Activation of plant immunity is commonly associated with the biosynthesis of defense-related metabolites,such as jasmonic acid(JA)and salicylic acid(SA).However,constitutive activation of the immune response or excess...Activation of plant immunity is commonly associated with the biosynthesis of defense-related metabolites,such as jasmonic acid(JA)and salicylic acid(SA).However,constitutive activation of the immune response or excessive accumulation of defense metabolites often negatively impacts plant growth.The regulatory mechanisms underlying the trade-off between plant immunity and growth remain elusive.In this study,we identified a homeobox transcription factor,HB34,as a key regulator that balances plant immunity and growth by differentially regulating the expression of JA biosynthetic and growth-related genes in Arabidopsis.Loss of HB34 enhances plant resistance to the necrotrophic pathogen Botrytis cinerea but impairs plant growth and development,accompanied by constitutive activation of JA-responsive genes.Mechanistically,HB34 negatively regulates the transcription of JA biosynthetic genes to suppress JA accumulation,and blocking JA biosynthesis attenuates the enhanced Botrytis cinerea resistance of hb34.Conversely,HB34 enhances the transcription of growth-related genes,whereas overexpression of these genes partially rescues growth defects,thereby decoupling the trade-off between enhanced defense and impaired plant growth.Our findings reveal a novel mechanism whereby a single transcription factor fine-tunes the trade-off between plant growth and immunity by differentially regulating JA biosynthetic and growth-related genes in Arabidopsis.展开更多
UDP-glycosyltransferases (UGTs) constitute the largest glycosyltransferase family in the plant kingdom,regulating many metabolic processes by transferring sugar moieties onto various small molecules. How-ever, their p...UDP-glycosyltransferases (UGTs) constitute the largest glycosyltransferase family in the plant kingdom,regulating many metabolic processes by transferring sugar moieties onto various small molecules. How-ever, their physiological significance in plants remains largely unknown. Here, we reveal the functionsand mechanisms of two Arabidopsis UGT genes, UGT73C3 and UGT73C4, which are strongly induced byPseudomonas syringae pv. tomato (Pst) DC3000. Overexpression of these genes significantly enhancedplant immune response, whereas their loss of function in double mutants led to increased sensitivity topathogen infections. However, single mutants showed no obvious alteration in pathogen resistance. Tofurther investigate the regulatory mechanisms of UGT73C3/C4 in plant immunity, we conducted compre-hensive secondary metabolome analyses and glycoside quantification. Overexpression lines accumulatedhigher levels of pinoresinol diglucosides than wild-type plants, both before and after Pst DC3000 treatment,whereas double mutants accumulated lower levels. Furthermore, in vitro and in vivo experiments demon-strated that UGT73C3 and UGT73C4 can glycosylate pinoresinol to form pinoresinol monoglucoside anddiglucoside. Moreover, pinoresinol glycosylation promotes the plant immune response by increasing reac-tive oxygen species production and callose deposition. Additionally, the transcription factor HB34 wasfound to activate UGT73C3 and UGT73C4 transcription and play a key role in plant immunity. Overall,this study reveals a novel pathway in which UGT73C3/C4-mediated pinoresinol glycosylation, regulatedby HB34, enhances the plant immune response.展开更多
Biomimetic scaffolds with extracellular matrix(ECM)-mimicking structure have been widely investigated in wound healing applications,while insufficient mechanical strength and limited biological activity remain major c...Biomimetic scaffolds with extracellular matrix(ECM)-mimicking structure have been widely investigated in wound healing applications,while insufficient mechanical strength and limited biological activity remain major challenges.Here,we present a microfluidic 3D printing biomimetic polyhydroxyalkanoates-based scaffold with excellent mechanical properties and hierarchical porous structures for enhanced wound healing.This scaffold is composed of poly(3-hydroxybutyrate-4-hydroxybutyrate)and polycaprolactone,endowing it with excellent tensile strength(2.99 MPa)and degradability(80%of weight loss within 7 d).The ECM-mimicking hierarchical porous structure allows bone marrow mesenchymal stem cells(BMSCs)and human umbilical vein endothelial cells(HUVECs)to proliferate and adhere on the scaffolds.Besides,anisotropic composite scaffolds loaded with BMSCs and HUVECs can significantly promote re-epithelization,collagen deposition and capillary formation in rat wound defects,indicating their satisfactory in vivo tissue regenerative activity.These results indicate the feasibility of polyhydroxyalkanoates-based biomimetic scaffolds for skin repair and regeneration,which also provide a promising therapeutic strategy in diverse tissue engineering applications.展开更多
基金supported by the Zhejiang Science and Technology Major Program on Agricultural New Variety Breeding(grant no.2021C02064)the National Natural Science Foundation of China(grant no.31970534)the National Youth Talent Support Program.
文摘Activation of plant immunity is commonly associated with the biosynthesis of defense-related metabolites,such as jasmonic acid(JA)and salicylic acid(SA).However,constitutive activation of the immune response or excessive accumulation of defense metabolites often negatively impacts plant growth.The regulatory mechanisms underlying the trade-off between plant immunity and growth remain elusive.In this study,we identified a homeobox transcription factor,HB34,as a key regulator that balances plant immunity and growth by differentially regulating the expression of JA biosynthetic and growth-related genes in Arabidopsis.Loss of HB34 enhances plant resistance to the necrotrophic pathogen Botrytis cinerea but impairs plant growth and development,accompanied by constitutive activation of JA-responsive genes.Mechanistically,HB34 negatively regulates the transcription of JA biosynthetic genes to suppress JA accumulation,and blocking JA biosynthesis attenuates the enhanced Botrytis cinerea resistance of hb34.Conversely,HB34 enhances the transcription of growth-related genes,whereas overexpression of these genes partially rescues growth defects,thereby decoupling the trade-off between enhanced defense and impaired plant growth.Our findings reveal a novel mechanism whereby a single transcription factor fine-tunes the trade-off between plant growth and immunity by differentially regulating JA biosynthetic and growth-related genes in Arabidopsis.
文摘UDP-glycosyltransferases (UGTs) constitute the largest glycosyltransferase family in the plant kingdom,regulating many metabolic processes by transferring sugar moieties onto various small molecules. How-ever, their physiological significance in plants remains largely unknown. Here, we reveal the functionsand mechanisms of two Arabidopsis UGT genes, UGT73C3 and UGT73C4, which are strongly induced byPseudomonas syringae pv. tomato (Pst) DC3000. Overexpression of these genes significantly enhancedplant immune response, whereas their loss of function in double mutants led to increased sensitivity topathogen infections. However, single mutants showed no obvious alteration in pathogen resistance. Tofurther investigate the regulatory mechanisms of UGT73C3/C4 in plant immunity, we conducted compre-hensive secondary metabolome analyses and glycoside quantification. Overexpression lines accumulatedhigher levels of pinoresinol diglucosides than wild-type plants, both before and after Pst DC3000 treatment,whereas double mutants accumulated lower levels. Furthermore, in vitro and in vivo experiments demon-strated that UGT73C3 and UGT73C4 can glycosylate pinoresinol to form pinoresinol monoglucoside anddiglucoside. Moreover, pinoresinol glycosylation promotes the plant immune response by increasing reac-tive oxygen species production and callose deposition. Additionally, the transcription factor HB34 wasfound to activate UGT73C3 and UGT73C4 transcription and play a key role in plant immunity. Overall,this study reveals a novel pathway in which UGT73C3/C4-mediated pinoresinol glycosylation, regulatedby HB34, enhances the plant immune response.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2020YFA0908200)the National Natural Science Foundation of China(Grant Nos.52073060 and 61927805)the Sun Yat-sen University Clinical Research 5010 Program(Grant No.2017008).
文摘Biomimetic scaffolds with extracellular matrix(ECM)-mimicking structure have been widely investigated in wound healing applications,while insufficient mechanical strength and limited biological activity remain major challenges.Here,we present a microfluidic 3D printing biomimetic polyhydroxyalkanoates-based scaffold with excellent mechanical properties and hierarchical porous structures for enhanced wound healing.This scaffold is composed of poly(3-hydroxybutyrate-4-hydroxybutyrate)and polycaprolactone,endowing it with excellent tensile strength(2.99 MPa)and degradability(80%of weight loss within 7 d).The ECM-mimicking hierarchical porous structure allows bone marrow mesenchymal stem cells(BMSCs)and human umbilical vein endothelial cells(HUVECs)to proliferate and adhere on the scaffolds.Besides,anisotropic composite scaffolds loaded with BMSCs and HUVECs can significantly promote re-epithelization,collagen deposition and capillary formation in rat wound defects,indicating their satisfactory in vivo tissue regenerative activity.These results indicate the feasibility of polyhydroxyalkanoates-based biomimetic scaffolds for skin repair and regeneration,which also provide a promising therapeutic strategy in diverse tissue engineering applications.
