Cry1Ac Transgenic Sugarcane Does Not Affect the Diversity of Microbial Communities and Has No Significant Effect on Enzyme Activities in Rhizosphere Soil within One Crop Season

Continuous cropping systems are the leading cause of decreased soil biological environments in terms of unstable microbial population and diversity index. Nonetheless, their responses to consecutive peanut monocropping cycles have not been thoroughly investigated. In this study, the structure and abundance of microbial communities were characterized using pyrosequencing-based approach in peanut monocropping cycles for three consecutive years. The results showed that continuous peanut cultivation led to a substantial decrease in soil microbial abundance and diversity from initial cropping cycle (T1) to later cropping cycle (T3). Peanut rhizosphere soil had Actinobacteria, Protobacteria, and Gemmatimonadetes as the major bacterial phyla. Ascomycota, Basidiomycota were the major fungal phylum, while Crenarchaeota and Euryarchaeota were the most dominant phyla of archaea. Several bacterial, fungal and archaeal taxa were significantly changed in abundance under continuous peanut cultivation. Bacterial orders, Actinomycetales, Rhodospirillales and Sphingomonadales showed decreasing trends from T1>T2>T3. While, pathogenic fungi Phoma was increased and beneficial fungal taxa Glomeraceae decreased under continuous monocropping. Moreover, Archaeal order Nitrososphaerales observed less abundant in first two cycles (T1&T2), however, it increased in third cycle (T3), whereas, Thermoplasmata exhibit decreased trends throughout consecutive monocropping. Taken together, we have shown the taxonomic profiles of peanut rhizosphere communities that were affected by continuous peanut monocropping. The results obtained from this study pave ways towards a better understanding of the peanut rhizosphere soil microbial communities in response to continuous cropping cycles, which could be used as bioindicator to monitor soil quality, plant health and land management practices.

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Responses of soil microbial communities and enzyme activities to nitrogen and phosphorus additions in Chinese fir plantations of subtropical China

Biogeosciences Discussions ◽

10.5194/bgd-12-10359-2015 ◽

2015 ◽

Vol 12 (13) ◽

pp. 10359-10387 ◽

Cited By ~ 4

Author(s):

W. Y. Dong ◽

X. Y. Zhang ◽

X. Y. Liu ◽

X. L. Fu ◽

F. S. Chen ◽

...

Keyword(s):

Microbial Community ◽

Microbial Communities ◽

Enzyme Activities ◽

Microbial Community Composition ◽

Soil Microbial Communities ◽

Chinese Fir ◽

Subtropical China ◽

Nitrogen And Phosphorus ◽

Soil Microbial ◽

Nutrient Additions

Abstract. Nitrogen (N) and phosphorus (P) additions to forest ecosystems are known to influence various above-ground properties, such as plant productivity and composition, and below-ground properties, such as soil nutrient cycling. However, our understanding of how soil microbial communities and their functions respond to nutrient additions in subtropical plantations is still not complete. In this study, we added N and P to Chinese fir plantations in subtropical China to examine how nutrient additions influenced soil microbial community composition and enzyme activities. The results showed that most soil microbial properties were responsive to N and/or P additions, but responses often varied depending on the nutrient added and the quantity added. For instance, there were more than 30 % greater increases in the activities of β-Glucosidase (βG) and N-acetyl-β-D-glucosaminidase (NAG) in the treatments that received nutrient additions compared to the control plot, whereas acid phosphatase (aP) activity was always higher (57 and 71 %, respectively) in the P treatment. N and P additions greatly enhanced the PLFA abundanceespecially in the N2P treatment, the bacterial PLFAs (bacPLFAs), fungal PLFAs (funPLFAs) and actinomycic PLFAs (actPLFAs) were about 2.5, 3 and 4 times higher, respectively, than in the CK. Soil enzyme activities were noticeably higher in November than in July, mainly due to seasonal differences in soil moisture content (SMC). βG or NAG activities were significantly and positively correlated with microbial PLFAs. There were also significant relationships between gram-positive (G+) bacteria and all three soil enzymes. These findings indicate that G+ bacteria is the most important microbial community in C, N, and P transformations in Chinese fir plantations, and that βG and NAG would be useful tools for assessing the biogeochemical transformation and metabolic activity of soil microbes. We recommend combined additions of N and P fertilizer to promote soil fertility and microbial activity in this kind of plantation.

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Effects of continuous cropping of Pinellia ternata (Thunb.) Breit. on soil physicochemical properties, enzyme activities, microbial communities and functional genes

Chemical and Biological Technologies in Agriculture ◽

10.1186/s40538-021-00243-6 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Yuan Zhao ◽

Xiao–Meng Qin ◽

Xue–Ping Tian ◽

Tao Yang ◽

Rong Deng ◽

...

Keyword(s):

Microbial Community ◽

Physicochemical Properties ◽

Soil Fertility ◽

Phenolic Acids ◽

Relative Abundance ◽

Enzyme Activities ◽

Rhizosphere Soil ◽

Functional Genes ◽

Continuous Cropping ◽

Pinellia Ternata

Abstract Background Pinellia ternata (Thunb.) Breit. is a commonly used herb in traditional Chinese medicine, and the main raw material of various Chinese patent medicines. Continuous cropping obstacle (CCO) is the main factor leading to the decline of crop yields and quality. Methods Metagenomics sequencing technology was used to analyze the microbial community and functional genes of continuous cropping (CC) and control (CK) soils of P. ternata. In addition, differences in physicochemical properties, enzyme activities, microbial community composition and the abundance of functional genes in CC and CK were evaluated, as well as the relationship between these factors and CCO. Results Results indicated that CC of P. ternata led to the decline of rhizosphere soil pH, nutrient imbalance and enzyme activity reduction. Metagenomic analysis indicted that CC also changed the composition of the microbial community, causing an increase in the relative abundance of pathogenic microorganisms such as Fusarium, Klebsiella oxytoca and Pectobacterium carotovorum in the P. ternata rhizosphere. The relative abundance of potentially beneficial Burkholderia and Bradyrhizobium was recorded to decrease. Results also showed that there were considerable differences in CC and CK about the abundances of functional genes related to soil enzymes and the degradation of P. ternata allelochemicals, as well as the microbial groups which they belong. These results clarified the effects of CC on the microbial community structure and functional genes of soil. In addition, Burkholderia and Bradyrhizobium might play important roles in enhancing soil fertility and reducing the toxicity of phenolic acids in rhizosphere soil. Conclusions CC of P. ternata changed the physicochemical properties, microbial community and functional genes of rhizosphere soil. Burkholderia and Bradyrhizobium for enhancing soil fertility and reducing the toxicity of phenolic acids might be potentially beneficial. These results provide theoretical guidance for bioremediation of CCO soil of P. ternata and other staple crops. Graphic abstract

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Patterns of extracellular enzyme activities among pelagic marine microbial communities: implications for cycling of dissolved organic carbon

Aquatic Microbial Ecology ◽

10.3354/ame038135 ◽

2005 ◽

Vol 38 ◽

pp. 135-145 ◽

Cited By ~ 55

Author(s):

C Arnosti ◽

S Durkin ◽

WH Jeffrey

Keyword(s):

Organic Carbon ◽

Dissolved Organic Carbon ◽

Microbial Communities ◽

Enzyme Activities ◽

Extracellular Enzyme ◽

Extracellular Enzyme Activities ◽

Marine Microbial Communities

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Extracellular Enzyme Activity and Microbial Diversity Measured on Seafloor Exposed Basalts from Loihi Seamount Indicate the Importance of Basalts to Global Biogeochemical Cycling

Applied and Environmental Microbiology ◽

10.1128/aem.01038-14 ◽

2014 ◽

Vol 80 (16) ◽

pp. 4854-4864 ◽

Cited By ~ 18

Author(s):

Myrna E. Jacobson Meyers ◽

Jason B. Sylvan ◽

Katrina J. Edwards

Keyword(s):

Enzyme Activity ◽

Microbial Communities ◽

Enzyme Activities ◽

Leucine Aminopeptidase ◽

Extracellular Enzyme ◽

Basaltic Rock ◽

Rrna Gene ◽

Content Type ◽

Shelf Sediments ◽

Potential Enzyme Activity

ABSTRACTSeafloor basalts are widely distributed and host diverse prokaryotic communities, but no data exist concerning the metabolic rates of the resident microbial communities. We present here potential extracellular enzyme activities of leucine aminopeptidase (LAP) and alkaline phosphatase (AP) measured on basalt samples from different locations on Loihi Seamount, HI, coupled with analysis of prokaryotic biomass and pyrosequencing of the bacterial 16S rRNA gene. The community maximum potential enzyme activity (Vmax) of LAP ranged from 0.47 to 0.90 nmol (g rock)−1h−1; theVmaxfor AP was 28 to 60 nmol (g rock)−1h−1. TheKmof LAP ranged from 26 to 33 μM, while theKmfor AP was 2 to 7 μM. Bacterial communities on Loihi basalts were comprised primarily ofAlpha-,Delta-, andGammaproteobacteria,Bacteroidetes, andPlanctomycetes. The putative ability to produce LAP is evenly distributed across the most commonly detected bacterial orders, but the ability to produce AP is likely dominated by bacteria in the ordersXanthomonadales,Flavobacteriales, andPlanctomycetales. The enzyme activities on Loihi basalts were compared to those of other marine environments that have been studied and were found to be similar in magnitude to those from continental shelf sediments and orders of magnitude higher than any measured in the water column, demonstrating that the potential for exposed basalts to transform organic matter is substantial. We propose that microbial communities on basaltic rock play a significant, quantifiable role in benthic biogeochemical processes.

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