Two-line hybrid breeding can fully utilize heterosis in crops.In thermo-sensitive genic male sterile(TGMS)lines,low critical sterility-inducing temperature(CSIT)is vital to safeguard the production of two-line hybrid ...Two-line hybrid breeding can fully utilize heterosis in crops.In thermo-sensitive genic male sterile(TGMS)lines,low critical sterility-inducing temperature(CSIT)is vital to safeguard the production of two-line hybrid seeds in rice(Oryza sativa),but the molecular mechanism determining CSIT is unclear.Here,we report the cloning of CSIT1,which encodes an E3 ubiquitin ligase,and show that CSIT1 modulates the CSIT of thermo-sensitive genic male sterility 5(tms5)-based TGMS lines through ribosome-associated quality control(RQC).Biochemical assays demonstrated that CSIT1 binds to the 80S ribosomes and ubiquitinates abnormal nascent polypeptides for degradation in the RQC process.Loss of CSIT1 function inhibits the possible damage of tms5 to the ubiquitination system and protein translation,resulting in enhanced accumulation of anther-related proteins such as catalase to suppress abnormal accumulation of reactive oxygen species and premature programmed cell death in the tapetum,thereby leading to a much higher CSIT in the tms5-based TGMS lines.Taken together,our findings reveal a regulatory mechanism of CSIT,providing new insights into RQC and potential targets for future two-line hybrid breeding.展开更多
Thermo-sensitive genic male-sterile(TGMS)lines are fertile at lower temperatures but male sterile above a critical sterility-inducing temperature(CSIT),which varies substantially across TGMS lines.Such lines are valua...Thermo-sensitive genic male-sterile(TGMS)lines are fertile at lower temperatures but male sterile above a critical sterility-inducing temperature(CSIT),which varies substantially across TGMS lines.Such lines are valuable resources for breeding two-line hybrid rice(Oryza sativa).However,as their utility is restricted by the CSIT,understanding its regulatory mechanisms has crucial breeding-associated implications.The thermo-sensitive genic male sterility 5(tms5)mutation is common to most TGMS lines.We previously revealed that tms5 mutants failed to recycle cyclic phosphate(cP)-containingΔCCA-tRNAs,particularly in pollen mother cells,resulting in fewer mature tRNAs,thereby causing TGMS.However,the CSIT-regulatory network in the tms5 lines remains unelucidated.Here,we characterized the CSITrelated ribosome-associated quality control 1(OsRqc1)gene.OsRqc1 binds to the 60S ribosomal subunits and functions in ribosomeassociated quality control.It also regulates the CSIT in tms5 lines by assisting OsVms1 in recruiting these subunits to generate cP-ΔCCAtRNAs.Variations in a 6-bp repeat in the 5′untranslated region of OsRqc1 in rice subspecies affect its transcription,thereby altering the CSIT in tms5 lines.These findings reveal the role of an OsRqc1-OsVms1 module in regulating CSIT,providing valuable insights into genetic variations in OsRqc1.Such results may facilitate the molecular breeding of rice two-line hybrid tms5 lines with specific CSITs,which can adapt to regions with different environments.展开更多
基金supported by the Open Competition Program of Top Ten Critical Priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province(2022SDZG05)the National Natural Science Foundation of China(31921004,32172017,32101775,and 32172097)+4 种基金the Guangdong Basic and Applied Research Foundation(2019B030302006 and 2022B1515120036)the Laboratory of Lingnan Modern Agriculture Project(NZ2021002 and NT2021002)the China Postdoctoral Science Foundation(2021M691086)the Natural Science Foundation of Guangdong Province(2022A1515012496)the Double First-Class Discipline Promotion Project(2021B10564001 and 2023B10564004).
文摘Two-line hybrid breeding can fully utilize heterosis in crops.In thermo-sensitive genic male sterile(TGMS)lines,low critical sterility-inducing temperature(CSIT)is vital to safeguard the production of two-line hybrid seeds in rice(Oryza sativa),but the molecular mechanism determining CSIT is unclear.Here,we report the cloning of CSIT1,which encodes an E3 ubiquitin ligase,and show that CSIT1 modulates the CSIT of thermo-sensitive genic male sterility 5(tms5)-based TGMS lines through ribosome-associated quality control(RQC).Biochemical assays demonstrated that CSIT1 binds to the 80S ribosomes and ubiquitinates abnormal nascent polypeptides for degradation in the RQC process.Loss of CSIT1 function inhibits the possible damage of tms5 to the ubiquitination system and protein translation,resulting in enhanced accumulation of anther-related proteins such as catalase to suppress abnormal accumulation of reactive oxygen species and premature programmed cell death in the tapetum,thereby leading to a much higher CSIT in the tms5-based TGMS lines.Taken together,our findings reveal a regulatory mechanism of CSIT,providing new insights into RQC and potential targets for future two-line hybrid breeding.
基金supported by the Biological Breeding-National Science and Technology Major Project of China(2023ZD04073)the Biological Breeding-Major Projects(2023ZD04076)+1 种基金the National Key Research and Development Program of China(2020YFA0509900)the National Natural Science Foundation of China(32330019,32471307,32171284,32370633,32170620).
文摘Thermo-sensitive genic male-sterile(TGMS)lines are fertile at lower temperatures but male sterile above a critical sterility-inducing temperature(CSIT),which varies substantially across TGMS lines.Such lines are valuable resources for breeding two-line hybrid rice(Oryza sativa).However,as their utility is restricted by the CSIT,understanding its regulatory mechanisms has crucial breeding-associated implications.The thermo-sensitive genic male sterility 5(tms5)mutation is common to most TGMS lines.We previously revealed that tms5 mutants failed to recycle cyclic phosphate(cP)-containingΔCCA-tRNAs,particularly in pollen mother cells,resulting in fewer mature tRNAs,thereby causing TGMS.However,the CSIT-regulatory network in the tms5 lines remains unelucidated.Here,we characterized the CSITrelated ribosome-associated quality control 1(OsRqc1)gene.OsRqc1 binds to the 60S ribosomal subunits and functions in ribosomeassociated quality control.It also regulates the CSIT in tms5 lines by assisting OsVms1 in recruiting these subunits to generate cP-ΔCCAtRNAs.Variations in a 6-bp repeat in the 5′untranslated region of OsRqc1 in rice subspecies affect its transcription,thereby altering the CSIT in tms5 lines.These findings reveal the role of an OsRqc1-OsVms1 module in regulating CSIT,providing valuable insights into genetic variations in OsRqc1.Such results may facilitate the molecular breeding of rice two-line hybrid tms5 lines with specific CSITs,which can adapt to regions with different environments.
