Effect of dibutyl phthalate on microbial function diversity and enzyme activity in wheat rhizosphere and non-rhizosphere soils

2020 ◽  
Vol 265 ◽  
pp. 114800
Author(s):  
Minling Gao ◽  
Youming Dong ◽  
Ze Zhang ◽  
Zhengguo Song
Keyword(s):  
Enzyme Activity ◽  
Dibutyl Phthalate ◽  
Rhizosphere Soils ◽  
Microbial Function ◽  
Wheat Rhizosphere

scholarly journals Stoichiometry constrains microbial response to root exudation – insights from a model and a field experiment in a temperate forest

2012 ◽  
Vol 9 (6) ◽  
pp. 6899-6945 ◽  
Author(s):  
J. E. Drake ◽  
B. A. Darby ◽  
M.-A. Giasson ◽  
M. A. Kramer ◽  
R. P. Phillips ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Microbial Biomass ◽  
Field Experiment ◽  
Microbial Activity ◽  
Microbial Respiration ◽  
Root Exudation ◽  
Rhizosphere Soils ◽  
Microbial Response ◽  
Wide Range ◽  
C And N

Abstract. Healthy plant roots release a wide range of chemicals into soils. This process, termed root exudation, is thought to increase the activity of microbes and the exo-enzymes they synthesize, leading to accelerated rates of carbon (C) mineralization and nutrient cycling in rhizosphere soils relative to bulk soils. The causal role of exudation, however, is difficult to isolate with in-situ observations, given the complex nature of the rhizosphere environment. We investigated the potential effects of root exudation on microbial and exo-enzyme activity using a theoretical model of decomposition and a field experiment, with a specific focus on the stoichiometric constraint of nitrogen (N) availability. The field experiment isolated the effect of exudation by pumping solutions of exudate mimics through microlysimeter "root simulators" into intact forest soils over two 50-day periods. Using a combined model-experiment approach, we tested two hypotheses: (1) exudation alone is sufficient to stimulate microbial and exo-enzyme activity in rhizosphere soils, and (2) microbial response to C-exudates (carbohydrates and organic acids) is constrained by N-limitation. Experimental delivery of exudate mimics containing C and N significantly increased microbial respiration, microbial biomass, and the activity of exo-enzymes that decompose labile components of soil organic matter (SOM, e.g., cellulose, amino sugars), while decreasing the activity of exo-enzymes that degrade recalcitrant SOM (e.g., polyphenols, lignin). However, delivery of C-only exudates had no effect on microbial biomass or overall exo-enzyme activity, and only increased microbial respiration. The theoretical decomposition model produced complementary results; the modeled microbial response to C-only exudates was constrained by limited N supply to support the synthesis of N-rich microbial biomass and exo-enzymes, while exuding C and N together elicited an increase in modeled microbial biomass, exo-enzyme activity, and decomposition. Thus, hypothesis (2) was supported, while hypothesis (1) was only supported when C and N compounds were exuded together. This study supports a cause-and-effect relationship between root exudation and enhanced microbial activity, and suggests that exudate stoichiometry is an important and underappreciated driver of microbial activity in rhizosphere soils.

Bacterial diversity and soil enzyme activity in diseased and disease free apple rhizosphere soils

2011 ◽  
Vol 61 (4) ◽  
pp. 765-772 ◽  
Author(s):  
Veerubommu Shanmugam ◽  
Rajni Verma ◽  
Subramani Rajkumar ◽  
Digvijay Singh Naruka
Keyword(s):  
Enzyme Activity ◽  
Bacterial Diversity ◽  
Soil Enzyme ◽  
Soil Enzyme Activity ◽  
Rhizosphere Soils ◽  
Disease Free

scholarly journals Intercropping Vicia sativa L. Improves the Moisture, Microbial Community, Enzyme Activity and Nutrient in Rhizosphere Soils of Young Kiwifruit Plants and Enhances Plant Growth

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 335
Author(s):  
Qiuping Wang ◽  
Cheng Zhang ◽  
Jiaohong Li ◽  
Xiaomao Wu ◽  
Youhua Long ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Microbial Community ◽  
Plant Growth ◽  
Chlorophyll Content ◽  
Plant Height ◽  
Leaf Length ◽  
Leaf Number ◽  
Leaf Width ◽  
Vicia Sativa ◽  
Rhizosphere Soils

Drought, low nutrition, and weeds have become the major limiting factors of young kiwifruit orchards. In this study, the effects of intercropping Vicia sativa L. on the moisture, microbe community, enzyme activity, and nutrients in rhizosphere soils of young kiwifruit plants and their growth were investigated. The results show that intercropping V. sativa could effectively enhance soil moisture by 1.39–1.47 folds compared with clean tillage. Moreover, intercropping V. sativa could significantly (p < 0.01) increase the microbial community, enzyme activity and nutrient of kiwifruit rhizosphere soils, and improve plant height, stem girth, leaf number, maximum leaf length, maximum leaf width, and chlorophyll content of young kiwifruit plants by 43.60%, 18.68%, 43.75%, 18.09%, 21.15%, and 67.57% compared to clean tillage, respectively. The moisture, microbial quantity, enzyme activity, and nutrients in rhizosphere soils of young kiwifruit plants exhibited good correlations with their plant height, stem girth, leaf number, maximum leaf length, maximum leaf width, and chlorophyll content. This study highlights that intercropping V. sativa in young kiwifruit orchard can be used as an effective, labor-saving, economical and sustainable practice to improve the moisture, microbial community, enzyme activity, and nutrient of soils, and enhance kiwifruit plant growth and control weeds.

Morphological and biochemical analyses of changes in rat hepatocytes related to wine and ethanol consumption

1984 ◽  
Vol 42 ◽  
pp. 232-233
Author(s):  
S.M. Geyer ◽  
C.L. Mendenhall ◽  
J.T. Hung ◽  
E.L. Cardell ◽  
R.L. Drake ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Enzyme Activity ◽  
Malic Enzyme ◽  
Smooth Endoplasmic Reticulum ◽  
Rat Hepatocytes ◽  
Mature Male ◽  
Treatment Groups ◽  
Malic Enzyme Activity ◽  
Biochemical Analyses

Thirty-three mature male Holtzman rats were randomly placed in 3 treatment groups: Controls (C); Ethanolics (E); and Wine drinkers (W). The animals were fed synthetic diets (Lieber type) with ethanol or wine substituted isocalorically for carbohydrates in the diet of E and W groups, respectively. W received a volume of wine which provided the same gram quantity of alcohol consumed by E. The animals were sacrificed by decapitation after 6 weeks and the livers processed for quantitative triglycerides (T3), proteins, malic enzyme activity (MEA), light microscopy (LM) and electron microscopy (EM). Morphometric analysis of randomly selected LM and EM micrographs was performed to determine organellar changes in centrilobular (CV) and periportal (PV) regions of the liver. This analysis (Table 1) showed that hepatocytes from E were larger than those in C and W groups. Smooth endoplasmic reticulum decreased in E and increased in W compared to C values.

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