The phytohormone auxin,and its directional transport through tissues,plays a fundamental role in the development of higher plants.This polar auxin transport predominantly relies on PIN-FORMED(PIN)auxin exporters.Hence...The phytohormone auxin,and its directional transport through tissues,plays a fundamental role in the development of higher plants.This polar auxin transport predominantly relies on PIN-FORMED(PIN)auxin exporters.Hence,PIN polarization is crucial for development,but its evolution during the rise of morpho-logical complexity in land plants remains unclear.Here,we performed a cross-species investigation by observing the trafficking and localization of endogenous and exogenous PINs in two bryophytes,Physco-mitrium patens and Marchantia polymorpha,and in theflowering plant Arabidopsis thaliana.We confirmed that the GFP fusion did not compromise the auxin export function of all examined PINs by using a radioac-tive auxin export assay and by observing the phenotypic changes in transgenic bryophytes.Endogenous PINs polarize tofilamentous apices,while exogenous Arabidopsis PINs distribute symmetrically on the membrane in both bryophytes.In the Arabidopsis root epidermis,bryophytic PINs have no defined polarity.Pharmacological interference revealed a strong cytoskeletal dependence of bryophytic but not Arabidopsis PIN polarization.The divergence of PIN polarization and trafficking is also observed within the bryophyte clade and between tissues of individual species.These results collectively reveal the divergence of PIN traf-ficking and polarity mechanisms throughout land plant evolution and the co-evolution of PIN sequence-based and cell-based polarity mechanisms.展开更多
Despite decades of efforts in genome sequencing and functional characterization,some important protein families remain poorly understood.In this study,we report the classification,evolution,and functions of the largel...Despite decades of efforts in genome sequencing and functional characterization,some important protein families remain poorly understood.In this study,we report the classification,evolution,and functions of the largely uncharacterized AIM24 protein family in plants,including the identification of a novel subfamily.We show that two AIM24 subfamilies(AIM24-A and AIM24-B)are commonly distributed in major plant groups.These two subfamilies not only have modest sequence similarities and different gene structures but also are of independent bacterial ancestry.We performed comparative functional investigations on the two AIM24 subfamilies using three model plants:the moss Physcomitrium patens,the liverwort Marchantia polymorpha,and the flowering plant Arabidopsis thaliana.Intriguingly,despite their significant differences in sequence and gene structure,both AIM24 subfamilies are involved in ER stress tolerance and the unfolded protein response(UPR).In addition,transformation of the AIM24-A gene from P.patens into the AIM24-B null mutant of A.thaliana could at least partially rescue ER stress tolerance and the UPR.We also discuss the role of AIM24 genes in plant development and other cellular activities.This study provides a unique example of parallel evolution in molecular functions and can serve as a foundation for further investigation of the AIM24 family in plants.展开更多
基金supported by the European Research Council Advanced Grant (ETAP-742985 to H.T.and J.F.)by the Ministry of Science and Technology (grant 110-2636-B-005-001 to K.-J.L.).
文摘The phytohormone auxin,and its directional transport through tissues,plays a fundamental role in the development of higher plants.This polar auxin transport predominantly relies on PIN-FORMED(PIN)auxin exporters.Hence,PIN polarization is crucial for development,but its evolution during the rise of morpho-logical complexity in land plants remains unclear.Here,we performed a cross-species investigation by observing the trafficking and localization of endogenous and exogenous PINs in two bryophytes,Physco-mitrium patens and Marchantia polymorpha,and in theflowering plant Arabidopsis thaliana.We confirmed that the GFP fusion did not compromise the auxin export function of all examined PINs by using a radioac-tive auxin export assay and by observing the phenotypic changes in transgenic bryophytes.Endogenous PINs polarize tofilamentous apices,while exogenous Arabidopsis PINs distribute symmetrically on the membrane in both bryophytes.In the Arabidopsis root epidermis,bryophytic PINs have no defined polarity.Pharmacological interference revealed a strong cytoskeletal dependence of bryophytic but not Arabidopsis PIN polarization.The divergence of PIN polarization and trafficking is also observed within the bryophyte clade and between tissues of individual species.These results collectively reveal the divergence of PIN traf-ficking and polarity mechanisms throughout land plant evolution and the co-evolution of PIN sequence-based and cell-based polarity mechanisms.
基金supported in part by grants from the National Natural Science Foundation of China(31970248,32070251,32170242)Yunnan Fundamental Research Projects(202101AT070186,202201AT070163)+2 种基金Postdoctoral Research Funding Projects of Yunnan Province,the Special Research Assistant Funding Project of the Chinese Academy of Sciences(2021)the China Postdoctoral Science Foundation(2022M723223)the Youth Innovation Promotion Association CAS(2022398).
文摘Despite decades of efforts in genome sequencing and functional characterization,some important protein families remain poorly understood.In this study,we report the classification,evolution,and functions of the largely uncharacterized AIM24 protein family in plants,including the identification of a novel subfamily.We show that two AIM24 subfamilies(AIM24-A and AIM24-B)are commonly distributed in major plant groups.These two subfamilies not only have modest sequence similarities and different gene structures but also are of independent bacterial ancestry.We performed comparative functional investigations on the two AIM24 subfamilies using three model plants:the moss Physcomitrium patens,the liverwort Marchantia polymorpha,and the flowering plant Arabidopsis thaliana.Intriguingly,despite their significant differences in sequence and gene structure,both AIM24 subfamilies are involved in ER stress tolerance and the unfolded protein response(UPR).In addition,transformation of the AIM24-A gene from P.patens into the AIM24-B null mutant of A.thaliana could at least partially rescue ER stress tolerance and the UPR.We also discuss the role of AIM24 genes in plant development and other cellular activities.This study provides a unique example of parallel evolution in molecular functions and can serve as a foundation for further investigation of the AIM24 family in plants.
