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1.
Curr Issues Mol Biol ; 46(8): 8874-8889, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39194741

RESUMO

Soil salinization/alkalization is a complex environmental factor that includes not only neutral salt NaCl but also other components like Na2CO3. miRNAs, as small molecules that regulate gene expression post-transcriptionally, are involved in plant responses to abiotic stress. In this study, maize seedling roots were treated for 5 h with 100 mM NaCl, 50 mM Na2CO3, and H2O, respectively. Sequencing analysis of differentially expressed miRNAs under these conditions revealed that the Na2CO3 treatment group had the most differentially expressed miRNAs. Cluster analysis indicated their main involvement in the regulation of ion transport, binding, metabolism, and phenylpropanoid and flavonoid biosynthesis pathways. The unique differentially expressed miRNAs in the NaCl treatment group were related to the sulfur metabolism pathway. This indicates a significant difference in the response patterns of maize to different treatment groups. This study provides theoretical evidence and genetic resources for further analysis of the molecular mechanisms behind maize's salt-alkali tolerance.

2.
BMC Microbiol ; 24(1): 92, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38500045

RESUMO

BACKGROUND: The soil biota consists of a complex assembly of microbial communities and other organisms that vary significantly across farming systems, impacting soil health and plant productivity. Despite its importance, there has been limited exploration of how different cropping systems influence soil and plant root microbiomes. In this study, we investigated soil physicochemical properties, along with soil and maize-root microbiomes, in an agroecological cereal-legume companion cropping system known as push-pull technology (PPT). This system has been used in agriculture for over two decades for insect-pest management, soil health improvement, and weed control in sub-Saharan Africa. We compared the results with those obtained from maize-monoculture (Mono) cropping system. RESULTS: The PPT cropping system changed the composition and diversity of soil and maize-root microbial communities, and led to notable improvements in soil physicochemical characteristics compared to that of the Mono cropping system. Distinct bacterial and fungal genera played a crucial role in influencing the variation in microbial diversity within these cropping systems. The relative abundance of fungal genera Trichoderma, Mortierella, and Bionectria and bacterial genera Streptomyces, RB41, and Nitrospira were more enriched in PPT. These microbial communities are associated with essential ecosystem services such as plant protection, decomposition, carbon utilization, bioinsecticides production, nitrogen fixation, nematode suppression, phytohormone production, and bioremediation. Conversely, pathogenic associated bacterial genus including Bryobacter were more enriched in Mono-root. Additionally, the Mono system exhibited a high relative abundance of fungal genera such as Gibberella, Neocosmospora, and Aspergillus, which are linked to plant diseases and food contamination. Significant differences were observed in the relative abundance of the inferred metabiome functional protein pathways including syringate degradation, L-methionine biosynthesis I, and inosine 5'-phosphate degradation. CONCLUSION: Push-pull cropping system positively influences soil and maize-root microbiomes and enhances soil physicochemical properties. This highlights its potential for agricultural and environmental sustainability. These findings contribute to our understanding of the diverse ecosystem services offered by this cropping system where it is practiced regarding the system's resilience and functional redundancy. Future research should focus on whether PPT affects the soil and maize-root microbial communities through the release of plant metabolites from the intercrop root exudates or through the alteration of the soil's nutritional status, which affects microbial enzymatic activities.


Assuntos
Microbiota , Resiliência Psicológica , Solo/química , Zea mays , Fungos/genética , Agricultura/métodos , Bactérias/genética , Microbiologia do Solo
3.
Ecotoxicol Environ Saf ; 272: 116087, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38340602

RESUMO

Understanding the physiological effects of herbicides on crops is crucial for crop production and environmental management. The effects of 4-hydroxyphenylpyruvate dioxygenase inhibitor (HPPDi) herbicides at different concentrations on chlorophyll content in maize leaves, fresh weight of roots, stems and leaves, and fluorescence substances and functional groups in root exudates (REs) were studied by UV-Vis absorption spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) and two-dimensional correlation analysis (2D-COS). The results showed that 5 mg/L and 10 mg/L HPPDi herbicides inhibited the synthesis of chlorophyll in maize leaves. The weight of roots, stems and leaves of maize after application was lighter than that of the control group. HPPDi herbicides affected the early growth of maize seedlings, and the effect was most obvious at high concentration. Synchronous fluorescence spectrum and three-dimensional (3D) fluorescence spectrum revealed that the fluorescence intensity of protein, fulvic acid and humic acid in maize REs changed prominently. With the increase of HPPDi herbicides concentration, the fluorescence intensity decreased gradually. Through FTIR and 2D-COS, functional groups such as C-H, CO, Cl, NO3-, C-O and O-H were found to participate in the interaction between HPPDi herbicides and maize REs as binding sites. C-O, C-Cl and C-C have the strongest binding ability, while CC and CO of aromatic rings, quinones or ketones first take part in the binding between HPPDi herbicides and maize REs. The results can provide a theoretical basis for evaluating the safety of HPPDi herbicides on maize and a method for discovering the effects of pesticides on environmental media and plant physiological effects.


Assuntos
Herbicidas , Herbicidas/química , Zea mays , Cetonas , Produtos Agrícolas , Clorofila
4.
Int J Mol Sci ; 25(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38892238

RESUMO

Flavonoids are secondary metabolites that play important roles in the resistance of plants to abiotic stress. Despite the widely reported adverse effects of lead (Pb) contamination on maize, the effects of Pb on the biosynthetic processes of flavonoids in maize roots are still unknown. In the present work, we employed a combination of multi-omics and conventional assay methods to investigate the effects of two concentrations of Pb (40 and 250 mg/kg) on flavonoid biosynthesis in maize roots and the associated molecular regulatory mechanisms. Analysis using conventional assays revealed that 40 and 250 mg/kg Pb exposure increased the lead content of maize root to 0.67 ± 0.18 mg/kg and 3.09 ± 0.02 mg/kg, respectively, but they did not result in significant changes in maize root length. The multi-omics results suggested that exposure to 40 mg/kg of Pb caused differential expression of 33 genes and 34 metabolites related to flavonoids in the maize root system, while 250 mg/kg of Pb caused differential expression of 34 genes and 31 metabolites. Not only did these differentially expressed genes and metabolites participate in transferase activity, anthocyanin-containing compound biosynthetic processes, metal ion binding, hydroxyl group binding, cinnamoyl transferase activity, hydroxycinnamoyl transferase activity, and flavanone 4-reductase activity but they were also significantly enriched in the flavonoid, isoflavonoid, flavone, and flavonol biosynthesis pathways. These results show that Pb is involved in the regulation of maize root growth by interfering with the biosynthesis of flavonoids in the maize root system. The results of this study will enable the elucidation of the mechanisms of the effects of lead on maize root systems.


Assuntos
Flavonoides , Regulação da Expressão Gênica de Plantas , Chumbo , Raízes de Plantas , Estresse Fisiológico , Transcriptoma , Zea mays , Zea mays/genética , Zea mays/metabolismo , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento , Flavonoides/biossíntese , Flavonoides/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Chumbo/toxicidade , Chumbo/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Estresse Fisiológico/genética , Metabolômica/métodos , Metaboloma/efeitos dos fármacos , Perfilação da Expressão Gênica/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
5.
Ecotoxicol Environ Saf ; 264: 115458, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37690173

RESUMO

Arbuscular mycorrhizal fungi (AMF) are symbiotic fungi that colonize plant roots, and they are more common in Cd-polluted habitats. However, there is limited understanding of the response of root traits and cadmium (Cd) uptake to AMF in different crop varieties. Two maize varieties, Panyu 3 and Ludan 8, with high and low Cd uptake capacities, respectively, were cultivated as host plants in a pot experiment with Cd-polluted soil (17.1 mg/kg Cd). The effects of AMF on the growth, mineral nutrient concentration, root traits, phytohormone concentrations and Cd uptake of the two maize varieties and their comprehensive response to AMF fungal inoculation were investigated. AMF improved growth, mineral nutrient levels and root morphology and increased lignin and phytohormone concentrations in roots and Cd uptake in the two maize varieties. However, the two maize varieties, Panyu 3 and Ludan 8, had different responses to AMF, and their comprehensive response indices were 753.6% and 389.4%, respectively. The root biomass, branch number, abscisic acid concentrations, lignin concentrations and Cd uptake of maize Panyu 3 increased by 151.1%, 28.6%, 139.7%, 99.5% and 84.7%, respectively. The root biomass, average diameter, auxin concentration, lignin concentration and Cd uptake of maize Ludan 8 increased by 168.7%, 31.8%, 31.4%, 41.7% and 136.7%, respectively. Moreover, Cd uptake in roots presented very significant positive correlations with the average root diameter and abscisic acid concentration. A structural equation model indicated that the root abscisic acid concentration and root surface area had positive effects on Cd uptake by the Panyu 3 maize roots; the root abscisic acid concentration and root tip number had positive effects on Cd uptake by the Ludan 8 maize roots. Thus, AMF differentially regulated Cd uptake in the two maize varieties, and the regulatory effect was closely related to root traits and phytohormone concentrations.


Assuntos
Micorrizas , Poluentes do Solo , Micorrizas/fisiologia , Cádmio/toxicidade , Cádmio/análise , Zea mays , Raízes de Plantas/química , Reguladores de Crescimento de Plantas , Ácido Abscísico/análise , Lignina/análise , Poluentes do Solo/toxicidade , Poluentes do Solo/análise , Minerais/análise , Solo/química
6.
J Exp Bot ; 73(1): 275-291, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34554248

RESUMO

The growth and development of maize (Zea mays L.) largely depends on its nutrient uptake through the root. Hence, studying its growth, response, and associated metabolic reprogramming to stress conditions is becoming an important research direction. A genome-scale metabolic model (GSM) for the maize root was developed to study its metabolic reprogramming under nitrogen stress conditions. The model was reconstructed based on the available information from KEGG, UniProt, and MaizeCyc. Transcriptomics data derived from the roots of hydroponically grown maize plants were used to incorporate regulatory constraints in the model and simulate nitrogen-non-limiting (N+) and nitrogen-deficient (N-) condition. Model-predicted flux-sum variability analysis achieved 70% accuracy compared with the experimental change of metabolite levels. In addition to predicting important metabolic reprogramming in central carbon, fatty acid, amino acid, and other secondary metabolism, maize root GSM predicted several metabolites (l-methionine, l-asparagine, l-lysine, cholesterol, and l-pipecolate) playing a regulatory role in the root biomass growth. Furthermore, this study revealed eight phosphatidylcholine and phosphatidylglycerol metabolites which, even though not coupled with biomass production, played a key role in the increased biomass production under N-deficient conditions. Overall, the omics-integrated GSM provides a promising tool to facilitate stress condition analysis for maize root and engineer better stress-tolerant maize genotypes.


Assuntos
Nitrogênio , Zea mays , Aminoácidos , Biomassa , Raízes de Plantas , Zea mays/genética
7.
Arch Microbiol ; 204(7): 373, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35672591

RESUMO

Herbaspirillum seropedicae is a plant growth-promoting bacteria isolated from diverse plant species. In this work, the main objective was to investigate the efficiency of H. seropedicae strain SmR1 in colonizing and increasing maize growth (DKB 390 variety) in the early stages of development under greenhouse conditions. Inoculation with H. seropedicae resulted in 19.43 % (regarding High and Low N controls) and 10.51% (regarding Low N control) in mean of increase of root biomass, for 1st and 2nd greenhouse experiments, respectively, mainly in the initial stages of plant development, at 21 days after emergence (DAE). Quantification of H. seropedicae in roots and leaves was performed by quantitative PCR. H. seropedicae was detected only in maize inoculated roots by qPCR, and a slight decrease in DNA copy number g-1 of fresh root weight was observed from 7 to 21 DAE, suggesting that there was initial effective colonization on maize plants. H. seropedicae strain SmR1 efficiently increased maize root biomass exhibiting its potential to be used as inoculant in agricultures systems.


Assuntos
Herbaspirillum , Zea mays , Biomassa , Herbaspirillum/genética , Desenvolvimento Vegetal , Raízes de Plantas/microbiologia , Zea mays/microbiologia
8.
Phytopathology ; 112(9): 1886-1893, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35297645

RESUMO

Bacillus spp. can exert plant growth-promoting effects and biocontrol effects after effective colonization, and bacterial chemotaxis toward plant root exudates is the initial step to colonize. Under biotic stress, plants are able to alter their root exudates to attract or avoid different types of microbes. Hence, Bacillus chemotaxis toward root exudates after pathogen infection is crucial for exerting their beneficial effects. In this study, the Bacillus amyloliquefaciens OR2-30 strain, which exhibited greater chemotaxis ability toward maize root exudates after Fusarium graminearum infection, was screened from 156 rhizosphere microorganisms. The infected maize root exudates were further confirmed to improve the swarming and biofilm formation ability of the OR2-30 strain. Chemotaxis, swarming, and biofilm formation ability were able to influence bacterial colonization. Indeed, the the OR2-30 strain displayed more effective colonization ability in the maize rhizosphere after F. graminearum inoculation. Moreover, lipopeptides produced by OR2-30 were identified as iturins and responsible for suppressing F. graminearum growth. Further study showed that lipopeptides suppressed the growth of F. graminearum by inhibiting conidia formation and germination, inducing reactive oxygen species production and causing cell death in mycelium. Eventually, the OR2-30 strain increased maize resistance against F. graminearum. These results suggested that maize root exudates could recruit B. amyloliquefacines OR2-30 after F. graminearum infection, and that OR2-30 then suppresses the F. graminearum by producing lipopeptides, such as iturins, to protect maize.


Assuntos
Bacillus amyloliquefaciens , Bacillus , Fusarium , Bacillus/fisiologia , Exsudatos e Transudatos/metabolismo , Fusarium/fisiologia , Lipopeptídeos/análise , Lipopeptídeos/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Exsudatos de Plantas/farmacologia , Raízes de Plantas/microbiologia , Zea mays/microbiologia
9.
Phytopathology ; 112(7): 1537-1544, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35113672

RESUMO

It has been reported that the root exudates of nonhost maize inhibit Phytophthora sojae because of the presence of benzoxazines in maize roots. To understand the concentrations of benzoxazines (Bxs) in maize root exudates and the molecular mechanism of P. sojae being inhibited, the transcriptomes of P. sojae responding to three different Bxs, 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA), 6-methoxy-2-benzoxazolinone (MBOA), and benzoxazolinone (BOA), were analyzed by RNA sequencing method. We detected DIMBOA, MBOA, and BOA with a concentration range of 7 to 126 µg/ml in root exudates of three tested maize cultivars (A6565, Pengyu 1, and Xianyu 696). DIMBOA, MBOA, and BOA inhibited chemotaxis and invasiveness of P. sojae zoospores and mycelial growth. The inhibition was regulated mainly by endocytosis and the calcium signaling pathway, PI3K-Akt signaling pathway, and mTOR signaling pathway; meanwhile, the glutathione signaling pathway was activated to increase the antioxidant capacity and efflux of toxic substances. It was speculated that endocytosis plays an important role in the response of P. sojae to Bxs, and the specific functions of genes in this pathway must be further studied. This result provides new insights into the response mechanisms of P. sojae response to Bxs.


Assuntos
Phytophthora , Zea mays , Benzoxazinas/metabolismo , Benzoxazinas/farmacologia , Resistência à Doença/genética , Exsudatos e Transudatos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Doenças das Plantas
10.
Genomics ; 112(6): 5157-5169, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32961281

RESUMO

Root system architecture (RSA), the spatio-temporal configuration of roots, plays vital roles in maize (Zea mays L.) development and productivity. We sequenced the maize root transcriptome of four key growth and development stages: the 6th leaf stage, the 12th leaf stage, the tasseling stage and the milk-ripe stage. Differentially expressed genes (DEGs) were detected. 81 DEGs involved in plant hormone signal transduction pathway and 26 transcription factor (TF) genes were screened. These DEGs and TFs were predicted to be potential candidate genes during maize root growth and development. Several of these genes are homologous to well-known genes regulating root architecture or development in Arabidopsis or rice, such as, Zm00001d005892 (AtERF109), Zm00001d027925 (AtERF73/HRE1), Zm00001d047017 (AtMYC2, OsMYC2), Zm00001d039245 (AtWRKY6). Identification of these key genes will provide a further understanding of the molecular mechanisms responsible for maize root growth and development, it will be beneficial to increase maize production and improve stress resistance by altering RSA traits in modern breeding.


Assuntos
Genes de Plantas , Raízes de Plantas/genética , Zea mays/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Fenótipo , Reguladores de Crescimento de Plantas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Reação em Cadeia da Polimerase , RNA-Seq , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
11.
Arch Microbiol ; 202(7): 1653-1662, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32274559

RESUMO

Azospirillum brasilense is a plant growth promoting bacteria used as an inoculant in diverse crops. Accurate analytical methods are required to enumerate viable cells in inoculant formulations or in planta. We developed a quantitative polymerase chain reaction (qPCR) assay associated to propidium monoazide (PMA) to evaluate the cell viability of A. brasilense in inoculant and in maize roots. A. brasilense was grown in culture medium and was exposed to 50 â„ƒ. Maize roots were grown in vitro and harvested 7 days after inoculation. Quantification was performed by qPCR, PMA-qPCR, and plate counting. Standard curves efficiency values ranged from 85 to 99%. The limit of detection was 104 CFU per gram of fresh root. Enumeration obtained in maize roots by qPCR where higher than enumeration by PMA-qPCR and by plate counting. PMA-qPCR assay was efficient in quantifying inoculant viable cells and provides reliable results in a quickly and accurately way compared to culture-dependent methods.


Assuntos
Azidas/metabolismo , Azospirillum brasilense/fisiologia , Microbiologia Industrial/métodos , Viabilidade Microbiana , Raízes de Plantas/microbiologia , Propídio/análogos & derivados , Reação em Cadeia da Polimerase em Tempo Real , Propídio/metabolismo , Zea mays/microbiologia
12.
Genome ; 63(1): 1-12, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31533014

RESUMO

The larvae of Holotrichia parallela, a destructive belowground herbivore, causes tremendous damages to maize plants. However, little is known if there are any defense mechanisms in maize roots to defend themselves against this herbivore. In the current research, we carried out RNA-sequencing to investigate the changes in gene transcription level in maize roots after H. parallela larvae infestation. A total of 644 up-regulated genes and 474 down-regulated genes was found. In addition, Gene ontology (GO) annotation analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed. Weighted gene co-expression network analysis (WGCNA) indicated that peroxidase genes may be the hub genes that regulate maize defenses to H. parallela larvae attack. We also found 105 transcription factors, 44 hormone-related genes, and 62 secondary metabolism-related genes within differentially expressed genes (DEGs). Furthermore, the expression profiles of 12 DEGs from the transcriptome analysis were confirmed by quantitative real-time PCR experiments. This transcriptome analysis provides insights into the molecular mechanisms of the underground defense in maize roots to H. parallela larvae attack and will help to select target genes of maize for defense against belowground herbivory.


Assuntos
Besouros/fisiologia , Herbivoria/genética , Zea mays/genética , Animais , Besouros/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Genes de Plantas , Larva/fisiologia , Reguladores de Crescimento de Plantas/fisiologia , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , RNA-Seq , Reação em Cadeia da Polimerase em Tempo Real , Metabolismo Secundário/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcriptoma , Zea mays/metabolismo
13.
Plant J ; 93(6): 1032-1044, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29364547

RESUMO

The maize nodal root system plays a crucial role in the development of the aboveground plant and determines the yield via the uptake of water and nutrients in the field. However, the genetic architecture of the maize nodal root system is not well understood, and it has become the 'dark matter' of maize genetics. Here, a large teosinte-maize population was analyzed, and high-resolution mapping revealed that 62 out of 133 quantitative trait loci (QTLs), accounting for approximately half of the total genetic variation in nodal root number, were derived from QTLs for flowering time, which was further validated through a transgenic analysis and a genome-wide association study. However, only 16% of the total genetic variation in nodal root number was derived from QTLs for plant height. These results gave a hint that flowering time played a key role in shaping nodal root number via indirect selection during maize domestication. Our results also supported that more aerial nodal roots and fewer crown roots might be favored in temperate maize, and this root architecture might efficiently improve root-lodging resistance and the ability to take up deep water and nitrogen under dense planting.


Assuntos
Genes de Plantas/genética , Raízes de Plantas/genética , Locos de Características Quantitativas/genética , Zea mays/genética , Mapeamento Cromossômico , Domesticação , Flores/genética , Flores/crescimento & desenvolvimento , Variação Genética , Estudo de Associação Genômica Ampla , Fenótipo , Raízes de Plantas/crescimento & desenvolvimento , Seleção Genética , Fatores de Tempo , Zea mays/crescimento & desenvolvimento
14.
Breed Sci ; 68(2): 268-277, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29875611

RESUMO

Root system architecture (RSA) plays an important role in the acquisition of mineral nutrients. Nevertheless, RSA has seldom been selected as an important agricultural trait in conventional breeding programs. Little is known about the response of RSA and phosphorus use efficiency (PUE) in regards to phosphorus (P) availability between parental inbred lines and their F1. In this study, 6 maize inbred lines and their 15 F1 generated by a diallel mating system, were used to analyze the genetic associations between RSA and PUE. Heterosis for PUE-related traits were comparatively greater under high P condition and reduced significantly under low P condition. Relative mid-parent heterosis for root traits were expressed more under the low P condition. Low P supply had a significant effect on heterosis, GCA and SCA of RSA- and PUE- related traits. The hybrid C3 (7922 × 8703-2), which had the highest PUE, showed an average yield with a lower P uptake under the both P conditions. Results from this study suggested breeding for a relatively high grain yield with reducing aboveground P demand and grain P concentration should be sufficient to reduce P fertilizer input and improve P efficiency.

16.
Antonie Van Leeuwenhoek ; 108(5): 1015-22, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26346477

RESUMO

A novel Gram-positive, aerobic, motile, endospore-forming, rod-shaped bacterium, designated 373(T) was isolated from surface-sterilised root tissue of a maize planted in Fangshan District of Beijing, Peopole's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Paenibacillus. The highest 16S rRNA gene sequence similarity was found between strain 373(T) and Paenibacillus hunanensis (98.1%), meanwhile the 16S rRNA gene sequence similarity between strain 373(T) and the type strains of other recognised members of the genus Paenibacillus were all below 95.6%. However, the DNA-DNA hybridization values between strain 373(T) and the type strain P. hunanensis DSM 22170(T) was 30.2%. The DNA G+C content of strain 373(T) was determined to be 46.0 mol%. The predominant respiratory quinone was identified as menaquinone-7 and the polar lipid profile was found to be composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were found to consist of anteiso-C15: 0 (59.6%), anteiso-C17: 0 (12.8%) and C16: 0 (6.7%). The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 373(T) from the closely related species in this genus Paenibacillus. Strain 373(T) is concluded to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus wenxiniae sp. nov. is proposed, with the type strain 373(T) (= CGMCC 1.15007 (T) = DSM100576 ).


Assuntos
Proteínas de Bactérias/genética , Endófitos/genética , Oxirredutases/genética , Paenibacillus/genética , Zea mays/microbiologia , Composição de Bases , Código de Barras de DNA Taxonômico , DNA Bacteriano , Endófitos/química , Endófitos/classificação , Paenibacillus/química , Paenibacillus/classificação , Fenótipo , Filogenia , RNA Ribossômico 16S/genética
17.
Plant Physiol Biochem ; 199: 107723, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37163805

RESUMO

Melatonin (MT) is essential for plant development and drought adaptation. However, the molecular and metabolic mechanisms underlying MT-induced drought tolerance in maize roots remain largely unclear. Herein, we investigated the effects of MT on drought tolerance in maize roots using integrated transcriptomic and metabolomic analyses, and identified MT-induced genes and metabolites associated with drought resistance. Compared with the untreated control plants, MT application alleviated the deleterious effects of drought on roots, by decreasing the malondialdehyde level and increasing the solute potential, eventually promoting root growth. Transcriptome and metabolome analysis demonstrated that MT significantly upregulates the expression of genes related to flavonoid biosynthesis (PAL, C4H, 4CL, HCT, CHS, CHI, F3'5'H, and DFR), activates drought-responsive transcription factors (ERFs, NACs, MYBs, and bHLHs), and regulates hormone signaling-related genes, especially ethylene response factors (ERF4, ERF81, and ERF110). Moreover, MT increased the accumulation of flavonoid metabolites, particularly apigenin, luteolin, and quercetin, under drought-stress conditions. These findings were further supported by quantitative real-time polymerase chain reaction analysis and total flavonoid measurements. Altogether, our findings suggest that MT promotes maize root growth during drought by regulating flavonoid synthesis pathways, transcription factors, and plant hormone signals. This study provides new insights into the complex mechanisms by which MT enhances crop resistance to drought damage.


Assuntos
Melatonina , Transcriptoma , Melatonina/farmacologia , Melatonina/metabolismo , Zea mays/metabolismo , Estresse Fisiológico/genética , Secas , Flavonoides/metabolismo , Metaboloma , Regulação da Expressão Gênica de Plantas
18.
Sci Total Environ ; 878: 162848, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-36931522

RESUMO

In this study, effect of nitrate-dependent suberization in maize root on cadmium (Cd) uptake and accumulation was investigated. Suberization in maize roots was significantly lower in plants grown with a high nitrate supply compared with low nitrate. This decrease was seen in the total amount of suberin, in which the aliphatic suberin amount was significantly decreased, whereas no difference in aromatic suberin content between different N-treatments. RNA-sequencing showed that suberin biosynthesis genes were upregulated in low nitrate treatment, which correlated well with the increased suberin content. Bioimaging and xylem sap analysis showed that reduced exodermal and endodermal suberization in roots of plants grown under high nitrate promoted radial Cd transport along the crown root. The enhanced suberization in crown roots of plants grown in low nitrate restricted the radial transport of Cd from epidermis to cortex via decreased accessibility to Cd related transporters at the plasmalemma. Also, under low nitrate supply, the Cd transport gene ZmNramp5 was upregulated in the crown root, which may enhance Cd uptake by root tip where exodermis and endodermis were not fully suberized. These results suggest that high nitrate supply enhances Cd uptake and radial transport in maize roots by reducing exodermal and endodermal suberization.


Assuntos
Cádmio , Nitratos , Cádmio/farmacologia , Nitratos/farmacologia , Zea mays , Raízes de Plantas , Transporte Biológico
19.
Plants (Basel) ; 11(5)2022 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-35270173

RESUMO

The aim of this work was to study maize root phenotype under sulfur deficiency stress towards revealing potential correlations between the altered phenotypic traits and the corresponding dry mass, sulfur, and iron allocation within plants at the whole-plant level. The dynamics of root morphological and anatomical traits were monitored. These traits were then correlated with plant foliage traits along with dry mass and sulfur and iron allocation dynamics in the shoot versus root. Plants grown under sulfate deprivation did not seem to invest in new root axes. Crown roots presented anatomical differences in all parameters studied; e.g., more and larger xylem vessels in order to maximize water and nutrient transport in the xylem sap. In the root system of S-deficient plants, a reduced concentration of sulfur was observed, whilst organic sulfur predominated over sulfates. A reduction in total iron concentration was monitored, and differences in its subcellular localization were observed. As expected, S-deprivation negatively affected the total sulfur concentration in the aerial plant part, as well as greatly impacted iron allocation in the foliage. Phenotypic adaptation to sulfur deprivation in maize presented alterations mainly in the root anatomy; towards competent handling of the initial sulfur and the induced iron deficiencies.

20.
Fitoterapia ; 163: 105314, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36174847

RESUMO

The ent-kaurane diterpenoid enriched fraction (EDEF) of maize root was isolated and purified, and 10 compounds, including 4 ent-kaurane diterpenoids, were isolated and identified. We evaluated their neuroprotective properties in vitro for the first time using an H2O2-induced oxidative damage model in SH-SY5Y cells. The results showed that pretreatment with maizediterpene D, a new ent-kaurane diterpenoid isolated from the EDEF, significantly attenuated H2O2-induced apoptosis by improving cell survival, reducing ROS production and increasing mitochondrial membrane potential. Mechanistically, the neuroprotective effect of maizediterpene D was confirmed to be related to the dual activation of IGF-1R and BDNF/TrkB crosstalk pathways. Our findings suggest that the EDEF and its active constituent maizediterpene D had good neuroprotective properties and could serve as potential candidates for the development of therapeutic drugs for oxidative stress-related diseases.


Assuntos
Diterpenos do Tipo Caurano , Diterpenos , Neuroblastoma , Fármacos Neuroprotetores , Humanos , Peróxido de Hidrogênio/farmacologia , Zea mays , Sobrevivência Celular , Estrutura Molecular , Estresse Oxidativo , Diterpenos do Tipo Caurano/farmacologia , Fármacos Neuroprotetores/farmacologia , Apoptose , Diterpenos/farmacologia , Linhagem Celular Tumoral
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