RESUMO
Bacterial wilt of tomato caused by Ralstonia solanacearum is a critical soilborne disease that drastically reduces yield. In the current study, an endophytic strain NEAU-CP5 with strong antagonistic activity against R. solanacearum was isolated from tomato seeds and characterized. The strain was identified as Bacillus velezensis based on 16S rRNA gene and whole genome sequence analysis. NEAU-CP5 can secrete amylase, protease, and cellulase, and also produce known antibacterial metabolites, including cyclo (leucylprolyl), cyclo (phenylalanyl-prolyl), cyclo (Pro-Gly), 3-benzyl-2,5-piperazinedione, pentadecanoic acid, eicosane, 2-methyoic acid, isovaleric acid, dibuty phthalate, and esters of fatty acids (HFDU), which may be responsible for its strong antibacterial activity. Fourteen gene clusters associated with antibacterial properties were also identified in the whole genome sequence of NEAU-CP5. Pot experiment demonstrated that the application of 108 CFU/mL NEAU-CP5 on tomato plants significantly reduced the incidence of tomato bacterial wilt by 68.36 ± 1.67 %. NEAU-CP5 also increased the activity of defense-related enzymes (CAT, POD, PPO, SOD, and PAL) in tomato plants. This is the first report of an effective control of bacterial wilt on tomato plants by B. velezensis and highlights the potential of NEAU-CP5 as a potential biocontrol agent for the management of tomato bacterial wilt.
Assuntos
Bacillus , Filogenia , Doenças das Plantas , RNA Ribossômico 16S , Ralstonia solanacearum , Sementes , Solanum lycopersicum , Solanum lycopersicum/microbiologia , Doenças das Plantas/microbiologia , Ralstonia solanacearum/genética , Bacillus/isolamento & purificação , Bacillus/genética , Bacillus/metabolismo , Bacillus/classificação , Sementes/microbiologia , RNA Ribossômico 16S/genética , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Endófitos/isolamento & purificação , Endófitos/genética , Endófitos/metabolismo , Genoma Bacteriano , Sequenciamento Completo do Genoma , Antibiose , Família Multigênica , Amilases/metabolismo , Amilases/genética , DNA Bacteriano/genéticaRESUMO
A novel mycelium-forming actinomycete, designated strain NEAU-S30T, was isolated from the sandy soil of a sea beach in Shouguang city, Shandong province, PR China. The strain developed long chains of non-motile cylindrical spores with smooth surfaces on aerial mycelia. The results of a polyphasic taxonomic study indicated that NEAU-S30T represented a member of the genus Glycomyces. The results of 16S rRNA gene sequence analysis indicated that NEAU-S30T was closely related to 'Glycomycesluteolus' (98.97â% sequence similarity), Glycomycesalgeriensis (98.90â%), 'Glycomyces tritici' (98.83â%) and Glycomyces lechevalierae (98.76â%). The average nucleotide identity (ANI) values between NEAU-S30T and 'G. luteolus' NEAU-A15, G. algeriensis DSM 44727T, 'G. tritici' NEAU-C2 and G. lechevalierae DSM 44724T were 87.77, 87.53, 87.41 and 87.80â%, respectively. The digital DNA G+C content of the genomic DNA was 70.5â%. The whole-cell sugars contained ribose and xylose. The predominant menaquinones were MK-10(H2), MK-10(H4) and MK-10(H6). The predominant fatty acids were anteiso-C15â:â0, iso-C16â:â0, anteiso-C17â:â0 and iso-C15â:â0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified glycolipid. On the basis of the results of comparative analysis of genotypic, phenotypic and chemotaxonomic data, the novel actinomycete strain NEAU-S30T (=JCM 33975T=CGMCC 4.7890T) represents the type strain of a novel species within the genus Glycomyces, for which the name Glycomyces niveus sp. nov. is proposed.
Assuntos
Actinobacteria , Actinomycetales , Areia , Solo , RNA Ribossômico 16S/genética , Composição de Bases , Ácidos Graxos/química , Filogenia , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem BacterianaRESUMO
A Gram-stain-negative, rod-shaped, indole-producing, and cellulose-degrading bacterial strain, designated NEAU-G-C5T, was isolated from soil collected from a forest in Dali city, Yunnan province, south China. 16S rRNA gene sequence analysis showed that strain NEAU-G-C5T was assigned to the genus Massilia and showed high sequence similarities to Massilia phosphatilytica 12-OD1T (98.32â%) and Massilia putida 6 NM-7T (98.41â%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-G-C5T formed a lineage related to M. phosphatilytica 12-OD1T and M. putida 6 NM-7T. The major fatty acids of the strain were C16â:â0, C16â:â1 ω7c, and C17â:â0 cyclo. The respiratory quinone was Q-8. The polar lipid profile of the strain showed the presence of diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. In addition, the average nucleotide identity values between strain NEAU-G-C5T and its reference strains M. phosphatilytica 12-OD1T, M. putida 6 NM-7T, M. norwichensis NS9T, and M. kyonggiensis TSA1T were 89.7, 88.2, 81.3, and 88.0â%, respectively, and the levels of digital DNA-DNA hybridization between them were found to be 58.5â% (54.9-62.0â%), 53.2â% (49.8-56.7â%), 31.9â% (28.6-35.5â%), and 57.7â% (54.1-61.2â%), respectively, which were lower than the accepted threshold values of 95-96â% and 70â%, respectively. The DNA G+C content of strain NEAU-G-C5T was 66.5âmol%. The strain could produce indoleacetic acid and cellulase. On the basis of the phenotypic, genotypic, and chemotaxonomic characteristics, we conclude that strain NEAU-G-C5T represents a novel species of the genus Massilia, for which the name Massilia luteola sp. nov. is proposed. The type strain is NEAU-G-C5T (=MCCC 1K08668T=KCTC 8080T).
Assuntos
Ácidos Graxos , Fosfolipídeos , Ácidos Graxos/química , Fosfolipídeos/análise , Solo , Filogenia , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Análise de Sequência de DNA , Composição de Bases , China , Técnicas de Tipagem Bacteriana , Indóis , Microbiologia do SoloRESUMO
A novel ligninase-producing and cellulose-degrading actinobacterium, designated strain NEAU-A12T, was isolated from a soil sample collected from Aohan banner, Chifeng City, Inner Mongolia Autonomous Region, PR China. A polyphasic taxonomic study was used to establish the status of strain NEAU-A12T. 16S rRNA gene sequence analysis revealed that strain NEAU-A12T belonged to the genus Actinoplanes and showed the highest similarity (98.3â%) to Actinoplanes palleronii DSM 43940T, while showing less than 98.3â% similarity to other members of the genus Actinoplanes. The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and glycosylphosphatidylinositol. The diagnostic sugars in cell hydrolysates were determined to be arabinose, glucose and xylose. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The major fatty acids were C15â:â0, C16â:â0, C16â:â1 ω7c and C17â:â0. Meanwhile, genomic analysis revealed a genome size of 10â192â524 bp and a DNA G+C content of 70.6âmol%, and indicated that strain NEAU-A12T had the potential to degrade lignin and cellulose, as well as produce bioactive compounds. In addition, the average nucleotide identity values between strain NEAU-A12T and its reference strains A. palleronii DSM 43940T, Actinoplanes regularis DSM 43151T, Actinoplanes philippinensis DSM 43019T, Actinoplanes xinjiangensis DSM 45184T and Actinoplanes italicus DSM 43146T were 80.3, 80.3, 84.1, 84.3 and 84.0â%, respectively. The levels of digital DNA-DNA hybridization between them were found to be 23.6â% (21.3-26.1â%), 23.8â% (21.5-26.3â%), 28.3â% (25.9-30.8â%), 28.6â% (26.0-30.9â%) and 28.4â% (26.2-31.1â%), respectively. Based on phenotypic, chemotaxonomic and genotypic data, strain NEAU-A12T is considered to represent a novel species of the genus Actinoplanes, for which the name Actinoplanes sandaracinus sp. nov. is proposed, with NEAU-A12T (=CCTCC AA 2020039T=DSM 112043T) as the type strain.
Assuntos
Actinoplanes , Celulose , Solo , RNA Ribossômico 16S/genética , Composição de Bases , Ácidos Graxos/química , Filogenia , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem BacterianaRESUMO
Two pink-pigmented bacteria, designated strains NEAU-140T and NEAU-KT, were isolated from field soil collected from Linyi, Shandong Province, PR China. Both isolates were aerobic, Gram-stain-negative, rod-shaped, and facultatively methylotrophic. 16S rRNA gene sequences analysis showed that these two strains belong to the genus Methylobacterium. Strain NEAU-140T exhibited high 16S rRNA gene sequence similarities to Methylobacterium radiotolerans NBRC 15690T (97.43â%) and Methylobacterium phyllostachyos NBRC 105206T (97.36â%). Strain NEAU-KT exhibited high 16S rRNA gene sequence similarities to M. phyllostachyos NBRC 105206T (99.00â%) and Methylobacterium longum DSM 23933T (98.72â%). A phylogenetic tree based on 16S rRNA gene sequences showed that strain NEAU-140T formed a clade with Methylobacterium aerolatum (95.94â%), Methylobacterium persicinum (95.66â%) and Methylobacterium komagatae (96.87â%), and strain NEAU-KT formed a cluster with M. phyllostachyos and M. longum. The predominant fatty acid in both strains was C18â:â1 ω7c. Both strains contained ubiquinone Q-10 as the only respiratory quinone. The polar lipid profiles of both strains contained diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine. Whole-genome phylogeny showed that strains NEAU-140T and NEAU-KT formed a phyletic line with M. aerolatum, M. persicinum, Methylobacterium radiotolerans, Methylobacterium fujisawaense, Methylobacterium oryzae, Methylobacterium tardum, M. longum and M. phyllostachyos. The orthologous average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain NEAU-140T and its closely related strains were lower than 82.62 and 25.90ââ%, respectively. The ANI and dDDH values between strain NEAU-KT and its closely related strains were lower than 86.29 and 31.7â%, respectively. The genomic DNA G+C contents were 71.63âmol% for strain NEAU-140T and 69.08âmol% for strain NEAU-KT. On the basis of their phenotypic and phylogenetic distinctiveness and the results of dDDH and ANI hybridization, these two isolates represent two novel species within the genus Methylobacterium, for which the names Methylobacterium amylolyticum sp. nov. (type strain NEAU-140T=MCCC 1K08801T=DSM 110568T) and Methylobacterium ligniniphilum sp. nov. (type strain NEAU-KT=MCCC 1K08800T=DSM 110567T) are proposed.
Assuntos
Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Ácidos Graxos , Methylobacterium , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , Microbiologia do Solo , RNA Ribossômico 16S/genética , Methylobacterium/genética , Methylobacterium/classificação , Methylobacterium/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/análise , China , Ubiquinona , Vitamina K 2/análogos & derivados , Vitamina K 2/análiseRESUMO
A novel actinobacterial strain (NEAU-HV9T) showing antibacterial activity against Ralstonia solanacearum and herbicidal activity against Amaranthus retroflexus L. was isolated from soil sampled in Bama yao Autonomous County, Hechi City, Guangxi Zhuang Autonomous Region. The strain is aerobic and Gram-positive. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain NEAU-HV9T belonged to the genus Streptomyces and showed high 16S rRNA sequence similarity to Streptomyces panaciradicis 1MR-8T (98.90â%), Streptomyces sasae JR-39T (98.89â%) and Streptomyces barringtoniae JA03T (98.69â%) and less than 98.5â% similarity to other members of the genus Streptomyces. The cell wall of strain NEAU-HV9T contained ll-diaminopimelic acid and the whole-cell hydrolysates were galactose, mannose and ribose. The predominant menaquinones were composed of MK-9(H2) and MK-9(H8). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. The major fatty acids were C16â:â0, iso-C16â:â0 and C17â:â1 ω8c. The genomic DNA G+C content of strain NEAU-HV9T was 70.6âmol%. Furthermore, the strain could be clearly distinguished from its closely related type strains by the combination of DNA-DNA hybridization results and some phenotypic characteristics. Meanwhile, strain NEAU-HV9T displayed herbicidal activity. Therefore, strain NEAU-HV9T represents a novel species within the genus Streptomyces, for which the name Streptomyces herbicida sp. nov. is proposed, with strain NEAU-HV9T (=CCTCC AA 2019088T=DSM 113364T) as the type strain.
Assuntos
Actinobacteria , Streptomyces , Ácidos Graxos/química , Fosfolipídeos/análise , Filogenia , Solo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , DNA Bacteriano/genética , Composição de Bases , Técnicas de Tipagem Bacteriana , China , Microbiologia do SoloRESUMO
Sugar transporters have significant contributions to regulate metabolic flux towards products and they are general potential targets for engineering of high-yield microbial cell factories. Streptomyces, well-known producers of natural product pharmaceuticals, contain an abundance of sugar transporters, while few of them are well characterized and applied. Here, we report a previously unidentified ATP-binding cassette (ABC) sugar transporter TP6568 found within a Streptomyces avermitilis transposon library, along with its key regulator GM006564. Subsequent in silico molecular docking and genetic experiments demonstrated that TP6568 possessed a broad substrate specificity. It could not only promote uptake of diverse monosaccharides and disaccharides, but also enhance the utilization of industrial carbon sources such as starch, sucrose, and dextrin. Constitutive overexpression of TP6568 resulted in decrease of residual total sugar by 36.16%, 39.04%, 38.40%, and 30.21% in engineered S. avermitilis S0, Streptomyces caniferus NEAU6, Streptomyces bingchenggensis BC-101-4, and Streptomyces roseosporus NRRL 11379 than their individual parent strain, respectively. Production of avermectin B1a, guvermectin, and milbemycin A3/A4 increased by 75.61%, 56.89%, and 41.13%, respectively. We then overexpressed TP6568 in combination with the regulator GM006564 in a high-yield strain S. avermitilis S45, and further fine-tuning of their overexpression levels boosted production of avermectin B1a by 50.97% to 7.02 g/L in the engineering strain. Our work demonstrates that TP6568 as a promising sugar transporter may have broad applications in construction of high-yield Streptomyces microbial cell factories for desirable natural product pharmaceuticals. KEY POINTS: ⢠TP6568 from Streptomyces avermitilis was identified as a sugar transporter ⢠TP6568 enhanced utilization of diverse industrially used sugars in Streptomyces ⢠TP6568 is a useful transporter to construct high-yield Streptomyces cell factories.
Assuntos
Produtos Biológicos , Streptomyces , Simulação de Acoplamento Molecular , Streptomyces/genética , Transportadores de Cassetes de Ligação de ATP/genética , Dissacarídeos , Preparações FarmacêuticasRESUMO
Soilborne diseases cause significant economic losses in agricultural production around the world. They are difficult to control because a host plant is invaded by multiple pathogens, and chemical control often does not work well. In this study, we isolated and identified an endophytic Streptomyces sp. NEAU-DD186 from moss, which showed broad-spectrum antifungal activity against 17 soilborne phytopathogenic fungi, with Bipolaris sorokiniana being the most prominent. The strain also exhibited strong antibacterial activity against soilborne phytopathogenic bacteria Ralstonia solanacearum. To evaluate its biocontrol potential, the strain was prepared into biofertilizer by solid-state fermentation. Response surface methodology was employed to optimize the fermentation conditions for maximizing spore production and revealed that the 1:1 ratio of vermicompost to wheat bran, a temperature of 28°C, and 50% water content with an inoculation amount of 15% represented the optimal parameters. Pot experiments showed that the application of biofertilizer with a spore concentration of 108 CFU/g soil could effectively suppress the occurrence of tomato bacterial wilt caused by R. solanacearum and wheat root rot caused by B. sorokiniana, and the biocontrol efficacy was 81.2 and 72.2%, respectively. Chemical analysis of strain NEAU-DD186 extracts using nuclear magnetic resonance spectrometry and mass analysis indicated that 25-O-malonylguanidylfungin A and 23-O-malonylguanidylfungin A were the main active constituents, which showed high activity against R. solanacearum (EC50 of 2.46 and 2.58 µg ml-1) and B. sorokiniana (EC50 of 3.92 and 3.95 µg ml-1). In conclusion, this study demonstrates that Streptomyces sp. NEAU-DD186 can be developed as biofertilizer to control soilborne diseases.
Assuntos
Doenças das Plantas , Streptomyces , Doenças das Plantas/prevenção & controle , Agricultura , Antibacterianos , AntifúngicosRESUMO
Gray mold, caused by Botrytis cinerea, is a prevalent postharvest disease of apple that limits their shelf life, resulting in significant economic losses. The use of antagonistic microorganisms has been shown to be an effective approach for managing postharvest diseases of fruit. In the present study, an endophytic yeast strain PGY-2 was isolated from apples and evaluated for its biocontrol efficacy against gray mold and its mechanisms of action. Results indicated that strain PGY-2, identified as Bullera alba, reduced the occurrence of gray mold on apples and significantly inhibited lesion development in pathogen-inoculated wounds. Gray mold control increased with the use of increasing concentrations of PGY-2, with the best disease control observed at 108 cells/mL. Notably, Bullera alba PGY-2 did not inhibit the growth of Botrytis cinerea in vitro indicating that the yeast antagonist did not produce antimicrobial compounds. The rapid colonization and stable population of PGY-2 in apple wounds at 4 °C and 25 °C confirmed its ability to compete with pathogens for nutrients and space. PGY-2 also had a strong ability to form a biofilm and enhanced the activity of multiple defense-related enzymes (POD, PPO, APX, SOD, PAL) in host tissues. Our study is the first time to report the use of Bullera alba PGY-2 as a biocontrol agent for postharvest diseases of apple and provide evidence that Bullera alba PGY-2 represents an endophytic antagonistic yeast with promising biocontrol potential and alternative to the use of synthetic, chemical fungicides for the control of postharvest gray mold in apples.
Assuntos
Antibiose , Botrytis , Endófitos , Frutas , Malus , Doenças das Plantas , Malus/microbiologia , Botrytis/crescimento & desenvolvimento , Botrytis/fisiologia , Botrytis/efeitos dos fármacos , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Endófitos/fisiologia , Endófitos/isolamento & purificação , Frutas/microbiologia , Leveduras/fisiologia , Leveduras/isolamento & purificação , Biofilmes/crescimento & desenvolvimentoRESUMO
Soybean (Glycine max L.) holds significant global importance and is extensively cultivated in Heilongjiang Province, China. Soybean can be infected by Fusarium species, causing root rot, seed decay, stem rot, and leaf blight. In 2021 to 2022, a field survey of soybean diseases was carried out in 11 regions of Heilongjiang Province, and 186 soybean leaves with leaf blight symptoms and 123 soybean roots with root rot symptoms were collected. Unexpectedly, a considerable number of Fusarium isolates were obtained not only from root samples but also from leaf samples. A total of 584 Fusarium isolates (416 from leaves and 168 from roots) were obtained and identified as 18 Fusarium species based on morphological features and multilocus phylogenetic analyses with tef1 and rpb2 sequences. Fusarium graminearum and Fusarium sp. 1 in FOSC were the dominant species within soybean leaf and root samples, respectively. Pathogenicity tests were conducted for all Fusarium isolates on both soybean leaves and roots. Results showed that F. graminearum, F. ipomoeae, F. citri, F. compactum, F. flagelliforme, F. acuminatum, and F. sporotrichioides were pathogenic to both soybean leaves and roots. F. solani, F. avenaceum, F. pentaseptatum, F. serpentinum, F. annulatum, and Fusarium sp. 1 in FOSC were pathogenic to soybean roots, not to leaves. To our knowledge, this is the first study to thoroughly investigate soybean-associated Fusarium populations in leaves and roots in Heilongjiang Province.
RESUMO
Alternaria species are fungal pathogens that can infect maize, causing leaf blight disease and significant economic losses. This study aimed to determine the baseline sensitivity to prochloraz of A. alternata isolates obtained from diseased maize leaves collected from Heilongjiang province by assessing the half-maximal effective concentration (EC50) values. The EC50 values of prochloraz ranged from 0.0550 µg/mL to 2.3258 µg/mL, with an average of 0.9995 ± 0.5192 µg/mL. At EC50 (1.2495 µg/mL) and 2EC50 (2.4990 µg/mL), prochloraz increased the number of mycelial offshoots, disrupted the cell membrane integrity of conidia and mycelia, and resulted in a reduced ergosterol content in the mycelia. Prochloraz significantly affected the mycelial cell membrane permeability and increased the malondialdehyde (MDA) content and superoxide dismutase (SOD) activity. No cross-resistance was detected between prochloraz and other fungicides. These data demonstrate that prochloraz is a promising fungicide for managing maize leaf blight caused by A. alternata and provide novel insights into understanding the mechanism of prochloraz toxicity against A. alternata isolates.
RESUMO
During our previous study, strain NEAU-J3T was classified as representing a novel genus 'Wangella' within the family Micromonosporaceae. Nevertheless, it is a great pity the name cannot be validated as the proposed genus name is illegitimate (Principle 2 of the ICNP). In this study, we describe Jidongwangia as a novel genus within the family Micromonosporaceae and a polyphasic approach was used to provide evidence to support the classification. The G+C content of the genomic DNA of the type strain is 71.6â%. Digital DNA-DNA hybridization and average nucleotide identity (ANI) values could be used to differentiate NEAU-J3T from its related type strains. The phenotypic, genetic and chemotaxonomic data also indicated that NEAU-J3T occupies a branch separated from those of known genera in the family Micromonosporaceae. Therefore, NEAU-J3T represents a novel species of a novel genus in the family Micromonosporaceae, for which the name Jidongwangia harbinensis gen. nov., sp. nov. is proposed. The type strain of Jidongwangia harbinensis is NEAU-J3T (= CGMCC 4.7039T = DSM 45747T).
Assuntos
Ácidos Graxos , Micromonosporaceae , Ácidos Graxos/química , DNA Bacteriano/genética , Composição de Bases , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Técnicas de Tipagem Bacteriana , ChinaRESUMO
Winter jujube originated from China and had an extremely high nutritional value. In 2021, symptomatic winter jujube fruits were collected from eight locations in Zhanhua District of Binzhou City, Shandong Province. In total, 108 fungal isolates were obtained and grouped into 11 species based on morphological characteristics and multilocus phylogenetic analysis, including Nothophoma quercina (43.52%), Fusarium lateritium (20.37%), Alternaria alternata (12.03%), F. proliferatum (7.41%), F. graminearum (4.63%), Botryosphaeria dothidea (3.70%), Fusarium sp. (2.78%), A. tenuissima (2.78%), Diaporthe eres (1.85%), Nigrospora oryzae (0.93%), and Cercospora nicotianae (0.93%). All fungal isolates obtained in this study showed aggressiveness on detached winter jujube fruits except N. oryzae and C. nicotianae isolates, of which F. proliferatum was the most virulent, while A. alternata isolates, which have been considered the major pathogen of winter jujube fruit rot, showed a relatively low-level virulence in this study. Furthermore, D. eres, F. graminearum, F. lateritium, and an unclassified Fusarium species were first reported as causal agents of winter jujube fruit rot. The typical symptoms of winter jujube fruit rot observed in this study could be distinguished into two types. N. quercina, A. alternata, A. tenuissima, Fusarium sp., D. nobilis, and F. lateritium isolates caused reddish brown to dark gray lesions on the peel, while B. dothidea, F. graminearum, and F. proliferatum isolates caused peel and pulp decay, resulting in red to reddish brown and water-soaked lesions. In addition, haplotype analysis of N. quercina isolates obtained in this study and validly published articles showed that there were 11 haplotypes worldwide; the isolates obtained in the current study were grouped into three haplotypes (Hap 1, Hap 2, and Hap 11), and two of them (Hap 2 and Hap 11) were confirmed as new haplotypes.
Assuntos
Frutas , Ziziphus , Virulência/genética , Filogenia , ChinaRESUMO
China is the largest strawberry producer and exporter worldwide and has been constantly challenged by fruit rot diseases in recent years. Symptoms of various diseases on strawberry fruits were observed in Huangqiyuan Base, an important strawberry-producing region in Shandong Province, and symptomatic samples were collected from January to April 2021 for follow-up studies. In the present study, 137 isolates were obtained and classified into nine species based on morphological characteristics and multilocus phylogenetic analysis (ITS, GAPDH, HIS3, RPB2, EF-1α, HSP60, G3PDH, and/or TUB2), namely, Botrytis cinerea, B. fabiopsis, Alternaria alternata, A. tenuissima, Fusarium proliferatum, F. graminearum, F. ipomoeae, F. incarnatum, and Colletotrichum siamense. Pathogenicity results suggested that all nine pathogenic species could induce fruits to exhibit symptoms similar to those naturally infected in fields. The symptoms around the inoculation points varied, including dense white mycelia caused by Botrytis spp., fading and depression caused by Fusarium spp., black-brown rot caused by Alternaria spp., and shrinkage and dehydration caused by Colletotrichum spp. Overall, B. cinerea was the dominant pathogen, accounting for 61.3% of the total isolates, and showed significantly higher virulence against strawberry fruits than other species. In addition, this is the first report to identify B. fabiopsis, A. alternata, A. tenuissima, F. proliferatum, F. graminearum, F. ipomoeae, and F. incarnatum as causal agents of strawberry fruit rot in Shandong Province, China.
Assuntos
Fragaria , Frutas , Virulência , Filogenia , ChinaRESUMO
Flowering is a crucial stage for plant reproductive success; therefore, the regulation of plant flowering has been widely researched. Although multiple well-defined endogenous and exogenous flowering regulators have been reported, new ones are constantly being discovered. Here, we confirm that a novel plant growth regulator guvermectin (GV) induces early flowering in Arabidopsis. Interestingly, our genetic experiments newly demonstrated that WRKY41 and its homolog WRKY53 were involved in GV-accelerated flowering as positive flowering regulators. Overexpression of WRKY41 or WRKY53 resulted in an early flowering phenotype compared to the wild type (WT). In contrast, the w41/w53 double mutants showed a delay in GV-accelerated flowering. Gene expression analysis showed that flowering regulatory genes SOC1 and LFY were upregulated in GV-treated WT, 35S:WRKY41, and 35S:WRKY53 plants, but both declined in w41/w53 mutants with or without GV treatment. Meanwhile, biochemical assays confirmed that SOC1 and LFY were both direct targets of WRKY41 and WRKY53. Furthermore, the early flowering phenotype of 35S:WRKY41 lines was abolished in the soc1 or lfy background. Together, our results suggest that GV plays a function in promoting flowering, which was co-mediated by WRKY41 and WRKY53 acting as new flowering regulators by directly activating the transcription of SOC1 and LFY in Arabidopsis.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , Flores , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/genética , Reguladores de Crescimento de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Two glycosylated naphthacemycins (naphthacemycins D1 and D2) were identified in Streptomyces sp. N12W1565. These two compounds not only showed antimicrobial potential against bacteria but also exhibited more aqueous solubility than naphthacemycins. Furthermore, the whole genome of Streptomyces sp. N12W1565 has been sequenced, the natY gene, located outside the biosynthetic gene cluster encoding a D-glucose glycosyltransferase, was identified to mediate glycosylation in the phenolic hydroxyl of the naphthacemycin core scaffold. Glycosyltransferase was elucidated in vitro by using a homologous enzyme, which showed potential as a biocatalyst.
Assuntos
Streptomyces , Antibacterianos/farmacologia , Glicosilação , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Família MultigênicaRESUMO
Streptomyces bingchenggensis is a promising producer of milbemycins (MILs), the macrolide pesticide used widely in agriculture. The relationship between different biosynthetic gene clusters (BGCs) and the MIL BGC remains unclear, which hinders the precise metabolic engineering of S. bingchenggensis for titer improvement. To address this issue, this study discovered the regulatory function of a previously unidentified regulator KelR on a type-II polyketide BGC, MIL BGC, and two other BGCs, and caused titer improvement. First, a type II polyketide synthase (PKS) gene cluster kel with a bidirectional effect on MIL biosynthesis was found using transcriptome analysis. A Streptomyces antibiotic regulatory protein (SARP) family regulator KelR from the kel cluster was then characterized as an activator of several BGCs including mil and kel clusters. Metabolic competition between mil and kel clusters at the late fermentation stage was confirmed. Finally, KelR and those BGCs were manipulated in S. bingchenggensis, which led to a 71.7% titer improvement of MIL A3/A4 to 4058.2 ± 71.0 mg/L. This study deciphered the regulatory function of a previously unidentified regulatory protein KelR on several BGCs including mil in S. bingchenggensis and provided an example of coordinating metabolic competition and coregulation for titer improvement of secondary metabolites.
Assuntos
Antibacterianos , Streptomyces , Macrolídeos/metabolismo , Família Multigênica , Streptomyces/genética , Streptomyces/metabolismo , Fatores de Transcrição/genéticaRESUMO
A Gram-positive, cellulose-degrading actinobacterium, designed strain NEAU-YM18T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) sampled in Langfang, Hebei Province, PR China. The novel strain was characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics confirmed that strain NEAU-YM18T belonged to the genus Catellatospora. Cells of strain NEAU-YM18T were observed to contain meso- and 3-hydroxy-diaminopimelic acids as diagnostic cell-wall amino acids. The acyl type of the cell-wall muramic acid was glycolyl. The whole-cell hydrolysates were xylose, glucose and ribose. The phospholipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were iso-C15â:â0, iso-C16â:â0, C18â:â1 ω9c and summed feature 5 (anteiso-C18â:â0/C18â:â2 ω6,9c). The menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The DNA G+C content was 71.1â%. The results of 16S rRNA gene sequence and phylogenetic analyses indicated that strain NEAU-YM18T was closely related to Catellatospora chokoriensis 2-25(1)T (98.4â% 16S rRNA gene sequence similarity), Catellatospora vulcania NEAU-JM1T (98.3%) and Catellatospora sichuanensis H14505T (98.3â%) and formed a branch with C. sichuanensis H14505T. Furthermore, the whole genome phylogeny of strain NEAU-YM18T showed that the strain formed an independent clade. The digital DNA-DNA hybridization results between NEAU-YM18T and C. chokoriensis 2-25(1)T, C. vulcania NEAU-JM1T and C. sichuanensis H14505T were 25.0, 24.7 and 24.7â%, respectively, and the whole-genome average nucleotide identity values between them were 81.5, 81.4 and 81.4â%, respectively. These genetic results and some phenotypic characteristics could distinguish strain NEAU-YM18T from its reference strains. In addition, genomic analysis confirmed that strain NEAU-YM18T had the potential to decompose cellulose and produce bioactive compounds. Therefore, strain NEAU-YM18T represents a novel species of the genus Catellatospora, for which the name Catellatospora tritici sp. nov. is proposed. The type strain is NEAU-YM18T (=CCTCC AA 2020040T=JCM 33977T).
Assuntos
Actinobacteria , Celulase , Técnicas de Tipagem Bacteriana , Composição de Bases , Celulase/genética , Celulase/metabolismo , Celulose/metabolismo , DNA Bacteriano/genética , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Rizosfera , Análise de Sequência de DNA , Solo , Microbiologia do Solo , Triticum/microbiologiaRESUMO
A novel cellulase-producing actinobacterium, designated strain NEAU-L178T, was isolated from soil sample collected from Qiqihaer, Heilongjiang Province, PR China. A polyphasic study was carried out to determine the taxonomic status of the strain. On the basis of 16S rRNA gene sequence analysis, strain NEAU-L178T should be classified into the genus Nonomuraea and is closely related to Nonomuraea cavernae SYSU K10005T (99.31â% 16S rRNA gene sequence similarity), Nonomuraea glycinis NEAU-BB2C19T (98.75â%), Nonomuraea guangzhouensis NEAU-ZJ3T (98.75â%) and 'Nonomuraea rhizosphaerae' NEAU-mq18T (98.34â%). The digital DNA-DNA hybridization values between them are 27.1, 26.1, 42.0 and 30.9â%, and the whole-genome average nucleotide identity values between them are 83.1, 82.3, 90.3 and 85.8â%, respectively. The whole-cell hydrolysates contained glucose, ribose, arabinose and madurose. The menaquinones were identified as MK-9(H0), MK-9(H4) and MK-9(H2). The major fatty acids were C16â:â0, iso-C17â:â0 and C17â:â0 10-methyl. The detected polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol and three unidentified phospholipids. The genomic DNA G+C content was 69.7âmol%. In addition, whole-genome analysis indicated that strain NEAU-L178T had the potential to degrade cellulose. Based on the phenotypic, genotypic, chemotaxonomic and phylogenetic data, strain NEAU-L178T can be differentiated from its close phylogenetic relatives and represents a novel species of the genus Nonomuraea, for which the name Nonomuraea aurantiaca sp. nov. is proposed. The type strain is NEAU-L178T (=JCM 34799T=CGMCC 4.7741T).
Assuntos
Actinomycetales , Celulase , Técnicas de Tipagem Bacteriana , Composição de Bases , Celulase/genética , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfatidiletanolaminas , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo , Microbiologia do SoloRESUMO
A novel lignin-degrading actinobacterium, designated NEAU-G5T, was isolated from pumpkin rhizosphere soil collected from field in Mudanjiang, Heilongjiang Province, northeast China, and characterized using polyphasic approach. The prior 16S rRNA gene sequence similarities and phylogenic analysis showed that strain NEAU-G5T exhibited close phylogenetic relatedness to Nocardia miyunensis NBRC 108239T (98.82â%), Nocardia nova NBRC 15556T (98.75â%), Nocardia jiangxiensis NBRC 101359T (98.68â%) and Nocardia macrotermitis RB20T (98.61â%). Morphological and chemotaxonomic characteristics indicated that strain NEAU-G5T could be assigned to the genus Nocardia. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, an unidentified phospholipid and an unidentified lipid. The predominant menaquinone was MK-8(H4, ω-cycl). The major fatty acids (>10â%) were identified as C16â:â0, C18â:â1 ω9c, 10-methyl C18â:â0 and C18â:â0. Mycolic acids were present. The genomic DNA G+C content of strain NEAU-G5T was 68âmol%. Moreover, based on digital DNA-DNA hybridization and average nucleotide identity values, strain NEAU-G5T could be differentiated from its reference strains. In addition, an azure B plate decolorization test and genomic analysis indicated that strain NEAU-G5T had the ability to degrade lignin. On the basis of polyphasic characteristics, strain NEAU-G5T represents a novel species of the genus Nocardia, with the name Nocardia albiluteola sp. nov. The type strain is NEAU-G5T (=CCTCC AA 2021018T=DSM 110547T).