Leaf color and photosynthesis are important factors for rice growth and development.Hence,improving the photosynthetic rate is an effective approach for increasing rice yield.We isolated a gene,chlorophyllide-a oxygen...Leaf color and photosynthesis are important factors for rice growth and development.Hence,improving the photosynthetic rate is an effective approach for increasing rice yield.We isolated a gene,chlorophyllide-a oxygenase 1(OsCAO1),which characterized a rice near-isogenic line named fgl(faded green leaf).展开更多
Lesion mimic mutants(LMMs) are advantageous materials for studying programmed cell death(PCD).Although some rice LMM genes have been cloned, the diversity of functions of these genes indicates that the mechanism of ce...Lesion mimic mutants(LMMs) are advantageous materials for studying programmed cell death(PCD).Although some rice LMM genes have been cloned, the diversity of functions of these genes indicates that the mechanism of cell death regulation in LMMs needs further study. In this study, we identified a rice light-dependent leaf lesion mimic mutant 4(llm4) that showed abnormal chloroplast structure, photoinhibition, reduced photosynthetic protein levels, massive accumulation of reactive oxygen species(ROS), and PCD. Map-based cloning and complementation testing revealed that LLM4 encodes zeaxanthin epoxidase(ZEP), an enzyme involved in the xanthophyll cycle, which functions in plant photoprotection,ROS scavenging, and carotenoid and abscisic acid(ABA) biosynthesis. The ABA content was decreased,and the contents of 24 carotenoids differed between the llm4 mutant and the wild type(WT). The llm4mutant showed reduced dormancy and greater sensitive to ABA than the WT. We concluded that the mutation of LLM4 resulted in the failure of xanthophyll cycle, in turn causing ROS accumulation. The excessive ROS accumulation damaged chloroplast structure and induced PCD, leading eventually to the formation of lesion mimics.展开更多
Clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)-mediated genome editing has greatly accelerated progress in plant genetic research and agricultural breeding by enabling targe...Clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)-mediated genome editing has greatly accelerated progress in plant genetic research and agricultural breeding by enabling targeted genomic modifications.Moreover,the prime editing system,derived from the CRISPR/Cas system,has opened the door for even more precise genome editing.Prime editing has the capability to facilitate all 12 types of base-to-base conversions,as well as desired insertions or deletions of fragments,without inducing double-strand breaks and requiring donor DNA templet.In a short time,prime editing has been rapidly verified as functional in various plants,and can be used in plant genome functional analysis as well as precision breeding of crops.In this review,we summarize the emergence and development of prime editing,highlight recent advances in improving its efficiency in plants,introduce the current applications of prime editing in plants,and look forward to future prospects for utilizing prime editing in genetic improvement and precision molecular breeding.展开更多
Anthocyanins are widely distributed in one or more parts of rice(Oryza sativa L.)plants,including seed coat,stigma,apiculus,leaf sheath and leaf blade,and are the main pigments used in rice to achieve different colors...Anthocyanins are widely distributed in one or more parts of rice(Oryza sativa L.)plants,including seed coat,stigma,apiculus,leaf sheath and leaf blade,and are the main pigments used in rice to achieve different colors(Hou et al,2009;Aizza and Dornelas,2011).In rice,tissue-specific color traits(especially the color of apiculus,namely the lemma and palea of the spikelet)are not only important for rice variety identification but also important for linkage analysis and rice domestication research(Saitoh et al,2004;Fan et al,2007;Lin et al,2019).The apiculus color is controlled by the complementary functions of three pairs of dominant genes,C,A and P.Gene C(chromogen)is a pigment gene,which is the basic gene for producing pigments.Gene A(activator)activates gene C,converting the chromogen into anthocyanins,and gene P(purple)controls the distribution of anthocyanins in various organs(Reddy,1996;Sakamoto et al,2001).展开更多
This study characterizes a brittle culm (bc88) mutant of rice (Oryza sativa L.) obtained by ethylene methylsulfonate (EMS)-induced mutagenesis of Wuyunjing 7. The bc88 mutant exhibits a diversity of pleiotropic phenot...This study characterizes a brittle culm (bc88) mutant of rice (Oryza sativa L.) obtained by ethylene methylsulfonate (EMS)-induced mutagenesis of Wuyunjing 7. The bc88 mutant exhibits a diversity of pleiotropic phenotypes, including brittle culm at the whole-plant growth stages, withered leaf tips at the seedling stage, and 18-d delay in heading date at the mature stage. Genetic analysis indicates that the bc88 mutant is controlled by a single recessive nuclear gene. The mutated bc88 gene isolated by map-based cloning contains only one point mutation in the 5th exon relative to its wild-type BC88 (LOC_Os09g25490 and Os09g0422500), leading to an amino acid change from P to L in bc88 plants. Alignment of the putative protein sequence with its homologs indicates that the mutation is located in the conserved region of the sequence. Detection of the transcription level of BC88 in rice plants shows that the expression level of BC88 is higher in spikes and culms than in leaves, roots, and leaf sheaths. These contribute to understanding of the molecular mechanism of cellulose synthesis. The target gene BC88 can be a useful tool in molecular marker-assisted selection for rice culm trait breeding.展开更多
An es-t (early senescence-temporary) mutant, produced by ethylene methylsulfonate treatment of strain Nipponbare, was identified in rice. The leaves of es-t appeared yellow at the seedling stage, and had decreased chl...An es-t (early senescence-temporary) mutant, produced by ethylene methylsulfonate treatment of strain Nipponbare, was identified in rice. The leaves of es-t appeared yellow at the seedling stage, and had decreased chlorophyll content. Rust spots were found during growth in es-t, especially at the leaf margin and tip. The plants showed a typical early-senescence phenotype at the milky stage. The leaf surface of es-t appeared smoother than wild-type leaves under a scanning electron microscope, because the leaves lack siliceous protuberances around the stoma. Chloroplasts grow abnormally and are filled with many starch grains in es-t. Paraffin section analysis showed that the development of the sclerenchyma cells and vascular bundles were also abnormal in es-t. Genetic analysis indicated that es-t was controlled by a recessive gene, which was finely mapped to a 42-kb interval on chromosome 5. These results will facilitate the positional cloning and functional studies of the gene.展开更多
基金supported by the Shenzhen Science and Technology Program,China(Grant No.KQTD2016113010482651)Natural Science Foundation of Zhejiang Province in China(Grant No.LR20C130001)Hainan Yazhou Bay Seed Laboratory,China(Grant No.B21HJ0219)。
文摘Leaf color and photosynthesis are important factors for rice growth and development.Hence,improving the photosynthetic rate is an effective approach for increasing rice yield.We isolated a gene,chlorophyllide-a oxygenase 1(OsCAO1),which characterized a rice near-isogenic line named fgl(faded green leaf).
基金the financial support of the National Natural Science Foundation of China (32060454, 32272109)Hainan Yazhou Bay Seed Laboratory (B21HJ0215)+1 种基金National Natural Science Foundation of China (32072048, U2004204)Specific Research Fund of The Innovation Platform for Academicians of Hainan Province。
文摘Lesion mimic mutants(LMMs) are advantageous materials for studying programmed cell death(PCD).Although some rice LMM genes have been cloned, the diversity of functions of these genes indicates that the mechanism of cell death regulation in LMMs needs further study. In this study, we identified a rice light-dependent leaf lesion mimic mutant 4(llm4) that showed abnormal chloroplast structure, photoinhibition, reduced photosynthetic protein levels, massive accumulation of reactive oxygen species(ROS), and PCD. Map-based cloning and complementation testing revealed that LLM4 encodes zeaxanthin epoxidase(ZEP), an enzyme involved in the xanthophyll cycle, which functions in plant photoprotection,ROS scavenging, and carotenoid and abscisic acid(ABA) biosynthesis. The ABA content was decreased,and the contents of 24 carotenoids differed between the llm4 mutant and the wild type(WT). The llm4mutant showed reduced dormancy and greater sensitive to ABA than the WT. We concluded that the mutation of LLM4 resulted in the failure of xanthophyll cycle, in turn causing ROS accumulation. The excessive ROS accumulation damaged chloroplast structure and induced PCD, leading eventually to the formation of lesion mimics.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC3400200)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(Grant No.CAAS-ZDRW202001)the Earmarked Fund for China Agriculture Research System(Grant No.CARS-01-07).
文摘Clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)-mediated genome editing has greatly accelerated progress in plant genetic research and agricultural breeding by enabling targeted genomic modifications.Moreover,the prime editing system,derived from the CRISPR/Cas system,has opened the door for even more precise genome editing.Prime editing has the capability to facilitate all 12 types of base-to-base conversions,as well as desired insertions or deletions of fragments,without inducing double-strand breaks and requiring donor DNA templet.In a short time,prime editing has been rapidly verified as functional in various plants,and can be used in plant genome functional analysis as well as precision breeding of crops.In this review,we summarize the emergence and development of prime editing,highlight recent advances in improving its efficiency in plants,introduce the current applications of prime editing in plants,and look forward to future prospects for utilizing prime editing in genetic improvement and precision molecular breeding.
基金supported by the Central Public Interest Scientific Institution Basal Research Fund of China National Rice Research Institute(Grant No.2017RG002-4)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences,and Science,Technology and Innovation Committee of Shenzhen Municipality(Grant Nos.JCYJ20170303154506881 and JCYJ20170412155447658).
文摘Anthocyanins are widely distributed in one or more parts of rice(Oryza sativa L.)plants,including seed coat,stigma,apiculus,leaf sheath and leaf blade,and are the main pigments used in rice to achieve different colors(Hou et al,2009;Aizza and Dornelas,2011).In rice,tissue-specific color traits(especially the color of apiculus,namely the lemma and palea of the spikelet)are not only important for rice variety identification but also important for linkage analysis and rice domestication research(Saitoh et al,2004;Fan et al,2007;Lin et al,2019).The apiculus color is controlled by the complementary functions of three pairs of dominant genes,C,A and P.Gene C(chromogen)is a pigment gene,which is the basic gene for producing pigments.Gene A(activator)activates gene C,converting the chromogen into anthocyanins,and gene P(purple)controls the distribution of anthocyanins in various organs(Reddy,1996;Sakamoto et al,2001).
基金supported by the National Natural Science Foundation of China (30971760, 31201183)the Zhejiang Provincial Qianjiang Talents Program of China ( 2010R10085)the Zhejiang Program of Education Department (Y201225687)
文摘This study characterizes a brittle culm (bc88) mutant of rice (Oryza sativa L.) obtained by ethylene methylsulfonate (EMS)-induced mutagenesis of Wuyunjing 7. The bc88 mutant exhibits a diversity of pleiotropic phenotypes, including brittle culm at the whole-plant growth stages, withered leaf tips at the seedling stage, and 18-d delay in heading date at the mature stage. Genetic analysis indicates that the bc88 mutant is controlled by a single recessive nuclear gene. The mutated bc88 gene isolated by map-based cloning contains only one point mutation in the 5th exon relative to its wild-type BC88 (LOC_Os09g25490 and Os09g0422500), leading to an amino acid change from P to L in bc88 plants. Alignment of the putative protein sequence with its homologs indicates that the mutation is located in the conserved region of the sequence. Detection of the transcription level of BC88 in rice plants shows that the expression level of BC88 is higher in spikes and culms than in leaves, roots, and leaf sheaths. These contribute to understanding of the molecular mechanism of cellulose synthesis. The target gene BC88 can be a useful tool in molecular marker-assisted selection for rice culm trait breeding.
基金supported by the National Special Program for Research and Transgenic Plants (2011ZX08009-003)the National Key Basic Research Program of China (2007CB10920203)the National Natural Science Foundation of China (30971760)
文摘An es-t (early senescence-temporary) mutant, produced by ethylene methylsulfonate treatment of strain Nipponbare, was identified in rice. The leaves of es-t appeared yellow at the seedling stage, and had decreased chlorophyll content. Rust spots were found during growth in es-t, especially at the leaf margin and tip. The plants showed a typical early-senescence phenotype at the milky stage. The leaf surface of es-t appeared smoother than wild-type leaves under a scanning electron microscope, because the leaves lack siliceous protuberances around the stoma. Chloroplasts grow abnormally and are filled with many starch grains in es-t. Paraffin section analysis showed that the development of the sclerenchyma cells and vascular bundles were also abnormal in es-t. Genetic analysis indicated that es-t was controlled by a recessive gene, which was finely mapped to a 42-kb interval on chromosome 5. These results will facilitate the positional cloning and functional studies of the gene.
