High chalkiness is a major problem in many rice-producing areas of the world, especially in hybrid rice （Oryza sativa L.） in China. We previously showed a major quantitative trait locus for the percentage of grains ...High chalkiness is a major problem in many rice-producing areas of the world, especially in hybrid rice （Oryza sativa L.） in China. We previously showed a major quantitative trait locus for the percentage of grains with white chalkiness （QTLqPGWC-8） in the interval G1149-R727 on chromosome 8 using a chromosome segment substitution line （CSSL）. Here, we selected the line-CSSL50 harboring the QTLqPGWC-8 allele from the CSSLs derived from a cross between Asominori （as a recurrent parent） and IR24 （as a donor parent）, which had higher percentage chalkiness, markedly different from that of Asominori. There were also significant differences in starch granules, appearance of amylose content （AAC） and milling qualities between Asominori and CSSL50, but not in grain size or thousand grain weight （TGW）. The BC4F2 and BC4F3 populations from a cross between CSSL50 and Asominori were used for fine mapping of qPGWC-8. We narrowed down the location of this QTL to a 142 kb region between Indel markers 8G-7 and 8G-9. QTLqPGWC-8 accounted for 50.9% of the difference in PGWC between the parents. The markers tightly linked to qPGWC-8 should facilitate cloning of the gene underlying this QTL and will be of value for marker-assisted selection in breeding rice varieties with better grain quality.展开更多
Phosphorus is an essential macronutrient for plant development and metabolism,and plants have evolved ingenious mechanisms to overcome phosphate(Pi)starvation.However,the molecular mechanisms underlying the regulation...Phosphorus is an essential macronutrient for plant development and metabolism,and plants have evolved ingenious mechanisms to overcome phosphate(Pi)starvation.However,the molecular mechanisms underlying the regulation of shoot and root architecture by low phosphorus conditions and the coordinated utilization of Pi and nitrogen remain largely unclear.Here,we show that Nodulation Signaling Pathway 1(NSP1)and NSP2 regulate rice tiller number by promoting the biosynthesis of strigolactones(SLs),a class of phytohormones with fundamental effects on plant architecture and environmental responses.We found that NSP1 and NSP2 are induced by Oryza sativa PHOSPHATE STARVATION RESPONSE2(OsPHR2)in response to low-Pi stress and form a complex to directly bind the promoters of SL biosynthesis genes,thus markedly increasing SL biosynthesis in rice.Interestingly,the NSP1/2–SL signaling module represses the expression of CROWN ROOTLESS 1(CRL1),a newly identified early SL-responsive gene in roots,to restrain lateral root density under Pi deficiency.We also demonstrated that GR24^(4DO) treatment under normal conditions inhibits the expression of OsNRTs and OsAMTs to suppress nitrogen absorption but enhances the expression of OsPTs to promote Pi absorption,thus facilitating the balance between nitrogen and phosphorus uptake in rice.Importantly,we found that NSP1p:NSP1 and NSP2p:NSP2 transgenic plants show improved agronomic traits and grain yield under low-and medium-phosphorus conditions.Taken together,these results revealed a novel regulatory mechanism of SL biosynthesis and signaling in response to Pi starvation,providing genetic resources for improving plant architecture and nutrient-use efficiency in low-Pi environments.展开更多
Multisubunit SKP1/Cullin1/F-box(SCF)E3 ligases play essential roles in regulating the stability of crucial regulatory factors and controlling growth and development in eukaryotes.Detecting E3 ligase activity in vitro ...Multisubunit SKP1/Cullin1/F-box(SCF)E3 ligases play essential roles in regulating the stability of crucial regulatory factors and controlling growth and development in eukaryotes.Detecting E3 ligase activity in vitro is important forexploring the molecular mechanism of protein ubiquitination.However,in vitro ubiquitination assay systems for multisubunit E3 ligases remain difficult to achieve,especially in plants,mainly owing to difficulties in achieving active components of multisubunit E3 ligases with high purity and characterizing specific E2 and E3 pairs.In this study,we characterized components of the rice ScFDiwARF3(SCFDs)E3 ligase,screened the coordinated E2,and reconstituted active ScFD3 E3 ligase in vitro.We further engineered SCFD3 E3 ligase using a fused SKP1-Cullin1-RBX1(eSCR)protein and found that both the wild-type SCFD3 E3 ligase and the engineered SCFD3 E3 ligase catalyzed ubiquitination of the substrate D53,which is the key transcriptional repressor in strigolactone signaling.Finally,we replaced D3 with other F-box proteins from rice and humans and reconstituted active escF E3 ligases,including escFaID2,escFBxL1s,and escFcDC4 E3 ligases.Our work reconstitutes functional SCF E3 ligases in vitro and generates an engineered system with interchangeable F-box proteins,providing a powerful platform for studying the mechanisms of multisubunit SCF E3 ligases in eukaryotes.展开更多
A horizontal distributor for biogas slurry application was proposed to explore the distribution performance through CFD analysis and verified by field test.The rheological properties of biogas slurry were analyzed at ...A horizontal distributor for biogas slurry application was proposed to explore the distribution performance through CFD analysis and verified by field test.The rheological properties of biogas slurry were analyzed at first,and key parameters were obtained for the next simulation.The effects of distribution modes,inlet direction,and outlets number on the velocity distribution of flow field and mass flow rate of the horizonal distributor were investigated by CFD simulations.Results of rheological properties indicated that biogas slurry was a non-Newtonian fluid and exhibited shear-thinning behavior.It can be well described by power-law model.The simulation results showed that the geometry of rotor,especially the block numbers was the main factor that determining the fluid movement and trajectory of distribution and output.The mode rotor 1 with two blocks reached the lowest variable coefficient of mass flow rate(4.49%),indicating a higher degree of uniformity.The upward inlet direction would obtain less dead zone,and the distributor with an even outlets number would possess more uniform distribution and less dead zone.The field test of the distributor with rotor 1,upward inlet direction,and 24 outlets has been carried on to verify the simulation results,the variable coefficient of mass flow was 13.06%,which was slightly higher than the simulation(9.23%),but it still within the range of requirement(<15%).The proposed model and the findings of this work are of guiding significance for the study of the utilization technology and equipment of liquid biogas residue.展开更多
Dear Editor,Genome editing has revolutionized speed breeding by enabling researchers to alter the genome directly as desired(Gao,2021).The most widely used CRISPR–Cas9 technology has mainly been applied to engineer n...Dear Editor,Genome editing has revolutionized speed breeding by enabling researchers to alter the genome directly as desired(Gao,2021).The most widely used CRISPR–Cas9 technology has mainly been applied to engineer null mutations in coding sequences,with the goal of creating loss-of-function alleles.Recently,upstream regulatory elements of the promoter region and 50 upstream open reading frame(uORF)have been engineered to generate gain-of-function alleles,producing versatile cis-regulatory effects,usually through changes in gene expression levels(Rodrıguez-Leal et al.,2017;Zhang et al.,2018;Song et al.,2022).展开更多
基金supported by the National Natural Science Foundation of China(30771325)National Key Transform Program(2008ZX08001-06)+2 种基金the earmarked fund for Modern Agro-industry Technology Research SystemJiangsu Cultivar Development Program(BE2008354 and BE2009301-3)the 111 project
文摘High chalkiness is a major problem in many rice-producing areas of the world, especially in hybrid rice （Oryza sativa L.） in China. We previously showed a major quantitative trait locus for the percentage of grains with white chalkiness （QTLqPGWC-8） in the interval G1149-R727 on chromosome 8 using a chromosome segment substitution line （CSSL）. Here, we selected the line-CSSL50 harboring the QTLqPGWC-8 allele from the CSSLs derived from a cross between Asominori （as a recurrent parent） and IR24 （as a donor parent）, which had higher percentage chalkiness, markedly different from that of Asominori. There were also significant differences in starch granules, appearance of amylose content （AAC） and milling qualities between Asominori and CSSL50, but not in grain size or thousand grain weight （TGW）. The BC4F2 and BC4F3 populations from a cross between CSSL50 and Asominori were used for fine mapping of qPGWC-8. We narrowed down the location of this QTL to a 142 kb region between Indel markers 8G-7 and 8G-9. QTLqPGWC-8 accounted for 50.9% of the difference in PGWC between the parents. The markers tightly linked to qPGWC-8 should facilitate cloning of the gene underlying this QTL and will be of value for marker-assisted selection in breeding rice varieties with better grain quality.
基金was supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA28030202)the National Key Research and Development of China(2022YFF1002901)+1 种基金the National Natural Science Foundation of China(32122012,32270327)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2019099).
文摘Phosphorus is an essential macronutrient for plant development and metabolism,and plants have evolved ingenious mechanisms to overcome phosphate(Pi)starvation.However,the molecular mechanisms underlying the regulation of shoot and root architecture by low phosphorus conditions and the coordinated utilization of Pi and nitrogen remain largely unclear.Here,we show that Nodulation Signaling Pathway 1(NSP1)and NSP2 regulate rice tiller number by promoting the biosynthesis of strigolactones(SLs),a class of phytohormones with fundamental effects on plant architecture and environmental responses.We found that NSP1 and NSP2 are induced by Oryza sativa PHOSPHATE STARVATION RESPONSE2(OsPHR2)in response to low-Pi stress and form a complex to directly bind the promoters of SL biosynthesis genes,thus markedly increasing SL biosynthesis in rice.Interestingly,the NSP1/2–SL signaling module represses the expression of CROWN ROOTLESS 1(CRL1),a newly identified early SL-responsive gene in roots,to restrain lateral root density under Pi deficiency.We also demonstrated that GR24^(4DO) treatment under normal conditions inhibits the expression of OsNRTs and OsAMTs to suppress nitrogen absorption but enhances the expression of OsPTs to promote Pi absorption,thus facilitating the balance between nitrogen and phosphorus uptake in rice.Importantly,we found that NSP1p:NSP1 and NSP2p:NSP2 transgenic plants show improved agronomic traits and grain yield under low-and medium-phosphorus conditions.Taken together,these results revealed a novel regulatory mechanism of SL biosynthesis and signaling in response to Pi starvation,providing genetic resources for improving plant architecture and nutrient-use efficiency in low-Pi environments.
基金The research was supported by grants from the National Natural Science Foundation of China(32133012,31788103,32100268,and 31900244)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2019099).
文摘Multisubunit SKP1/Cullin1/F-box(SCF)E3 ligases play essential roles in regulating the stability of crucial regulatory factors and controlling growth and development in eukaryotes.Detecting E3 ligase activity in vitro is important forexploring the molecular mechanism of protein ubiquitination.However,in vitro ubiquitination assay systems for multisubunit E3 ligases remain difficult to achieve,especially in plants,mainly owing to difficulties in achieving active components of multisubunit E3 ligases with high purity and characterizing specific E2 and E3 pairs.In this study,we characterized components of the rice ScFDiwARF3(SCFDs)E3 ligase,screened the coordinated E2,and reconstituted active ScFD3 E3 ligase in vitro.We further engineered SCFD3 E3 ligase using a fused SKP1-Cullin1-RBX1(eSCR)protein and found that both the wild-type SCFD3 E3 ligase and the engineered SCFD3 E3 ligase catalyzed ubiquitination of the substrate D53,which is the key transcriptional repressor in strigolactone signaling.Finally,we replaced D3 with other F-box proteins from rice and humans and reconstituted active escF E3 ligases,including escFaID2,escFBxL1s,and escFcDC4 E3 ligases.Our work reconstitutes functional SCF E3 ligases in vitro and generates an engineered system with interchangeable F-box proteins,providing a powerful platform for studying the mechanisms of multisubunit SCF E3 ligases in eukaryotes.
基金supported by the Jiangsu Modern Agricultural Machinery Equipment and Technology Demonstration and Promotion Project(Grant No.NJ2021-23)Jiangsu Province Agricultural Science and Technology Independent Innovation Fund Project(Grant No.CX(22)3093)+1 种基金the Fundamental Research Fund of the Chinese Academy of Agricultural Sciences at the Institute Level(Grant No.S202106-02)the Key Research and Development Program of Hebei Province(Grant No.20327313D).
文摘A horizontal distributor for biogas slurry application was proposed to explore the distribution performance through CFD analysis and verified by field test.The rheological properties of biogas slurry were analyzed at first,and key parameters were obtained for the next simulation.The effects of distribution modes,inlet direction,and outlets number on the velocity distribution of flow field and mass flow rate of the horizonal distributor were investigated by CFD simulations.Results of rheological properties indicated that biogas slurry was a non-Newtonian fluid and exhibited shear-thinning behavior.It can be well described by power-law model.The simulation results showed that the geometry of rotor,especially the block numbers was the main factor that determining the fluid movement and trajectory of distribution and output.The mode rotor 1 with two blocks reached the lowest variable coefficient of mass flow rate(4.49%),indicating a higher degree of uniformity.The upward inlet direction would obtain less dead zone,and the distributor with an even outlets number would possess more uniform distribution and less dead zone.The field test of the distributor with rotor 1,upward inlet direction,and 24 outlets has been carried on to verify the simulation results,the variable coefficient of mass flow was 13.06%,which was slightly higher than the simulation(9.23%),but it still within the range of requirement(<15%).The proposed model and the findings of this work are of guiding significance for the study of the utilization technology and equipment of liquid biogas residue.
基金supported by grants from the National Key R&D Program of China (2022YFF1003403)the CAS Project for Young Scientists in Basic Research (YSBR-078)+1 种基金the National Natural Science Foundation of China (31788103,32122064,31801014,31900168)the Chinese Academy of Sciences (XDA24030504).
文摘Dear Editor,Genome editing has revolutionized speed breeding by enabling researchers to alter the genome directly as desired(Gao,2021).The most widely used CRISPR–Cas9 technology has mainly been applied to engineer null mutations in coding sequences,with the goal of creating loss-of-function alleles.Recently,upstream regulatory elements of the promoter region and 50 upstream open reading frame(uORF)have been engineered to generate gain-of-function alleles,producing versatile cis-regulatory effects,usually through changes in gene expression levels(Rodrıguez-Leal et al.,2017;Zhang et al.,2018;Song et al.,2022).
