Rice(Oryza sativa L.) is one of the most important food crops worldwide and a model monocot plant for gene function analysis, so it is an ideal system for studying flower development. This study reports a mutant, name...Rice(Oryza sativa L.) is one of the most important food crops worldwide and a model monocot plant for gene function analysis, so it is an ideal system for studying flower development. This study reports a mutant, named multi-floret spikelet 3(mfs3), which is related to the spikelet development in rice and derived from the ethylmethane sulfonate(EMS)-treated rice cultivar XIDA 1 B. In mfs3, the main body of palea(bop) was degenerated severely and only glume-like marginal regions of palea(mrp) remained, while other floral organs developed normally, indicating that the palea identity was seriously influenced by the mutation. It was also observed that the number of floral organs was increased in some spikelets, including 2 lemmas, 4 mrp, 4 lodicules, 8–10 stamens, and 2 pistils, which meant that the spikelet determinacy was lost to some degree in mfs3. Furthermore, genetic analysis demonstrated that the mfs3 trait was controlled by a single recessive gene. Using 426 F2 mutants derived from the cross between sterile line 56 S and mfs3, the MULTI-FLORET SPIKELET 3(MFS3) gene was mapped between the molecular markers RM19347 and RM19352 on Chr.6, with a physical distance of 106.3 kb. Sequencing of candidate genes revealed that an 83-bp fragment loss and a base substitution occurred in the LOC_Os06 g04540 gene in the mutant, confirming preliminarily that the LOC_Os06 g04540 gene was the MFS3 candidate gene. Subsequent q PCR analysis showed that the mutation caused the down-regulation of Os MADS1 and FON1 genes, and the up-regulation of Os IDS1 and SNB genes, which are all involved in the regulation of spikelet development. The MFS3 mutation also significantly reduced the transcription of the REP gene, which is involved in palea development. These results indicated that the MFS3 gene might be involved in the spikelet meristem determinacy and palea identity by regulating the expression of these related genes.展开更多
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
基金supported by the National Natural Science Foundation of China (31271304)the National Key Research and Development Program of China (2017YFD0100202)+2 种基金the Natural Science Foundation of Chongqing, China (CSTC2017jcyj BX0062)the Graduate Student Scientific Research Innovation Projects in Chongqing, China (CYS2015066)the Fundamental Research Funds for the Central Universities, China (XDJK2016A013)
文摘Rice(Oryza sativa L.) is one of the most important food crops worldwide and a model monocot plant for gene function analysis, so it is an ideal system for studying flower development. This study reports a mutant, named multi-floret spikelet 3(mfs3), which is related to the spikelet development in rice and derived from the ethylmethane sulfonate(EMS)-treated rice cultivar XIDA 1 B. In mfs3, the main body of palea(bop) was degenerated severely and only glume-like marginal regions of palea(mrp) remained, while other floral organs developed normally, indicating that the palea identity was seriously influenced by the mutation. It was also observed that the number of floral organs was increased in some spikelets, including 2 lemmas, 4 mrp, 4 lodicules, 8–10 stamens, and 2 pistils, which meant that the spikelet determinacy was lost to some degree in mfs3. Furthermore, genetic analysis demonstrated that the mfs3 trait was controlled by a single recessive gene. Using 426 F2 mutants derived from the cross between sterile line 56 S and mfs3, the MULTI-FLORET SPIKELET 3(MFS3) gene was mapped between the molecular markers RM19347 and RM19352 on Chr.6, with a physical distance of 106.3 kb. Sequencing of candidate genes revealed that an 83-bp fragment loss and a base substitution occurred in the LOC_Os06 g04540 gene in the mutant, confirming preliminarily that the LOC_Os06 g04540 gene was the MFS3 candidate gene. Subsequent q PCR analysis showed that the mutation caused the down-regulation of Os MADS1 and FON1 genes, and the up-regulation of Os IDS1 and SNB genes, which are all involved in the regulation of spikelet development. The MFS3 mutation also significantly reduced the transcription of the REP gene, which is involved in palea development. These results indicated that the MFS3 gene might be involved in the spikelet meristem determinacy and palea identity by regulating the expression of these related genes.
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.
