ERD4 proteins,members of the early responsive-to-dehydration family,act as plasma membrane ion channels that contribute to ion homeostasis and modulate plant response to abiotic stresses.However,the functions of ERD4 ...ERD4 proteins,members of the early responsive-to-dehydration family,act as plasma membrane ion channels that contribute to ion homeostasis and modulate plant response to abiotic stresses.However,the functions of ERD4 homologs in non-vascular species remain largely unexplored.Here,we characterized an ERD4 family homolog in Physcomitrium patens(Hedw.)Mitt.,PpCSC1(Calcium-permeable Stress-responsive Cation Channel 1),and investigated its role in salt stress response.PpCSC1 localized to the plasma membrane and functioned as a non-selective cation channel permeable to Na^(+),K^(+),Ca^(2+),and Mg^(2+).Under salt treatment,PpCSC1 transcripts were markedly downregulated,whereas overexpression lines exhibited enhanced salt sensitivity.Ion content analysis further revealed reduced K^(+)accumulation,lowered K^(+)/Na^(+)ratios,and elevated Mg^(2+)levels,collectively disrupting ionic homeostasis and impairing salt tolerance.Transcriptional regulation analysis revealed that the C2H2-type zinc finger transcription factor PpSTOP2 directly activated PpCSC1 expression.Notably,PpSTOP2 knockout plants displayed reduced PpCSC1 mRNA accumulation and improved salt tolerance.Together,these findings indicate that PpCSC1 is a plasma membrane-localized cation channel that negatively regulates salt tolerance by disturbing ion balance,and that its regulation by PpSTOP2 integrates upstream signaling with downstream physiological responses.This work provides new insight into how non-selective ion channels shape stress adaptation in early land plants.展开更多
Mosses play a crucial role in environmental protection,ecological preservation,and horticulture.While the effects of nanomaterials on angiosperms have been widely studied,their impact on bryophytes remains underexplor...Mosses play a crucial role in environmental protection,ecological preservation,and horticulture.While the effects of nanomaterials on angiosperms have been widely studied,their impact on bryophytes remains underexplored.In this study,we investigated the effects of mesoporous silica nanoparticles(MSNs)and virus-like mesoporous silica nanoparticles(VMSNs)on the model moss species Physcomitrium patens(P.patens).Our results revealed that MSNs,with an average size of approximately 123 nm,are nontoxic to P.patens and enhance its salt tolerance.The expression of key genes involved in stress responses were significantly induced in MSN-treated plants under salt stress,including peroxidase(POX),L-ascorbate oxidase(L-AO),alternative oxidase(AOX),and calcium-dependent protein kinase(CPK).MSN treatment reduced the accumulation of H_(2)O_(2) and O_(2)^(·-),increased Ca^(2+)signaling,and modulated reactive oxygen species(ROS)homeostasis,collectively improving moss tolerance to salt stress.MSNs were observed on the cell surface,in intercellular space,and within the cytosol and vesicles.They were transported bidirectionally between rhizoids and apical leaves.This study provides novel insights into the distribution,transport,and functional mechanisms of MSNs in mosses,offering a valuable foundation for the application of nanomaterials in plant stress biology and ecological management of bryophytes.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31970658 and No.32400208)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LD24C130002 and No.LQN25C020001)the Scientific Research Foundation of China Jiliang University.
文摘ERD4 proteins,members of the early responsive-to-dehydration family,act as plasma membrane ion channels that contribute to ion homeostasis and modulate plant response to abiotic stresses.However,the functions of ERD4 homologs in non-vascular species remain largely unexplored.Here,we characterized an ERD4 family homolog in Physcomitrium patens(Hedw.)Mitt.,PpCSC1(Calcium-permeable Stress-responsive Cation Channel 1),and investigated its role in salt stress response.PpCSC1 localized to the plasma membrane and functioned as a non-selective cation channel permeable to Na^(+),K^(+),Ca^(2+),and Mg^(2+).Under salt treatment,PpCSC1 transcripts were markedly downregulated,whereas overexpression lines exhibited enhanced salt sensitivity.Ion content analysis further revealed reduced K^(+)accumulation,lowered K^(+)/Na^(+)ratios,and elevated Mg^(2+)levels,collectively disrupting ionic homeostasis and impairing salt tolerance.Transcriptional regulation analysis revealed that the C2H2-type zinc finger transcription factor PpSTOP2 directly activated PpCSC1 expression.Notably,PpSTOP2 knockout plants displayed reduced PpCSC1 mRNA accumulation and improved salt tolerance.Together,these findings indicate that PpCSC1 is a plasma membrane-localized cation channel that negatively regulates salt tolerance by disturbing ion balance,and that its regulation by PpSTOP2 integrates upstream signaling with downstream physiological responses.This work provides new insight into how non-selective ion channels shape stress adaptation in early land plants.
基金funded by grants from the National Natural Science Foundation of China(No.32300244)Natural Science Foundation of Hubei Province(2023AFB661 and 2024AFB824)+2 种基金Hubei Key Laboratory of Embryonic Stem Cell Research,Hubei University of Medicine(2024ESOF002)Scientific Research Plan of Education Department of Hubei Province(B2022004)National Natural Science Foundation of China(52373305).
文摘Mosses play a crucial role in environmental protection,ecological preservation,and horticulture.While the effects of nanomaterials on angiosperms have been widely studied,their impact on bryophytes remains underexplored.In this study,we investigated the effects of mesoporous silica nanoparticles(MSNs)and virus-like mesoporous silica nanoparticles(VMSNs)on the model moss species Physcomitrium patens(P.patens).Our results revealed that MSNs,with an average size of approximately 123 nm,are nontoxic to P.patens and enhance its salt tolerance.The expression of key genes involved in stress responses were significantly induced in MSN-treated plants under salt stress,including peroxidase(POX),L-ascorbate oxidase(L-AO),alternative oxidase(AOX),and calcium-dependent protein kinase(CPK).MSN treatment reduced the accumulation of H_(2)O_(2) and O_(2)^(·-),increased Ca^(2+)signaling,and modulated reactive oxygen species(ROS)homeostasis,collectively improving moss tolerance to salt stress.MSNs were observed on the cell surface,in intercellular space,and within the cytosol and vesicles.They were transported bidirectionally between rhizoids and apical leaves.This study provides novel insights into the distribution,transport,and functional mechanisms of MSNs in mosses,offering a valuable foundation for the application of nanomaterials in plant stress biology and ecological management of bryophytes.
