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Alternation of soil bacterial and fungal communities by tomato-rice rotation in Hainan Island in Southeast of China.
Ma, X, Du, M, Liu, P, Tang, Y, Li, H, Yuan, Q, Ruan, Y, Meng, L, Zhang, J, Lin, M, et al
Archives of microbiology. 2021;(3):913-925
Abstract
Tomato-rice rotation is prevalent in subtropical and tropical regions in China. This practice enhances crop productivity and the disease suppression property of soils against soil-borne plant pathogens. To explore the variations and dynamics of bacterial and fungal communities, bulk soil samples were collected during two consecutive years under a rotation system between tomato and rice originated from the year of 2010 in Hainan Island, and 16S rDNA and ITS amplicons were sequenced by Illumina MiSeq. The results demonstrated that potentially beneficial bacterial phyla Acidobacteria, Chloroflexi and genus Paenibacillus, as well as the fungal genus Mortierella were significantly enriched, while the potentially pathogenic fungal genus Fusarium was significantly decreased during the crop rotation. Measurements of soil physicochemical properties indicated that the soil acidification was improved. Redundancy analysis (RDA) revealed the correlation of the microbial community with soil pH and identified soil total phosphorus (TP) level as the highest determinant factor for both bacterial and fungal communities. This work provides a preliminary description of changes of the bacterial and fungal communities related to tomato-rice rotation in China and offered experimental evidences for exploring the effects of this agricultural practice on soil ecology.
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2.
Arsenic speciation in the phloem exudates of rice and its role in arsenic accumulation in rice grains.
Ye, W, Zhang, J, Fan, T, Lu, H, Chen, H, Li, X, Hua, R
Ecotoxicology and environmental safety. 2017;:87-91
Abstract
Arsenic (As) speciation in the phloem sap of rice plants and its role in As accumulation in rice grains remain largely uncharacterized. In the present study, we tested As chemical species in the phloem exudates of rice treated with arsenate [As(V)], arsenite [As(III)], monomethylarsonic acid [MMA(V)], or dimethylarsinic acid [DMA(V)]. As(V) was the main species (58%) in the phloem exudates of As(V)-exposed rice, whereas As(III) predominated (69%) in As(III)-exposed rice. A large proportion of As(V) (41-45%) was observed in the phloem exudates when rice was treated with methylated As species. High concentrations of phytochelatins were detected in the phloem exudates when the As(V) treatment level was increased. The role of phloem transport was analyzed by applying a ±stem-girdling treatment to the rice plants, limiting phloem transport to the grain in rice pulsed with As(III), As(V), MMA(V), or DMA(V). The findings of the present study indicate that organic As is more mobile than inorganic As during phloem transport. Phloem transport accounted for 54% of As(III), 56% of As(V), 100% of MMA(V), and 89% of DMA(V) transport to the grain. The total As concentration and As(III) percentage in rice phloem and grain were significantly affected by increasing the phosphate concentration in the medium.
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3.
Paenibacillusoryzae sp. nov., isolated from rice roots.
Zhang, J, Ma, XT, Gao, JS, Zhao, JJ, Yin, HQ, Zhang, CW, Zhang, RJ, Zhang, XX
International journal of systematic and evolutionary microbiology. 2016;(12):5000-5004
Abstract
A novel endophytic bacterium, strain 1DrF-4T, isolated from rice roots, was characterized on the basis of its phenotypic characteristics and genotypic information. The novel strain was Gram-positive-staining, endospore-forming, facultatively anaerobic, motile and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 1DrF-4T formed a monophyletic clade within the genus Paenibacillus. The most phylogenetically related species was Paenibacillus pinesoli KACC 17472T, with which strain 1DrF-4T showed 16S rRNA gene sequence similarity of 95.2 %. 16S rRNA gene sequence similarities with type strains of other species of the genus Paenibacillus were less than 95 %. The predominant cellular fatty acids were anteiso-C15 : 0 (61.1 %) and C16 : 0 (11.1 %), which is one of the characteristic traits of the genus Paenibacillus. The quinone system contained exclusively menaquinone MK-7. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, glycolipid and an unknown phospholipid. The DNA G+C content was 50.16 mol%, which was within the range reported for species of the genus Paenibacillus. Characterization by genotypic, chemotaxonomic and phenotypic analysis indicated that strain 1DrF-4T (=ACCC 19927T=JCM 30486T) represents a novel species of the genus Paenibacillus, for which the name Paenibacillusoryzae sp. nov. is proposed.
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4.
Novosphingobium oryzae sp. nov., a potential plant-promoting endophytic bacterium isolated from rice roots.
Zhang, L, Gao, JS, Kim, SG, Zhang, CW, Jiang, JQ, Ma, XT, Zhang, J, Zhang, XX
International journal of systematic and evolutionary microbiology. 2016;(1):302-307
Abstract
A novel endophytic bacterium, strain ZYY112T, isolated from rice roots, was characterized by a polyphasic approach. In phylogenetic analyses based on 16S rRNA gene sequences, ZYY112T showed highest sequence similarity to Novosphingobium sediminicola HU1-AH51T (97.2 %) and less than 97 % similarity with respect to other Novosphingobium species with validly published names. The DNA G+C content of strain ZYY112T was 60.8 mol%. The level of DNA-DNA relatedness between strain ZYY112T and N. sediminicola DSM 27057T was 33.7 % (reciprocal 5.2 %), which supported the suggestion that ZYY112T represented a novel species of the genus Novosphingobium. Ubiquinone Q-10 was the unique respiratory quinone (100 %). The polar lipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, an unknown aminolipid and an unknown phospholipid. The major fatty acids of strain ZYY112T were summed feature 8 (consisting of C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (consisting of C16 : 1ω7c and/or C16 : 1ω6c), C14 : 0 2-OH and C16 : 0. The major polyamine of ZYY112T was spermidine, which is a characteristic trait of the genus Novosphingobium. Characterization by genotypic, chemotaxonomic and phenotypic analysis indicated that strain ZYY112T represents a novel species of the genus Novosphingobium, for which the name Novosphingobium oryzae sp. nov. is proposed. The type strain is ZYY112T ( = ACCC 06131T = JCM 30537T).
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5.
Bacillus oryzisoli sp. nov., isolated from rice rhizosphere.
Zhang, XX, Gao, JS, Zhang, L, Zhang, CW, Ma, XT, Zhang, J
International journal of systematic and evolutionary microbiology. 2016;(9):3432-3436
Abstract
The taxonomy of strain 1DS3-10T, a Gram-staining-positive, endospore-forming bacterium isolated from rice rhizosphere, was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that the novel strain was grouped with established members of the genus Bacillus and appeared to be closely related to the type strains Bacillus benzoevorans DSM 5391T (97.9 %), Bacillus circulans DSM 11T (97.7 %), Bacillus novalis JCM 21709T (97.3 %), Bacillus soli JCM 21710T (97.3 %), Bacillus oceanisediminis CGMCC 1.10115T (97.3 %) and BacillusnealsoniiFO-92T (97.1 %). The fatty acid profile of strain 1DS3-10T, which showed a predominance of iso-C15 : 0 and anteiso-C15 : 0, supported the allocation of the strain to the genus Bacillus. The predominant menaquinone was MK-7 (100 %). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and unknown aminolipids. Cell-wall peptidoglycan contained meso-diaminopimelic acid. DNA-DNA hybridization values between strain 1DS3-10T and the type strains of closely related species were 25-33 %, which supported that 1DS3-10T represented a novel species in the genus Bacillus. The results of some physiological and biochemical tests also allowed the phenotypic differentiation of strain 1DS3-10T from the most closely related recognized species. On the basis of the phylogenetic and phenotypic evidence, strain 1DS3-10T represents a novel species of the genus Bacillus, for which the name Bacillus oryzisoli sp. nov. is proposed. The type strain of the novel species is 1DS3-10T (=ACCC 19781T=DSM 29761T).