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1.
J Agric Food Chem ; 72(19): 10842-10852, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38708761

RESUMEN

Guvermectin, as a novel nucleoside-like biopesticide, could increase the rice yield excellently, but the potential environmental behaviors remain unclear, which pose potential health risks. Therefore, the uptake and biotransformation of guvermectin in three types of crops (rice, lettuce, and carrot) were first evaluated with a hydroponic system. Guvermectin could be rapidly absorbed and reached equilibrium in roots (12-36 h) and shoots (24-60 h) in three plants, and guvermectin was also vulnerable to dissipation in roots (t1/2 1.02-3.65 h) and shoots (t1/2 9.30-17.91 h). In addition, 8 phase I and 2 phase II metabolites, transformed from guvermectin degradation in vivo and in vitro exposure, were identified, and one was confirmed as psicofuranine, which had antibacterial and antitumor properties; other metabolites were nucleoside-like chemicals. Molecular simulation and quantitative polymerase chain reaction further demonstrated that guvermectin was metabolized by the catabolism pathway of an endogenous nucleotide. Guvermectin had similar metabolites in three plants, but the biotransformation ability had a strong species dependence. In addition, all the metabolites exhibit neglectable toxicities (bioconcentration factor <2000 L/kg b.w., LC50,rat > 5000 mg/kg b.w.) by prediction. The study provided valuable evidence for the application of guvermectin and a better understanding of the biological behavior of nucleoside-like pesticides.


Asunto(s)
Biotransformación , Daucus carota , Ivermectina , Lactuca , Oryza , Raíces de Plantas , Ivermectina/metabolismo , Ivermectina/análogos & derivados , Raíces de Plantas/metabolismo , Raíces de Plantas/química , Raíces de Plantas/crecimiento & desarrollo , Lactuca/metabolismo , Lactuca/química , Lactuca/crecimiento & desarrollo , Oryza/metabolismo , Oryza/crecimiento & desarrollo , Oryza/química , Daucus carota/metabolismo , Daucus carota/química , Productos Agrícolas/metabolismo , Productos Agrícolas/química , Productos Agrícolas/crecimiento & desarrollo
2.
J Agric Food Chem ; 72(15): 8365-8371, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38588402

RESUMEN

Plant growth regulators (PGRs) play an important role in alleviating the detrimental effects of biotic and abiotic stress and improving crop yield and quality. As a novel PGR from Streptomyces registered in 2021, guvermectin (GV) has the potential to improve plant yield and defense, making its application in agriculture a subject of interest. Here, we describe the discovery process, functional activities, agricultural applications, toxicity, environmental safety, and biosynthetic mechanism of GV. This Perspective provides a guide for the development of novel PGRs from microorganisms.


Asunto(s)
Adenosina/análogos & derivados , Reguladores del Crecimiento de las Plantas , Plantas , Reguladores del Crecimiento de las Plantas/farmacología , Estrés Fisiológico , Agricultura , Desarrollo de la Planta
3.
Artículo en Inglés | MEDLINE | ID: mdl-38619981

RESUMEN

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 (98.32 %) and Massilia putida 6 NM-7T (98.41 %). 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 C16 : 0, C16 : 1 ω7c, and C17 : 0 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 88.0 %, respectively, and the levels of digital DNA-DNA hybridization between them were found to be 58.5 % (54.9-62.0 %), 53.2 % (49.8-56.7 %), 31.9 % (28.6-35.5 %), and 57.7 % (54.1-61.2 %), respectively, which were lower than the accepted threshold values of 95-96 % and 70 %, respectively. The DNA G+C content of strain NEAU-G-C5T was 66.5 mol%. 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).


Asunto(s)
Ácidos Grasos , Fosfolípidos , Ácidos Grasos/química , Fosfolípidos/análisis , Suelo , Filogenia , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Análisis de Secuencia de ADN , Composición de Base , China , Técnicas de Tipificación Bacteriana , Indoles , Microbiología del Suelo
4.
Int J Biol Macromol ; 267(Pt 2): 131510, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38608989

RESUMEN

Bacterial diseases caused substantial yield losses worldwide, with the rise of antibiotic resistance, there is a critical need for alternative antibacterial compounds. Natural products (NPs) from microorganisms have emerged as promising candidates due to their potential as cost-effective and environmentally friendly bactericides. However, the precise mechanisms underlying the antibacterial activity of many NPs, including Guvermectin (GV), remain poorly understood. Here, we sought to explore how GV interacts with Guanosine 5'-monophosphate synthetase (GMPs), an enzyme crucial in bacterial guanine synthesis. We employed a combination of biochemical and genetic approaches, enzyme activity assays, site-directed mutagenesis, bio-layer interferometry, and molecular docking assays to assess GV's antibacterial activity and its mechanism targeting GMPs. The results showed that GV effectively inhibits GMPs, disrupting bacterial guanine synthesis. This was confirmed through drug-resistant assays and direct enzyme inhibition studies. Bio-layer interferometry assays demonstrated specific binding of GV to GMPs, with dependency on Xanthosine 5'-monophosphate. Site-directed mutagenesis identified key residues crucial for the GV-GMP interaction. This study elucidates the antibacterial mechanism of GV, highlighting its potential as a biocontrol agent in agriculture. These findings contribute to the development of novel antibacterial agents and underscore the importance of exploring natural products for agricultural disease management.


Asunto(s)
Adenosina/análogos & derivados , Antibacterianos , Ivermectina , Antibacterianos/farmacología , Antibacterianos/química , Ivermectina/farmacología , Ivermectina/análogos & derivados , Ivermectina/química , Simulación del Acoplamiento Molecular , Productos Biológicos/farmacología , Productos Biológicos/química , Pruebas de Sensibilidad Microbiana , Ligasas de Carbono-Nitrógeno/metabolismo , Ligasas de Carbono-Nitrógeno/química , Ligasas de Carbono-Nitrógeno/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/química , Mutagénesis Sitio-Dirigida
5.
Phytopathology ; 114(2): 340-347, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38349678

RESUMEN

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.


Asunto(s)
Enfermedades de las Plantas , Streptomyces , Enfermedades de las Plantas/prevención & control , Agricultura , Antibacterianos , Antifúngicos
6.
J Agric Food Chem ; 72(9): 4649-4657, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38383306

RESUMEN

Oomycetes are well-known phytopathogens that seriously threaten many important crops worldwide. In this study, the endophytic actinobacterium Streptomyces sp. NEAU-S7GS2 demonstrated significant antagonistic activity against Phytophthora and Pythium and showed a potent biocontrol effect on suppression of soybean phytophthora root rot and pepper phytophthora blight. Two compounds were subsequently isolated as the main active components by bioassay-guided fractionation and identified as lydicamycins A and B. These two compounds showed high antioomycete activity against Phytophthora and Pythium with EC50 values of 0.73-2.67 µg/mL, which are equal to or lower than those of commercialized drug metalaxyl. In vivo bioassay using detached leaves demonstrated that lydicamycin A had a better control efficiency against soybean phytophthora root rot than metalaxyl. Taken together, these results suggest that the biocontrol agent Streptomyces sp. NEAU-S7GS2 and lydicamycins have the potential to be developed as promising pesticides to control diseases caused by oomycetes.


Asunto(s)
Phytophthora , Pythium , Streptomyces , Glycine max , Productos Agrícolas , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología , Alcoholes Grasos , Pirrolidinonas
7.
Artículo en Inglés | MEDLINE | ID: mdl-38329394

RESUMEN

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' (98.97 % sequence similarity), Glycomycesalgeriensis (98.90 %), 'Glycomyces tritici' (98.83 %) and Glycomyces lechevalierae (98.76 %). 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 87.80 %, respectively. The digital DNA G+C content of the genomic DNA was 70.5 %. 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-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C15 : 0. 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.


Asunto(s)
Actinobacteria , Actinomycetales , Arena , Suelo , ARN Ribosómico 16S/genética , Composición de Base , Ácidos Grasos/química , Filogenia , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana
8.
Artículo en Inglés | MEDLINE | ID: mdl-38315525

RESUMEN

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 (98.90 %), Streptomyces sasae JR-39T (98.89 %) and Streptomyces barringtoniae JA03T (98.69 %) and less than 98.5 % 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 C16 : 0, iso-C16 : 0 and C17 : 1 ω8c. The genomic DNA G+C content of strain NEAU-HV9T was 70.6 mol%. 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.


Asunto(s)
Actinobacteria , Streptomyces , Ácidos Grasos/química , Fosfolípidos/análisis , Filogenia , Suelo , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Composición de Base , Técnicas de Tipificación Bacteriana , China , Microbiología del Suelo
9.
Artículo en Inglés | MEDLINE | ID: mdl-38180325

RESUMEN

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 (98.3 %) to Actinoplanes palleronii DSM 43940T, while showing less than 98.3 % 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 C15 : 0, C16 : 0, C16 : 1 ω7c and C17 : 0. Meanwhile, genomic analysis revealed a genome size of 10 192 524 bp and a DNA G+C content of 70.6 mol%, 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 84.0 %, respectively. The levels of digital DNA-DNA hybridization between them were found to be 23.6 % (21.3-26.1 %), 23.8 % (21.5-26.3 %), 28.3 % (25.9-30.8 %), 28.6 % (26.0-30.9 %) and 28.4 % (26.2-31.1 %), 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.


Asunto(s)
Actinoplanes , Celulosa , Suelo , ARN Ribosómico 16S/genética , Composición de Base , Ácidos Grasos/química , Filogenia , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana
10.
Appl Microbiol Biotechnol ; 108(1): 72, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38194147

RESUMEN

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.


Asunto(s)
Productos Biológicos , Streptomyces , Simulación del Acoplamiento Molecular , Streptomyces/genética , Transportadoras de Casetes de Unión a ATP/genética , Disacáridos , Preparaciones Farmacéuticas
11.
Plant Dis ; : PDIS08231476SC, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-37858971

RESUMEN

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.

12.
J Agric Food Chem ; 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37910789

RESUMEN

Streptomyces is an effective source of new natural bioherbicides. In this study, a novel isolated strain NEAU-HV44 showed strong inhibitory activity against Amaranthus retroflexus L. and was concluded to the genus Streptomyces. Strain NEAU-HV44 fermentation conditions were optimized to maximize the herbicidal activity. The supernatant of strain NEAU-HV44 could significantly control the growth of weeds (A. retroflexus L., Setaria viridis, Portulaca oleracea L., and Chenopodium album) and crops (maize, soybean, wheat, Chinese cabbage, cucumber, tomato, and romaine lettuce) with dose-dependent in preemergence. Notably, weeds were more sensitive to a low-concentration supernatant extract than crops in preemergence. In postemergence, the 2 mg mL-1 supernatant extract could significantly reduce the height and >50% biomass (fresh weight) of tested weeds. The supernatant extract could cause cell membrane destabilization and the cell death of weeds. In addition, the growth of tomato was also inhibited at a high concentration, but no obvious symptoms were observed on soybean and romaine lettuce after spraying the supernatant extract. Then two novel julichrome monomers, julichromes Q12 (1) and Q13 (2), and two known julichromes, julichrome Q3.3 (3) and julichrome Q3.5 (4), were isolated from the supernatant extract of strain NEAU-HV44 by bioactivity-guided approach. This is the first report of the herbicidal activity of julichromes. These four herbicidal compounds could inhibit the shoot and root growth of weeds at 0.2 mg mL-1, and compound 4 could completely inhibit the growth of P. oleracea L. Thus, julichromes (Q12, Q13, Q3.3, Q3.5 1-4) may be new bioherbicidal candidates.

13.
Chemosphere ; 343: 140232, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37734508

RESUMEN

Cr(VI) widely exists in the environment and has highly toxic, carcinogenic and mutagenic effects on all organisms. Physical/chemical methods to remove chromium pollution are economically expensive and have disadvantages like high reagent consumption, energy requirements and so on, while bioremediation is an eco-friendly, simple and cost-effective way. In this study, a novel Cr(VI)-reducing strain, Microbacterium sp. NEAU-W11, was reported, and its reduction mechanism was investigated. Microbacterium sp. NEAU-W11 could effectively degrade Cr(VI) under the conditions of pH 7-10, 15-35 °C, and the coexistence of metal pollutants such as Pb and Ni, etc. In addition, both Fe3+ and Cu2+ could improve the reducing ability of strain NEAU-W11, and glucose and lactose as electron donors also had promoting effect. Heat treatment of resting cells confirmed that chromium removal was not biological sorption but biological reduction. The active reductase of strain NEAU-W11 to chromium(VI) mainly existed in the cell cytoplasm, which is the first report in the genus Microbacterium. Micro-characterization of strain NEAU-W11 and the reduction products identified the reduction products as Cr(III)-ligand complexes bound to extracellular polymeric substances (EPS). Collectively, this study systematically investigated the degradation mechanism of Microbacterium sp. NEAU-W11 and the distribution of degradation product Cr(III), providing a new reduction mechanism for the genus Microbacterium, providing a new perspective for a comprehensive understanding of the degradation and transport of chromium by bacteria, and providing theoretical reference for the migration of metal ions in environmental governance.

14.
Sci Total Environ ; 903: 166113, 2023 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-37572911

RESUMEN

Guvermectin is a novel biopesticide often used as seed soaking to promote the rice yield. However, its biotoxicity and degradation behavior in soils were still not disclosed, which posed a knowledge gap to guide its rational application. Therefore, the degradation behaviors of guvermectin in four typical soils under aerobic and anaerobic conditions were investigated in the laboratory. The results showed that guvermectin was degraded fast with DT50 ranging from 0.95 to 10.10 d, and the degradation rate was higher in aerobic condition than that in anaerobic condition. Eight transformation products were screened using UPLC-QTOF/MS. The acute toxicities tests of guvermectin to Coturnix coturnix japonica and Apis mellifera were measured by biological laboratory experiments, and the acute and chronic toxicities of transformation products to Danio rerio, Daphnia magna Straus and Green algae were predicted by ECOSAR software. The results showed that guvermectin has low toxic to quail and honeybee (LD50 2000 mg a.i./kg body weight, LD50 Ëƒ 100 µg a.i./bee), and its transformation products were also low toxic class to Danio rerio, Daphnia magna Straus and Green algae (LC50/EC50 > 100 mg a.i./L). However, the nucleoside-like metabolites may pose a potential risk due to their similarity to genetic material, which should be concerned. The findings provided important environmental risk assessment data for the rational use of guvermectin.

15.
Plant Dis ; 107(12): 3773-3782, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37408124

RESUMEN

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.


Asunto(s)
Fragaria , Frutas , Virulencia , Filogenia , China
16.
Nat Commun ; 14(1): 3444, 2023 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-37301894

RESUMEN

The cone photoreceptors in our eyes selectively transduce the natural light into spiking representations, which endows the brain with high energy-efficiency color vision. However, the cone-like device with color-selectivity and spike-encoding capability remains challenging. Here, we propose a metal oxide-based vertically integrated spiking cone photoreceptor array, which can directly transduce persistent lights into spike trains at a certain rate according to the input wavelengths. Such spiking cone photoreceptors have an ultralow power consumption of less than 400 picowatts per spike in visible light, which is very close to biological cones. In this work, lights with three wavelengths were exploited as pseudo-three-primary colors to form 'colorful' images for recognition tasks, and the device with the ability to discriminate mixed colors shows better accuracy. Our results would enable hardware spiking neural networks with biologically plausible visual perception and provide great potential for the development of dynamic vision sensors.


Asunto(s)
Visión de Colores , Células Fotorreceptoras Retinianas Conos , Percepción de Color , Percepción Visual , Luz , Color
17.
J Agric Food Chem ; 71(19): 7348-7358, 2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37129443

RESUMEN

Rice direct seeding technology has been considered as a promising alternative to traditional transplanting because of its advantages in saving labor and water. However, the poor emergence and seedling growth caused by chill stress are the main bottlenecks in wide-scale adoption of direct-seeded rice in Heilongjiang Province, China. Here, we found that natural plant growth regulator guvermectin (GV) effectively improved rice seed germination and seedling growth under chilling stress. Results from 2 year field trials showed that seed-soaking with GV not only enhanced the emergence rate and seedling growth but also increased the panicle number per plant and grain number per panicle, resulting in 9.0 and 6.8% increase in the yield of direct-seeded rice, respectively. Integrative physiological, transcriptomic, and metabolomic assays revealed that GV promoted seed germination under chilling stress mainly by enhancing the activities of α-amylase and antioxidant enzymes (superoxide dismutase, peroxidase, and catalase), increasing the contents of soluble sugar and soluble protein, improving the biosynthesis of glutathione and flavonoids, as well as activating gibberellin-responsive transcription factors and inhibiting the abscisic acid signaling pathway. These findings indicate that seed-soaking with GV has good potential to improve seedling establishment and yield of direct-seeded rice even under chilling stress.


Asunto(s)
Germinación , Oryza , Oryza/genética , Transcriptoma , Semillas , Plantones/genética , Estrés Fisiológico
18.
Int J Mol Sci ; 24(9)2023 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-37176133

RESUMEN

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.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Unión al ADN/metabolismo , Flores , Regulación de la Expresión Génica de las Plantas , Proteínas de Dominio MADS/genética , Reguladores del Crecimiento de las Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
19.
Artículo en Inglés | MEDLINE | ID: mdl-36748694

RESUMEN

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 71.6 %. 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).


Asunto(s)
Ácidos Grasos , Micromonosporaceae , Ácidos Grasos/química , ADN Bacteriano/genética , Composición de Base , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Técnicas de Tipificación Bacteriana , China
20.
ACS Chem Biol ; 18(1): 102-111, 2023 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-36623177

RESUMEN

Guvermectin is a novel plant growth regulator that has been registered as a new agrochemical in China. It is an adenosine analogue with an unusual psicofuranose instead of ribose. Herein, the gene cluster responsible for guvermectin biosynthesis in Streptomyces caniferus NEAU6 is identified using gene interruption and heterologous expression experiments. A key intermediate psicofuranine 6'-phosphate (PMP) is chemically synthesized, and the functions of GvmB, C, D, and E are verified by individual stepwise enzyme reactions in vitro. The results also show that the biosynthesis of guvermectin is coupled with adenosine production by a single cluster. The higher catalytic efficiency of GvmB on PMP than AMP ensures the effective biosynthesis of guvermectin. Moreover, a phosphoribohydrolase GvmA is employed in the pathway that can hydrolyze AMP but not PMP and shows higher catalytic efficiency for the AMP hydrolysis than that of the AMP dephosphorylation by GvmB, leading to shunting of adenosine biosynthesis toward the production of guvermectin. Finally, the crystal structure of GvmE in complex with the product PMP has been solved. Glu160 at the C-terminal is identified as the acid/base for protonation/deprotonation of N7 of the adenine ring, demonstrating that GvmE is a noncanonical adenine phosphoribosyltransferase.


Asunto(s)
Adenina Fosforribosiltransferasa , Ácido Glutámico , Adenina Fosforribosiltransferasa/química , Adenosina , Adenosina Monofosfato/química , Modelos Moleculares
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