scholarly journals Grazing intensity changed the activities of nitrogen assimilation related enzymes in desert Steppe Plants

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aimin Zhu ◽  
Haili Liu ◽  
Yuehua Wang ◽  
Hailian Sun ◽  
Guodong Han
Keyword(s):  
Nitrogen Assimilation ◽  
Net Primary Productivity ◽  
Assimilation Efficiency ◽  
Nitrate Content ◽  
Limiting Factor ◽  
Desert Steppe ◽  
Grassland Ecosystems ◽  
Heavy Grazing ◽  
Grassland Plants ◽  
Grazing Disturbance

Abstract Background Nitrogen, as a limiting factor for net primary productivity in grassland ecosystems, is an important link in material cycles in grassland ecosystems. However, the nitrogen assimilation efficiency and mechanisms of grassland plants under grazing disturbance are still unclear. This study investigated Stipa breviflora desert steppe which had been grazed for 17 years and sampled the root system and leaf of the constructive species Stipa breviflora during the peak growing season under no grazing, light grazing, moderate grazing and heavy grazing treatments. The activities of enzymes related to nitrogen assimilation in roots and leaves were measured. Results Compared with no grazing, light grazing and moderate grazing significantly increased the activities of nitrate reductase (NR), glutamine synthetase (GS), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) in leaves, and GS, GOT and GPT in roots of Stipa breviflora, while heavy grazing significantly decreased the activities of GS in leaves and NR in roots of Stipa breviflora. NR, GOT and GPT activities in leaves and roots of Stipa breviflora were positively correlated with nitrogen content, soluble protein, free amino acid and nitrate content. Conclusions Grazing disturbance changed the activities of nitrogen assimilation related enzymes of grassland plants, and emphasized that light grazing and moderate grazing were beneficial for nitrogen assimilation by grassland plants. Therefore, establishing appropriate stocking rates is of great significance for material flows in this grassland ecosystem and for the stability and sustainable utilization of grassland resources.

scholarly journals Grazing Intensity Changed The Activities of Nitrogen Assimilation Related Enzymes In Desert Steppe Plants

2021 ◽  
Author(s):  
Aimin Zhu ◽  
Guodong Han ◽  
Haili Liu ◽  
Yuehua Wang
Keyword(s):  
Nitrogen Content ◽  
Root System ◽  
Total Nitrogen ◽  
Nitrogen Assimilation ◽  
Rhizosphere Soil ◽  
Total Nitrogen Content ◽  
Desert Steppe ◽  
Related Factors ◽  
Heavy Grazing ◽  
Grassland Plants

Abstract Background: The study on nitrogen assimilation mechanism of grazing grassland plants is of great significance to reveal the law of nutrient absorption and utilization of grassland vegetation. Methods: This study took Stipa breviflora desert steppe which was grazed for 17 years as the research object, and sampled the root system, leaf and rhizosphere soil of constructive species Stipa breviflora under the treatments of no grazing, light grazing, moderate grazing and heavy grazing during the peak growing season. The activities of enzymes related to nitrogen assimilation in roots and leaves were measured, and the related factors affecting nitrogen content were analyzed. Results: The results showed that heavy grazing significantly increased the total nitrogen content in the root system of Stipa breviflora, but decreased the total nitrogen content in the leaves, and the performance of grazing prohibition was consistent with that of heavy grazing; The activities of Nitrate reductase (NR), glutamine synthetase (GS), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) were stronger under light or moderate grazing. Under grazing prohibition and heavy grazing, the content of proline in roots and leaves of Stipa breviflora increased significantly, especially in leaves; NR, GS, GOT and GPT were significantly correlated with total nitrogen content in roots and leaves of Stipa breviflora. Conclusions: Grazing prohibition and heavy grazing were not conducive to the nitrogen absorption and utilization of Stipa breviflora, which was closely related to the reduction of nitrate and ammonium nitrogen contents in the rhizosphere soil of Stipa breviflora by grazing. Grazing prohibition and heavy grazing affected the nitrogen content of Stipa breviflora by affecting the activities of related enzymes in the process of nitrogen assimilation of roots and leaves.

scholarly journals DIFFERENT NITRATE AND AMMONIUM LEVELS MEDIA ON CHANGES OF NITROGEN ASSIMILATION ENZYMES IN RICE

2021 ◽  
Vol 7 (1) ◽  
pp. 25-31
Author(s):  
Tri Handoyo ◽  
Laily Ilman Widuri ◽  
Didik Pudji Restanto
Keyword(s):  
Nitrogen Assimilation ◽  
Glutamate Synthase ◽  
Nitrogen Sources ◽  
Nitrate Content ◽  
Limiting Factor ◽  
Rice Plants ◽  
Glutamine Synthase ◽  
N Assimilation ◽  
Rice Yields ◽  
Different Sources

Nitrogen (N) is an important nutrient for the growth and development of rice plants, required in large quantity and often limiting factor of rice yields. The research was to understand the different sources and levels of nitrogen in rice plant on the activity of N assimilation enzymes, including nitrate reductase (NR), glutamine synthase (GS) content, glutamate synthase (Gogat) content, content, ammonium (NH4+) and nitrate (NO3-) content on the leaves. Paddy (Ciherang variety) was grown in sand media containing Hoagland solution with different sources (ammonium and nitrate) and levels (0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 mM) of nitrogen. Nitrogen assimilation was observed from leaves at one month of age. The NR activity increased on both Nitrogen sources, it was a higher activity in media contained nitrate. Also, the activity of GS showed higher in media contains nitrate, but its activity was decreased after application 1.6 mM of nitrate and 3.2 mM of ammonium. Western blot analysis of GS1 and GS2 showed that the band pattern of protein was similar to these enzyme activities. Nitrate content in leaves gradually increased in both sources of nitrogen and higher than 3.2 mM ammonium application caused an increase in ammonium content in leaves, but the nitrate content decreased. This research resulted that the available source of N for rice was in nitrate form, easily by the rice plants during the growth stage.

scholarly journals Biochar effect - mediated ammonium transporter genes and GDH may be the core of improvement nitrogen assimilation in cotton seedling

2020 ◽  
Author(s):  
Lei Feng ◽  
Guangmu Tang ◽  
Wanli Xu ◽  
Meiying Gu ◽  
Zengchao Geng
Keyword(s):  
Seedling Growth ◽  
Fine Roots ◽  
Nitrogen Assimilation ◽  
Surface Soil ◽  
Soil Layer ◽  
Assimilation Efficiency ◽  
Seedling Stage ◽  
Nitrogen Efficiency ◽  
Ammonium Transporter ◽  
Cotton Seedling

AbstractBiochar enhancement of nitrogen efficiency in crops is highly essential not only to reduce costs of agricultural production but also to conserve resources, lower energy consumption for products of these fertilizers, strengthen soil health, and eventually helps in slowing climate change; however nitrogen efficiency physiology by biochar effects is not clear. Here, we reported on the morphological, nitrogen metabolism and cytokinin, at seedling stage, under different layers of biochar and limited urea conditions grown in soil culture. Expression profile of miRNAs and AOB was further studied in fine and medium roots. It showed active root absorption area, fresh weight, and nitrogen agronomic efficiency responded significantly under biochar and reduction by 20% urea condition in the surface soil layer. Also, NR and GPT activity in fine roots remarkably increased with cytokinin, but decreased significantly in medium roots, meanwhile both NR and GDH activity did so. GOGAT activity was to be dependent with biochar and urea locations. In addition, AMT1;1, gdh3 and gdh2 in fine roots showed their up-regulation with reduction 20% urea and biochar. It revealed that co-expression of gdh3 and gdh2 in fine roots significantly affected nitrogen assimilation under reduction 20% urea with biochar on surface soil at seedling stage.HighlightsThe co-expression of ammonium transporter gene and GDH induced by biochar effect improves nitrogen efficiency and seedling growth.These data emphasizes the importance of effects of cytokinin on nitrate reductase activity closely related to the position under biochar condition, which is a key element of enhancement nitrogen assimilation efficiency in cotton seedling.Biochar addition applied into 0 to 10cm soil had a more positive effect on seedling growth than that into 10 to 20cm soil layers.

scholarly journals Net Primary Productivity Loss under different drought levels in different grassland ecosystems

2020 ◽  
Vol 274 ◽  
pp. 111144
Author(s):  
Tianjie Lei ◽  
Jie Feng ◽  
Juan Lv ◽  
Jiabao Wang ◽  
Hongquan Song ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Productivity Loss ◽  
Grassland Ecosystems

Microbial Dynamic Changes under Different Grazing Intensities in Growing Seasons of Desert Steppe

2013 ◽  
Vol 864-867 ◽  
pp. 2635-2638
Author(s):  
Jing He ◽  
Ting Ting Yang ◽  
Tao Shi ◽  
Guo Zheng Yao
Keyword(s):  
Soil Bacteria ◽  
Measured Data ◽  
Desert Steppe ◽  
Dynamic Changes ◽  
Soil Microbial ◽  
Growing Seasons ◽  
Grassland Ecosystems ◽  
Ground Survey ◽  
Grazing Intensities ◽  
Microbial Dynamic

Soil microbial plays a very important role in the grassland ecosystems, but measured data is very lack. In this paper, based on the ground survey data microbial dynamic changes in growing seasons of Desert steppe in 2012 was estimated. The main conclusions are as follows: soil bacteria number began to increase in May, reached to highest value in July and then began to decrease. Actinomycetes population increased first and then decreased. Fungus amount decreased in beginning and then increased. Grazing significantly affect the number of soil microbial, shown as soil microbial of very severe grazing fences are significantly lower than other fences.

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