Gibberellin(GA)is one of the major plant hormones that promote parthenocarpy,a highly valuable agronomic trait.Here,we demonstrated that exogenous GA3application triggered the formation of parthenocarpic fruits with s...Gibberellin(GA)is one of the major plant hormones that promote parthenocarpy,a highly valuable agronomic trait.Here,we demonstrated that exogenous GA3application triggered the formation of parthenocarpic fruits with smaller size but unchanged shape in tomato(Solanum lycopersicum).These fruits exhibited a thicker pericarp,undeveloped ovules,and few jelly tissues,leading to smaller locules with empty cavities.Histological investigation showed that GA treatment produced more cell layers with larger cells in the pericarp,suggesting its promotion in both cell division and expansion.Transcriptomic analyses between GA-3and mock-treated unpollinated ovaries/fruits identified a large number of differentially expressed genes related to hormones,cell division,cell expansion,and transcription factors,implying that they coordinately regulated parthenocarpy conferred by GA.In particular,the downregulation of five reported repressors of tomato parthenocarpy,including two auxin signaling components,AUXIN RESPONSE FACTOR5(SlARF5)and Sl ARF7,and three MADS-box genes,TOMATO APETALA3(TAP3),TOMATO PISTILLATA(TPI),and AGAMOUS-LIKE6(SlAGL6),after GA treatment might play a key role in this process.Furthermore,we found that the knockdown of a GA signaling factor SlMYB33,which was depressed by GA treatment,induced parthenocarpic fruit set in tomato,an effect that might have been achieved by enhancing GA biosynthesis and decreasing the expression of some repressors of tomato parthenocarpy.Thus,our results provide a basis for understanding the regulatory mechanism of GA in tomato parthenocarpy.展开更多
Polyamines(PAs)and ethylene are involved in the modulation of plant growth and development.However,their roles in fruit-set,especially in exogenous gibberellin(GA_(3))-induced grape parthenocarpic berries,and the rela...Polyamines(PAs)and ethylene are involved in the modulation of plant growth and development.However,their roles in fruit-set,especially in exogenous gibberellin(GA_(3))-induced grape parthenocarpic berries,and the related competitive action mode are poorly understood.For this,we,here performed their content determination,bioinformatics and expression pattern analysis of genes to identify the key ones in the competitive network of polyamines metabolic and ethylene biosynthesis(PMEB)pathways.The content of putrescine(Put)significantly increased;while 1-aminocyclopropanecarboxylic acid(ACC)sharply decreased during the fruit-set process of GA_(3)-induced grape parthenocarpic seedless berries.Totally,twenty-five genes in PMEB pathways,including 20 polyamines metabolic(PM)genes and 5 ethylene biosynthesis(EB)ones were identified in grape,of which 8 PM and 2 EB genes possessed the motifs responsive to phytohormone GA.The expression levels of most PMEB genes kept changing during grape fruit-set generating a competitive action mode of GA_(3)-mediated two metabolic fluxes toward PAs and ethylene synthesis.Exogenous GA_(3)might enhance grape fruit-set of parthenocarpic berries via up-regulation of VvSAMS4,VvSAMDC1/2,VvODC1,VvSPDS1,and VvPAO1 to promote PAs accumulation,whereby repressing the ethylene synthesis by down-regulation of VvACS1 and VvACO_(2).Our findings provide novel insights into GA_(3)-mediated competitive inhibition of ethylene by PAs to promote the fruit-set of parthenocarpic berries in grape,which has important implications for molecular breeding of seedless grape with high fruit-setting rate.展开更多
Fruit set is inhibited by adverse temperatures,with consequences on yield.We isolated a tomato mutant producing fruits under non-permissive hot temperatures and identified the causal gene as SIHB15A,belonging to class...Fruit set is inhibited by adverse temperatures,with consequences on yield.We isolated a tomato mutant producing fruits under non-permissive hot temperatures and identified the causal gene as SIHB15A,belonging to classⅢhomeodomain leucine-zipper transcription factors.SIHB15A,loss-of-function mu-tants display aberrant ovule development that mimics transcriptional changes occurring in fertilized ovules and leads to parthenocarpic fruit set under optimal and non-permissive temperatures,in field and greenhouse conditions.Under cold growing conditions,SIHB15A is subjected to conditional haploinsufficiency and recessive dosage sensitivity controlled by microRNA 166(miR166).Knockdown of SIHB15A alleles by miR166 leads to a continuum of aberrant ovules correlating with parthenocarpic fruit set.Consistent with this,plants harboring an Slhb15a-miRNA166-resisiant allele developed normal ovules and were unable to set parthenocarpic fruit under cold conditions.DNA affinity purification sequencing and RNA-sequencing analyses revealed that SIHB15A is a bifunctional transcription factor expressed in the ovule integument.SIHB15A binds to the promoters of auxin-related genes to repress auxin signaling and to the promoters of ethylene-related genes to activate their expression.A survey of tomato genetic biodiversity identified pat and pat-1,two historical parthenocarpic mutants,as alleles of SIHB15A.Taken together,our findings demonstrate the role of SIHB15A as a sentinel to prevent fruit set in the absence of fertilization and provide a mean to enhance fruiting under extreme temperatures.展开更多
基金supported by the Key Program of Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2021JZ-13)。
文摘Gibberellin(GA)is one of the major plant hormones that promote parthenocarpy,a highly valuable agronomic trait.Here,we demonstrated that exogenous GA3application triggered the formation of parthenocarpic fruits with smaller size but unchanged shape in tomato(Solanum lycopersicum).These fruits exhibited a thicker pericarp,undeveloped ovules,and few jelly tissues,leading to smaller locules with empty cavities.Histological investigation showed that GA treatment produced more cell layers with larger cells in the pericarp,suggesting its promotion in both cell division and expansion.Transcriptomic analyses between GA-3and mock-treated unpollinated ovaries/fruits identified a large number of differentially expressed genes related to hormones,cell division,cell expansion,and transcription factors,implying that they coordinately regulated parthenocarpy conferred by GA.In particular,the downregulation of five reported repressors of tomato parthenocarpy,including two auxin signaling components,AUXIN RESPONSE FACTOR5(SlARF5)and Sl ARF7,and three MADS-box genes,TOMATO APETALA3(TAP3),TOMATO PISTILLATA(TPI),and AGAMOUS-LIKE6(SlAGL6),after GA treatment might play a key role in this process.Furthermore,we found that the knockdown of a GA signaling factor SlMYB33,which was depressed by GA treatment,induced parthenocarpic fruit set in tomato,an effect that might have been achieved by enhancing GA biosynthesis and decreasing the expression of some repressors of tomato parthenocarpy.Thus,our results provide a basis for understanding the regulatory mechanism of GA in tomato parthenocarpy.
基金supported by grants from Jiangsu province seed industry revitalization of the leading project(JBGS[2021]086)the National Natural Science Funds(31972373,32272647,32202433)+1 种基金the Provincial Natural Science Foundation of Jiangsu(BK20200541)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD),and Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX22_0754,SJCX23-0209).
文摘Polyamines(PAs)and ethylene are involved in the modulation of plant growth and development.However,their roles in fruit-set,especially in exogenous gibberellin(GA_(3))-induced grape parthenocarpic berries,and the related competitive action mode are poorly understood.For this,we,here performed their content determination,bioinformatics and expression pattern analysis of genes to identify the key ones in the competitive network of polyamines metabolic and ethylene biosynthesis(PMEB)pathways.The content of putrescine(Put)significantly increased;while 1-aminocyclopropanecarboxylic acid(ACC)sharply decreased during the fruit-set process of GA_(3)-induced grape parthenocarpic seedless berries.Totally,twenty-five genes in PMEB pathways,including 20 polyamines metabolic(PM)genes and 5 ethylene biosynthesis(EB)ones were identified in grape,of which 8 PM and 2 EB genes possessed the motifs responsive to phytohormone GA.The expression levels of most PMEB genes kept changing during grape fruit-set generating a competitive action mode of GA_(3)-mediated two metabolic fluxes toward PAs and ethylene synthesis.Exogenous GA_(3)might enhance grape fruit-set of parthenocarpic berries via up-regulation of VvSAMS4,VvSAMDC1/2,VvODC1,VvSPDS1,and VvPAO1 to promote PAs accumulation,whereby repressing the ethylene synthesis by down-regulation of VvACS1 and VvACO_(2).Our findings provide novel insights into GA_(3)-mediated competitive inhibition of ethylene by PAs to promote the fruit-set of parthenocarpic berries in grape,which has important implications for molecular breeding of seedless grape with high fruit-setting rate.
基金INRAE,CNRS,and the LabEx Saclay Plant Sciences-SPS(ANR-10-LABX-40-SPS)The A.B.team received funding from the European Research Council(ERC-SEXYPARTH,341076)from the Horizon 2020 research and innovation program(TOMRES,727929).
文摘Fruit set is inhibited by adverse temperatures,with consequences on yield.We isolated a tomato mutant producing fruits under non-permissive hot temperatures and identified the causal gene as SIHB15A,belonging to classⅢhomeodomain leucine-zipper transcription factors.SIHB15A,loss-of-function mu-tants display aberrant ovule development that mimics transcriptional changes occurring in fertilized ovules and leads to parthenocarpic fruit set under optimal and non-permissive temperatures,in field and greenhouse conditions.Under cold growing conditions,SIHB15A is subjected to conditional haploinsufficiency and recessive dosage sensitivity controlled by microRNA 166(miR166).Knockdown of SIHB15A alleles by miR166 leads to a continuum of aberrant ovules correlating with parthenocarpic fruit set.Consistent with this,plants harboring an Slhb15a-miRNA166-resisiant allele developed normal ovules and were unable to set parthenocarpic fruit under cold conditions.DNA affinity purification sequencing and RNA-sequencing analyses revealed that SIHB15A is a bifunctional transcription factor expressed in the ovule integument.SIHB15A binds to the promoters of auxin-related genes to repress auxin signaling and to the promoters of ethylene-related genes to activate their expression.A survey of tomato genetic biodiversity identified pat and pat-1,two historical parthenocarpic mutants,as alleles of SIHB15A.Taken together,our findings demonstrate the role of SIHB15A as a sentinel to prevent fruit set in the absence of fertilization and provide a mean to enhance fruiting under extreme temperatures.
