Plants overcome environmental stress by generating metabolic pathways.Thus,it is crucial to understand the physiological mechanisms of plant responses to changing environments.Ardisia crenata var.bicolor has an import...Plants overcome environmental stress by generating metabolic pathways.Thus,it is crucial to understand the physiological mechanisms of plant responses to changing environments.Ardisia crenata var.bicolor has an important ornamental and medicinal value.To reveal the impact of elevational gradient on the habitat soil and plant physiological attributes of this species,we collected root topsoil(0–20 cm)and subsoil(20–40 cm)samples and upper leaves at the initial blooming phase,in a survey of six elevations at 1,257 m,1,538 m,1,744 m,1,970 m,2,135 m,and 2,376 m,with 18 block plots,and 5sampling points at each site.Temperature decreases with an increase in elevation,and soil variables,and enzymatic activities fluctuated in both the topsoil and subsoil,with all of them increasing with elevation and decreasing with soil depth.Redundancy analysis was conducted to explore the correlation between the distribution of A.crenata var.bicolor along the elevational gradient and soil nutrients and enzyme activities,the soil properties were mainly affected by p H at low elevations,and governed by total phosphorus(TP)and available nitrogen(AN)at high elevations.The levels of chlorophyll,carbohydrates,and enzymatic activity except for anthocyanin in this species showed significant variation depending on physiological attributes evaluated at the different collection elevations.The decline in chlorophyll a and b may be associated with the adaptive response to avoid environmental stress,while its higher soluble sugar and protein contents play important roles in escaping adverse climatic conditions,and the increases in activities of antioxidant enzymes except peroxidase(POD)reflect this species’higher capacity for reactive oxygen scavenging(ROS)at high elevations.This study provides supporting evidence that elevation significantly affects the physiological attributes of A.crenata var.bicolor on Gaoligong Mountain,which is helpful for understanding plant adaptation strategies and the plasticity of plant physiological traits along the elevational gradients.展开更多
Objective:To elucidate the potential anti-inflammatory mechanisms of Rhamnus crenata leaf extracts using RAW264.7 cells.Methods:We used 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay to measure ce...Objective:To elucidate the potential anti-inflammatory mechanisms of Rhamnus crenata leaf extracts using RAW264.7 cells.Methods:We used 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay to measure cell viability.Nitric oxide(NO)production was measured using Griess reagent.Western blotting and RT-PCR assays were carried out for analyzing the protein and gene expressions of pro-inflammatory mediators,respectively.Moreover,PD98059(ERK1/2 inhibitor),SB203580(p38 inhibitor),SP600125(JNK inhibitor),and BAY11-7082(NF-κB inhibitor)were used to evaluate the anti-inflammatory mechanism of Rhamnus crenata leaf extract.Results:Rhamnus crenata leaf extracts significantly inhibited the production of the pro-inflammatory mediators such as NO,iNOS,COX-2,IL-1β,and TNF-αin lipopolysaccharide(LPS)-stimulated RAW264.7 cells.Rhamnus crenata leaf extracts also suppressed LPS-induced degradation of IκB-αand nuclear accumulation of p65,which resulted in the inhibition of NF-κB activation in RAW264.7 cells.Additionally,the extracts attenuated the phosphorylation of p38,ERK1/2,and JNK in LPS-stimulated RAW264.7 cells.Moreover,HO-1 expression induced by Rhamnus crenata leaf extracts was significantly downregulated by SB230580,PD98059,SP600125 and BAY11-7082.Conclusions:Rhamnus crenata leaf extract may upregulate HO-1 expression through inhibition of p38,ERK1/2,and NF-κB activation,which may contribute to the anti-inflammatory activity of the extracts.Rhamnus crenata leaf extracts may have great potential for the development of anti-inflammatory drugs to treat acute and chronic inflammatory diseases.展开更多
基金supported by the Doctoral Research Fund Project of Southwest Forestry University(CN)(Grant No.111806)。
文摘Plants overcome environmental stress by generating metabolic pathways.Thus,it is crucial to understand the physiological mechanisms of plant responses to changing environments.Ardisia crenata var.bicolor has an important ornamental and medicinal value.To reveal the impact of elevational gradient on the habitat soil and plant physiological attributes of this species,we collected root topsoil(0–20 cm)and subsoil(20–40 cm)samples and upper leaves at the initial blooming phase,in a survey of six elevations at 1,257 m,1,538 m,1,744 m,1,970 m,2,135 m,and 2,376 m,with 18 block plots,and 5sampling points at each site.Temperature decreases with an increase in elevation,and soil variables,and enzymatic activities fluctuated in both the topsoil and subsoil,with all of them increasing with elevation and decreasing with soil depth.Redundancy analysis was conducted to explore the correlation between the distribution of A.crenata var.bicolor along the elevational gradient and soil nutrients and enzyme activities,the soil properties were mainly affected by p H at low elevations,and governed by total phosphorus(TP)and available nitrogen(AN)at high elevations.The levels of chlorophyll,carbohydrates,and enzymatic activity except for anthocyanin in this species showed significant variation depending on physiological attributes evaluated at the different collection elevations.The decline in chlorophyll a and b may be associated with the adaptive response to avoid environmental stress,while its higher soluble sugar and protein contents play important roles in escaping adverse climatic conditions,and the increases in activities of antioxidant enzymes except peroxidase(POD)reflect this species’higher capacity for reactive oxygen scavenging(ROS)at high elevations.This study provides supporting evidence that elevation significantly affects the physiological attributes of A.crenata var.bicolor on Gaoligong Mountain,which is helpful for understanding plant adaptation strategies and the plasticity of plant physiological traits along the elevational gradients.
基金supported by the research project of the National Institute of Forest Science(project No.FP0400-2019-01-2022).
文摘Objective:To elucidate the potential anti-inflammatory mechanisms of Rhamnus crenata leaf extracts using RAW264.7 cells.Methods:We used 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay to measure cell viability.Nitric oxide(NO)production was measured using Griess reagent.Western blotting and RT-PCR assays were carried out for analyzing the protein and gene expressions of pro-inflammatory mediators,respectively.Moreover,PD98059(ERK1/2 inhibitor),SB203580(p38 inhibitor),SP600125(JNK inhibitor),and BAY11-7082(NF-κB inhibitor)were used to evaluate the anti-inflammatory mechanism of Rhamnus crenata leaf extract.Results:Rhamnus crenata leaf extracts significantly inhibited the production of the pro-inflammatory mediators such as NO,iNOS,COX-2,IL-1β,and TNF-αin lipopolysaccharide(LPS)-stimulated RAW264.7 cells.Rhamnus crenata leaf extracts also suppressed LPS-induced degradation of IκB-αand nuclear accumulation of p65,which resulted in the inhibition of NF-κB activation in RAW264.7 cells.Additionally,the extracts attenuated the phosphorylation of p38,ERK1/2,and JNK in LPS-stimulated RAW264.7 cells.Moreover,HO-1 expression induced by Rhamnus crenata leaf extracts was significantly downregulated by SB230580,PD98059,SP600125 and BAY11-7082.Conclusions:Rhamnus crenata leaf extract may upregulate HO-1 expression through inhibition of p38,ERK1/2,and NF-κB activation,which may contribute to the anti-inflammatory activity of the extracts.Rhamnus crenata leaf extracts may have great potential for the development of anti-inflammatory drugs to treat acute and chronic inflammatory diseases.
