Comprehensive untargeted and targeted analysis of root exudate composition has advanced our understanding of rhizosphere processes.However,little is known about exudate spatial distribution and regulation.We studied t...Comprehensive untargeted and targeted analysis of root exudate composition has advanced our understanding of rhizosphere processes.However,little is known about exudate spatial distribution and regulation.We studied the specific metabolite signatures of asparagus root exudates,root outer(epidermis and exodermis),and root inner tissues(cortex and vasculature).The greatest differences were found between exudates and root tissues.In total,263 non-redundant metabolites were identified as significantly differentially abundant between the three root fractions,with the majority being enriched in the root exudate and/or outer tissue and annotated as‘lipids and lipid-like molecules’or‘phenylpropanoids and polyketides’.Spatial distribution was verified for three selected compounds using MALDI-TOF mass spectrometry imaging.Tissue-specific proteome analysis related root tissue-specific metabolite distributions and rhizodeposition with underlying biosynthetic pathways and transport mechanisms.The proteomes of root outer and inner tissues were spatially very distinct,in agreement with the fundamental differences between their functions and structures.According to KEGG pathway analysis,the outer tissue proteome was characterized by a high abundance of proteins related to‘lipid metabolism’,‘biosynthesis of other secondary metabolites’and‘transport and catabolism’,reflecting its main functions of providing a hydrophobic barrier,secreting secondary metabolites,and mediating water and nutrient uptake.Proteins more abundant in the inner tissue related to‘transcription’,‘translation’and‘folding,sorting and degradation’,in accord with the high activity of cortical and vasculature cell layers in growth-and development-related processes.In summary,asparagus root fractions accumulate specific metabolites.This expands our knowledge of tissue-specific plant cell function.展开更多
Rapid climate change has led to enhanced soil salinity,one of the major determinants of land degradation,resulting in low agricultural productivity.This has a strong negative impact on food security and environmental ...Rapid climate change has led to enhanced soil salinity,one of the major determinants of land degradation,resulting in low agricultural productivity.This has a strong negative impact on food security and environmental sustainability.Plants display various physiological,developmental,and cellular responses to deal with salt stress.Recent studies have highlighted the root cap as the primary stress sensor and revealed its crucial role in halotropism.The root cap covers the primary root meristem and is the first cell type to sense and respond to soil salinity,relaying the signal to neighboring cell types.However,it remains unclear how root-cap cells perceive salt stress and contribute to the salt-stress response.Here,we performed a root-cap cell-specific proteomics study to identify changes in the proteome caused by salt stress.The study revealed a very specific salt-stress response pattern in root-cap cells compared with non-rootcap cells and identified several novel proteins unique to the root cap.Root-cap-specific protein–protein interaction(PPI)networks derived by superimposing proteomics data onto known global PPI networks revealed that the endoplasmic reticulum(ER)stress pathway is specifically activated in root-cap cells upon salt stress.Importantly,we identified root-cap-specific jacalin-associated lectins(JALs)expressed in response to salt stress.A JAL10-GFP fusion protein was shown to be localized to the ER.Analysis of jal10 mutants indicated a role for JAL10 in regulating the ER stress pathway in response to salt.Taken together,our findings highlight the participation of specific root-cap proteins in salt-stress response pathways.Furthermore,root-cap-specific JAL proteins and their role in the salt-mediated ER stress pathway open a new avenue for exploring tolerance mechanisms and devising better strategies to increase plant salinity tolerance and enhance agricultural productivity.展开更多
基金the German Federal Ministry of Education and Research(FKZ:01EA1706).
文摘Comprehensive untargeted and targeted analysis of root exudate composition has advanced our understanding of rhizosphere processes.However,little is known about exudate spatial distribution and regulation.We studied the specific metabolite signatures of asparagus root exudates,root outer(epidermis and exodermis),and root inner tissues(cortex and vasculature).The greatest differences were found between exudates and root tissues.In total,263 non-redundant metabolites were identified as significantly differentially abundant between the three root fractions,with the majority being enriched in the root exudate and/or outer tissue and annotated as‘lipids and lipid-like molecules’or‘phenylpropanoids and polyketides’.Spatial distribution was verified for three selected compounds using MALDI-TOF mass spectrometry imaging.Tissue-specific proteome analysis related root tissue-specific metabolite distributions and rhizodeposition with underlying biosynthetic pathways and transport mechanisms.The proteomes of root outer and inner tissues were spatially very distinct,in agreement with the fundamental differences between their functions and structures.According to KEGG pathway analysis,the outer tissue proteome was characterized by a high abundance of proteins related to‘lipid metabolism’,‘biosynthesis of other secondary metabolites’and‘transport and catabolism’,reflecting its main functions of providing a hydrophobic barrier,secreting secondary metabolites,and mediating water and nutrient uptake.Proteins more abundant in the inner tissue related to‘transcription’,‘translation’and‘folding,sorting and degradation’,in accord with the high activity of cortical and vasculature cell layers in growth-and development-related processes.In summary,asparagus root fractions accumulate specific metabolites.This expands our knowledge of tissue-specific plant cell function.
基金supported by IISER Tirupati and by an Early Career Research award from the Science and Engineering Research Board,Department of Science and Technology,Govt.of India(ECR/2016/001071)to E.R.K.K.D.acknowledges the CSIR-JRF fellowship and Bi-nationally supervised doctoral degree scholarship from DAAD(91730390)for her PhD.A.M.and A.P.G.acknowledge funding from IISER Tirupati for graduate studies.S.C.acknowledges funding from IISER Tirupati and the Ramalingaswami Re-entry Fellowship(BT/RLF/Re-entry/05/2018)Department of Biotechnology,Government of India.
文摘Rapid climate change has led to enhanced soil salinity,one of the major determinants of land degradation,resulting in low agricultural productivity.This has a strong negative impact on food security and environmental sustainability.Plants display various physiological,developmental,and cellular responses to deal with salt stress.Recent studies have highlighted the root cap as the primary stress sensor and revealed its crucial role in halotropism.The root cap covers the primary root meristem and is the first cell type to sense and respond to soil salinity,relaying the signal to neighboring cell types.However,it remains unclear how root-cap cells perceive salt stress and contribute to the salt-stress response.Here,we performed a root-cap cell-specific proteomics study to identify changes in the proteome caused by salt stress.The study revealed a very specific salt-stress response pattern in root-cap cells compared with non-rootcap cells and identified several novel proteins unique to the root cap.Root-cap-specific protein–protein interaction(PPI)networks derived by superimposing proteomics data onto known global PPI networks revealed that the endoplasmic reticulum(ER)stress pathway is specifically activated in root-cap cells upon salt stress.Importantly,we identified root-cap-specific jacalin-associated lectins(JALs)expressed in response to salt stress.A JAL10-GFP fusion protein was shown to be localized to the ER.Analysis of jal10 mutants indicated a role for JAL10 in regulating the ER stress pathway in response to salt.Taken together,our findings highlight the participation of specific root-cap proteins in salt-stress response pathways.Furthermore,root-cap-specific JAL proteins and their role in the salt-mediated ER stress pathway open a new avenue for exploring tolerance mechanisms and devising better strategies to increase plant salinity tolerance and enhance agricultural productivity.
