Panicle number per plant,grain number per panicle,and grain weight are three key factors influencing rice grain yield.Gn1a,a major QTL for grain number per panicle,encodes the cytokinin oxidase/dehydrogenase(CKX)OsCKX...Panicle number per plant,grain number per panicle,and grain weight are three key factors influencing rice grain yield.Gn1a,a major QTL for grain number per panicle,encodes the cytokinin oxidase/dehydrogenase(CKX)OsCKX2.While the use of elite Gn1a alleles has been well documented in indica rice cultivars,their potential in japonica rice remains largely unexplored.In this study,we characterized three suppressor mutants of the rice cytokinin receptor mutant pal1/ohk4 and found that all causal genes were novel alleles of Gn1a identified through the MutMap approach.These three suppressor mutants caused single amino acid substitutions in the FAD-binding domain(G556D and G156D)and the cytokinin-binding domain(Y357C),resulting in significantly reduced enzymatic activity of OsCKX2 and elevated cytokinin levels in the panicle.Haplotype analysis of Gn1a using a natural population from the 3K Rice Genomes Project showed that G556D,G156D,and Y357C were novel alleles of Gn1a.G556,G156,and Y357 were highly conserved,whereas four natural variants G54A,A105V,H116R,and N535K identified in different haplotypes of Gn1a showed extremely low conservation.By backcrossing the suppressor mutants with their original wild-type Huaidao 5,an elite japonica rice variety,we developed improved lines carrying only the gn1a mutation.The improved lines showed a significant increase in grain number per panicle,grain weight,panicle number per plant,plant height,and stem thickness,leading to a 25.7%-28.7%increase in grain yield per plot compared with Huaidao 5.This study provides valuable Gn1a alleles for synergistic improvement of the three key yield factors and offers germplasm resources for high-yielding breeding in japonica rice.展开更多
Significant achievements have been made in breeding programs for the heavy-panicle-type(HPT)rice(Oryza sativa) in Southwest China. The HPT varieties now exhibit excellent lodging resistance,allowing them to overcome t...Significant achievements have been made in breeding programs for the heavy-panicle-type(HPT)rice(Oryza sativa) in Southwest China. The HPT varieties now exhibit excellent lodging resistance,allowing them to overcome the greater pressures caused by heavy panicles. However, the genetic mechanism of this lodging resistance remains elusive. Here, we isolated a major quantitative trait locus, Panicle Neck Diameter 1(PND1), andidentified the causal gene as GRAIN NUMBER 1 A/CYTOKININ OXIDASE 2(Gn1 A/Os CKX2). The null gn1 a allele from rice line R498(gn1 aR498) improved lodging resistance through increasing the culm diameter and promoting crown root development.Loss-of-function of Gn1 a/Os CKX2 led to cytokinin accumulation in the crown root tip and accelerated the development of adventitious roots. Gene pyramiding between the null gn1 aR498 allele with two gain-of-function alleles, STRONG CULM 2(SCM2)and SCM3, further improved lodging resistance.Moreover, Gn1 a/Os CKX2 had minimal influence on overall rice quality. Our research thus highlights the distinct genetic components of lodging resistance of HPT varieties and provides a strategy for tailormade crop improvement of both yield and lodging resistance in rice.展开更多
Rice yield is an important and complex agronomic trait controlled by multiple genes.In recent decades,dozens of yield-associated genes in rice have been cloned,many of which can increase production in the form of loss...Rice yield is an important and complex agronomic trait controlled by multiple genes.In recent decades,dozens of yield-associated genes in rice have been cloned,many of which can increase production in the form of loss or degeneration of function.However,mutations occurring randomly under natural conditions have provided very limited genetic resources for yield increases.In this study,potentially yield-increasing alleles of two genes closely associated with yield were edited artificially.The recently developed CRISPR/Cas9system was used to edit two yield genes:Grain number 1a(Gn1a)and DENSE AND ERECT PANICLE1(DEP1).Several mutants were identified by a target sequence analysis.Phenotypic analysis confirmed one mutant allele of Gn1a and three of DEP1 conferring yield superior to that conferred by other natural high-yield alleles.Our results demonstrate that favorable alleles of the Gnla and DEP1 genes,which are considered key factors in rice yield increases,could be developed by artificial mutagenesis using genome editing technology.展开更多
Using the isotope enabled ECHAM4,GISS E and HadCM3 GCMs,the spatial distribution of mean 6180 in precipitation,mean seasonality and the correlations of 6180 in precipitation with temperature and precipitation amount a...Using the isotope enabled ECHAM4,GISS E and HadCM3 GCMs,the spatial distribution of mean 6180 in precipitation,mean seasonality and the correlations of 6180 in precipitation with temperature and precipitation amount are analyzed.The simulated results are in agreement with stable isotopic features by GNIP observations.Over East Asia.the distribution of~180 in precipita-tion is of marked latitude effect and altitude effect.The latitude effect is covered by the continent effect in some regions.The larg-est seasonality of^lSo in precipitation appears in eastern Siberia controlled by cold high pressure,and the smallest seasonality is in the western Pacific controlled by the subtropical high.Relatively weak seasonality appears in middle latitudes where oceanic and continental air masses frequently interact.However,three GCMs show significant systematic lower~180 for inland mid-high lati-tudes than GNIP data,which is related to the used isotopic scheme in GCMs.Temperature effect occurs mainly in inland mid-high latitudes.The higher the latitude and the closer the distance to inland is,then the stronger the temperature effect.Amount effect occurs mainly in low-mid latitudes and monsoon areas,with the strongest effect in low-latitude coasts or islands.However,three GCMs provide virtually non-existent amount effect in arid regions over Central Asia.The enrichment action of stable isotopes in falling raindrops under a cloud base,which is enlarged by these modes,is responsible for such a result.A significant difference between spatial distributions ofδ^18O statistics by GCMs simulations and by GNIP observations is that the standard deviation of GCMs statistics is greater than that of GNIP statistics.In contrast,by comparing parallel time series at a single station,the standard deviations of GCMs simulations are smaller than that of GNIP observations.展开更多
基金supported by the Biological Breeding-National Science and Technology Major Project,China(Grant No.2023ZD0406801)the National Natural Science Foundation of China(Grant No.32300278)+2 种基金the Key R&D Plan of Shandong Province,China(Grant No.2024LZGC009)the Innovation Program of Chinese Academy of Agricultural Sciences(Grant No.CAAS-CSCB-202402)the Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences,China(Grant No.CXGC2025B09).
文摘Panicle number per plant,grain number per panicle,and grain weight are three key factors influencing rice grain yield.Gn1a,a major QTL for grain number per panicle,encodes the cytokinin oxidase/dehydrogenase(CKX)OsCKX2.While the use of elite Gn1a alleles has been well documented in indica rice cultivars,their potential in japonica rice remains largely unexplored.In this study,we characterized three suppressor mutants of the rice cytokinin receptor mutant pal1/ohk4 and found that all causal genes were novel alleles of Gn1a identified through the MutMap approach.These three suppressor mutants caused single amino acid substitutions in the FAD-binding domain(G556D and G156D)and the cytokinin-binding domain(Y357C),resulting in significantly reduced enzymatic activity of OsCKX2 and elevated cytokinin levels in the panicle.Haplotype analysis of Gn1a using a natural population from the 3K Rice Genomes Project showed that G556D,G156D,and Y357C were novel alleles of Gn1a.G556,G156,and Y357 were highly conserved,whereas four natural variants G54A,A105V,H116R,and N535K identified in different haplotypes of Gn1a showed extremely low conservation.By backcrossing the suppressor mutants with their original wild-type Huaidao 5,an elite japonica rice variety,we developed improved lines carrying only the gn1a mutation.The improved lines showed a significant increase in grain number per panicle,grain weight,panicle number per plant,plant height,and stem thickness,leading to a 25.7%-28.7%increase in grain yield per plot compared with Huaidao 5.This study provides valuable Gn1a alleles for synergistic improvement of the three key yield factors and offers germplasm resources for high-yielding breeding in japonica rice.
基金supported by the National Natural Science Foundation of China(92535301)Sichuan Science and Technology Program(2021YJ0501)。
文摘Significant achievements have been made in breeding programs for the heavy-panicle-type(HPT)rice(Oryza sativa) in Southwest China. The HPT varieties now exhibit excellent lodging resistance,allowing them to overcome the greater pressures caused by heavy panicles. However, the genetic mechanism of this lodging resistance remains elusive. Here, we isolated a major quantitative trait locus, Panicle Neck Diameter 1(PND1), andidentified the causal gene as GRAIN NUMBER 1 A/CYTOKININ OXIDASE 2(Gn1 A/Os CKX2). The null gn1 a allele from rice line R498(gn1 aR498) improved lodging resistance through increasing the culm diameter and promoting crown root development.Loss-of-function of Gn1 a/Os CKX2 led to cytokinin accumulation in the crown root tip and accelerated the development of adventitious roots. Gene pyramiding between the null gn1 aR498 allele with two gain-of-function alleles, STRONG CULM 2(SCM2)and SCM3, further improved lodging resistance.Moreover, Gn1 a/Os CKX2 had minimal influence on overall rice quality. Our research thus highlights the distinct genetic components of lodging resistance of HPT varieties and provides a strategy for tailormade crop improvement of both yield and lodging resistance in rice.
基金the Department of Sciences and Technology of Yunnan Province (2016BB001)the National Basic Research Program of China (2013CB835200)a Key Grant of Yunnan Provincial Science and Technology Department (2013GA004)
文摘Rice yield is an important and complex agronomic trait controlled by multiple genes.In recent decades,dozens of yield-associated genes in rice have been cloned,many of which can increase production in the form of loss or degeneration of function.However,mutations occurring randomly under natural conditions have provided very limited genetic resources for yield increases.In this study,potentially yield-increasing alleles of two genes closely associated with yield were edited artificially.The recently developed CRISPR/Cas9system was used to edit two yield genes:Grain number 1a(Gn1a)and DENSE AND ERECT PANICLE1(DEP1).Several mutants were identified by a target sequence analysis.Phenotypic analysis confirmed one mutant allele of Gn1a and three of DEP1 conferring yield superior to that conferred by other natural high-yield alleles.Our results demonstrate that favorable alleles of the Gnla and DEP1 genes,which are considered key factors in rice yield increases,could be developed by artificial mutagenesis using genome editing technology.
基金supported by the National Natural Science Foundation of China(Grant Nos.41171035,40871094)the Construct Program of the Key Discipline in Hunan Province(No.2012001)+1 种基金Open Fund of Key Laboratory of Tibetan Environment Changes and Land Surface Processes,CAS(No.2011004)Scientific Research Fund of Hunan Provincial Education Department(No.09A056)
文摘Using the isotope enabled ECHAM4,GISS E and HadCM3 GCMs,the spatial distribution of mean 6180 in precipitation,mean seasonality and the correlations of 6180 in precipitation with temperature and precipitation amount are analyzed.The simulated results are in agreement with stable isotopic features by GNIP observations.Over East Asia.the distribution of~180 in precipita-tion is of marked latitude effect and altitude effect.The latitude effect is covered by the continent effect in some regions.The larg-est seasonality of^lSo in precipitation appears in eastern Siberia controlled by cold high pressure,and the smallest seasonality is in the western Pacific controlled by the subtropical high.Relatively weak seasonality appears in middle latitudes where oceanic and continental air masses frequently interact.However,three GCMs show significant systematic lower~180 for inland mid-high lati-tudes than GNIP data,which is related to the used isotopic scheme in GCMs.Temperature effect occurs mainly in inland mid-high latitudes.The higher the latitude and the closer the distance to inland is,then the stronger the temperature effect.Amount effect occurs mainly in low-mid latitudes and monsoon areas,with the strongest effect in low-latitude coasts or islands.However,three GCMs provide virtually non-existent amount effect in arid regions over Central Asia.The enrichment action of stable isotopes in falling raindrops under a cloud base,which is enlarged by these modes,is responsible for such a result.A significant difference between spatial distributions ofδ^18O statistics by GCMs simulations and by GNIP observations is that the standard deviation of GCMs statistics is greater than that of GNIP statistics.In contrast,by comparing parallel time series at a single station,the standard deviations of GCMs simulations are smaller than that of GNIP observations.
