In rice,the spikelet is the basic unit of inflorescence,and its development is important for determining the grain yield and quality.We reported a rice spikelet mutant multi-floret spikelet 4(mfs4)which resulted in th...In rice,the spikelet is the basic unit of inflorescence,and its development is important for determining the grain yield and quality.We reported a rice spikelet mutant multi-floret spikelet 4(mfs4)which resulted in the production of extra floral organs or a whole extra floret,and elongated sterile lemmas.The results suggested that the mutation of the MFS4 gene interfered with spikelet meristem determinacy and floral organ identity.In addition,the plant height and the grain length and width in the mfs4 mutant were all less than those in the wild type.Using the bulked segregant analysis method,the MFS4 gene was localized in a 557-kb region on the long arm of chromosome 1.Sequence analysis showed that there was a C-base deletion at the open reading frame of LOC_Os01g67430.Further tests indicated that a wild type copy of LOC_Os01g67430 was able to reverse the mfs4 defects,which indicated that LOC_Os01g67430 was the MFS4 gene.The MFS4 gene encodes a lipase located in the mitochondria and is expressed strongly in the young inflorescence.qRT-PCR results showed that the expression of some genes that were known to regulate spikelet meristem determinacy and grain size were decreased in the mfs4 mutant,which indicated that the MFS4 gene regulates spikelet meristem determinacy and grain size by modulating the expression of these genes.展开更多
Inflorescence structure of rice,including the number and length of branches,and the density of the spikelet,can greatly affect the number of grains per panicle,which is one of the key factors in yield compositions.Her...Inflorescence structure of rice,including the number and length of branches,and the density of the spikelet,can greatly affect the number of grains per panicle,which is one of the key factors in yield compositions.Here we identified five allelic mutants sb1-1/2/3/4/5 that related to branch development of rice.In these mutants,the branch meristem fate was prolonged sharply,resulting in delay of transition from branches to spikelets,and then increased the numbers of branches and spikelets per panicle.SB1 encodes a nuclear RING-like domain protein of SHI/LRP/SRS family and strongly expressed in branch meristems.The results of protein interaction and chromatin immunoprecipitation further suggested that SB1 directly repressed the expression of DEP1,TAW1,MOC1 and IPA1 by interacting with a co-repressor complex to affect acetylation level of histone H3 on target regions.Thus,we proposed that SB1 is a transcription repressor of branch meristem activity by widely and negatively regulating a series of genes that maintain branch meristem fate.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.31971919,31730063)the Natural Science Foundation Project of Chongqing Science and Technology Commission,China(Grant No.cstc2020jcyj-jqX0020)+1 种基金National Key Program for Research and Development of China(Grant No.2017YFD0100202)Chongqing Graduate Research and Innovation Project Funding,China(Grant No.CYS20123).
文摘In rice,the spikelet is the basic unit of inflorescence,and its development is important for determining the grain yield and quality.We reported a rice spikelet mutant multi-floret spikelet 4(mfs4)which resulted in the production of extra floral organs or a whole extra floret,and elongated sterile lemmas.The results suggested that the mutation of the MFS4 gene interfered with spikelet meristem determinacy and floral organ identity.In addition,the plant height and the grain length and width in the mfs4 mutant were all less than those in the wild type.Using the bulked segregant analysis method,the MFS4 gene was localized in a 557-kb region on the long arm of chromosome 1.Sequence analysis showed that there was a C-base deletion at the open reading frame of LOC_Os01g67430.Further tests indicated that a wild type copy of LOC_Os01g67430 was able to reverse the mfs4 defects,which indicated that LOC_Os01g67430 was the MFS4 gene.The MFS4 gene encodes a lipase located in the mitochondria and is expressed strongly in the young inflorescence.qRT-PCR results showed that the expression of some genes that were known to regulate spikelet meristem determinacy and grain size were decreased in the mfs4 mutant,which indicated that the MFS4 gene regulates spikelet meristem determinacy and grain size by modulating the expression of these genes.
基金supported by the National Natural Science Foundation of China(Grant No.31971919)the National Key Program for Research and Development of China(Grant No.2017YFD0100202)+1 种基金the Project Sponsored by Natural Science Foundation of Chongqing,China(Grant No.cstc2020jcyjjqX0020)Chongqing Graduate Research and Innovation Project funding in China(Grant No.CYS20123)。
文摘Inflorescence structure of rice,including the number and length of branches,and the density of the spikelet,can greatly affect the number of grains per panicle,which is one of the key factors in yield compositions.Here we identified five allelic mutants sb1-1/2/3/4/5 that related to branch development of rice.In these mutants,the branch meristem fate was prolonged sharply,resulting in delay of transition from branches to spikelets,and then increased the numbers of branches and spikelets per panicle.SB1 encodes a nuclear RING-like domain protein of SHI/LRP/SRS family and strongly expressed in branch meristems.The results of protein interaction and chromatin immunoprecipitation further suggested that SB1 directly repressed the expression of DEP1,TAW1,MOC1 and IPA1 by interacting with a co-repressor complex to affect acetylation level of histone H3 on target regions.Thus,we proposed that SB1 is a transcription repressor of branch meristem activity by widely and negatively regulating a series of genes that maintain branch meristem fate.
