3-hydroxy-3methylglutaryl Coenzyme A reductase, the rate limiting enzyme of mevalonate pathway, generates, in addition to cholesterol, a range of products involved in several biological functions: oligoprenyl groups, ...3-hydroxy-3methylglutaryl Coenzyme A reductase, the rate limiting enzyme of mevalonate pathway, generates, in addition to cholesterol, a range of products involved in several biological functions: oligoprenyl groups, dolichol and ubiquinone. The latter, in particular, participates in electron transport chain and, in turn, in tissue energy supply. The enzyme is inhibited by statins that, besides lowering cholesterolemia, seem to impair human energy-dependent myocardial functions (e.g. stroke volume, cardiac output, and contractile index). The modulation of heart contractile properties could be explained by the decrease of ventricle ubiquinone content and/or by putative changes in proportion of the different myosin heavy chain isoforms. Since we previously demonstrated that chronic statin treatment modifies myosin heavy chain isoform pattern in skeletal muscle impairing its functional properties, this work was aimed at investigating the effects of statin chronic treatment on both ventricle ubiquinone content and myosin heavy chain isoforms. Our results showed that simvastatin treatment leads to a reduced amount of rat ventricle ubiquinone and to β myosin heavy chain disappearance. Thus, statins which are prescribed to prevent cardiovascular disease, might induce cardiac metabolic and structural modifications whose functional implications on contractility are still to be established and carefully considered.展开更多
Fruit pigmentation is a major signal that attracts frugivores to enable seed dispersal.In mostfleshy fruit,green chlorophyll typically accumulates early in development and is replaced by a range of pigments during rip...Fruit pigmentation is a major signal that attracts frugivores to enable seed dispersal.In mostfleshy fruit,green chlorophyll typically accumulates early in development and is replaced by a range of pigments during ripening.In species such as grape and strawberry,chlorophyll is replaced by red anthocyanins produced by theflavonoid biosynthetic pathway.Eggplant(Solanum melongena)is unique,as its fruit accumulates an-thocyanins beginning from fruit set,and these are later replaced by the yellowflavonoid-pathway interme-diate naringenin chalcone.To decipher the genetic regulation of this extraordinary pigmentation shift,we integrated mRNA and microRNA(miRNA)profiling data obtained from developing eggplant fruit.We discovered that SQUAMOSA PROMOTER BINDING-LIKE(i.e.,SPL6a,SPL10,and SPL15),MYB1,and MYB2 transcription factors(TFs)regulate anthocyanin biosynthesis in early fruit development,whereas the MYB12 TF controls later accumulation of naringenin chalcone.We further show that miRNA157 and miRNA858 negatively regulate the expression of SPLs and MYB12,respectively.Taken together,ourfind-ings suggest that opposing and complementary expression of miRNAs and TFs controls the pigmentation switch in eggplant fruit skin.Intriguingly,despite the distinctive pigmentation pattern in eggplant,fruit development in other species makes use of homologous regulatory factors to control the temporal and spatial production of different pigment classes.展开更多
N-hydroxy-pipecolic acid(NHP)activates plant systemic acquired resistance(SAR).Enhanced defense responses are typically accompanied by deficiency in plant development and reproduction.Despite of extensive studies on S...N-hydroxy-pipecolic acid(NHP)activates plant systemic acquired resistance(SAR).Enhanced defense responses are typically accompanied by deficiency in plant development and reproduction.Despite of extensive studies on SAR induction,the effects of NHPmetabolismon plant growth remain largely unclear.In this study,we discovered that NHP glycosylation is a critical factor that fine-tunes the tradeoff between SAR defense and plant growth.We demonstrated that a UDP-glycosyltransferase(UGT76B1)forming NHP glycoside(NHPG)controls the NHP to NHPG ratio.Consistently,the ugt76b1 mutant exhibits enhanced SAR response and an inhibitory effect on plant growth,while UGT76B1 overexpression attenuates SAR response,promotes growth,and delays senescence,indicating that NHP levels are dependent on UGT76B1 function in the course of SAR.Furthermore,our results suggested that,upon pathogen attack,UGT76B1-mediated NHP glycosylation forms a‘‘hand brake’’on NHP accumulation by attenuating the positive regulation of NHP biosynthetic pathway genes,highlighting the complexity of SAR-associated networks.In addition,we showed that UGT76B1-mediated NHP glycosylation in the local site is important for fine-tuning SAR response.Our results implicate that engineering plant immunity through manipulating the NHP/NHPG ratio is a promising method to balance growth and defense response in crops.展开更多
文摘3-hydroxy-3methylglutaryl Coenzyme A reductase, the rate limiting enzyme of mevalonate pathway, generates, in addition to cholesterol, a range of products involved in several biological functions: oligoprenyl groups, dolichol and ubiquinone. The latter, in particular, participates in electron transport chain and, in turn, in tissue energy supply. The enzyme is inhibited by statins that, besides lowering cholesterolemia, seem to impair human energy-dependent myocardial functions (e.g. stroke volume, cardiac output, and contractile index). The modulation of heart contractile properties could be explained by the decrease of ventricle ubiquinone content and/or by putative changes in proportion of the different myosin heavy chain isoforms. Since we previously demonstrated that chronic statin treatment modifies myosin heavy chain isoform pattern in skeletal muscle impairing its functional properties, this work was aimed at investigating the effects of statin chronic treatment on both ventricle ubiquinone content and myosin heavy chain isoforms. Our results showed that simvastatin treatment leads to a reduced amount of rat ventricle ubiquinone and to β myosin heavy chain disappearance. Thus, statins which are prescribed to prevent cardiovascular disease, might induce cardiac metabolic and structural modifications whose functional implications on contractility are still to be established and carefully considered.
基金the Abney Foundation,Leona M.and Harry B.Helmsley Charitable TrustJeanne and Joseph Nissim Foundation for Life Sciences+1 种基金Tom and Sondra Rykoff Family Foundation Researchthe Raymond Burton Plant Genome Research Fund for supporting the AA lab activity.
文摘Fruit pigmentation is a major signal that attracts frugivores to enable seed dispersal.In mostfleshy fruit,green chlorophyll typically accumulates early in development and is replaced by a range of pigments during ripening.In species such as grape and strawberry,chlorophyll is replaced by red anthocyanins produced by theflavonoid biosynthetic pathway.Eggplant(Solanum melongena)is unique,as its fruit accumulates an-thocyanins beginning from fruit set,and these are later replaced by the yellowflavonoid-pathway interme-diate naringenin chalcone.To decipher the genetic regulation of this extraordinary pigmentation shift,we integrated mRNA and microRNA(miRNA)profiling data obtained from developing eggplant fruit.We discovered that SQUAMOSA PROMOTER BINDING-LIKE(i.e.,SPL6a,SPL10,and SPL15),MYB1,and MYB2 transcription factors(TFs)regulate anthocyanin biosynthesis in early fruit development,whereas the MYB12 TF controls later accumulation of naringenin chalcone.We further show that miRNA157 and miRNA858 negatively regulate the expression of SPLs and MYB12,respectively.Taken together,ourfind-ings suggest that opposing and complementary expression of miRNAs and TFs controls the pigmentation switch in eggplant fruit skin.Intriguingly,despite the distinctive pigmentation pattern in eggplant,fruit development in other species makes use of homologous regulatory factors to control the temporal and spatial production of different pigment classes.
基金We are grateful to the Adelis Foundation,the Leona M.and Harry B.Helmsley Charitable Trust,the Jeanne and Joseph Nissim Foundation for Life Sciences,and especially the Tom and Sondra Rykoff Family Foundation Research for supporting the A.A.laboratory activityJ.C.was supported by the PBC(Public and Budgeting Committee)of the State of Israel Council for Higher Education fellowship program.A.A.is the incumbent of the Peter J.Cohn Professorial Chair
文摘N-hydroxy-pipecolic acid(NHP)activates plant systemic acquired resistance(SAR).Enhanced defense responses are typically accompanied by deficiency in plant development and reproduction.Despite of extensive studies on SAR induction,the effects of NHPmetabolismon plant growth remain largely unclear.In this study,we discovered that NHP glycosylation is a critical factor that fine-tunes the tradeoff between SAR defense and plant growth.We demonstrated that a UDP-glycosyltransferase(UGT76B1)forming NHP glycoside(NHPG)controls the NHP to NHPG ratio.Consistently,the ugt76b1 mutant exhibits enhanced SAR response and an inhibitory effect on plant growth,while UGT76B1 overexpression attenuates SAR response,promotes growth,and delays senescence,indicating that NHP levels are dependent on UGT76B1 function in the course of SAR.Furthermore,our results suggested that,upon pathogen attack,UGT76B1-mediated NHP glycosylation forms a‘‘hand brake’’on NHP accumulation by attenuating the positive regulation of NHP biosynthetic pathway genes,highlighting the complexity of SAR-associated networks.In addition,we showed that UGT76B1-mediated NHP glycosylation in the local site is important for fine-tuning SAR response.Our results implicate that engineering plant immunity through manipulating the NHP/NHPG ratio is a promising method to balance growth and defense response in crops.
