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
Plant root systems are essential for many physiological processes,including water and nutrient absorption.MADS-box transcription factor(TF)genes have been characterized as the important regulators of root development ...Plant root systems are essential for many physiological processes,including water and nutrient absorption.MADS-box transcription factor(TF)genes have been characterized as the important regulators of root development in plants;however,the underlying mechanism is largely unknown,including chrysanthemum.Here,it was found that the overexpression of CmANR1,a chrysanthemum MADS-box TF gene,promoted both adventitious root(AR)and lateral root(LR)development in chrysanthemum.Whole transcriptome sequencing analysis revealed a series of differentially expressed unigenes(DEGs)in the roots of CmANR1-transgenic chrysanthemum plants compared to wild-type plants.Functional annotation of these DEGs by alignment with Gene Ontology(GO)terms and biochemical pathway Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis indicated that CmANR1 TF exhibited“DNA binding”and“catalytic”activity,as well as participated in“phytohormone signal transduction”.Both chromatin immunoprecipitation–polymerase chain reaction(ChIP-PCR)and gel electrophoresis mobility shift assays(EMSA)indicated the direct binding of CmPIN2 to the recognition site CArG-box motif by CmANR1.Finally,a firefly luciferase imaging assay demonstrated the transcriptional activation of CmPIN2 by CmANR1 in vivo.Overall,our results provide novel insights into the mechanisms of MADS-box TF CmANR1 modulation of both AR and LR development,which occurs by directly regulating auxin transport gene CmPIN2 in chrysanthemum.展开更多
The auxin polar transporter,PIN-FORMED 2(PIN2)plays an important role in root development.However,it remains unclear whether PIN2 genes form two Liriodendron species,L.chinense(LcPIN2)and L.tulipifera(LtPIN2),are both...The auxin polar transporter,PIN-FORMED 2(PIN2)plays an important role in root development.However,it remains unclear whether PIN2 genes form two Liriodendron species,L.chinense(LcPIN2)and L.tulipifera(LtPIN2),are both involved in root development and whether and to what extent these two genes diverge in function.Here,we cloned and overexpressed LcPIN2 and LtPIN2 in Arabidopsis thaliana wild-type(WT)and Atpin2 mutant.Phylogenetic and sequence analysis showed a small degree of differentiation between these two Liriodendron PIN2 genes.Tissue-specific gene expression analysis indicated that both Liriodendron PIN2 genes were highly expressed in roots,implying a potential role in root development.Finally,heterologous overexpression of LcPIN2 and LtPIN2 in Arabidopsis both significantly increased the root length compared to wild-type and empty vector.Furthermore,the root length defect in Atpin2 was complemented both by LcPIN2 and LtPIN2.However,heterologous overexpression of LcPIN2 and LtPIN2 cannot rescue the defect in root gravitropism of Atpin2 mutants.Taken together,ourfindings unravel PIN2 genes from the magnoliids plant Liriodendron were functionally conserved with AtPIN2 in the dicotyledonous plant Arabidopsis in regard to the regulation of root length,but not root gravitropism.This study also provides a potential target for genetic improvement of the root system in these valuable forest trees Liriodendron.展开更多
Plant growth depends on tightly coordinated auxin signaling and directional auxin transport,yet the molecular feedback mechanism that directly links these processes during root gravitropism has remained mechanisticall...Plant growth depends on tightly coordinated auxin signaling and directional auxin transport,yet the molecular feedback mechanism that directly links these processes during root gravitropism has remained mechanistically unresolved.The recent study by Rodriguez et al.(Cell,2025)reveals a novel cell-surface auxin signaling pathway.It is shown that gravity perception-induced initial auxin asymmetry activates transmembrane kinase 1(TMK1)in the lower side cells of the root.The activated TMK1 then interacts with pin-formed 2(PIN2)and phosphorylates its hydrophilic loop,thereby stabilizing the PIN2 protein.This asymmetric distribution of PIN2 further enhances the auxin flow on the lower side,thus forming a self-reinforcing positive feedback loop that drives force for root tip gravitropic bending.This study provides an updated perspective on the auxin signal and transport feedback,signifying a new advancement in our comprehension of the mechanisms underlying plant adaptive growth.展开更多
TiO_(2) nanoparticles(nano-TiO_(2))are widely used in the world,and a considerable amount of nano-TiO_(2) is released into the environment,with toxic effects on organisms.In the various species of higher plants,growth...TiO_(2) nanoparticles(nano-TiO_(2))are widely used in the world,and a considerable amount of nano-TiO_(2) is released into the environment,with toxic effects on organisms.In the various species of higher plants,growth,including seed germination,root elongation,and biomass accumulation,is affected by nano-TiO_(2).However,the underlying molecular mechanisms remain to be elucidated.In this study,we observed that nano-TiO_(2) promoted root elongation in a dose-dependent manner.Furthermore,we found that nano-TiO_(2) elevated auxin accumulation in the root tips of the auxin marker lines DII-VENUS and DR5::GUS,and,correspondingly,quantitative real-time PCR analysis revealed that nano-TiO_(2) increased the expression levels of auxin biosynthesis-and transport-related genes.GFP fluorescence observation using transgenic PIN2-GFP indicated that nano-TiO_(2) promoted root growth by inducing PIN2 accumulation.Thus,we propose that nano-TiO_(2) promote root growth in Arabidopsis thaliana by altering the expression levels of auxin biosynthesis-and transport-related genes.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This work was supported by grants from the National Natural Science Foundation of China(31601728)Shandong Province(ZR2016CQ13)Young Scientists Funds of Shandong Agricultural University(564024,24024).
文摘Plant root systems are essential for many physiological processes,including water and nutrient absorption.MADS-box transcription factor(TF)genes have been characterized as the important regulators of root development in plants;however,the underlying mechanism is largely unknown,including chrysanthemum.Here,it was found that the overexpression of CmANR1,a chrysanthemum MADS-box TF gene,promoted both adventitious root(AR)and lateral root(LR)development in chrysanthemum.Whole transcriptome sequencing analysis revealed a series of differentially expressed unigenes(DEGs)in the roots of CmANR1-transgenic chrysanthemum plants compared to wild-type plants.Functional annotation of these DEGs by alignment with Gene Ontology(GO)terms and biochemical pathway Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis indicated that CmANR1 TF exhibited“DNA binding”and“catalytic”activity,as well as participated in“phytohormone signal transduction”.Both chromatin immunoprecipitation–polymerase chain reaction(ChIP-PCR)and gel electrophoresis mobility shift assays(EMSA)indicated the direct binding of CmPIN2 to the recognition site CArG-box motif by CmANR1.Finally,a firefly luciferase imaging assay demonstrated the transcriptional activation of CmPIN2 by CmANR1 in vivo.Overall,our results provide novel insights into the mechanisms of MADS-box TF CmANR1 modulation of both AR and LR development,which occurs by directly regulating auxin transport gene CmPIN2 in chrysanthemum.
基金supported by the Youth Foundation of the Natural Science Foundation of Jiangsu Province(BK20210614)the Nature Science Foundation of China(32071784)+1 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_0921).
文摘The auxin polar transporter,PIN-FORMED 2(PIN2)plays an important role in root development.However,it remains unclear whether PIN2 genes form two Liriodendron species,L.chinense(LcPIN2)and L.tulipifera(LtPIN2),are both involved in root development and whether and to what extent these two genes diverge in function.Here,we cloned and overexpressed LcPIN2 and LtPIN2 in Arabidopsis thaliana wild-type(WT)and Atpin2 mutant.Phylogenetic and sequence analysis showed a small degree of differentiation between these two Liriodendron PIN2 genes.Tissue-specific gene expression analysis indicated that both Liriodendron PIN2 genes were highly expressed in roots,implying a potential role in root development.Finally,heterologous overexpression of LcPIN2 and LtPIN2 in Arabidopsis both significantly increased the root length compared to wild-type and empty vector.Furthermore,the root length defect in Atpin2 was complemented both by LcPIN2 and LtPIN2.However,heterologous overexpression of LcPIN2 and LtPIN2 cannot rescue the defect in root gravitropism of Atpin2 mutants.Taken together,ourfindings unravel PIN2 genes from the magnoliids plant Liriodendron were functionally conserved with AtPIN2 in the dicotyledonous plant Arabidopsis in regard to the regulation of root length,but not root gravitropism.This study also provides a potential target for genetic improvement of the root system in these valuable forest trees Liriodendron.
基金supported by the National Natural Science Foundation of China(32372599)the Agricultural Science and Technology Innovation Program(No.CAAS-BRC-GLCA-2025-01).
文摘Plant growth depends on tightly coordinated auxin signaling and directional auxin transport,yet the molecular feedback mechanism that directly links these processes during root gravitropism has remained mechanistically unresolved.The recent study by Rodriguez et al.(Cell,2025)reveals a novel cell-surface auxin signaling pathway.It is shown that gravity perception-induced initial auxin asymmetry activates transmembrane kinase 1(TMK1)in the lower side cells of the root.The activated TMK1 then interacts with pin-formed 2(PIN2)and phosphorylates its hydrophilic loop,thereby stabilizing the PIN2 protein.This asymmetric distribution of PIN2 further enhances the auxin flow on the lower side,thus forming a self-reinforcing positive feedback loop that drives force for root tip gravitropic bending.This study provides an updated perspective on the auxin signal and transport feedback,signifying a new advancement in our comprehension of the mechanisms underlying plant adaptive growth.
基金This work is supported by the National Science Foundation of China(No.31970289).
文摘TiO_(2) nanoparticles(nano-TiO_(2))are widely used in the world,and a considerable amount of nano-TiO_(2) is released into the environment,with toxic effects on organisms.In the various species of higher plants,growth,including seed germination,root elongation,and biomass accumulation,is affected by nano-TiO_(2).However,the underlying molecular mechanisms remain to be elucidated.In this study,we observed that nano-TiO_(2) promoted root elongation in a dose-dependent manner.Furthermore,we found that nano-TiO_(2) elevated auxin accumulation in the root tips of the auxin marker lines DII-VENUS and DR5::GUS,and,correspondingly,quantitative real-time PCR analysis revealed that nano-TiO_(2) increased the expression levels of auxin biosynthesis-and transport-related genes.GFP fluorescence observation using transgenic PIN2-GFP indicated that nano-TiO_(2) promoted root growth by inducing PIN2 accumulation.Thus,we propose that nano-TiO_(2) promote root growth in Arabidopsis thaliana by altering the expression levels of auxin biosynthesis-and transport-related genes.
