To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,lig...To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant component.The results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress levels.Phosphorous utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe drought.Growth was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each component.Changes in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that P.yunnanensis seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization efficiencies.Overall,these results suggest that the physiological activities of all organs of P.yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs.Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P.yunnanensis seedlings.展开更多
Traumatic brain injury is a severe health problem leading to autophagy and apoptosis in the brain.3,6-Dibromo-beta-fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine(P7C3-A20)can be neuroprotective in various disea...Traumatic brain injury is a severe health problem leading to autophagy and apoptosis in the brain.3,6-Dibromo-beta-fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine(P7C3-A20)can be neuroprotective in various diseases,including ischemic stroke and neurodegenerative diseases.However,whether P7C3-A20 has a therapeutic effect on traumatic brain injury and its possible molecular mechanisms are unclear.Therefore,in the present study,we investigated the therapeutic effects of P7C3-A20 on traumatic brain injury and explored the putative underlying molecular mechanisms.We established a traumatic brain injury rat model using a modified weight drop method.P7C3-A20 or vehicle was injected intraperitoneally after traumatic brain injury.Severe neurological deficits were found in rats after traumatic brain injury,with deterioration in balance,walking function,and learning memory.Furthermore,hematoxylin and eosin staining showed significant neuronal cell damage,while terminal deoxynucleotidyl transferase mediated dUTP nick end labeling staining indicated a high rate of apoptosis.The presence of autolysosomes was observed using transmission electron microscope.P7C3-A20 treatment reversed these pathological features.Western blotting showed that P7C3-A20 treatment reduced microtubule-associated protein 1 light chain 3-Ⅱ(LC3-Ⅱ)autophagy protein,apoptosis-related proteins(namely,Bcl-2/adenovirus E1B 19-kDa-interacting protein 3[BNIP3],and Bcl-2 associated x protein[Bax]),and elevated ubiquitin-binding protein p62(p62)autophagy protein expression.Thus,P7C3-A20 can treat traumatic brain injury in rats by inhibiting excessive autophagy and apoptosis.展开更多
Background:Nitrogen(N)deposition affects forest stoichiometric flexibility through changing soil nutrient availability to influence plant uptake.However,the effect of N deposition on the flexibility of carbon(C),N,and...Background:Nitrogen(N)deposition affects forest stoichiometric flexibility through changing soil nutrient availability to influence plant uptake.However,the effect of N deposition on the flexibility of carbon(C),N,and phosphorus(P)in forest plant-soil-microbe systems remains unclear.Methods:We conducted a meta-analysis based on 751 pairs of observations to evaluate the responses of plant,soil and microbial biomass C,N and P nutrients and stoichiometry to N addition in different N intensity(050,50–100,>100 kg·ha^(-1)·year^(-1)of N),duration(0–5,>5 year),method(understory,canopy),and matter(ammonium N,nitrate N,organic N,mixed N).Results:N addition significantly increased plant N:P(leaf:14.98%,root:13.29%),plant C:P(leaf:6.8%,root:25.44%),soil N:P(13.94%),soil C:P(10.86%),microbial biomass N:P(23.58%),microbial biomass C:P(12.62%),but reduced plant C:N(leaf:6.49%,root:9.02%).Furthermore,plant C:N:P stoichiometry changed significantly under short-term N inputs,while soil and microorganisms changed drastically under high N addition.Canopy N addition primarily affected plant C:N:P stoichiometry through altering plant N content,while understory N inputs altered more by influencing soil C and P content.Organic N significantly influenced plant and soil C:N and C:P,while ammonia N changed plant N:P.Plant C:P and soil C:N were strongly correlated with mean annual precipitation(MAT),and the C:N:P stoichiometric flexibility in soil and plant under N addition connected with soil depth.Besides,N addition decoupled the correlations between soil microorganisms and the plant.Conclusions:N addition significantly increased the C:P and N:P in soil,plant,and microbial biomass,reducing plant C:N,and aggravated forest P limitations.Significantly,these impacts were contingent on climate types,soil layers,and N input forms.The findings enhance our comprehension of the plant-soil system nutrient cycling mechanisms in forest ecosystems and plant strategy responses to N deposition.展开更多
Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutr...Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutrients vary with tree size,organ age,or root order at the individual level remains limited.We determined C,N,and P contents and their stoichiometric ratios(i.e.,nutrient traits)in needles,branches,and fine roots at different organ ages(0-3-year-old needles and branches)and root orders(1st-4th order roots)from 64 Pinus koraiensis of varying size(Diameter at breast height ranged from 0.3 to 100 cm)in northeast China.Soil factors were also measured.The results show that nutrient traits were regulated by tree size,organ age,or root order rather than soil factors.At a whole-plant level,nutrient traits decreased in needles and fine roots but increased in branches with tree size.At the organ level,age or root order had a negative effect on C,N,and P and a positive effect on stoichiometric ratios.Our results demonstrate that nutrient variations are closely related to organ-specific functions and ecophysiological processes at an individual level.It is suggested that the nutrient acquisition strategy by younger trees and organ fractions with higher nutrient content is for survival.Conversely,nutrient storage strategy in older trees and organ fractions are mainly for steady growth.Our results clarified the nutrient utilization strategies during tree and organ ontogeny and suggest that tree size and organ age or root order should be simultaneously considered to understand the complexities of nutrient variations.展开更多
背景:目前已有针对miRNA/mRNA轴调节骨关节炎疾病进程的分子机制研究。先前生物信息学研究发现具有临床预测价值的mRNA(磷脂酶Cδ3:phospholipase C delta 3,PLCD3)及其靶向miRNA(miR-34a-5p),尚缺实验验证其调控骨关节炎的具体作用及...背景:目前已有针对miRNA/mRNA轴调节骨关节炎疾病进程的分子机制研究。先前生物信息学研究发现具有临床预测价值的mRNA(磷脂酶Cδ3:phospholipase C delta 3,PLCD3)及其靶向miRNA(miR-34a-5p),尚缺实验验证其调控骨关节炎的具体作用及机制。目的:探讨miR-34a-5p/PLCD3轴对骨关节炎进展的调控作用及机制。方法:选择15例膝骨关节炎患者的滑膜为骨关节炎组,同时选择同期因创伤致髌骨骨折行内固定术的15例年轻患者的健康滑膜为对照组,Real-time PCR法检测滑膜中PLCD3及miR-34a-5p的表达。通过细胞转染的方法,将人滑膜关节炎成纤维细胞(human fibroblast like synovial cells-osteoarthritis,HFLS-OA)进行处理,并分为miR-34a-5p模拟物组、pCDH-PLCD3组、miR-34a-5p模拟物+pCDH-PLCD3组、miR-34a-5p抑制剂组、si-PLCD3组、miR-34a-5p抑制剂+si-PLCD3组,通过Real-time PCR法检测PLCD3和miR-34a-5p表达的关系;通过CCK-8法、细胞划痕实验检测各组HFLS-OA细胞活力及细胞迁移的影响;使用Western Blot法检测凋亡标记蛋白表达水平;使用ELISA法检测炎症因子的表达。结果与结论:①PLCD3是miR-34a-5p的直接靶标,同时PLCD3和miR-34a-5p表达水平呈负相关。②PLCD3上调会促进HFLS-OA细胞的增殖并抑制细胞迁移,而miR-34a-5p上调会显著抑制HFLS-OA细胞的活性并增强细胞迁移;miR-34a-5p过表达使HFLS-OA细胞Casp3和Casp9蛋白水平显著升高,而PLCD3过表达则表现出相反趋势。③PLCD3过表达显著增加了HFLS-OA细胞白细胞介素6和肿瘤坏死因子α的表达,而miR-34a-5p模拟物则表现出保护活性。④结果说明,miR-34a-5p/PLCD3轴可能通过调节滑膜细胞的炎症过程或凋亡来影响骨关节炎的进展。展开更多
基金This study was supported by the National Natural Science Foundation of China(31960306).
文摘To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant component.The results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress levels.Phosphorous utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe drought.Growth was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each component.Changes in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that P.yunnanensis seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization efficiencies.Overall,these results suggest that the physiological activities of all organs of P.yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs.Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P.yunnanensis seedlings.
基金supported by National Natural Science Foundation of China,No.32102745(to XL).
文摘Traumatic brain injury is a severe health problem leading to autophagy and apoptosis in the brain.3,6-Dibromo-beta-fluoro-N-(3-methoxyphenyl)-9H-carbazole-9-propanamine(P7C3-A20)can be neuroprotective in various diseases,including ischemic stroke and neurodegenerative diseases.However,whether P7C3-A20 has a therapeutic effect on traumatic brain injury and its possible molecular mechanisms are unclear.Therefore,in the present study,we investigated the therapeutic effects of P7C3-A20 on traumatic brain injury and explored the putative underlying molecular mechanisms.We established a traumatic brain injury rat model using a modified weight drop method.P7C3-A20 or vehicle was injected intraperitoneally after traumatic brain injury.Severe neurological deficits were found in rats after traumatic brain injury,with deterioration in balance,walking function,and learning memory.Furthermore,hematoxylin and eosin staining showed significant neuronal cell damage,while terminal deoxynucleotidyl transferase mediated dUTP nick end labeling staining indicated a high rate of apoptosis.The presence of autolysosomes was observed using transmission electron microscope.P7C3-A20 treatment reversed these pathological features.Western blotting showed that P7C3-A20 treatment reduced microtubule-associated protein 1 light chain 3-Ⅱ(LC3-Ⅱ)autophagy protein,apoptosis-related proteins(namely,Bcl-2/adenovirus E1B 19-kDa-interacting protein 3[BNIP3],and Bcl-2 associated x protein[Bax]),and elevated ubiquitin-binding protein p62(p62)autophagy protein expression.Thus,P7C3-A20 can treat traumatic brain injury in rats by inhibiting excessive autophagy and apoptosis.
基金supported by the National Natural Science Foundation of China(Nos.31800369,32271686,U1904204)the State Scholarship Fund of Chinathe Innovation Scientists and Technicians Troop Construction Projects of Henan Province(No.182101510005)。
文摘Background:Nitrogen(N)deposition affects forest stoichiometric flexibility through changing soil nutrient availability to influence plant uptake.However,the effect of N deposition on the flexibility of carbon(C),N,and phosphorus(P)in forest plant-soil-microbe systems remains unclear.Methods:We conducted a meta-analysis based on 751 pairs of observations to evaluate the responses of plant,soil and microbial biomass C,N and P nutrients and stoichiometry to N addition in different N intensity(050,50–100,>100 kg·ha^(-1)·year^(-1)of N),duration(0–5,>5 year),method(understory,canopy),and matter(ammonium N,nitrate N,organic N,mixed N).Results:N addition significantly increased plant N:P(leaf:14.98%,root:13.29%),plant C:P(leaf:6.8%,root:25.44%),soil N:P(13.94%),soil C:P(10.86%),microbial biomass N:P(23.58%),microbial biomass C:P(12.62%),but reduced plant C:N(leaf:6.49%,root:9.02%).Furthermore,plant C:N:P stoichiometry changed significantly under short-term N inputs,while soil and microorganisms changed drastically under high N addition.Canopy N addition primarily affected plant C:N:P stoichiometry through altering plant N content,while understory N inputs altered more by influencing soil C and P content.Organic N significantly influenced plant and soil C:N and C:P,while ammonia N changed plant N:P.Plant C:P and soil C:N were strongly correlated with mean annual precipitation(MAT),and the C:N:P stoichiometric flexibility in soil and plant under N addition connected with soil depth.Besides,N addition decoupled the correlations between soil microorganisms and the plant.Conclusions:N addition significantly increased the C:P and N:P in soil,plant,and microbial biomass,reducing plant C:N,and aggravated forest P limitations.Significantly,these impacts were contingent on climate types,soil layers,and N input forms.The findings enhance our comprehension of the plant-soil system nutrient cycling mechanisms in forest ecosystems and plant strategy responses to N deposition.
基金supported by the National Key R&D Program of China (2022YFD2201100)Natural Science Foundation of Heilongjiang Province of China (TD2023C006)the Fundamental Research Funds for the Central Universities (2572022DS13).
文摘Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutrients vary with tree size,organ age,or root order at the individual level remains limited.We determined C,N,and P contents and their stoichiometric ratios(i.e.,nutrient traits)in needles,branches,and fine roots at different organ ages(0-3-year-old needles and branches)and root orders(1st-4th order roots)from 64 Pinus koraiensis of varying size(Diameter at breast height ranged from 0.3 to 100 cm)in northeast China.Soil factors were also measured.The results show that nutrient traits were regulated by tree size,organ age,or root order rather than soil factors.At a whole-plant level,nutrient traits decreased in needles and fine roots but increased in branches with tree size.At the organ level,age or root order had a negative effect on C,N,and P and a positive effect on stoichiometric ratios.Our results demonstrate that nutrient variations are closely related to organ-specific functions and ecophysiological processes at an individual level.It is suggested that the nutrient acquisition strategy by younger trees and organ fractions with higher nutrient content is for survival.Conversely,nutrient storage strategy in older trees and organ fractions are mainly for steady growth.Our results clarified the nutrient utilization strategies during tree and organ ontogeny and suggest that tree size and organ age or root order should be simultaneously considered to understand the complexities of nutrient variations.
