Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of co...Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.展开更多
Grain weight,a key determinant of yield in rice(Oryza sativa L.),is governed primarily by genetic factors,whereas grain chalkiness,a detriment to grain quality,is intertwined with environmental factors such as mineral...Grain weight,a key determinant of yield in rice(Oryza sativa L.),is governed primarily by genetic factors,whereas grain chalkiness,a detriment to grain quality,is intertwined with environmental factors such as mineral nutrients.Nitrogen(N)is recognized for its effect on grain chalkiness,but the underlying molecular mechanisms remain to be clarified.This study revealed the pivotal role of rice NODULE INCEPTION-LIKE PROTEIN 3(OsNLP3)in simultaneously regulating grain weight and grain chalkiness.Our investigation showed that loss of OsNLP3 leads to a reduction in both grain weight and dimension,in contrast to the enhancement observed with OsNLP3 overexpression.OsNLP3 directly suppresses the expression of OsCEP6.1 and OsNF-YA8,which were identified as negative regulators associated with grain weight.Consequently,two novel regulatory modules,OsNLP3-OsCEP6.1 and OsNLP3-OsNF-YA8,were identified as key players in grain weight regulation.Notably,the OsNLP3-OsNF-YA8 module not only increases grain weight but also mitigates grain chalkiness in response to N.This research clarifies the molecular mechanisms that orchestrate grain weight through the OsNLP3-OsCEP6.1 and OsNLP3-OsNF-YA8 modules,highlighting the pivotal role of the OsNLP3-OsNF-YA8 module in alleviating grain chalkiness.These findings reveal potential targets for simultaneous enhancement of rice yield and quality.展开更多
Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)usin...Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)using GLU-SSSLs,which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74(HJX74)as recipient parent.Among the QTL,qGL1-2,qGL1-4,qGL9-2,qGW2-2,qGW9-1 and qTKW9-2 contributed to high grain yield.GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing,and is a novel allele of GS9.The kernel of NIL-gl9was slenderer and longer than that of HJX74,and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74.The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74.Thus,gl9 increased grain yield and appearance quality simultaneously.Three pyramid lines,NIL-gs3/gl9,NIL-GW7/gl9 and NIL-gw8/gl9,were developed and the kernel of each was longer than that of the corresponding recipient parent lines.The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality.展开更多
Grain chalkiness,an undesirable trait caused by complex factors,has great negative impacts on the quality and economic value of rice.However,little is known about the regulatory mechanism of grain chalkiness,particula...Grain chalkiness,an undesirable trait caused by complex factors,has great negative impacts on the quality and economic value of rice.However,little is known about the regulatory mechanism of grain chalkiness,particularly the effect of endoplasmic reticulum(ER)stress.Here,a genome-wide association study(GWAS)reveals that the transcription factor Osb ZIP60 is a vital regulator of rice grain chalkiness.Genetic analysis demonstrates that knockout of Osb ZIP60 results in extremely high grain chalkiness and aberrant structure of storage substances.Notably,the expression of unfolded protein response(UPR)genes,such as OsbZIP50,Os Bi P1,Os Bi P2 and Os Bi P3,is up-regulated in the endosperm cells of osbzip60,and overexpression of all these UPR genes causes various degrees of chalkiness.Furthermore,Osb ZIP60 is found to activate the expression of key genes related to grain chalkiness,such as GPA3,FSE1,FLO7,Chalk5,Os NF-YB1,and Os PK2,whose expression is significantly suppressed in osbzip60 and overexpression lines of Osb ZIP50,Os Bi P1,Os Bi P2,and Os Bi P3.Our study provides novel insights into the function of Osb ZIP60 and the role of the UPR pathway in the formation of grain chalkiness in rice.展开更多
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
Dear Editor Through the efficient use of heterosis, hybrid rice varieties generally have higher grain yield potential than inbred varieties. With the significant advantage in grain yield, over the past 30 years approx...Dear Editor Through the efficient use of heterosis, hybrid rice varieties generally have higher grain yield potential than inbred varieties. With the significant advantage in grain yield, over the past 30 years approximately half of China＇s total rice-growing area is planted with rice hybrids. However, grain quality has now become one of the most important targets in hybrid rice breeding for meeting consumer demands. Grain shape and chalkiness are two important components of rice grain quality, in which slender grains （typically, grain length-to-width ratio 〉3） with low chatkiness are preferred by most consumers of hybrid rice.展开更多
基金supported by the National 863 Program of China (2011AA10A101)the Chinese High-Yielding Transgenic Program (2011ZX08001-004)a project of the State Key Laboratory of Rice Biology,China(ZZKT201101)
文摘Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.
基金supported by grants from the National Natural Science Foundation of China(32321001 to Z.Z.and C.-B.X.and 32100208 to J.W.)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24010303)+1 种基金the Anhui Provincial Natural Science Foundation(2108085QC103)the Fundamental Research Funds for the Central Universities(WK9100000023).
文摘Grain weight,a key determinant of yield in rice(Oryza sativa L.),is governed primarily by genetic factors,whereas grain chalkiness,a detriment to grain quality,is intertwined with environmental factors such as mineral nutrients.Nitrogen(N)is recognized for its effect on grain chalkiness,but the underlying molecular mechanisms remain to be clarified.This study revealed the pivotal role of rice NODULE INCEPTION-LIKE PROTEIN 3(OsNLP3)in simultaneously regulating grain weight and grain chalkiness.Our investigation showed that loss of OsNLP3 leads to a reduction in both grain weight and dimension,in contrast to the enhancement observed with OsNLP3 overexpression.OsNLP3 directly suppresses the expression of OsCEP6.1 and OsNF-YA8,which were identified as negative regulators associated with grain weight.Consequently,two novel regulatory modules,OsNLP3-OsCEP6.1 and OsNLP3-OsNF-YA8,were identified as key players in grain weight regulation.Notably,the OsNLP3-OsNF-YA8 module not only increases grain weight but also mitigates grain chalkiness in response to N.This research clarifies the molecular mechanisms that orchestrate grain weight through the OsNLP3-OsCEP6.1 and OsNLP3-OsNF-YA8 modules,highlighting the pivotal role of the OsNLP3-OsNF-YA8 module in alleviating grain chalkiness.These findings reveal potential targets for simultaneous enhancement of rice yield and quality.
基金supported by the major science and technology research projects of Guangdong Laboratory for Lingnan Modern Agriculture(NT2021001)the Key Projects of Basic Research and Applied Basic Research of Guangdong Province(2019B030302006)+1 种基金the National Natural Science Foundation of China(32072040,31622041)the National Innovation and Entrepreneurship Training Program for College Students(202110564045)。
文摘Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)using GLU-SSSLs,which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74(HJX74)as recipient parent.Among the QTL,qGL1-2,qGL1-4,qGL9-2,qGW2-2,qGW9-1 and qTKW9-2 contributed to high grain yield.GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing,and is a novel allele of GS9.The kernel of NIL-gl9was slenderer and longer than that of HJX74,and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74.The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74.Thus,gl9 increased grain yield and appearance quality simultaneously.Three pyramid lines,NIL-gs3/gl9,NIL-GW7/gl9 and NIL-gw8/gl9,were developed and the kernel of each was longer than that of the corresponding recipient parent lines.The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality.
基金supported by grants from the National Key Research and Development Program of China (2021YFF1000202)the National Natural Science Foundation of China (31771368, 31821005,31701397)+3 种基金Ten-thousand Talents Programs of ChinaFundamental Research Funds for the Central Universities (2662020SKPY006)Wuhan Applied Foundational Frontier Project (2020020601012257)Hubei Hongshan Laboratory (2021hszd005),China
文摘Grain chalkiness,an undesirable trait caused by complex factors,has great negative impacts on the quality and economic value of rice.However,little is known about the regulatory mechanism of grain chalkiness,particularly the effect of endoplasmic reticulum(ER)stress.Here,a genome-wide association study(GWAS)reveals that the transcription factor Osb ZIP60 is a vital regulator of rice grain chalkiness.Genetic analysis demonstrates that knockout of Osb ZIP60 results in extremely high grain chalkiness and aberrant structure of storage substances.Notably,the expression of unfolded protein response(UPR)genes,such as OsbZIP50,Os Bi P1,Os Bi P2 and Os Bi P3,is up-regulated in the endosperm cells of osbzip60,and overexpression of all these UPR genes causes various degrees of chalkiness.Furthermore,Osb ZIP60 is found to activate the expression of key genes related to grain chalkiness,such as GPA3,FSE1,FLO7,Chalk5,Os NF-YB1,and Os PK2,whose expression is significantly suppressed in osbzip60 and overexpression lines of Osb ZIP50,Os Bi P1,Os Bi P2,and Os Bi P3.Our study provides novel insights into the function of Osb ZIP60 and the role of the UPR pathway in the formation of grain chalkiness in rice.
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.
文摘Dear Editor Through the efficient use of heterosis, hybrid rice varieties generally have higher grain yield potential than inbred varieties. With the significant advantage in grain yield, over the past 30 years approximately half of China＇s total rice-growing area is planted with rice hybrids. However, grain quality has now become one of the most important targets in hybrid rice breeding for meeting consumer demands. Grain shape and chalkiness are two important components of rice grain quality, in which slender grains （typically, grain length-to-width ratio 〉3） with low chatkiness are preferred by most consumers of hybrid rice.
