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1.
Pestic Biochem Physiol ; 178: 104916, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34446192

RESUMO

Soybean root rot occurs globally and seriously affects soybean production. To avoid the many disadvantages of chemical fungicides, the addition of Bacillus is gradually becoming an alternative strategy to tackle soybean root rot. However, the molecular mechanism of phytopathogenic fungi in this process by Bacillus inhibition is rarely reported. In this study, we isolated a strain of B. subtilis HSY21 from soybean rhizosphere soil, which had an inhibition rate of 81.30 ± 0.15% (P < 0.05) against Fusarium oxysporum. The control effects of this strain against soybean root rot under greenhouse and field conditions were 63.83% and 57.07% (P < 0.05), respectively. RNA-seq analysis of F. oxysporum after treatment with strain HSY21 revealed 1445 downregulated genes and 1561 upregulated genes. Among them, genes involved in mycelial growth, metabolism regulation, and disease-related enzymes were mostly downregulated. The activities of cellulase, ß-glucosidase, α-amylase, and pectin-methyl- galacturonase as well as levels of oxalic acid and ergosterol in F. oxysporum were significantly decreased after HSY21 treatment. These results demonstrated that B. subtilis HSY21 could effectively control F. oxysporum by inhibiting its growth and the expression of pathogenic genes, thus indicating that this strain may be an ideal candidate for the prevention and control of soybean root rot.


Assuntos
Fusarium , Bacillus subtilis/genética , Fusarium/genética , Doenças das Plantas/genética , Soja/genética , Virulência
2.
Plant Cell Rep ; 40(10): 1907-1922, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34322731

RESUMO

KEY MESSAGE: MsCML46 enhances tolerance to abiotic stresses through alleviating osmotic stress and oxidative damage by regulating the expression of stress-related genes to optimize osmolytes levels and antioxidant enzyme activity in transgenic tobacco. Abiotic stresses are major environmental factors that constraint crop productivity worldwide. Various stimuli regulate intracellular calcium levels and calcium-mediated signal transduction, and cellular responses. Ca2+ signals are perceived by different Ca2+ receptors. Calmodulin-like protein (CML) is one of the best-characterized Ca2+ sensors which shares sequence similarity with highly conserved calmodulin (CaM) ubiquitously expressed in plants. Currently, the molecular and physiological functions of CMLs are largely unknown. In this study, the MsCML46 was characterized in alfalfa (Medicago sativa cv. Zhaodong) under freezing stress. Results showed that MsCML46 was localized to the cytoplasm of Arabidopsis, and its expression was strongly elevated by cold, drought, salt, saline-alkali, and ABA treatments. Overexpressing MsCML46 in tobacco enhanced tolerance to freezing, drought, and salt stresses as evidenced by improved contents of osmotic regulatory solutes and antioxidant enzyme activity but decreased reactive oxygen species (ROS) accumulation. Furthermore, cold, drought, and salt stresses increased the expression of stress-related genes in transgenic tobacco. MsCML46 binds free Ca2+ to promote signal transduction and maintain higher K+/Na+ ratio. In this way, it protects intracellular homeostasis under sodium ion toxicity. These results suggest that MsCML46 plays a crucial role in resisting abiotic stresses and can be exploited in genetic engineering for crops.

3.
J Photochem Photobiol B ; 222: 112274, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34330082

RESUMO

Photodynamic therapy (PDT) has gained much attention in tumor therapy because of its special advantages. PDT heavily depends on the oxygen, yet the tumor microenvironment (TME) is a hypoxic and acid milieu, which weakens the PDT effect. Based on the consideration that the TME deteriorated by the PDT oxygen consumption could activate the hypoxic-sensitive small-molecule drug, we designed and prepared an integrated nanocomposite including zirconium ion metal organic framework (carrier), pyropheophorbide-a (PPa, photosensitizer), and 6-amino flavone (AF, hypoxic-sensitive drug), aiming to exert a cascaded PDT-chemotherapy (CT) antitumor effect and to solve the hypoxic challenge. The prepared nanocomposite showed great stability under the physiological (pH 7.4) condition and could continuously release PPa and AF under slightly acidic pH condition (pH 6.4), suggesting a tumor microenvironment responsive feature. Systematical in vitro and in vivo researches under various conditions (light, dark, hypoxic and normoxic) have showed that the obtained Zr-MOF@PPa/AF@PEG nanoparticles (NPs) had good biocompatibility and could achieve efficient antitumor effects based on PDT- chemotherapy (CT) cascade process. Finally, bright red fluorescence was observed in the tumor cells after internalization implying an application potential in tumor imaging.


Assuntos
Clorofila/análogos & derivados , Flavonoides/química , Estruturas Metalorgânicas/química , Nanocompostos/química , Fotoquimioterapia/métodos , Nanomedicina Teranóstica , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Clorofila/química , Clorofila/metabolismo , Clorofila/uso terapêutico , Liberação Controlada de Fármacos , Feminino , Flavonoides/metabolismo , Flavonoides/uso terapêutico , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Nanocompostos/uso terapêutico , Nanocompostos/toxicidade , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Polietilenoglicóis/química , Oxigênio Singlete/metabolismo , Microambiente Tumoral , Zircônio/química
4.
Angew Chem Int Ed Engl ; 60(15): 8344-8351, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33491871

RESUMO

The 10-nuclear heteroatom cluster modified {SbW8 O30 } was successfully synthesized and exhibited inhibitory activity (IC50 =0.29 µM). Based on proteomics analysis, Na4 Ni2 Sb2 W2 -SbW8 inhibited ATP production by affecting the expression of 16 related proteins, hindering metabolic functions in vivo and cell proliferation due to reactive oxygen species (ROS) stress. In particular, the low expression of FAD/FMN-binding redox enzymes (relative expression ratio of the experimental group to the control=0.43843) could be attributed to the redox mechanism of Na4 Ni2 Sb2 W2 -SbW8 , which was consistent with the effect of polyoxometalates (POMs) and FMN-binding proteins on ATP formation. An electrochemical study showed that Na4 Ni2 Sb2 W2 -SbW8 combined with FMN to form Na4 Ni2 Sb2 W2 -SbW8 -2FMN complex through a one-electron process of the W atoms. Na4 Ni2 Sb2 W2 -SbW8 acted as catalase and glutathione peroxidase to protect the cell from ROS stress, and the inhibition rates were 63.3 % at 1.77 µM of NADPH and 86.06 % at 10.62 µM of 2-hydroxyterephthalic acid. Overall, our results showed that POMs can be specific oxidative/antioxidant regulatory agents.


Assuntos
Trifosfato de Adenosina/antagonistas & inibidores , Antioxidantes/farmacologia , Mitocôndrias/efeitos dos fármacos , Proteômica , Análise de Célula Única , Tetrahymena thermophila/efeitos dos fármacos , Trifosfato de Adenosina/biossíntese , Antimônio/química , Antimônio/farmacologia , Antioxidantes/química , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/química , Oxigênio/farmacologia , Tetrahymena thermophila/crescimento & desenvolvimento , Tungstênio/química , Tungstênio/farmacologia
5.
Biomater Sci ; 8(21): 6045-6055, 2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33000800

RESUMO

In this paper, a nanocomposite was constructed to achieve improved photodynamic therapy (PDT) via disrupting the redox balance in cancer cells. Firstly, Sb2Se3 nanorods were synthesized as a new photosensitizer, displaying high photothermal conversion efficiency (45.2%) and reactive oxygen species (ROS) production due to the narrow band gap (1.1 eV) and a good NIR response. Moreover, the mechanism was investigated, demonstrating that dissolved O2 and photoinduced electrons manipulated ROS generation. Then, mesoporous silica was coated outside to improve the biocompatibility and to supply abundant space for the anticancer drug (doxorubicin, DOX). The sensitive Se-Se linker was grafted outside via a silane coupling reaction to block DOX molecules in the mesopores. As we know, the Se-Se group is sensitive to GSH, which can induce Se-Se linker bond breakage and targeted drug release due to the high expression of GSH in tumor cells. What is more, the consumption of intracellular GSH can also disrupt the redox balance in cancer cells, which would promote the PDT efficiency. The high-Z element of Sb possesses a high X-ray attenuation coefficient, giving the composite high contrast in CT imaging. This is associated with thermal imaging and multi-therapy (PDT/PTT/chemotherapy) to reveal the potential application to cancer treatment.


Assuntos
Neoplasias , Fotoquimioterapia , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Neoplasias/tratamento farmacológico , Oxirredução , Espécies Reativas de Oxigênio
6.
Plant Pathol J ; 36(5): 398-405, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33082724

RESUMO

Nutrient manipulation is a promising strategy for controlling plant diseases in sustainable agriculture. Although many studies have investigated the relationships between certain elements and plant diseases, few have comprehensively explored how differing mineral nutrition levels might affect plant-fungal pathogen interactions, namely plant susceptibility and resistance. Here, we systematically explored the effects of the seven mineral elements that plants require in the greatest amounts for normal development on the susceptibility of soybean plants (Glycine max) to Fusarium oxysporum infection in controlled greenhouse conditions. Nitrogen (N) negligibly affected plant susceptibility to infection in the range 4 to 24 mM for both tested soybean cultivars. At relatively high concentrations, phosphorus (P) increased plant susceptibility to infection, which led to severely reduced shoot and root dry weights. Potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), and iron (Fe) induced plant resistance to infection as their concentrations were increased. For K and Ca, moderate concentrations had a positive effect on plant resistance to the pathogen, whereas relatively high doses of either element adversely affected plant growth and promoted disease symptoms. Further experiments were conducted, assessing disease suppression by selected combinations of macro-elements and Fe at screened concentrations, i.e., K (9 mM) plus Fe (0.2 mM), and S (4 mM) plus Fe (0.2 mM). The disease index was significantly reduced by the combination of K plus Fe. In conclusion, this systematic investigation of soybean plant responses to F. oxysporum infection provides a solid basis for future environmentally-friendly choices for application in soybean disease control programs.

7.
3 Biotech ; 10(8): 335, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32656068

RESUMO

Pectin Methylesterase Inhibitors (PMEI) gene family is widely spread in plants and plays crucial roles in plant development as well as biotic and abiotic stress response. However, little information was known about the function of PMEI genes in soybean. Herein, we identified 170 PMEI genes in soybean. These PMEI genes were divided into four groups (I-IV) based on phylogenetic analysis, and they were unevenly distributed in 18 soybean chromosomes. Gene structures and motif pattern analyses revealed that the PMEI genes in the same group showed the same characteristics. For the GmPMEI genes, gene duplication events occurred broadly, 52 pairs tandem duplication events and 55 pairs segmental duplication events suggested that the GmPMEI genes had high homology. Besides, the PMEI genes presented different expression patterns in different tissues, while several of these genes were expressed only in flowers. Under the biotic and abiotic stresses, PMEI genes had significant positive impact on the tolerance ability of soybean, and the ABA-responsive elements and SA-responsive elements played vital roles in responding to a variety of stresses. This study provides insights into the evolution and potential functions of GmPMEIs.

8.
Plant Cell Rep ; 39(8): 997-1011, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32333150

RESUMO

KEY MESSAGE: MsCBL4 expression in tobacco enhanced its salt and saline-alkali stress tolerance by regulating calcium accumulation in roots, indicating the important role of calcium metabolism in plant saline-alkali stress tolerance The calcineurin B-like (CBL) family of proteins play important roles in plant abiotic stress tolerance and signal transduction. CBL4 is known to participate in the Salt Overly Sensitive pathway; however, little is currently known regarding the mechanisms underlying the response of CBL4 to saline-alkali stress. In this study, we cloned and characterized the alfalfa MsCBL4 gene. We found that MsCBL4 showed the highest expression in root tissues and was induced by salt and saline-alkali stress, with the latter causing higher induction. Overexpression of MsCBL4 in tobacco enhanced salt and saline-alkali stress tolerance and reduced the Na+/K+ ratio in roots of transgenic lines. Salt (30 and 300 mM NaCl) and saline-alkali (30 mM NaHCO3) stress assays performed for MsCBL4 transgenic tobacco lines revealed a substantial influx of sodium ions in roots under saline-alkali stress and indicated that the expression of MsCBL4 had little influence on sodium ion content reduction. In contrast, in roots subjected to saline-alkali stress, calcium accumulation occurred and was significantly enhanced by the overexpression of MsCBL4. Physiological and biochemical analyses indicated that MsCBL4 plays an important role in saline-alkali stress tolerance via its influence on the regulation of calcium transport and accumulation. These results provide novel insights into the saline-alkali stress tolerance mechanisms of plants.


Assuntos
Álcalis/farmacologia , Cálcio/metabolismo , Medicago sativa/metabolismo , Proteínas de Plantas/metabolismo , Estresse Salino , Sódio/metabolismo , Tabaco/genética , Sequência de Aminoácidos , Transporte Biológico , Catalase/metabolismo , Quelantes/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Especificidade de Órgãos/efeitos dos fármacos , Peroxidase/metabolismo , Fenótipo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Potássio/metabolismo , Estresse Salino/efeitos dos fármacos , Cloreto de Sódio , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
9.
PeerJ ; 8: e8471, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32117614

RESUMO

Valine-glutamine (VQ) proteins are plant-specific proteins that play crucial roles in plant development as well as biotic and abiotic stress responses. VQ genes have been identified in various plants; however, there are no systematic reports in Cicer arietinum or Medicago truncatula. Herein, we identified 19 and 32 VQ genes in C. arietinum and M. truncatula, respectively. A total of these VQ genes were divided into eight groups (I-VIII) based on phylogenetic analysis. Gene structure analyses and motif patterns revealed that these VQ genes might have originated from a common ancestor. In silico analyses demonstrated that these VQ genes were expressed in different tissues. qRT-PCR analysis indicated that the VQ genes were differentially regulated during multiple abiotic stresses. This report presents the first systematic analysis of VQ genes from C. arietinum and M. truncatula and provides a solid foundation for further research of the specific functions of VQ proteins.

10.
Funct Integr Genomics ; 20(4): 537-550, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32034565

RESUMO

The teosinte branched1, cycloidea, and proliferating cell factor family (TCP) proteins, plant-specific transcription factors, are involved in the regulation of plant development; however, the TCP gene family of legumes has been based primarily on a single crop. Here, a total of 55, 22, 26, 21, and 25 genes containing the VQ motif were identified from the genomes of Glycine max, Cicer arietinum, Phaseolus vulgaris, Medicago truncatula, and Lotus japonicus, respectively. Based on the phylogenetic analysis, we divided these TCP genes into three distinct subfamilies: PCF, CYC/TB1, and CIN. The conserved domain analysis indicated that the TCP gene family members contain the bHLH and R domains. The TCP genes from the same evolutionary branches of legumes shared similar motifs and structures. The promoter analysis revealed that cis-elements were related to stress responses, phytohormone responses, and physical and reproductive growth regulation. In addition, the TCP genes presented different expression patterns in the five legumes. Most of them showed specific expression patterns during development. The results of qRT-PCR indicated that the TCP genes played regulatory roles in both salt and drought stresses. The present study provides novel and detailed information regarding the legume TCP gene family, which aids in functional characterisation of the TCP genes in other plants.


Assuntos
Secas , Fabaceae/genética , Proteínas de Plantas/genética , Estresse Salino , Fatores de Transcrição/genética , Motivos de Aminoácidos , Fabaceae/metabolismo , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo
11.
Transgenic Res ; 28(5-6): 589-599, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31595387

RESUMO

During the Green Revolution in the 1960s, breeding dwarf cultivars turned out to be a landmark, leading to a significant increase in the global production of wheat and rice. The most direct and effective strategy for breeding dwarf crops, among others, would be to control endogenous gibberellin (GA) levels of the crops. GA 2-oxidases are a group of 2-oxoglutarate-dependent dioxygenases that catalyze the deactivation of bioactive GAs. The ArabidopsisAtGA2ox1 gene was transformed into maize with the aim of obtaining a height-reduced GM maize. The characterization of the GM maize revealed that the highest plant height reduction was accomplished by a 74% decline in GA1 level, and by approximately twofold increases in both chlorophyll content and root/shoot ratio over the wild-type (WT). Interestingly, the stem cells of the GM maize were condensed, and the typical vascular bundle structure was found to be deformed. Based on a 2-season field trial, the GM maize exhibited a higher harvest index (9-17%) and grain yield (10-14%) than the WT. The current results suggest that a modulation of the endogenous GA level would be a sensible approach for improving the crop architecture and grain yield in maize.


Assuntos
Arabidopsis/genética , Giberelinas/metabolismo , Oxigenases de Função Mista/genética , Zea mays/genética , Proteínas de Arabidopsis/genética , Cruzamento , Dioxigenases/genética , Regulação da Expressão Gênica de Plantas/genética , Oryza/genética , Oryza/crescimento & desenvolvimento , Triticum/genética , Triticum/crescimento & desenvolvimento , Zea mays/crescimento & desenvolvimento
12.
Biol Open ; 8(9)2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31471294

RESUMO

Abiotic stresses restrict the productivity and quality of agricultural crops. Glutathione S-transferase (GST) utilizes glutathione to scavenge reactive oxygen species (ROS) that result from abiotic stresses. This study aimed to determine the expression pattern of the MsGSTU8 gene and its effects on saline-alkali tolerance. MsGSTU8, from alfalfa (Medicago sativa 'Zhaodong'), was transformed into transgenic tobacco (Nicotiana tabacum) and overexpressed to determine its effects on saline-alkali tolerance. The gene products in alfalfa localized to the cytoplasm and the transcript levels were higher in the leaves than the roots and stems. Expression was strongly induced by cold, drought, salt and saline-alkali stresses as well as abscisic acid (ABA) treatments. The transgenic tobacco lines had significantly higher transcription levels of the abiotic stress-related genes and higher GST activity than the wild types. Transgenic tobacco lines with saline-alkali treatments maintained their chlorophyll content, showed improved antioxidant enzyme activity and soluble sugar levels, reduced ion leakage, O2 .-, H2O2 accumulation and malondialdehyde content. Our results indicate that overexpression of MsGSTU8 could improve resistance to saline-alkali stresses by decreasing the accumulation of ROS and increasing the levels of antioxidant enzymes. Furthermore, they suggest that MsGSTU8 could be utilized for transgenic crop plant breeding.

13.
Genet Mol Biol ; 42(3): 611-623, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31188936

RESUMO

MYB is a large family of plant transcription factors. Its function has been identified in several plants, while there are few reports in Medicago truncatula. In this study, we used RNA-seq data to analyze and identify R2R3-MYB genes in the genome of Medicago truncatula. Phylogenetic analysis classified 150 MtMYB genes into 21 subfamilies with homologs. Out of the 150 MtMYB genes, 139 were distributed among 8 chromosomes, with tandem duplications (TD) and segment duplications (SD). Microarray data were used for functional analysis of the MtMYB genes during growth and developmental processes providing evidence for a role in tissues differentiation, seed development processes, and especially the nodulation process. Furthermore, we investigated the expression of MtMYB genes in response to abiotic stresses using RNA-seq data, which confirmed the critical roles in signal transduction and regulation processes under abiotic stress. We used quantitative real-time PCR (qRT-PCR) to validate expression profiles. The expression pattern of M. truncatula MYB genes under different abiotic stress conditions suggest that some may play a major role in cross-talk among different signal transduction pathways in response to abiotic stresses. Our study will serve as a foundation for future research into the molecular function of M. truncatula R2R3-MYB genes.

14.
Genetica ; 147(2): 185-196, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30905050

RESUMO

The amino acid/auxin permease (AAAP) gene family plays an important role in the long-distance amino acid transport pathway and takes part in various stages of plant growth and development. However, little is known about the AAAP gene family in Medicago truncatula. Here, we identified 86 putative MtAAAP family members using genome sequence information. Based on phylogenetic analysis, these MtAAAP genes were categorized into eight distinct subfamilies. The MtAAAP genes were mapped on 8 chromosomes and duplication events appeared widely, with 19 and 21 pairs of MtAAAP genes showing segment and tandem duplication events, respectively. Ratio of Ka/Ks indicated that duplicated genes underwent purifying selection. Analysis of RNA-seq data showed that MtAAAP genes exhibited specific expression patterns among different tissues and abiotic stress, indicating that MtAAAP members were involved in plant developmental regulation and stress responses. Expression patterns of 16 MtAAAP genes under abiotic stress were verified by qRT-PCR. The present study provides a foundation for the functional analysis of MtAAAPs in developmental regulation and stress responses.


Assuntos
Sistemas de Transporte de Aminoácidos/genética , Regulação da Expressão Gênica de Plantas , Medicago/genética , Proteínas de Plantas/genética , Sistemas de Transporte de Aminoácidos/metabolismo , Duplicação Gênica , Genoma de Planta , Medicago/metabolismo , Família Multigênica , Filogenia , Proteínas de Plantas/metabolismo , Seleção Genética , Estresse Fisiológico
15.
Materials (Basel) ; 12(1)2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30621026

RESUMO

The two-step austempering process has been reported to be an effective method to accelerate the bainitic transformation process by introducing martensite (Q-M-B). However, in this study, it was found that the Q-M-B process reduced the incubation time, but the transformation duration remained nearly unchanged. The notably reduced activation energy barrier for nucleation of bainitic ferrite on the preformed martensite should be responsible for the reduced duration time of the Q-M-B process. A process that both of the two steps were above, Ms (Q-B-B), has been demonstrated to increase transformation rate and improve the amount of bainitic ferrite, which probably results from the additional hysteresis free energy provided by the first quenching process.

16.
J Sci Food Agric ; 99(1): 281-289, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29855046

RESUMO

BACKGROUND: Bacteria with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity could decrease the ethylene level, confer resistance of plant, and stimulate plant growth under biotic and abiotic stress conditions. RESULTS: Plant growth-promoting rhizobacteria (PGPR) strains Enterobacter aerogenes (LJL-5) and Pseudomonas aeruginosa (LJL-13) were obtained from the rhizosphere of alfalfa grown under saline-alkali conditions. The ACC deaminase activity of E. aerogenes (LJL-5) and Ps. aeruginosa (LJL-13) was approximately 2-5 µmol mg-1  h-1 . indole acetic acid synthesis was increased with the increasing concentration of l-tryptophan. Siderophore production and phosphate solubilization in Ps. aeruginosa (LJL-13) were higher than those in E. aerogenes (LJL-5). Compared to the non-inoculated seedlings (1.31 ng mL-1  h-1 ), inoculated alfalfa seedlings with E. aerogenes (LJL-5) (0.90 ng mL-1  h-1 ) and Ps. aeruginosa (LJL-13) (0.78 ng mL-1  h-1 ) emitted lower levels of ethylene. Under saline-alkali conditions in the greenhouse, inoculation with E. aerogenes (LJL-5) and Ps. aeruginosa (LJL-13) increased the biomass, soil and plant analyzer development (SPAD), and P content of alfalfa plants, and also induced the activity of antioxidant enzymes (superoxide dismutase, peroxidase and catalase), promoted the accumulation of antioxidant substances and removed various harmful substances. Under saline-alkali conditions in the field (2012, 2013, and 2014), inoculation of alfalfa with E. aerogenes (LJL-5) and Ps. aeruginosa (LJL-13) significantly increased the shoot height, fresh and dry weights, yield and crude protein content of alfalfa plants, but decreased the fiber content. CONCLUSION: Two PGPR strains were isolated from the rhizosphere of alfalfa in saline-alkali conditions. Both strains could promote alfalfa growth in saline-alkali soil, and could be used as biofertilizer to promote plant growth under stress and reduce environmental pollution caused by fertilizers simultaneously. © 2018 Society of Chemical Industry.


Assuntos
Enterobacter aerogenes/metabolismo , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/microbiologia , Reguladores de Crescimento de Plantas/metabolismo , Pseudomonas aeruginosa/metabolismo , Solo/química , Proteínas de Bactérias/metabolismo , Carbono-Carbono Liases/metabolismo , Enterobacter aerogenes/enzimologia , Enterobacter aerogenes/genética , Etilenos/metabolismo , Concentração de Íons de Hidrogênio , Ácidos Indolacéticos/metabolismo , Medicago sativa/química , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/genética , Microbiologia do Solo
17.
Genes Genomics ; 40(8): 857-864, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30047115

RESUMO

Although much work has explored how microbes can benefit plant growth, the mechanisms underlying this intriguing process remain largely unknown, especially considering the diversity of bacteria that surrounds plants. The objective of the present study was to identify bacterial genes contributing to plant-microbe associations, beneficial effects, and host specificities. For this purpose, comparative genomics investigation of 151 plant-associated bacteria was performed. A principal component analysis of seven key genomic features revealed patterns in the specific properties of these bacteria: N2-fixing bacteria were more closely related to pathogenic ones than to beneficial bacteria. A common set of genes over-represented in these plant-associated bacteria were found to be remarkably similar in terms of (1) genetic information processing, (2) amino acid metabolism, (3) metabolism of cofactors and vitamins, (4) nucleotide metabolism, (5) human diseases, and (6) metabolism of terpenoids and polyketides. Although we did not detect a common genetic basis for these beneficial effects, further in-depth analysis revealed that each of five beneficial bacterial groups shared specific gene sets. Functional annotation showed that environmental information processing, genetic information processing and cellular processes predominated in these beneficial groups. Hypothesizing that plant-associated bacteria may have overlapping strategies to colonize their plant hosts, we successfully identified many putative genes that determine host specificities. Most of these genes were classified as transcription factors, enzymes, transporters, and chemotaxis regulators. Comparative genomics provides a powerful tool for helping to identify genes that are common among species. Genome-based views of plant-associated bacteria reveal specific interactions between bacteria and plant hosts.


Assuntos
Bactérias/genética , Interações Hospedeiro-Patógeno/genética , Filogenia , Plantas/genética , Aminoácidos/genética , Bactérias/classificação , Bactérias/metabolismo , Genoma Bacteriano/genética , Genômica , Humanos , Fixação de Nitrogênio/genética , Plantas/metabolismo , Plantas/microbiologia , Simbiose/genética
18.
Genet Mol Biol ; 41(3): 638-648, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30004107

RESUMO

Medicago ruthenica is a perennial forage legume with the remarkable ability to survive under unfavorable environmental conditions. It has been identified as an excellent species of Medicago that can adapt to various environmental stresses including low temperature, drought, and salinity. To investigate its potential as a genetic resource, we performed transcriptome sequencing and analysis in M. ruthenica under abiotic stresses. We generated >120 million reads from six cDNA libraries, resulting in 79,249 unique transcripts, most of which were highly similar to transcripts from M. truncatula (44,608, 56.3%) and alfalfa (M. sativa, 48,023, 60.6%). Based on gene expression profiles, 2,721 transcripts were identified as abiotic stress responsive genes which were predicted to be mainly involved in phytohormone signaling pathways, transcriptional regulation, and ROS-scavenging. These results suggest that they play critical roles in the response to abiotic stress. In summary, we identified genes in our transcriptome dataset involved in the regulation of the abiotic stress response in M. ruthenica which will provide a valuable resource for the future identification and functional analysis of candidate genes for adaption to unfavorable conditions. The genes identified here could be also useful for improving stress tolerance traits in alfalfa through molecular breeding in the future.

19.
Int J Genomics ; 2018: 7658910, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29854720

RESUMO

Auxin response factors (ARFs) have been reported to play vital roles during plant growth and development. In order to reveal specific functions related to vegetative organs in grasses, an in-depth study of the ARF gene family was carried out in switchgrass (Panicum virgatum L.), a warm-season C4 perennial grass that is mostly used as bioenergy and animal feedstock. A total of 47 putative ARF genes (PvARFs) were identified in the switchgrass genome (2n = 4x = 36), 42 of which were anchored to the seven pairs of chromosomes and found to be unevenly distributed. Sixteen PvARFs were predicted to be potential targets of small RNAs (microRNA160 and 167). Phylogenetically speaking, PvARFs were divided into seven distinct subgroups based on the phylogeny, exon/intron arrangement, and conserved motif distribution. Moreover, 15 pairs of PvARFs have different temporal-spatial expression profiles in vegetative organs (2nd, 3rd, and 4th internode and leaves), which implies that different PvARFs have specific functions in switchgrass growth and development. In addition, at least 14 pairs of PvARFs respond to naphthylacetic acid (NAA) treatment, which might be helpful for us to study on auxin response in switchgrass. The comprehensive analysis, described here, will facilitate the future functional analysis of ARF genes in grasses.

20.
J Exp Bot ; 69(20): 4739-4756, 2018 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-29757397

RESUMO

Gametocidal (Gc) chromosomes can kill gametes that lack them by causing chromosomal breakage to ensure their preferential transmission, and they have been exploited in genetic breeding. The present study investigated the possible roles of small RNAs (sRNAs) in Gc action. By sequencing two small RNA libraries from the anthers of Triticum aestivum cv. Chinese Spring (CS) and the Chinese Spring-Gc 3C chromosome monosomic addition line (CS-3C), we identified 239 conserved and 72 putative novel miRNAs, including 135 differentially expressed miRNAs. These miRNAs were predicted to target multiple genes with various molecular functions relevant to the features of Gc action, including sterility and genome instability. The transgenic overexpression of miRNA, which was up-regulated in CS-3C, reduced rice fertility. The CS-3C line exhibited a genome-wide reduction in 24 nt siRNAs compared with that of the CS line, particularly in transposable element (TE) and repetitive DNA sequences. Corresponding to this reduction, the bisulfite sequencing analysis of four retro-TE sequences showed a decrease in CHH methylation, typical of RNA-directed DNA methylation (RdDM). These results demonstrate that both miRNA-directed regulation of gene expression and siRNA-directed DNA methylation of target TE loci could play a role in Gc action.


Assuntos
Cromossomos de Plantas/fisiologia , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Triticum/genética , Genes de Plantas/fisiologia , MicroRNAs/metabolismo , Reprodução , Triticum/metabolismo
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