Rice,a critical global staple crop,relies heavily on heading date,a key agronomic trait marking the transition from vegetative to reproductive growth.Understanding the genetic regulation of heading date is vital for e...Rice,a critical global staple crop,relies heavily on heading date,a key agronomic trait marking the transition from vegetative to reproductive growth.Understanding the genetic regulation of heading date is vital for enhancing the adaptability of high-quality rice varieties across diverse geographical regions and for bolstering local food security.In this study,we uncovered a novel role for OsCATA,a catalase gene,in the regulation of photoperiodic flowering in rice.We identified a novel allele of OsELF3.1,whose mutation resulted in delayed heading.Further analyses revealed that OsELF3.1 physically interacted with OsCATA.Notably,OsCATA exhibited rhythmic expression patterns similar to OsELF3.1 and,when mutated,also delayed flowering.Expression analyses showed that the delayed heading phenotype could be attributed to elevated Ghd7 expression under both long-day and short-day conditions,with OsCATA expression positively regulated by OsELF3.1.Double mutants of OsELF3.1 and OsCATA displayed a heading delay similar to that of oself3.1 single mutants.Additionally,OsELF3.1 could interact with Ghd7 in vivo,alleviating its suppression of Ehd1.Luciferase assays confirmed that Ghd7 repressed Ehd1 expression,while OsELF3.1 mitigated this repression.Collectively,our findings reveal that OsCATA is critical in suppressing Ghd7 expression through the OsELF3.1-OsCATA-Ghd7 transcriptional pathway,thereby regulating rice heading.展开更多
Seed dormancy of cultivated rice was largely weakened during the progress of domestication.Correct timing and uniformity of seed germination are important for rapid seedling establishment and highyield production.In t...Seed dormancy of cultivated rice was largely weakened during the progress of domestication.Correct timing and uniformity of seed germination are important for rapid seedling establishment and highyield production.In the present study,we found that the heading-date gene Ghd7 acted as a negative regulator of germination.A mutant of ghd7 showed low sensitivity to exogenous ABA treatment during seed germination.Further investigation revealed reduced accumulation of ABA in mature ghd7 seeds as a consequence of dampened expression of OsNCED genes.Moreover,elevated GA_(3) level was detected in seeds of ghd7 mutant during imbibition course,which was attributed to the induction of genes responsible for the synthesis pathways of bioactive GAs.Thus,Ghd7 inhibits seed germination by increasing the ABA/GA_(3) ratio.Besides revealing pleiotropic effects of Ghd7,our results indicate its role in linking seed germination to growth-phase transition in rice,which would enrich the theoretical basis for future breeding practices.展开更多
Ghd7 is an important gene involved in the photoperiod flowering pathway in rice.A Ghd7-involved transcriptional regulatory network has been established,but its translational regulatory pathway is poorly understood.The...Ghd7 is an important gene involved in the photoperiod flowering pathway in rice.A Ghd7-involved transcriptional regulatory network has been established,but its translational regulatory pathway is poorly understood.The mutant suppressor of overexpression of Ghd7(sog7)was identified from EMS-induced mutagenesis on the background of ZH11 overexpressing Ghd7.Mut Map analysis revealed that SOG7 is allelic to Ghd8 and delayed flowering under long-day(LD)conditions.Biochemical assays showed that Ghd8 interacts with OsHAP5C and Ghd7 both in vivo and in vitro.Surprisingly,a point mutation E96K in theα2 helix of the Ghd8 histone fold domain(HFD)destroyed its ability to interact with Ghd7.The prediction of the structure shows that mutated amino acid is located in the interaction region of CCT/NF-YB/YC complexes,which alter the structure ofα4 of Ghd8.This structural difference prevents the formation of complex NF-YB/YC.The triple complex of Ghd8-OsHAP5C-Ghd7 directly bound to the promotor of Hd3a and downregulated the expression of Ehd1,Hd3a and RFT1,and finally resulted in a delayed heading.These findings are helpful in deeply understanding the Ghd7-involved photoperiod flowering pathway and promote the elucidation of rice heading.展开更多
Sucrose functions as a signaling molecule in several metabolic pathways as well as in various developmental processes.However,the molecular mechanisms by which sucrose regulates these processes remain largely unknown....Sucrose functions as a signaling molecule in several metabolic pathways as well as in various developmental processes.However,the molecular mechanisms by which sucrose regulates these processes remain largely unknown.In the present study,we demonstrate that sucrose promotes flowering by mediating the stability of a regulatory protein that represses flowering in rice.Exogenous application of sucrose promoted flowering by inducing florigen gene expression.Reduction of sucrose levels in the phloem through genetic modifications,such as the overexpression of the vacuolar invertase OsVIN2 or the mutation of OsSUT2,a sucrose transporter,delayed flowering.Analysis of relative transcript levels of floral regulatory genes showed that sucrose activated Ehd1 upstream of the florigen,with no significant effect on the expression of other upstream genes.Examination of protein stability after sucrose treatment of major floral repressors revealed that the Ghd7 protein was specifically degraded.The Ghd7 protein interacted with the E3 ligase IPA INTERACTING PROTEIN1(IPI1),and sucrose-induced K48-linked polyubiquitination of Ghd7 via IPI1,leading to protein degradation.Mutants defective in IPI1 delayed flowering,confirming its role in modulating proteins involved in flowering.We conclude that sucrose acts as a signaling molecule to induce flowering by promoting Ghd7 degradation via IPI1.展开更多
Heading date and photoperiod sensitivity are fundamental traits that determine rice adaptation to a wide range of geographic environments. By quantitative trait locus （QTL） mapping and candidate gene analysis using ...Heading date and photoperiod sensitivity are fundamental traits that determine rice adaptation to a wide range of geographic environments. By quantitative trait locus （QTL） mapping and candidate gene analysis using whole- genome re-sequencing, we found that Oryza sativa Pseudo-Response Regulator37 （OsPRR37; hereafter PRR37） is respon- sible for the Early heading7-2 （EH7-2）/Heading date2 （Hd2） QTL which was identified from a cross of late-heading rice ＇Milyang23 （M23）＇ and early-heading rice ＇H143＇. H143 contains a missense mutation of an invariantly conserved amino acid in the CCT （CONSTANS, CO-like, and TOC1） domain of PRR37 protein. In the world rice collection, different types of nonfunctional PRR37 alleles were found in many European and Asian rice cultivars. Notably, the japonica varieties harboring nonfunctional alleles of both Ghd7/Hd4 and PRR37/Hd2 flower extremely early under natural long-day condi- tions, and are adapted to the northernmost regions of rice cultivation, up to 53~ N latitude. Genetic analysis revealed that the effects of PRR37 and Ghd7 alleles on heading date are additive, and PRR37 down-regulates Hd3a expression to suppress flowering under long-day conditions. Our results demonstrate that natural variations in PRR37/Hd2 and GhdT/ Hd4 have contributed to the expansion of rice cultivation to temperate and cooler regions.展开更多
Chlorophyll content is one of the most important physiological traits as it is closely related to leaf photo- synthesis and crop yield potential. So far, few genes have been reported to be involved in natural variatio...Chlorophyll content is one of the most important physiological traits as it is closely related to leaf photo- synthesis and crop yield potential. So far, few genes have been reported to be involved in natural variation of chlorophyll content in rice （Oryza sativa） and the extent of variations explored is very limited. We con- ducted a genome-wide association study （GWAS） using a diverse worldwide collection of 529 O. sativa accessions. A total of 46 significant association loci were identified. Three F2 mapping populations with parents selected from the association panel were tested for validation of GWAS signals. We clearly demon- strated that Grain number, plant height, andheading date7 （GhdT） was a major locus for natural variation of chlorophyll content at the heading stage by combining evidence from near-isogenic lines and transgenic plants. The enhanced expression of Ghd7 decreased the chlorophyll content, mainly through down- regulating the expression of genes involved in the biosynthesis of chlorophyll and chloroplast. In addition, Narrow leaf1 （NAL1） corresponded to one significant association region repeatedly detected over two years. We revealed a high degree of polymorphism in the 5＇ UTR and four non-synonymous SNPs in the cod- ing region of NAL1, and observed diverse effects of the major haplotypes. The loci or candidate genes iden- tified would help to fine-tune and optimize the antenna size of canopies in rice breeding.展开更多
基金funded by the Biological Breeding-National Science and Technology Major Projects,China(Grant No.2023ZD04066)the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LZ24C130006,LTGN24C130007)+5 种基金the Open Project Program of the State Key Laboratory of Rice Biology and Breeding,China(Grant No.20240107)the Xi’nan League Science and Technology Project,China(Grant No.2023DXZD0001)the Joint Research and Development Program on Rice Breeding in Inner Mongolia Autonomous Region,China(Grant No.YZ2023004)the China Agriculture Research System(Grant No.CARS-01)the Central Public-interest Scientific Institution Basal Research Fund,China(Grant No.CPSIBRF-CNRRI-202301)the Agricultural Science and Technology Innovation Program(ASTIP).
文摘Rice,a critical global staple crop,relies heavily on heading date,a key agronomic trait marking the transition from vegetative to reproductive growth.Understanding the genetic regulation of heading date is vital for enhancing the adaptability of high-quality rice varieties across diverse geographical regions and for bolstering local food security.In this study,we uncovered a novel role for OsCATA,a catalase gene,in the regulation of photoperiodic flowering in rice.We identified a novel allele of OsELF3.1,whose mutation resulted in delayed heading.Further analyses revealed that OsELF3.1 physically interacted with OsCATA.Notably,OsCATA exhibited rhythmic expression patterns similar to OsELF3.1 and,when mutated,also delayed flowering.Expression analyses showed that the delayed heading phenotype could be attributed to elevated Ghd7 expression under both long-day and short-day conditions,with OsCATA expression positively regulated by OsELF3.1.Double mutants of OsELF3.1 and OsCATA displayed a heading delay similar to that of oself3.1 single mutants.Additionally,OsELF3.1 could interact with Ghd7 in vivo,alleviating its suppression of Ehd1.Luciferase assays confirmed that Ghd7 repressed Ehd1 expression,while OsELF3.1 mitigated this repression.Collectively,our findings reveal that OsCATA is critical in suppressing Ghd7 expression through the OsELF3.1-OsCATA-Ghd7 transcriptional pathway,thereby regulating rice heading.
基金This work was supported by the National Key Research and Development Program of China(2017YFD0100406)China Postdoctoral Science Foundation(2019M652606).
文摘Seed dormancy of cultivated rice was largely weakened during the progress of domestication.Correct timing and uniformity of seed germination are important for rapid seedling establishment and highyield production.In the present study,we found that the heading-date gene Ghd7 acted as a negative regulator of germination.A mutant of ghd7 showed low sensitivity to exogenous ABA treatment during seed germination.Further investigation revealed reduced accumulation of ABA in mature ghd7 seeds as a consequence of dampened expression of OsNCED genes.Moreover,elevated GA_(3) level was detected in seeds of ghd7 mutant during imbibition course,which was attributed to the induction of genes responsible for the synthesis pathways of bioactive GAs.Thus,Ghd7 inhibits seed germination by increasing the ABA/GA_(3) ratio.Besides revealing pleiotropic effects of Ghd7,our results indicate its role in linking seed germination to growth-phase transition in rice,which would enrich the theoretical basis for future breeding practices.
基金supported by the Youth Foundation of China(31601283)。
文摘Ghd7 is an important gene involved in the photoperiod flowering pathway in rice.A Ghd7-involved transcriptional regulatory network has been established,but its translational regulatory pathway is poorly understood.The mutant suppressor of overexpression of Ghd7(sog7)was identified from EMS-induced mutagenesis on the background of ZH11 overexpressing Ghd7.Mut Map analysis revealed that SOG7 is allelic to Ghd8 and delayed flowering under long-day(LD)conditions.Biochemical assays showed that Ghd8 interacts with OsHAP5C and Ghd7 both in vivo and in vitro.Surprisingly,a point mutation E96K in theα2 helix of the Ghd8 histone fold domain(HFD)destroyed its ability to interact with Ghd7.The prediction of the structure shows that mutated amino acid is located in the interaction region of CCT/NF-YB/YC complexes,which alter the structure ofα4 of Ghd8.This structural difference prevents the formation of complex NF-YB/YC.The triple complex of Ghd8-OsHAP5C-Ghd7 directly bound to the promotor of Hd3a and downregulated the expression of Ehd1,Hd3a and RFT1,and finally resulted in a delayed heading.These findings are helpful in deeply understanding the Ghd7-involved photoperiod flowering pathway and promote the elucidation of rice heading.
基金supported in part by grants from the National Research Foundation of Korea (2020R1A2C2006826 to G.A.,2021R1C1C2007906 to J.Y.,2023R1A2C1003142 to J.-S.J.,and RS-2023-00208027 to L.-H.C.)the Rural Development Administration (RDA),Republic of Korea (RS-2022-RD010220)
文摘Sucrose functions as a signaling molecule in several metabolic pathways as well as in various developmental processes.However,the molecular mechanisms by which sucrose regulates these processes remain largely unknown.In the present study,we demonstrate that sucrose promotes flowering by mediating the stability of a regulatory protein that represses flowering in rice.Exogenous application of sucrose promoted flowering by inducing florigen gene expression.Reduction of sucrose levels in the phloem through genetic modifications,such as the overexpression of the vacuolar invertase OsVIN2 or the mutation of OsSUT2,a sucrose transporter,delayed flowering.Analysis of relative transcript levels of floral regulatory genes showed that sucrose activated Ehd1 upstream of the florigen,with no significant effect on the expression of other upstream genes.Examination of protein stability after sucrose treatment of major floral repressors revealed that the Ghd7 protein was specifically degraded.The Ghd7 protein interacted with the E3 ligase IPA INTERACTING PROTEIN1(IPI1),and sucrose-induced K48-linked polyubiquitination of Ghd7 via IPI1,leading to protein degradation.Mutants defective in IPI1 delayed flowering,confirming its role in modulating proteins involved in flowering.We conclude that sucrose acts as a signaling molecule to induce flowering by promoting Ghd7 degradation via IPI1.
文摘Heading date and photoperiod sensitivity are fundamental traits that determine rice adaptation to a wide range of geographic environments. By quantitative trait locus （QTL） mapping and candidate gene analysis using whole- genome re-sequencing, we found that Oryza sativa Pseudo-Response Regulator37 （OsPRR37; hereafter PRR37） is respon- sible for the Early heading7-2 （EH7-2）/Heading date2 （Hd2） QTL which was identified from a cross of late-heading rice ＇Milyang23 （M23）＇ and early-heading rice ＇H143＇. H143 contains a missense mutation of an invariantly conserved amino acid in the CCT （CONSTANS, CO-like, and TOC1） domain of PRR37 protein. In the world rice collection, different types of nonfunctional PRR37 alleles were found in many European and Asian rice cultivars. Notably, the japonica varieties harboring nonfunctional alleles of both Ghd7/Hd4 and PRR37/Hd2 flower extremely early under natural long-day condi- tions, and are adapted to the northernmost regions of rice cultivation, up to 53~ N latitude. Genetic analysis revealed that the effects of PRR37 and Ghd7 alleles on heading date are additive, and PRR37 down-regulates Hd3a expression to suppress flowering under long-day conditions. Our results demonstrate that natural variations in PRR37/Hd2 and GhdT/ Hd4 have contributed to the expansion of rice cultivation to temperate and cooler regions.
文摘Chlorophyll content is one of the most important physiological traits as it is closely related to leaf photo- synthesis and crop yield potential. So far, few genes have been reported to be involved in natural variation of chlorophyll content in rice （Oryza sativa） and the extent of variations explored is very limited. We con- ducted a genome-wide association study （GWAS） using a diverse worldwide collection of 529 O. sativa accessions. A total of 46 significant association loci were identified. Three F2 mapping populations with parents selected from the association panel were tested for validation of GWAS signals. We clearly demon- strated that Grain number, plant height, andheading date7 （GhdT） was a major locus for natural variation of chlorophyll content at the heading stage by combining evidence from near-isogenic lines and transgenic plants. The enhanced expression of Ghd7 decreased the chlorophyll content, mainly through down- regulating the expression of genes involved in the biosynthesis of chlorophyll and chloroplast. In addition, Narrow leaf1 （NAL1） corresponded to one significant association region repeatedly detected over two years. We revealed a high degree of polymorphism in the 5＇ UTR and four non-synonymous SNPs in the cod- ing region of NAL1, and observed diverse effects of the major haplotypes. The loci or candidate genes iden- tified would help to fine-tune and optimize the antenna size of canopies in rice breeding.
