Heterosis and polyploidy have an overwhelming influence on plant evolution.Recently,polyploid rice hybrids have been used to breed new rice varieties because they combine the advantages of both heterosis and polyploid...Heterosis and polyploidy have an overwhelming influence on plant evolution.Recently,polyploid rice hybrids have been used to breed new rice varieties because they combine the advantages of both heterosis and polyploidy.In this study,we generated six rice lines:autotetraploid rice hybrids and their autotetraploid parents,diploid donors,and hybrids of the diploid donors.To investigate the molecular mechanism controlling the effects of both hybridization and polyploidization,we performed bisulfite and RNA sequencing on young panicles at the pollen meiosis stage to compare the DNA metabolomes and transcriptomes among the six rice lines.The hybrids lines were hypermethylated compared to their corresponding parents and the autotetraploid lines showed globally increased DNA methylation of their transposable elements compared to the diploid donors.The alteration in DNA methylation level corresponded to the differential gene expressions among the rice genotypes,suggesting that methylation changes induced by polyploidization and hybridization may affect gene expression.Groups of gene candidates were identified that may be associated with heterosis and polyploidy.Our results provide DNA information that can be used to investigate epigenetic modification during heterosis and polyploidy in rice.展开更多
The identification of seed development-related regulators is critical for the genetic improvement of yield and grain quality in cereal crops.SQUAMOSA PROMOTER BINDING PROTEIN-LIKE14(OsSPL14)is a well-studied,plant-spe...The identification of seed development-related regulators is critical for the genetic improvement of yield and grain quality in cereal crops.SQUAMOSA PROMOTER BINDING PROTEIN-LIKE14(OsSPL14)is a well-studied,plant-specific transcription factor;however,its roles in controlling rice grain appearance quality and the underlying molecular mechanisms have not been fully elucidated.In this study,we demon-strate that OsSPL14 positively regulates appearance quality by controlling grain chalkiness in rice.Genetic analysis revealed that knockdown or knockout of OsSPL14 leads to a chalky grain phenotype,which is associated with significant defects in compound starch granules and notable changes in both starch and protein contents in the endosperm.Transcript analysis identified multiple genes regulated by OsSPL14,including the key granule-bound starch synthase gene Waxy(Wx)and the protein disulfide isomerase-like enzyme-encoding gene PDIL1-1.Both in vitro and in vivo assays demonstrated that OsSPL14 directly binds to the GTAC-box motif in the Wx and PDIL1-1 promoters to enhance their expression.Protein-protein inter-action experiments further revealed that OsSPL14 interacts with the nuclear transcription factor Y(NF-Y)heterodimer OsNF-YB9/YC8-12 to promote the transcription of Wx and PDIL1-1,thereby enhancing rice grain appearance quality.Our findings uncover a novel regulatory pathway controlled by OsSPL14 and pro-vide new insights into the molecular mechanisms underlying rice grain appearance quality,with promising implications for genetic improvement in rice.展开更多
基金supported by the Key Research and Development Program of Hubei Province(2020BBA032)the Wuhan Science and Technology Major Project “Development and application of polyploid rice”,the Open Research Fund of State Key Laboratory of Hybrid Rice(Hunan Hybrid Rice Research Center)(19KF06)the Youth Grant of Hubei University.
文摘Heterosis and polyploidy have an overwhelming influence on plant evolution.Recently,polyploid rice hybrids have been used to breed new rice varieties because they combine the advantages of both heterosis and polyploidy.In this study,we generated six rice lines:autotetraploid rice hybrids and their autotetraploid parents,diploid donors,and hybrids of the diploid donors.To investigate the molecular mechanism controlling the effects of both hybridization and polyploidization,we performed bisulfite and RNA sequencing on young panicles at the pollen meiosis stage to compare the DNA metabolomes and transcriptomes among the six rice lines.The hybrids lines were hypermethylated compared to their corresponding parents and the autotetraploid lines showed globally increased DNA methylation of their transposable elements compared to the diploid donors.The alteration in DNA methylation level corresponded to the differential gene expressions among the rice genotypes,suggesting that methylation changes induced by polyploidization and hybridization may affect gene expression.Groups of gene candidates were identified that may be associated with heterosis and polyploidy.Our results provide DNA information that can be used to investigate epigenetic modification during heterosis and polyploidy in rice.
基金supported by grants from the National Natural Science Foundation of China(32472141 and 32101746)the Natural Science Foundation of Hubei Province(JCZRLH202500540,2021CFB033).
文摘The identification of seed development-related regulators is critical for the genetic improvement of yield and grain quality in cereal crops.SQUAMOSA PROMOTER BINDING PROTEIN-LIKE14(OsSPL14)is a well-studied,plant-specific transcription factor;however,its roles in controlling rice grain appearance quality and the underlying molecular mechanisms have not been fully elucidated.In this study,we demon-strate that OsSPL14 positively regulates appearance quality by controlling grain chalkiness in rice.Genetic analysis revealed that knockdown or knockout of OsSPL14 leads to a chalky grain phenotype,which is associated with significant defects in compound starch granules and notable changes in both starch and protein contents in the endosperm.Transcript analysis identified multiple genes regulated by OsSPL14,including the key granule-bound starch synthase gene Waxy(Wx)and the protein disulfide isomerase-like enzyme-encoding gene PDIL1-1.Both in vitro and in vivo assays demonstrated that OsSPL14 directly binds to the GTAC-box motif in the Wx and PDIL1-1 promoters to enhance their expression.Protein-protein inter-action experiments further revealed that OsSPL14 interacts with the nuclear transcription factor Y(NF-Y)heterodimer OsNF-YB9/YC8-12 to promote the transcription of Wx and PDIL1-1,thereby enhancing rice grain appearance quality.Our findings uncover a novel regulatory pathway controlled by OsSPL14 and pro-vide new insights into the molecular mechanisms underlying rice grain appearance quality,with promising implications for genetic improvement in rice.
