The spatiotemporal regulation of polar auxin transport by PIN-FORMED(PIN)efflux carriers is essential for coordinating plant development with environmental cues.However,whether and how osmotic stress signaling affects...The spatiotemporal regulation of polar auxin transport by PIN-FORMED(PIN)efflux carriers is essential for coordinating plant development with environmental cues.However,whether and how osmotic stress signaling affects auxin transport to regulate plant stress adaptation remain largely unclear.In this study,we identify SnRK2.5,an abscisic acid–independent member of the SNF1-related protein kinase family,as a key molecular link between osmotic stress signaling and auxin transport regulation in Arabidopsis.Osmotic stress activates SnRK2.5,which directly phosphorylates PIN2 at Ser237 and Ser259.Genetic and cell biological analyses demonstrate that these phosphorylation events govern PIN2 vesicular trafficking,vacuolar targeting,and auxin transport activity.Disruption of these phosphorylation sites impairs PIN2-dependent auxin redistribution,thereby compromising root tropic responses and reducing osmotic stress tolerance.Our findings uncover a regulatory mechanism by which SnRK2.5-mediated phosphorylation of PIN2 dynamically adjusts auxin flux in response to water availability,representing a critical adaptive strategy that optimizes plant growth under osmotic stress.展开更多
Background:Depression is becoming increasingly prevalent around the world,imposing a substantial burden on individuals,families,as well as society.Quercetin is known to be highly effective in treating depression.Howev...Background:Depression is becoming increasingly prevalent around the world,imposing a substantial burden on individuals,families,as well as society.Quercetin is known to be highly effective in treating depression.However,additional research is needed to dissect the mechanisms of its anti-depressive effects.Methods:For this study,Sprague-Dawley(SD)rats were randomized into the control,model,quercetin,or fluoxetine group.The latter three groups were exposed to chronic unpredictable mild stress(CUMS)for 42 d.The first two groups received saline solution daily via oral gavage.Meanwhile,the quercetin group was orally administered a quercetin suspension(52.08 mg/kg)every day,while the fluoxetine group was orally administered a fluoxetine solution(2.08 mg/kg).Here,fluoxetine served as the positive control drug to compare the therapeutic effects of quercetin.The experimental period was 6 weeks.Depressive behaviors in rats were assessed through various physiological and behavioral measures.Additionally,pathological changes in hippocampal tissues were examined using Nissl staining.Serum cytokines were detected using an enzymelinked immunosorbent assay(ELISA),and immunohistochemistry was employed to quantify the levels and integral optical density(IOD)values of ionized calcium binding adaptor molecule-1(Iba-1)expression in the brain.Real-time fluorescence quantitative PCR(RT-qPCR)was utilized to evaluate the mRNA levels of inflammatory indicators as well as toll-like receptor 4(TLR4),and nuclear factor-κappa B P65(NF-κB P65)in hippocampus.Western blot(WB)technique was employed to observe the protein levels of TLR4,NF-κB P65,and phospho-NF-κB P65(p-NF-κB P65).Results:After 42 d of exposure to CUMS,rats exhibited a slow increase in body weight,a reduction in food intake,an abnormal preference for sugar water,and aberrant open-field behaviors.Pathological analysis revealed the disintegration,rupture,interruption,and disorganization of hippocampal neuronal cells after CUMS exposure,along with a decrease in Nissl bodies in the CA1 region.This was accompanied by the elevated expression of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)in the serum and the upregulation of IL-1β,IL-6,and TNF-αmRNA expression in the hippocampus.Increases in Iba-1-positive cells and the IOD values of Iba-1 were detected in hippocampal microglia.Furthermore,TLR4 and NF-κB P65 mRNA and protein levels were upregulated in hippocampal tissues.Quercetin,an antidepressant,could alleviate depression-like symptoms in rats and downregulate inflammatory factors associated with the TLR4/NF-κB signaling pathway in hippocampal microglia,and its therapeutic effect was comparable to fluoxetine.Conclusion:In rat models of CUMS,quercetin may act as an antidepressant by inhibiting inflammation in hippocampal microglia via TLR4/NF-κB signaling pathway.These results offer experimental and theoretical support for applying quercetin in the clinical management of depression.展开更多
基金supported by grants from the National Key R&D Program of China(2022YFA1303400)the Fundamental Research Funds for the Central Universities(KJJQ2024007)+2 种基金the National Natural Science Foundation of China(32270301)to Q.Z.the Pinduoduo-China Agricultural University Research Fund(PC2024B01005)the Hainan Provincial Natural Science Foundation of China(323CXTD379)to J.Z.
文摘The spatiotemporal regulation of polar auxin transport by PIN-FORMED(PIN)efflux carriers is essential for coordinating plant development with environmental cues.However,whether and how osmotic stress signaling affects auxin transport to regulate plant stress adaptation remain largely unclear.In this study,we identify SnRK2.5,an abscisic acid–independent member of the SNF1-related protein kinase family,as a key molecular link between osmotic stress signaling and auxin transport regulation in Arabidopsis.Osmotic stress activates SnRK2.5,which directly phosphorylates PIN2 at Ser237 and Ser259.Genetic and cell biological analyses demonstrate that these phosphorylation events govern PIN2 vesicular trafficking,vacuolar targeting,and auxin transport activity.Disruption of these phosphorylation sites impairs PIN2-dependent auxin redistribution,thereby compromising root tropic responses and reducing osmotic stress tolerance.Our findings uncover a regulatory mechanism by which SnRK2.5-mediated phosphorylation of PIN2 dynamically adjusts auxin flux in response to water availability,representing a critical adaptive strategy that optimizes plant growth under osmotic stress.
基金supported by the National Natural Science Foundation of China(Nos.81673881 and 81202644)Hebei Province Natural Science Foundation Traditional Chinese Medicine Joint Fund Cultivation Project(No.H2022423375)Graduate Innovation Project of Hebei University of Chinese Medicine in 2023(No.XCXZZBS2023003).
文摘Background:Depression is becoming increasingly prevalent around the world,imposing a substantial burden on individuals,families,as well as society.Quercetin is known to be highly effective in treating depression.However,additional research is needed to dissect the mechanisms of its anti-depressive effects.Methods:For this study,Sprague-Dawley(SD)rats were randomized into the control,model,quercetin,or fluoxetine group.The latter three groups were exposed to chronic unpredictable mild stress(CUMS)for 42 d.The first two groups received saline solution daily via oral gavage.Meanwhile,the quercetin group was orally administered a quercetin suspension(52.08 mg/kg)every day,while the fluoxetine group was orally administered a fluoxetine solution(2.08 mg/kg).Here,fluoxetine served as the positive control drug to compare the therapeutic effects of quercetin.The experimental period was 6 weeks.Depressive behaviors in rats were assessed through various physiological and behavioral measures.Additionally,pathological changes in hippocampal tissues were examined using Nissl staining.Serum cytokines were detected using an enzymelinked immunosorbent assay(ELISA),and immunohistochemistry was employed to quantify the levels and integral optical density(IOD)values of ionized calcium binding adaptor molecule-1(Iba-1)expression in the brain.Real-time fluorescence quantitative PCR(RT-qPCR)was utilized to evaluate the mRNA levels of inflammatory indicators as well as toll-like receptor 4(TLR4),and nuclear factor-κappa B P65(NF-κB P65)in hippocampus.Western blot(WB)technique was employed to observe the protein levels of TLR4,NF-κB P65,and phospho-NF-κB P65(p-NF-κB P65).Results:After 42 d of exposure to CUMS,rats exhibited a slow increase in body weight,a reduction in food intake,an abnormal preference for sugar water,and aberrant open-field behaviors.Pathological analysis revealed the disintegration,rupture,interruption,and disorganization of hippocampal neuronal cells after CUMS exposure,along with a decrease in Nissl bodies in the CA1 region.This was accompanied by the elevated expression of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)in the serum and the upregulation of IL-1β,IL-6,and TNF-αmRNA expression in the hippocampus.Increases in Iba-1-positive cells and the IOD values of Iba-1 were detected in hippocampal microglia.Furthermore,TLR4 and NF-κB P65 mRNA and protein levels were upregulated in hippocampal tissues.Quercetin,an antidepressant,could alleviate depression-like symptoms in rats and downregulate inflammatory factors associated with the TLR4/NF-κB signaling pathway in hippocampal microglia,and its therapeutic effect was comparable to fluoxetine.Conclusion:In rat models of CUMS,quercetin may act as an antidepressant by inhibiting inflammation in hippocampal microglia via TLR4/NF-κB signaling pathway.These results offer experimental and theoretical support for applying quercetin in the clinical management of depression.
