The Arabidopsis thaliana Calmodulin-binding Transcription Activator(CAMTA)transcription factors CAMTA1,CAMTA2,and CAMTA3(CAMTA123)serve as master regulators of salicylic acid(SA)-mediated immunity,repressing the biosy...The Arabidopsis thaliana Calmodulin-binding Transcription Activator(CAMTA)transcription factors CAMTA1,CAMTA2,and CAMTA3(CAMTA123)serve as master regulators of salicylic acid(SA)-mediated immunity,repressing the biosynthesis of SA in healthy plants.Here,we show that CAMTA123 also repress the biosynthesis of pipecolic acid(Pip)in healthy plants.Loss of CAMTA123 function resulted in the induction of AGD2-like defense response protein 1(ALD1),which encodes an enzyme involved in Pip biosynthesis.Induction of ALD1 resulted in the accumulation of high levels of Pip,which brought about increased levels of the SA receptor protein NPR1 without induction of NPR1 expression or requirement for an increase in SA levels.Pip-mediated induction of ALD1 and genes regulating the biosynthesis of SA—CBP60g,SARD1,PAD4,and EDS1—was largely dependent on NPR1.Furthermore,Pip-mediated increase in NPR1 protein levels was associated with priming of Pip and SA biosynthesis genes to induction by low levels of SA.Taken together,our findings expand the role for CAMTA123 in regulating key immunity genes and suggest a working model whereby loss of CAMTA123 repression leads to the induction of plant defense genes and initiation of SAR.展开更多
Salicylic acid(SA)has long been known to be essential for basal defense and systemic acquired resistance(SAR).N-Hydroxypipecolic acid(NHP),a recently discovered plant metabolite,also plays a key role in SAR and to a l...Salicylic acid(SA)has long been known to be essential for basal defense and systemic acquired resistance(SAR).N-Hydroxypipecolic acid(NHP),a recently discovered plant metabolite,also plays a key role in SAR and to a lesser extent in basal resistance.Following pathogen infection,levels of both compounds are dramatically increased.Analysis of SA-or SAR-deficient mutants has uncovered how SA and NHP are biosynthesized.The completion of the SA and NHP biosynthetic pathways in Arabidopsis allowed better understanding of how they are regulated.In this review,we discuss recent progress on SA and NHP biosynthesis and their regulation in plant immunity.展开更多
The ascomycete insect pathogenic fungi such as Metarhizium species have been demonstrated with the abilities to form the rhizosphere or endophytic relationships with different plants for nutrient exchanges.In this stu...The ascomycete insect pathogenic fungi such as Metarhizium species have been demonstrated with the abilities to form the rhizosphere or endophytic relationships with different plants for nutrient exchanges.In this study,after the evident infeasibility of bacterial disease development in the boxed sterile soils,we established a hydroponic system for the gnotobiotic growth of Arabidopsis thaliana with the wild-type and transgenic strain of Metarhizium robertsii.The transgenic fungus could produce a high amount of pipecolic acid(PIP),a pivotal plant-immune-stimulating metabolite.Fungal inoculation experiments showed that M.robertsii could form a non-selective rhizosphere relationship with Arabidopsis.Similar to the PIP uptake by plants after exogenous application,PIP level increased in Col-0 and could be detected in the PIP-non-producing Arabidopsis mutant(ald1)after fungal inoculations,indicating that plants can absorb the PIP produced by fungi.The transgenic fungal strain had a better efficacy than the wild type to defend plants against the bacterial pathogen and aphid attacks.Contrary to ald1,fmo1 plants could not be boosted to resist bacterial infection after treatments.After fungal inoculations,the phytoalexins camalexin and aliphatic glucosinolate were selectively increased in Arabidopsis via both PIP-dependent and-independent ways.This study unveils the potential mechanism of the fungus-mediated beneficial promotion of plant immunity against biological stresses.The data also highlight the added values of M.robertsii to plants beyond the direct suppression of insect pest populations.展开更多
Esophageal squamous cell carcinoma(ESCC)is a major histological subtype of esophageal cancer with a poor prognosis.Although several serum metabolomic investigations have been reported,ESCC tumor-associated metabolic a...Esophageal squamous cell carcinoma(ESCC)is a major histological subtype of esophageal cancer with a poor prognosis.Although several serum metabolomic investigations have been reported,ESCC tumor-associated metabolic alterations and predictive biomarkers in sera have not been defined.Here,we enrolled 34 treatment-naive patients with ESCC and collected their pre-and post-esophagectomy sera together with the sera from 34 healthy volunteers for a metabolomic survey.Our comprehensive analysis identified ESCC tumor-associated metabolic alterations as represented by a panel of 12 serum metabolites.Notably,postoperative abrosia and parenteral nutrition substantially perturbed the serum metabolome.Furthermore,we performed an examination using sera from carcinogen-induced mice at the dysplasia and ESCC stages and identified three ESCC tumor-associated metabolites conserved between mice and humans.Notably,among these metabolites,the level of pipecolic acid was observed to be progressively increased in mouse sera from dysplasia to cancerization,and it could be used to accurately discriminate between mice at the dysplasia stage and healthy control mice.Furthermore,this metabolite is essential for ESCC cells to restrain oxidative stress-induced DNA damage and cell proliferation arrest.Together,this study revealed a panel of 12 ESCC tumor-associated serum metabolites with potential for monitoring therapeutic efficacy and disease relapse,presented evidence for refining parenteral nutrition composition,and highlighted serum pipecolic acid as an attractive biomarker for predicting ESCC tumorigenesis.展开更多
Chloroplasts are central to plant immunity,with the chloroplast-localized protein AGD2-LIKE DEFENSE RESPONSE PROTEIN 1(ALD1)playing a critical role in producing pipecolic acid(Pip),a key immune signal.However,the regu...Chloroplasts are central to plant immunity,with the chloroplast-localized protein AGD2-LIKE DEFENSE RESPONSE PROTEIN 1(ALD1)playing a critical role in producing pipecolic acid(Pip),a key immune signal.However,the regulation of ALD1 and how pathogens evade ALD1-mediated defenses remain poorly understood.Using the geminivirus tomato yellow leaf curl China virus and its associated betasatellite(TYLCCNV/TYLCCNB)as a model,we uncovered a defense mechanism involving organellar single-stranded DNA-binding protein 1(OSB1),which stabilizes ALD1 and promotes Pip biosynthesis to strengthen immunity.Crucially,the viralβC1 effector encoded by TYLCCNB disrupts this pathway by binding OSB1 and sequestering it away from chloroplasts,thereby blocking OSB1-ALD1 interaction,destabilizing ALD1,and suppressing Pip-dependent defenses.Strikingly,βC1 mutants defective in OSB1 binding fail to interfere with the OSB1-ALD1 stability,and TYLCCNV infections carrying these mutants induce attenuated symptoms in Nicotiana benthamiana.Our study not only reveals how ALD1-OSB1 cooperates in chloroplast immunity but also demonstrates how geminiviruses,as a tractable model,can dissect pathogen counter-defense strategies.展开更多
基金This work was supported by grants to M.F.T.from Michigan AgBioRe-search(M1CL02415)the MSU Foundation and infrastructure support from the Chemical Sciences,Geosciences,and Biosciences Division,Of fice of Basic Energy Sciences,US Department of Energy(DE-FG02-91ER20021).
文摘The Arabidopsis thaliana Calmodulin-binding Transcription Activator(CAMTA)transcription factors CAMTA1,CAMTA2,and CAMTA3(CAMTA123)serve as master regulators of salicylic acid(SA)-mediated immunity,repressing the biosynthesis of SA in healthy plants.Here,we show that CAMTA123 also repress the biosynthesis of pipecolic acid(Pip)in healthy plants.Loss of CAMTA123 function resulted in the induction of AGD2-like defense response protein 1(ALD1),which encodes an enzyme involved in Pip biosynthesis.Induction of ALD1 resulted in the accumulation of high levels of Pip,which brought about increased levels of the SA receptor protein NPR1 without induction of NPR1 expression or requirement for an increase in SA levels.Pip-mediated induction of ALD1 and genes regulating the biosynthesis of SA—CBP60g,SARD1,PAD4,and EDS1—was largely dependent on NPR1.Furthermore,Pip-mediated increase in NPR1 protein levels was associated with priming of Pip and SA biosynthesis genes to induction by low levels of SA.Taken together,our findings expand the role for CAMTA123 in regulating key immunity genes and suggest a working model whereby loss of CAMTA123 repression leads to the induction of plant defense genes and initiation of SAR.
文摘Salicylic acid(SA)has long been known to be essential for basal defense and systemic acquired resistance(SAR).N-Hydroxypipecolic acid(NHP),a recently discovered plant metabolite,also plays a key role in SAR and to a lesser extent in basal resistance.Following pathogen infection,levels of both compounds are dramatically increased.Analysis of SA-or SAR-deficient mutants has uncovered how SA and NHP are biosynthesized.The completion of the SA and NHP biosynthetic pathways in Arabidopsis allowed better understanding of how they are regulated.In this review,we discuss recent progress on SA and NHP biosynthesis and their regulation in plant immunity.
基金supported by the Chinese Academy of Sciences(XDPB16,QYZDJ-SSW-SMC028)the National Natural Science Foundation of China(32021001,31530001)。
文摘The ascomycete insect pathogenic fungi such as Metarhizium species have been demonstrated with the abilities to form the rhizosphere or endophytic relationships with different plants for nutrient exchanges.In this study,after the evident infeasibility of bacterial disease development in the boxed sterile soils,we established a hydroponic system for the gnotobiotic growth of Arabidopsis thaliana with the wild-type and transgenic strain of Metarhizium robertsii.The transgenic fungus could produce a high amount of pipecolic acid(PIP),a pivotal plant-immune-stimulating metabolite.Fungal inoculation experiments showed that M.robertsii could form a non-selective rhizosphere relationship with Arabidopsis.Similar to the PIP uptake by plants after exogenous application,PIP level increased in Col-0 and could be detected in the PIP-non-producing Arabidopsis mutant(ald1)after fungal inoculations,indicating that plants can absorb the PIP produced by fungi.The transgenic fungal strain had a better efficacy than the wild type to defend plants against the bacterial pathogen and aphid attacks.Contrary to ald1,fmo1 plants could not be boosted to resist bacterial infection after treatments.After fungal inoculations,the phytoalexins camalexin and aliphatic glucosinolate were selectively increased in Arabidopsis via both PIP-dependent and-independent ways.This study unveils the potential mechanism of the fungus-mediated beneficial promotion of plant immunity against biological stresses.The data also highlight the added values of M.robertsii to plants beyond the direct suppression of insect pest populations.
基金supported by the National Natural Science Foundation of China(Grant Nos.31970708,81770147,81802891,and 82002953)the National Scientific and Technological Major Special Project of China(Grant No.2019ZX09201004-002-013)+11 种基金the National Thirteenth Five-Year Science and Technology Major Special Project for New Drug Innovation and Development(Grant No.2017ZX09304001)the Research fund of Shanghai Municipal Commission of Health(Grant No.20174Y0090)the Shanghai Rising-Star Program(Grant No.18QA1404100)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learningthe Shanghai Youth Talent Programthe Shanghai Municipal Key Clinical Specialty(Grant No.shslczdzk03701)the Three-Year Plan of Shanghai Municipality for Further Accelerating The Development of Traditional Chinese Medicine[Grant No.ZY(20182020)-CCCX-1016]the Shanghai Chenguang Program(Grant No.18CG47)the grant from Nantong Tumor Hospital(Grant No.BS201909)the Gaofeng Clinical Medicine Grant of Shanghai Municipal Education Commissionthe Health Commission of Pudong New Area Health and Family Planning Scientific Research Project(Grant No.PW2019E-1)the Xinling Scholar Program of Shanghai University of Traditional Chinese Medicine,China。
文摘Esophageal squamous cell carcinoma(ESCC)is a major histological subtype of esophageal cancer with a poor prognosis.Although several serum metabolomic investigations have been reported,ESCC tumor-associated metabolic alterations and predictive biomarkers in sera have not been defined.Here,we enrolled 34 treatment-naive patients with ESCC and collected their pre-and post-esophagectomy sera together with the sera from 34 healthy volunteers for a metabolomic survey.Our comprehensive analysis identified ESCC tumor-associated metabolic alterations as represented by a panel of 12 serum metabolites.Notably,postoperative abrosia and parenteral nutrition substantially perturbed the serum metabolome.Furthermore,we performed an examination using sera from carcinogen-induced mice at the dysplasia and ESCC stages and identified three ESCC tumor-associated metabolites conserved between mice and humans.Notably,among these metabolites,the level of pipecolic acid was observed to be progressively increased in mouse sera from dysplasia to cancerization,and it could be used to accurately discriminate between mice at the dysplasia stage and healthy control mice.Furthermore,this metabolite is essential for ESCC cells to restrain oxidative stress-induced DNA damage and cell proliferation arrest.Together,this study revealed a panel of 12 ESCC tumor-associated serum metabolites with potential for monitoring therapeutic efficacy and disease relapse,presented evidence for refining parenteral nutrition composition,and highlighted serum pipecolic acid as an attractive biomarker for predicting ESCC tumorigenesis.
基金supported by the National Key Research and Development Program of China(2021YFD1400400)to Fangfang Lithe National Natural Science Foundation of China(W2411024)to Xueping Zhou,respectively.
文摘Chloroplasts are central to plant immunity,with the chloroplast-localized protein AGD2-LIKE DEFENSE RESPONSE PROTEIN 1(ALD1)playing a critical role in producing pipecolic acid(Pip),a key immune signal.However,the regulation of ALD1 and how pathogens evade ALD1-mediated defenses remain poorly understood.Using the geminivirus tomato yellow leaf curl China virus and its associated betasatellite(TYLCCNV/TYLCCNB)as a model,we uncovered a defense mechanism involving organellar single-stranded DNA-binding protein 1(OSB1),which stabilizes ALD1 and promotes Pip biosynthesis to strengthen immunity.Crucially,the viralβC1 effector encoded by TYLCCNB disrupts this pathway by binding OSB1 and sequestering it away from chloroplasts,thereby blocking OSB1-ALD1 interaction,destabilizing ALD1,and suppressing Pip-dependent defenses.Strikingly,βC1 mutants defective in OSB1 binding fail to interfere with the OSB1-ALD1 stability,and TYLCCNV infections carrying these mutants induce attenuated symptoms in Nicotiana benthamiana.Our study not only reveals how ALD1-OSB1 cooperates in chloroplast immunity but also demonstrates how geminiviruses,as a tractable model,can dissect pathogen counter-defense strategies.
