Plant architecture is a collection of major agronomic traits that determines rice grain production,and it is mainly influenced by tillering,tiller angle,plant height and panicle morphology(Wang and Li 2006).Tiller ang...Plant architecture is a collection of major agronomic traits that determines rice grain production,and it is mainly influenced by tillering,tiller angle,plant height and panicle morphology(Wang and Li 2006).Tiller angle is one of the critical components that determines rice plant architecture,which in turn influences grain yield mainly due to its large impact on plant density(Wang et al.2022).展开更多
Because plant mechanical strength influences plant growth and development,the regulatory mechanisms underlying cell-wall synthesis deserve investigation.Rice mutants are useful for such research.We have identified a n...Because plant mechanical strength influences plant growth and development,the regulatory mechanisms underlying cell-wall synthesis deserve investigation.Rice mutants are useful for such research.We have identified a novel brittle culm 25(bc25)mutant with reduced growth and partial sterility.BC25 encodes an UDP-glucuronic acid decarboxylase involved in cellulose synthesis and belongs to the UXS family.A single-nucleotide mutation in BC25 accounts for its altered cell morphology and cellwall composition.Transmission electron microscopy analysis showed that the thickness of the secondary cell wall was reduced in bc25.Monosaccharide analysis revealed significant increases in content of rhamnose and arabinose but not of other monosaccharides,indicating that BC25 was involved in xylose synthesis with some level of functional redundancy.Enzymatic assays suggested that BC25 functions with high activity to interconvert UDP-glucuronic acid(UDP-Glc A)and UDP-xylose.GUS staining showed that BC25 was ubiquitously expressed with higher expression in culm,root and sheath,in agreement with that shown by quantitative real-time(q RT)-PCR.RNA-seq further suggested that BC25 is involved in sugar metabolism.We conclude that BC25 strongly influences rice cell wall formation.展开更多
Pigmented rice stands out for its nutritional value and is gaining more and more attention.Wild rice,domes-ticated red rice,and weedy rice all have a red pericarp and a comprehensive genetic background in terms of the...Pigmented rice stands out for its nutritional value and is gaining more and more attention.Wild rice,domes-ticated red rice,and weedy rice all have a red pericarp and a comprehensive genetic background in terms of the red-pericarp phenotype.We performed population genetic analyses using 5104 worldwide rice acces-sions,including 2794 accessions with red or black pericarps,85 of which were newly sequenced in this study.The results suggested an evolutionary trajectory of red landraces originating from wild rice,and the split times of cultivated red and white rice populations were estimated to be within the past 3500 years.Cultivated red rice was found to feralize to weedy rice,and weedy rice could be further re-domesticated to cultivated red rice.A genome-wide association study based on the 2794 accessions with pigmented peri-carps revealed several new candidate genes associated with the red-pericarp trait for further functional characterization.Our results provide genomic evidence for the origin of pigmented rice and a valuable genomic resource for genetic investigation and breeding of pigmented rice.展开更多
Tiller angle is a key agricultural trait that establishes plant architecture,which in turn strongly affects grain yield by influencing planting density in rice.The shoot gravity response plays a crucial role in the re...Tiller angle is a key agricultural trait that establishes plant architecture,which in turn strongly affects grain yield by influencing planting density in rice.The shoot gravity response plays a crucial role in the regulation of tiller angle in rice,but the underlying molecular mechanism is largely unknown.Here,we report the identification of the BIG TILLER ANGLE2(BTA2),which regulates tiller angle by controlling the shoot gravity response in rice.Loss-of-function mutation of BTA2 dramatically reduced auxin content and affected auxin distribution in rice shoot base,leading to impaired gravitropism and therefore a big tiller angle.BTA2 interacted with AUXIN RESPONSE FACTOR7(ARF7)to modulate rice tiller angle through the gravity signaling pathway.The BTA2 protein was highly conserved during evolution.Sequence variation in the BTA2 promoter of indica cultivars harboring a less expressed BTA2 allele caused lower BTA2 expression in shoot base and thus wide tiller angle during rice domestication.Overexpression of BTA2 significantly increased grain yield in the elite rice cultivar Huanghuazhan under appropriate dense planting conditions.Our findings thus uncovered the BTA2-ARF7 module that regulates tiller angle by mediating the shoot gravity response.Our work offers a target for genetic manipulation of plant architecture and valuable information for crop improvement by producing the ideal plant type.展开更多
Nucleotide-binding site and leucine-rich repeat(NLR)proteins are activated by detecting pathogen effectors,which in turn trigger host defenses and cell death.Although many NLRs have been identified,the mechanisms resp...Nucleotide-binding site and leucine-rich repeat(NLR)proteins are activated by detecting pathogen effectors,which in turn trigger host defenses and cell death.Although many NLRs have been identified,the mechanisms responsible for NLR-triggered defense responses are still poorly understood.In this study,through a genome-wide association study approach,we identified a novel NLR gene,Blast Resistance Gene 8(BRG8),which confers resistance to rice blast and bacterial blight diseases.BRG8 overexpression and complementation lines exhibit enhanced resistance to both pathogens.Subcellular localization assays showed that BRG8 is localized in both the cytoplasm and the nucleus.Additional evidence revealed that nuclear-localized BRG8 can enhance rice immunity without a hypersensitive response(HR)-like phenotype.We also demonstrated that the coiled-coil domain of BRG8 not only physically interacts with itself but also interacts with the KNOX II protein HOMEOBOX ORYZA SATIVA59(HOS59).Knockout mutants of HOS59 in the BRG8 background show enhanced resistance to Magnaporthe oryzae strain CH171 and Xoo strain CR4,similar to that of the BRG8 background.By contrast,overexpression of HOS59 in the BRG8 background will compromise the HR-like phenotype and resistance response.Further analysis revealed that HOS59 promotes the degradation of BRG8 via the 26S proteasome pathway.Collectively,our study highlights HOS59 as an NLR immune regulator that fine-tunes BRG8-mediated immune responses against pathogens,providing new insights into NLR associations and functions in plant immunity.展开更多
基金grants from the Natural Science Foundation of Zhejiang Province,China(LTGN23C130001)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City,China(2021JJLH0045)+1 种基金the State Key Laboratory of Rice Biology and Breeding-Independent Project,China(2023ZZKT20304)the China Agriculture Research System(CARS-01-14)。
文摘Plant architecture is a collection of major agronomic traits that determines rice grain production,and it is mainly influenced by tillering,tiller angle,plant height and panicle morphology(Wang and Li 2006).Tiller angle is one of the critical components that determines rice plant architecture,which in turn influences grain yield mainly due to its large impact on plant density(Wang et al.2022).
基金supported by the Key Research and Development Program of Zhejiang Province(2021C02056,2021C02063-6)the National Key Research and Development Program of China(2021YFD1200503)+1 种基金the Fundamental Research Funds for Central Public Welfare Research Institutes of China National Rice Research Institute(CPSIBRF-CNRRI-202101)Chinese Academy of Agricultural Sciences(CAAS-ASTIP-201X-CNRRI)。
文摘Because plant mechanical strength influences plant growth and development,the regulatory mechanisms underlying cell-wall synthesis deserve investigation.Rice mutants are useful for such research.We have identified a novel brittle culm 25(bc25)mutant with reduced growth and partial sterility.BC25 encodes an UDP-glucuronic acid decarboxylase involved in cellulose synthesis and belongs to the UXS family.A single-nucleotide mutation in BC25 accounts for its altered cell morphology and cellwall composition.Transmission electron microscopy analysis showed that the thickness of the secondary cell wall was reduced in bc25.Monosaccharide analysis revealed significant increases in content of rhamnose and arabinose but not of other monosaccharides,indicating that BC25 was involved in xylose synthesis with some level of functional redundancy.Enzymatic assays suggested that BC25 functions with high activity to interconvert UDP-glucuronic acid(UDP-Glc A)and UDP-xylose.GUS staining showed that BC25 was ubiquitously expressed with higher expression in culm,root and sheath,in agreement with that shown by quantitative real-time(q RT)-PCR.RNA-seq further suggested that BC25 is involved in sugar metabolism.We conclude that BC25 strongly influences rice cell wall formation.
基金supported by the Department of Science and Technology of Zhejiang Province (2022C02032 and 2020C02002)the National Natural Science Foundation of China (31971865)CIC-MCP to L.F.
文摘Pigmented rice stands out for its nutritional value and is gaining more and more attention.Wild rice,domes-ticated red rice,and weedy rice all have a red pericarp and a comprehensive genetic background in terms of the red-pericarp phenotype.We performed population genetic analyses using 5104 worldwide rice acces-sions,including 2794 accessions with red or black pericarps,85 of which were newly sequenced in this study.The results suggested an evolutionary trajectory of red landraces originating from wild rice,and the split times of cultivated red and white rice populations were estimated to be within the past 3500 years.Cultivated red rice was found to feralize to weedy rice,and weedy rice could be further re-domesticated to cultivated red rice.A genome-wide association study based on the 2794 accessions with pigmented peri-carps revealed several new candidate genes associated with the red-pericarp trait for further functional characterization.Our results provide genomic evidence for the origin of pigmented rice and a valuable genomic resource for genetic investigation and breeding of pigmented rice.
基金supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021JJLH0045)the Natural Science Foundation of Zhejiang Province(LTGN23C130001)+2 种基金National Key R&D Program of China(2020YFE0202300)the Key Research and Development Program of Zhejiang Province(2021C02056)the Agricultural Science and Technology Innovation Program(CAAS‐ASTIP‐2013‐CNRRI).
文摘Tiller angle is a key agricultural trait that establishes plant architecture,which in turn strongly affects grain yield by influencing planting density in rice.The shoot gravity response plays a crucial role in the regulation of tiller angle in rice,but the underlying molecular mechanism is largely unknown.Here,we report the identification of the BIG TILLER ANGLE2(BTA2),which regulates tiller angle by controlling the shoot gravity response in rice.Loss-of-function mutation of BTA2 dramatically reduced auxin content and affected auxin distribution in rice shoot base,leading to impaired gravitropism and therefore a big tiller angle.BTA2 interacted with AUXIN RESPONSE FACTOR7(ARF7)to modulate rice tiller angle through the gravity signaling pathway.The BTA2 protein was highly conserved during evolution.Sequence variation in the BTA2 promoter of indica cultivars harboring a less expressed BTA2 allele caused lower BTA2 expression in shoot base and thus wide tiller angle during rice domestication.Overexpression of BTA2 significantly increased grain yield in the elite rice cultivar Huanghuazhan under appropriate dense planting conditions.Our findings thus uncovered the BTA2-ARF7 module that regulates tiller angle by mediating the shoot gravity response.Our work offers a target for genetic manipulation of plant architecture and valuable information for crop improvement by producing the ideal plant type.
基金supported by the National Natural Science Foundation of China(32201739)the Natural Science Foundation of Zhejiang Province(LQ22C130006)+2 种基金the National Key Research and Development Program of China(2021YFD1200503)the Key Research and Development Program of Zhejiang Province(2021C02056)the Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP2013-CNRRI).
文摘Nucleotide-binding site and leucine-rich repeat(NLR)proteins are activated by detecting pathogen effectors,which in turn trigger host defenses and cell death.Although many NLRs have been identified,the mechanisms responsible for NLR-triggered defense responses are still poorly understood.In this study,through a genome-wide association study approach,we identified a novel NLR gene,Blast Resistance Gene 8(BRG8),which confers resistance to rice blast and bacterial blight diseases.BRG8 overexpression and complementation lines exhibit enhanced resistance to both pathogens.Subcellular localization assays showed that BRG8 is localized in both the cytoplasm and the nucleus.Additional evidence revealed that nuclear-localized BRG8 can enhance rice immunity without a hypersensitive response(HR)-like phenotype.We also demonstrated that the coiled-coil domain of BRG8 not only physically interacts with itself but also interacts with the KNOX II protein HOMEOBOX ORYZA SATIVA59(HOS59).Knockout mutants of HOS59 in the BRG8 background show enhanced resistance to Magnaporthe oryzae strain CH171 and Xoo strain CR4,similar to that of the BRG8 background.By contrast,overexpression of HOS59 in the BRG8 background will compromise the HR-like phenotype and resistance response.Further analysis revealed that HOS59 promotes the degradation of BRG8 via the 26S proteasome pathway.Collectively,our study highlights HOS59 as an NLR immune regulator that fine-tunes BRG8-mediated immune responses against pathogens,providing new insights into NLR associations and functions in plant immunity.
