how drought stress affects plant growth and development and describes how PGPR can trigger plant drought stress responses at the physiological, morphological, and molecular levels.
Assuntos
Secas , Desenvolvimento Vegetal , Resistência à Seca , Reguladores de Crescimento de Plantas , AclimataçãoRESUMO
BACKGROUND: Plant growth promoting rhizobacteria (PGPR), such as Bradyrhizobium japonicum IRAT FA3, are able to improve seed germination and plant growth under various biotic and abiotic stress conditions, including high salinity stress. PGPR can affect plants' responses to stress via multiple pathways which are often interconnected but were previously thought to be distinct. Although the overall impacts of PGPR on plant growth and stress tolerance have been well documented, the underlying mechanisms are not fully elucidated. This work contributes to understanding how PGPR promote abiotic stress by revealing major plant pathways triggered by B. japonicum under salt stress. RESULTS: The plant growth-promoting rhizobacterial (PGPR) strain Bradyrhizobium japonicum IRAT FA3 reduced the levels of sodium in Arabidopsis thaliana by 37.7%. B. japonicum primed plants as it stimulated an increase in jasmonates (JA) and modulated hydrogen peroxide production shortly after inoculation. B. japonicum-primed plants displayed enhanced shoot biomass, reduced lipid peroxidation and limited sodium accumulation under salt stress conditions. Q(RT)-PCR analysis of JA and abiotic stress-related gene expression in Arabidopsis plants pretreated with B. japonicum and followed by six hours of salt stress revealed differential gene expression compared to non-inoculated plants. Response to Desiccation (RD) gene RD20 and reactive oxygen species scavenging genes CAT3 and MDAR2 were up-regulated in shoots while CAT3 and RD22 were increased in roots by B. japonicum, suggesting roles for these genes in B. japonicum-mediated salt tolerance. B. japonicum also influenced reductions of RD22, MSD1, DHAR and MYC2 in shoots and DHAR, ADC2, RD20, RD29B, GTR1, ANAC055, VSP1 and VSP2 gene expression in roots under salt stress. CONCLUSION: Our data showed that MYC2 and JAR1 are required for B. japonicum-induced shoot growth in both salt stressed and non-stressed plants. The observed microbially influenced reactions to salinity stress in inoculated plants underscore the complexity of the B. japonicum jasmonic acid-mediated plant response salt tolerance.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Tolerância ao Sal/fisiologia , Estresse Fisiológico , Sódio/metabolismo , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismoRESUMO
The practice of using recycled wastewater (RWW) has been successfully adopted to address the growing demand for clean water. However, chemicals of emerging concern (CECs) including pharmaceutical products remain in the RWW even after additional cleaning. When RWW is used to irrigate crops or landscapes, these chemicals can enter these and adjacent environments. Unfortunately, the overall composition and concentrations of CECs found in different RWW sources vary, and even the same source can vary over time. Therefore, we selected one compound that is found frequently and in high concentrations in many RWW sources, acetaminophen (APAP), to use for our study. Using greenhouse grown eggplants treated with APAP concentrations within the ranges found in RWW effluents, we investigated the short-term impacts of APAP on the soil bacterial population under agricultural settings. Using Illumina sequencing-based approaches, we showed that APAP has the potential to cause shifts in the microbial community most likely by positively selecting for bacteria that are capable of metabolizing the breakdown products of APAP such as glycosides and carboxylic acids. Community-level physiological profiles of carbon metabolism were evaluated using Biolog EcoPlate as a proxy for community functions. The Biolog plates indicated that the metabolism of amines, amino acids, carbohydrates, carboxylic acids, and polymers was significantly higher in the presence of APAP. Abundance of microorganisms of importance to plant health and productivity was altered by APAP. Our results indicate that the soil microbial community and functions could be altered by APAP at concentrations found in RWW. Our findings contribute to the knowledge base needed to guide policies regulating RWW reuse in agriculture and also highlight the need to further investigate the effects of CECs found in RWW on soil microbiomes.
Assuntos
Microbiota , Águas Residuárias , Solo/química , Acetaminofen/metabolismo , Irrigação Agrícola/métodos , Bactérias/genética , Produtos Agrícolas , Ácidos Carboxílicos/metabolismo , Microbiologia do SoloRESUMO
Beneficial rhizobacteria can stimulate changes in plant root development. Although root system growth is mediated by multiple factors, the regulated distribution of the phytohormone auxin within root tissues plays a principal role. Auxin transport facilitators help to generate the auxin gradients and maxima that determine root structure. Here, we show that the plant-growth-promoting rhizobacterial strain Bradyrhizobium japonicum IRAT FA3 influences specific auxin efflux transporters to alter Arabidopsis thaliana root morphology. Gene expression profiling of host transcripts in control and B. japonicum-inoculated roots of the wild-type A. thaliana accession Col-0 confirmed upregulation of PIN2, PIN3, PIN7, and ABCB19 with B. japonicum and identified genes potentially contributing to a diverse array of auxin-related responses. Cocultivation of the bacterium with loss-of-function auxin efflux transport mutants revealed that B. japonicum requires PIN3, PIN7, and ABCB19 to increase lateral root development and utilizes PIN2 to reduce primary root length. Accelerated lateral root primordia production due to B. japonicum was not observed in single pin3, pin7, or abcb19 mutants, suggesting independent roles for PIN3, PIN7, and ABCB19 during the plant-microbe interaction. Our work demonstrates B. japonicum's influence over host transcriptional reprogramming during plant interaction with this beneficial microbe and the subsequent alterations to root system architecture.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Bradyrhizobium , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Raízes de Plantas/genéticaRESUMO
Aldehyde dehydrogenases (ALDHs) is a protein superfamily that catalyzes the oxidation of aldehyde molecules into their corresponding non-toxic carboxylic acids, and responding to different environmental stresses, offering promising genetic approaches for improving plant adaptation. The aim of the current study is the functional analysis for systematic identification of S. lycopersicum ALDH gene superfamily. We performed genome-based ALDH genes identification and functional classification, phylogenetic relationship, structure and catalytic domains analysis, and microarray based gene expression. Twenty nine unique tomato ALDH sequences encoding 11 ALDH families were identified, including a unique member of the family 19 ALDH. Phylogenetic analysis revealed 13 groups, with a conserved relationship among ALDH families. Functional structure analysis of ALDH2 showed a catalytic mechanism involving Cys-Glu couple. However, the analysis of ALDH3 showed no functional gene duplication or potential neo-functionalities. Gene expression analysis reveals that particular ALDH genes might respond to wounding stress increasing the expression as ALDH2B7. Overall, this study reveals the complexity of S. lycopersicum ALDH gene superfamily and offers new insights into the structure-functional features and evolution of ALDH gene families in vascular plants. The functional characterization of ALDHs is valuable and promoting molecular breeding in tomato for the improvement of stress tolerance and signaling.
Assuntos
Aldeído Desidrogenase/genética , Genoma de Planta , Proteínas de Plantas/genética , Solanum lycopersicum/genética , Aldeído Desidrogenase/química , Aldeído Desidrogenase/classificação , Aldeído Desidrogenase/metabolismo , Sítios de Ligação , Biocatálise , Coenzimas/química , Coenzimas/metabolismo , Regulação da Expressão Gênica de Plantas , Ligação de Hidrogênio , Ligantes , Solanum lycopersicum/metabolismo , Simulação de Dinâmica Molecular , Família Multigênica , Análise de Sequência com Séries de Oligonucleotídeos , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Estrutura Terciária de Proteína , Estresse FisiológicoRESUMO
The efficacy of a rhizobacterium Streptomyces aurantiogriseus VSMGT1014 for the production of bioactive metabolites with antifungal properties was evaluated under in vitro conditions. The production of bioactive metabolites by S. aurantiogriseus VSMGT1014 in International Streptomyces Project-2 (ISP-2) broth, supplemented with glucose and ammonium acetate was found to be the most suitable carbon and nitrogen sources for the maximum production of bioactive metabolites against rice pathogen, Rhizoctonia solani. The zone of inhibition range from 23.5 to 28.5 mm and 10.3 to 18.3 mm for glucose and ammonium acetate supplemented media, respectively. The culture filtrate of S. aurantiogriseus VSMGT1014 at pH 7.5, 37 °C at 120 rpm in 6 days of incubation showed the maximum production of bioactive metabolites with antagonistic potential. The crude metabolite was characterized by different spectral studies such as Ultraviolet spectrum, infrared-spectrum and based on the different analytical techniques, including thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with the retention time 29.4 and the bioactive metabolite was identified as phenazine, which was confirmed by pure phenazine compound as positive control.
Assuntos
Antifúngicos/metabolismo , Oryza/microbiologia , Fenazinas/metabolismo , Doenças das Plantas/microbiologia , Rhizoctonia/efeitos dos fármacos , Streptomyces/metabolismo , Acetatos/metabolismo , Antifúngicos/química , Antifúngicos/isolamento & purificação , Meios de Cultura/química , Glucose/metabolismo , Fenazinas/química , Fenazinas/isolamento & purificação , Análise Espectral , TemperaturaRESUMO
BACKGROUND: A molecular-level understanding of the loss of CURVY1 (CVY1) gene expression (which encodes a member of the receptor-like protein kinase family) was investigated to gain insights into the mechanisms controlling cell morphogenesis and development in Arabidopsis thaliana. RESULTS: Using a reverse genetic and cell biology approaches, we demonstrate that CVY1 is a new DISTORTED gene with similar phenotypic characterization to previously characterized ARP2/3 distorted mutants. Compared to the wild type, cvy1 mutant displayed a strong distorted trichome and altered pavement cell phenotypes. In addition, cvy1 null-mutant flowers earlier, grows faster and produces more siliques than WT and the arp2/3 mutants. The CVY1 gene is ubiquitously expressed in all tissues and seems to negatively regulate growth and yield in higher plants. CONCLUSIONS: Our results suggest that CURVY1 gene participates in several biochemical pathways in Arabidopsis thaliana including (i) cell morphogenesis regulation through actin cytoskeleton functional networks, (ii) the transition of vegetative to the reproductive stage and (iii) the production of seeds.
Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Flores/fisiologia , Desenvolvimento Vegetal/genética , Proteínas Serina-Treonina Quinases/genética , Receptores de Superfície Celular/genética , Sementes/crescimento & desenvolvimento , Actinas/metabolismo , Arabidopsis/citologia , Proteínas de Arabidopsis/metabolismo , Parede Celular/metabolismo , Genes de Plantas , Morfogênese , Fenótipo , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Tricomas/crescimento & desenvolvimentoRESUMO
African sorghum opaque beers play a vital role in the diet of millions of consumers. In the current study we investigated the growth profiles of yeast strains isolated from kpete-kpete, a traditional starter used to produce tchoukoutou, an opaque sorghum beer in Benin. 10 yeast strains were isolated from sorghum beer starters and cultivated under both liquid and solid media for phenotypic growth characterization. All yeast isolates were able to grow both on solid and liquid media. Based on their growth profiles, the isolates were clustered into three groups: (i) the aggressive growth pattern (30%), (ii) the moderate growth pattern (50%), and (iii) the slow growth pattern (20%). Based on gene expression pattern, absorbance (A(600 nm)) and diameter of growth in both liquid and solid media respectively, yeast strains YK34, YK15 and YK48 were clustered in the first group, and referred to as the most aggressive growth strains, followed by group 2 (YK24, YK5, YK12, YK20, YK2) and group 3 (YK37, YK41). This growth pattern was confirmed by Invertase gene expression profiling of the yeasts showing group 1 with high level of Invertase gene expression followed by group 2 and group 3 respectively. Our results suggest that YK34, YK15 and YK48 and YK2 yeast strains constitute the best candidates in fermentation of sorghum beer production based on growth rate and assimilation of carbon and nitrogen sources.
Assuntos
Candida/isolamento & purificação , DNA Fúngico/isolamento & purificação , Saccharomyces cerevisiae/isolamento & purificação , Cerveja/microbiologia , Candida/classificação , Candida/genética , Candida/crescimento & desenvolvimento , DNA Fúngico/genética , Fermentação , Manipulação de Alimentos , Microbiologia de Alimentos , Fenótipo , Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Sorghum/química , TranscriptomaRESUMO
BACKGROUND: WD40 domains have been found in a plethora of eukaryotic proteins, acting as scaffolding molecules assisting proper activity of other proteins, and are involved in multi-cellular processes. They comprise several stretches of 44-60 amino acid residues often terminating with a WD di-peptide. They act as a site of protein-protein interactions or multi-interacting platforms, driving the assembly of protein complexes or as mediators of transient interplay among other proteins. In Arabidopsis, members of WD40 protein superfamily are known as key regulators of plant-specific events, biologically playing important roles in development and also during stress signaling. RESULTS: Using reverse genetic and protein modeling approaches, we characterize GIGANTUS1 (GTS1), a new member of WD40 repeat protein in Arabidopsis thaliana and provide evidence of its role in controlling plant growth development. GTS1 is highly expressed during embryo development and negatively regulates seed germination, biomass yield and growth improvement in plants. Structural modeling analysis suggests that GTS1 folds into a ß-propeller with seven pseudo symmetrically arranged blades around a central axis. Molecular docking analysis shows that GTS1 physically interacts with two ribosomal protein partners, a component of ribosome Nop16, and a ribosome-biogenesis factor L19e through ß-propeller blade 4 to regulate cell growth development. CONCLUSIONS: Our results indicate that GTS1 might function in plant developmental processes by regulating ribosomal structural features, activities and biogenesis in plant cells. Our results suggest that GIGANTUS1 might be a promising target to engineer transgenic plants with higher biomass and improved growth development for plant-based bioenergy production.
Assuntos
Arabidopsis/embriologia , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Biomassa , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Germinação/fisiologia , Ribossomos/metabolismo , Sementes/embriologia , Sementes/metabolismo , Sementes/fisiologiaRESUMO
Thiosemicarbazones have become one of the promising compounds as new clinical candidates due to their wide spectrum of pharmaceutical activities. The wide range of their biological activities depends generally on their related aldehyde or ketone groups. Here, we report the pharmacological activities of some thiosemicarbazones synthesized in this work. Benzophenone and derivatives were used with N(4)-phenyl-3-thiosemicarbazide to synthesize corresponding five thiosemicarbazones (1-5). Their structures were characterized by spectrometrical methods analysis IR, NMR (1)H & (13)C and MS. The compounds were then screened in vitro for their antiparasitic activity and toxicity on Trypanosoma brucei brucei and Artemia salina Leach respectively. The selectivity index of each compound was also determined. Four thiosemicarbazones such as 4, 2, 3 and 1 reveal interesting trypanocidal activities with their half inhibitory concentration (IC50) equal to 2.76, 2.83, 3.86 and 8.48 µM respectively, while compound 5 (IC50 = 12.16 µM) showed a moderate anti-trypanosomal activity on parasite. In toxicity test, except compound 1, which showed a half lethal concentration LC50 >281 µM, the others exerted toxic effect on larvae with LC50 of 5.56, 13.62, 14.55 and 42.50 µM respectively for thiosemicarbazones 4, 5, 3 and 2. In agreement to their selectivity index, which is greater than 1 (SI >1), these compounds clearly displayed significant selective pharmaceutical activities on the parasite tested. The thiosemicarbazones 2-5 that displayed significant anti-trypanosomal and cytoxicity activities are suggested to have anti-neoplastic and anti-cancer activities.
Assuntos
Artemia/efeitos dos fármacos , Tiossemicarbazonas/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico , Animais , Humanos , Tiossemicarbazonas/síntese química , Trypanosoma brucei brucei/patogenicidade , Tripanossomíase Africana/parasitologia , Tripanossomíase Africana/patologiaRESUMO
Isoflavone reductase-like proteins (IRLs) are enzymes with key roles in the metabolism of diverse flavonoids. Last identified olive pollen allergen (Ole e 12) is an IRL relevant for allergy amelioration, since it exhibits high prevalence among atopic patients. The goals of this study are the characterization of (A) the structural-functionality of Ole e 12 with a focus in its catalytic mechanism, and (B) its molecular allergenicity by extensive analysis using different molecular computer-aided approaches covering (1) physicochemical properties and functional-regulatory motifs, (2) sequence analysis, 2-D and 3D structural homology modeling comparative study and molecular docking, (3) conservational and evolutionary analysis, (4) catalytic mechanism modeling, and (5) sequence, structure-docking based B-cell epitopes prediction, while T-cell epitopes were predicted by inhibitory concentration and binding score methods. Structural-based detailed features, phylogenetic and sequences analysis have identified Ole e 12 as phenylcoumaran benzylic ether reductase. A catalytic mechanism has been proposed for Ole e 12 which display Lys133 as one of the conserved residues of the IRLs catalytic tetrad (Asn-Ser-Tyr-Lys). Structure characterization revealed a conserved protein folding among plants IRLs. However, sequence polymorphism significantly affected residues involved in the catalytic pocket structure and environment (cofactor and substrate interaction-recognition). It might also be responsible for IRLs isoforms functionality and regulation, since micro-heterogeneities affected physicochemical and posttranslational motifs. This polymorphism might have large implications for molecular differences in B- and T-cells epitopes of Ole e 12, and its identification may help designing strategies to improve the component-resolving diagnosis and immunotherapy of pollen and food allergy through development of molecular tools.
Assuntos
Alérgenos/imunologia , Epitopos/genética , Oxirredutases/química , Oxirredutases/imunologia , Alérgenos/química , Sequência de Aminoácidos , Catálise , Domínio Catalítico , Clonagem Molecular , Epitopos/química , Epitopos/imunologia , Humanos , Modelos Moleculares , Olea/enzimologia , Olea/imunologia , Oxirredutases/metabolismo , Filogenia , Pólen/enzimologia , Pólen/imunologia , Homologia de Sequência de Aminoácidos , Relação Estrutura-AtividadeRESUMO
BACKGROUND: ANGUSTIFOLIA (AN), one of the CtBP family proteins, plays a major role in microtubule-dependent cell morphogenesis. Microarray analysis of mammalian AN homologs suggests that AN might function as a transcriptional activator and regulator of a wide range of genes. Genetic characterization of AN mutants suggests that AN might be involved in multiple biological processes beyond cell morphology regulation. RESULTS: Using a reverse genetic approach, we provide in this paper the genetic, biochemical, and physiological evidence for ANGUSTIFOLIA's role in other new biological functions such as abiotic and biotic stress response in higher plants. The T-DNA knockout an-t1 mutant exhibits not only all the phenotypes of previously described angustifolia null mutants, but also copes better than wild type under dehydration and pathogen attack. The stress tolerance is accompanied by a steady-state modulation of cellular H(2)O(2) content, malondialdehyde (MDA) derived from cellular lipid peroxidation, and over-expression of stress responsive genes. Our results indicate that ANGUSTIFOLIA functions beyond cell morphology control through direct or indirect functional protein interaction networks mediating other biological processes such as drought and pathogen attacks. CONCLUSIONS: Our results indicate that the ANGUSTIFOLIA gene participates in several biochemical pathways controlling cell morphogenesis, abiotic, and biotic stress responses in higher plants. Our results suggest that the in vivo function of plant ANGUSTIFOLIA has been overlooked and it needs to be further studied beyond microtubule-dependent cell morphogenesis.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas Repressoras/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Secas , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Morfogênese , Estresse Oxidativo , Doenças das Plantas/microbiologia , Pseudomonas syringae/fisiologia , Proteínas Repressoras/genética , Estresse FisiológicoRESUMO
The arbuscular mycorrhizal (AM) symbiosis, formed between the majority of land plants and ubiquitous soil fungi of the phylum Glomeromycota, is responsible for massive nutrient transfer and global carbon sequestration. AM fungi take up nutrients from the soil and exchange them against photosynthetically fixed carbon (C) from the host. Recent studies have demonstrated that reciprocal reward strategies by plant and fungal partners guarantee a "fair trade" of phosphorus against C between partners [Kiers ET, et al. (2011) Science 333:880-882], but whether a similar reward mechanism also controls nitrogen (N) flux in the AM symbiosis is not known. Using mycorrhizal root organ cultures, we manipulated the C supply to the host and fungus and followed the uptake and transport of N sources in the AM symbiosis, the enzymatic activities of arginase and urease, and fungal gene expression in the extraradical and intraradical mycelium. We found that the C supply of the host plant triggers the uptake and transport of N in the symbiosis, and that the increase in N transport is orchestrated by changes in fungal gene expression. N transport in the symbiosis is stimulated only when the C is delivered by the host across the mycorrhizal interface, not when C is supplied directly to the fungal extraradical mycelium in the form of acetate. These findings support the importance of C flux from the root to the fungus as a key trigger for N uptake and transport and provide insight into the N transport regulation in the AM symbiosis.
Assuntos
Carbono/metabolismo , Micorrizas/metabolismo , Nitrogênio/metabolismo , Simbiose , Transporte BiológicoRESUMO
Aldehyde dehydrogenases (ALDHs) are members of NAD(P)(+)-dependent protein superfamily that catalyze the oxidation of a wide range of endogenous and exogenous highly reactive aliphatic and aromatic aldehyde molecules to their corresponding non toxic carboxylic acids. Research evidence has shown that ALDHs represent a promising class of genes to improve growth development, seed storage and environmental stress adaptation in higher plants. The recently completed genome sequences of several plant species have resulted in the identification of a large number of ALDH genes, most of which still need to be functionally characterized. In this paper, we identify members of the ALDH gene superfamily in soybean genome, and provide a unified nomenclature for the entire soybean ALDH gene families. The soybean genome contains 18 unique ALDH sequences encoding members of five ALDH families involved in a wide range of metabolic and molecular detoxification pathways. In addition, we describe the biochemical requirements and cellular metabolic pathways of selected members of ALDHs in soybean responses to environmental stress conditions.
Assuntos
Aldeído Desidrogenase/genética , Aldeído Desidrogenase/metabolismo , Glycine max/enzimologia , Filogenia , Proteínas de Soja/genética , Aldeído Desidrogenase/classificação , Regulação da Expressão Gênica de Plantas , Família Multigênica , Proteínas de Soja/metabolismo , Glycine max/crescimento & desenvolvimentoRESUMO
Selected members of plant pathogenesis-related and seed storage proteins represent specific groups of proteins with potential characteristics of allergens. Efforts to understand the mechanism by which pathogenesis-related proteins mediate a broad cross-reactivity in pollen-plant food allergens are still limited. In this study, computational biology approach was used to reveal specific structural implications and conservation of different epitopes from members of Bet v 1 and nsLTP protein families mediating cross-reactivity between pollen and food (fruits, vegetables, legumes, and nut/seeds) allergens. A commonly shared epitope conservation was found among all pollen and food Bet v 1 and nsLTP protein families, respectively. However, other allergenic epitopes were also specifically detected in each family. The implication of these conserved epitopes in a broad cross-reactivity for allergy clinical trials is here discussed.
Assuntos
Antígenos de Plantas/genética , Proteínas de Transporte/genética , Biologia Computacional/métodos , Reações Cruzadas/genética , Hipersensibilidade Alimentar/genética , Modelos Moleculares , Rinite Alérgica Sazonal/genética , Sequência de Aminoácidos , Antígenos de Plantas/química , Antígenos de Plantas/imunologia , Sequência de Bases , Proteínas de Transporte/química , Proteínas de Transporte/imunologia , Reações Cruzadas/imunologia , Bases de Dados Genéticas , Epitopos/genética , Humanos , Modelos Genéticos , Dados de Sequência MolecularRESUMO
Plant defensins represent a major innate immune protein superfamily with strong inhibitory effects on infectious diseases of humans, antifungal/antibacterial activities, proteinase and insect amylase inhibitory activities. They are generally defined by their conserved cysteine scaffold with α-helix and triple strand anti parallel ß-sheet connected to the scaffold. With the genome of more plant species being fully sequenced, significant information about newly sequenced defensin proteins has been revealed. In this paper, we identify members of defensin protein families across plant species and use protein-modeling-based structural reconstitution to reveal specific three dimensional hidden features of plant defensins mediating defense responses and other interesting biological activities in plants. Our data revealed that plant defensins are structurally similar to their insect counterparts despite the low amino acid sequence similarity between these two organisms. The molecular and structural relationship among plant defensins and defensins from other species is discussed.
Assuntos
Defensinas/química , Família Multigênica , Proteínas de Plantas/química , Plantas/metabolismo , Sequência de Aminoácidos , Anti-Infecciosos/química , Sequência Conservada/genética , Defensinas/genética , Evolução Molecular , Modelos Moleculares , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/genética , Estrutura Secundária de Proteína , Homologia de Sequência de AminoácidosRESUMO
The partially dominant, autoactive maize disease resistance gene Rp1-D21 causes hypersensitive response (HR) lesions to form spontaneously on leaves and stems in the absence of pathogen recognition. The maize nested association mapping (NAM) population consists of 25 200-line subpopulations each derived from a cross between the maize line B73 and one of 25 diverse inbred lines. By crossing a line carrying the Rp1-D21 gene with lines from three of these subpopulations and assessing the F(1) progeny, we were able to map several novel loci that modify the maize HR, using both single-population quantitative trait locus (QTL) and joint analysis of all three populations. Joint analysis detected QTL in greater number and with greater confidence and precision than did single population analysis. In particular, QTL were detected in bins 1.02, 4.04, 9.03, and 10.03. We have previously termed this technique, in which a mutant phenotype is used as a "reporter" for a trait of interest, Mutant-Assisted Gene Identification and Characterization (MAGIC).
Assuntos
Proteínas de Transporte/genética , Resistência à Doença/genética , Genes de Plantas , Doenças das Plantas/genética , Proteínas de Plantas/genética , Locos de Características Quantitativas , Zea mays/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Cruzamentos Genéticos , Estudos de Associação Genética , Variação Genética , Peptídeos e Proteínas de Sinalização Intracelular , Mutação , FenótipoRESUMO
Extraction of plant genomic DNA for subsequent genetic studies is often lengthy and difficult. In addition, it requires the use of toxic reagents that remove secondary plant products, which otherwise interfere with the polymerase chain reaction steps. Here we describe a simple cost-efficient one-step protocol for PCR-based analysis in Arabidopsis thaliana. This protocol is quick, performed at room temperature without the need for DNA extraction. Potential applications in higher plants are here discussed.
Assuntos
Arabidopsis/genética , DNA de Plantas/genética , Reação em Cadeia da Polimerase/métodos , GenótipoRESUMO
BACKGROUND: The completion of maize genome sequencing has resulted in the identification of a large number of uncharacterized genes. Gene annotation and functional characterization of gene products are important to uncover novel protein functionality. RESULTS: In this paper, we identify, and annotate members of all the maize aldehyde dehydrogenase (ALDH) gene superfamily according to the revised nomenclature criteria developed by ALDH Gene Nomenclature Committee (AGNC). The maize genome contains 24 unique ALDH sequences encoding members of ten ALDH protein families including the previously identified male fertility restoration RF2A gene, which encodes a member of mitochondrial class 2 ALDHs. Using computational modeling analysis we report here the identification, the physico-chemical properties, and the amino acid residue analysis of a novel tunnel like cavity exclusively found in the maize sterility restorer protein, RF2A/ALDH2B2 by which this protein is suggested to bind variably long chain molecular ligands and/or potentially harmful molecules. CONCLUSIONS: Our finding indicates that maize ALDH superfamily is the most expanded of plant ALDHs ever characterized, and the mitochondrial maize RF2A/ALDH2B2 is the only plant ALDH that harbors a newly defined pocket/cavity with suggested functional specificity.