The major storage substance in rice endosperm is starch, which accounts for 80% of dry matter weight. In this study, rice mutant flo7, selected from the progeny of Nipponbare＇s tissue culture, displayed floury and op...The major storage substance in rice endosperm is starch, which accounts for 80% of dry matter weight. In this study, rice mutant flo7, selected from the progeny of Nipponbare＇s tissue culture, displayed floury and opaque endosperm. Compared with its corresponding wild type （WT） Nipponbare, the mutant rio7 produced longer, narrower, thinner and lighter grains. The levels of glucose, fructose and sucrose in the mutant flo7 endosperm were higher than those in the WT endosperm, whereas the protein content was not affected. With respect to both amylose content and gel consistency, the mutant flo7 was lower than WT, but its alkali value was higher. Scanning electron microscopic examinations showed that the endosperm of the mutant flo7 contained irregular, loosely packed and compound starch granules. Genetic analysis indicated that the mutant phenotype was determined by a single recessive nuclear gene The flo7 locus was mapped to a region on the long arm of chromosome 12, within a 95.1 kb interval defined by the markers C2-11 and C5-15. There are 13 open reading frames in the mapping interval. Transcription profiling of the developing grains showed that a number of genes involved in starch synthesis were affected differently in the mutant flo7.展开更多
This study was carried out to facilitate the functional analysis of rice genes. Some 297 insertion plants (1.7%) of the entire lines with the endogenous retrotransposon Tos17 were produced. Phenotypes of these plants ...This study was carried out to facilitate the functional analysis of rice genes. Some 297 insertion plants (1.7%) of the entire lines with the endogenous retrotransposon Tos17 were produced. Phenotypes of these plants in the S2 genera-tion were observed in the field according to different leaf types. Rolling leaf mutants showed thinner sclerenchyma-tous cells, defective arrangement of vascular bundles, and well-formed bulliform cells as compared to the parental cultivar. Two new copies of Tos17 were detected in the rolling leaf type. In the new leaf type, the copy number and activation of Tos12, 15 did not appear as ‘Ilpum’. Flanking sequence tag (FST) analysis of Tos17 in the rolling leaf mutant indicated that new copies of Tos17 were transposed on chromosomes 11 and 12. Annotated homologues of the tagging genes on chromosome 11 were arabinoxylan rabinofuranohydrolase isoenzyme AXAH-I and II. The tagging gene in chromosome 12 was highly correlated with 6 kinds of genes including a transcript regulated factor and a rough sheath 2-like protein. This rolling leaf and flanking sequence data will stimulate the functional analysis of rice genes.展开更多
Physicochemical properties of endosperm starches in milled rice determine its cooking and eating quality.Amylose is synthesized by granule-bound starch synthase I(GBSSI),whilst amylopectin is synthesized by the synerg...Physicochemical properties of endosperm starches in milled rice determine its cooking and eating quality.Amylose is synthesized by granule-bound starch synthase I(GBSSI),whilst amylopectin is synthesized by the synergistic activities of starch synthases(SSs),branching enzymes(BEs)and debranching enzymes(DBEs).However,the complexes formed by starch biosynthetic enzymes are not well characterized.Gene expression profiles and protein complexes were determined in white-core(GM645)and waxy(GM077)mutants derived from a high amylose indica rice Guangluai 4(GLA4).In GM645,genes including AGPS1,GBSSI,SSIIa,BEI,BEIIa,BEIIb,PUL,ISA1 and SP were significantly downregulated during seed development.In GM077,the expression levels of AGPL2,AGPS1,AGPS2b,SSIIIa,BEI,PUL and ISA1 were significantly upregulated.Co-immunoprecipitation assays revealed interactions of SSs-BEs,SSs-PUL and BEs-PUL in developing seeds.However,weak SSI-SSIIa interaction was detected in GM077,whilst SSI-PUL interaction was absent.Weak interaction signals for SSI-SSIIa,SSIIa-BEI,SSIIa-BEIIb,BEI-BEIIb and SSI-BEI were also observed in GM645.These results suggest that the protein-protein interactions for starch biosynthesis are modified in mutants,which provides insight into the mechanisms of starch biosynthesis,particularly in indica rice.展开更多
Endosperm mutants are critical to the studies on both starch synthesis and metabolism and genetic improvement of starch quality in maize.In the present study,a novel maize endosperm mutant A0178 of natural variation w...Endosperm mutants are critical to the studies on both starch synthesis and metabolism and genetic improvement of starch quality in maize.In the present study,a novel maize endosperm mutant A0178 of natural variation was used as the experimental material and identified and then characterized.Through phenotypic identification,genetic analysis,main ingredients measurement and embryo rescue,development of genetic mapping population from A0178,the endosperm mutant gene was located.The results showed that the mutant exhibited extremely low germination ability as attributed to the inhibited embryo development,and amounts of sugars were accumulated in the mutant seeds and more sugars content was detected at 23 days after pollination(DAP)in A0178 than B73.Employing genetic linkage analysis,the mutant trait was mapped in the bin 5.04 on chromosome 5.Sequence analysis showed that two sites of base transversion and insertion presented in the protein coding region and non-coding region of the mutant brittle-1(bt1),the adenylate translocator encoding gene involved in the starch synthesis.The single base insertion in the coding region cause frameshift mutation,early termination and lose of function of Brittle-1(BT1).All results suggested that bt1 is a novel allelic gene and the causal gene of this endosperm mutant,providing insights on the mechanism of endosperm formation in maize.展开更多
基金supported by China National Natural Science Foundation (Grant Nos. 31471472 and 31301303)Natural Science Foundation of Zhejiang Province,China (Grant Nos. LY13C130003 and LY14C130012)
文摘The major storage substance in rice endosperm is starch, which accounts for 80% of dry matter weight. In this study, rice mutant flo7, selected from the progeny of Nipponbare＇s tissue culture, displayed floury and opaque endosperm. Compared with its corresponding wild type （WT） Nipponbare, the mutant rio7 produced longer, narrower, thinner and lighter grains. The levels of glucose, fructose and sucrose in the mutant flo7 endosperm were higher than those in the WT endosperm, whereas the protein content was not affected. With respect to both amylose content and gel consistency, the mutant flo7 was lower than WT, but its alkali value was higher. Scanning electron microscopic examinations showed that the endosperm of the mutant flo7 contained irregular, loosely packed and compound starch granules. Genetic analysis indicated that the mutant phenotype was determined by a single recessive nuclear gene The flo7 locus was mapped to a region on the long arm of chromosome 12, within a 95.1 kb interval defined by the markers C2-11 and C5-15. There are 13 open reading frames in the mapping interval. Transcription profiling of the developing grains showed that a number of genes involved in starch synthesis were affected differently in the mutant flo7.
文摘This study was carried out to facilitate the functional analysis of rice genes. Some 297 insertion plants (1.7%) of the entire lines with the endogenous retrotransposon Tos17 were produced. Phenotypes of these plants in the S2 genera-tion were observed in the field according to different leaf types. Rolling leaf mutants showed thinner sclerenchyma-tous cells, defective arrangement of vascular bundles, and well-formed bulliform cells as compared to the parental cultivar. Two new copies of Tos17 were detected in the rolling leaf type. In the new leaf type, the copy number and activation of Tos12, 15 did not appear as ‘Ilpum’. Flanking sequence tag (FST) analysis of Tos17 in the rolling leaf mutant indicated that new copies of Tos17 were transposed on chromosomes 11 and 12. Annotated homologues of the tagging genes on chromosome 11 were arabinoxylan rabinofuranohydrolase isoenzyme AXAH-I and II. The tagging gene in chromosome 12 was highly correlated with 6 kinds of genes including a transcript regulated factor and a rough sheath 2-like protein. This rolling leaf and flanking sequence data will stimulate the functional analysis of rice genes.
基金National Key Research and Development Program of China(Grant No.2016YFD0400104)the Natural Science Foundation of China(Grant Nos.31800640 and 31871531).
文摘Physicochemical properties of endosperm starches in milled rice determine its cooking and eating quality.Amylose is synthesized by granule-bound starch synthase I(GBSSI),whilst amylopectin is synthesized by the synergistic activities of starch synthases(SSs),branching enzymes(BEs)and debranching enzymes(DBEs).However,the complexes formed by starch biosynthetic enzymes are not well characterized.Gene expression profiles and protein complexes were determined in white-core(GM645)and waxy(GM077)mutants derived from a high amylose indica rice Guangluai 4(GLA4).In GM645,genes including AGPS1,GBSSI,SSIIa,BEI,BEIIa,BEIIb,PUL,ISA1 and SP were significantly downregulated during seed development.In GM077,the expression levels of AGPL2,AGPS1,AGPS2b,SSIIIa,BEI,PUL and ISA1 were significantly upregulated.Co-immunoprecipitation assays revealed interactions of SSs-BEs,SSs-PUL and BEs-PUL in developing seeds.However,weak SSI-SSIIa interaction was detected in GM077,whilst SSI-PUL interaction was absent.Weak interaction signals for SSI-SSIIa,SSIIa-BEI,SSIIa-BEIIb,BEI-BEIIb and SSI-BEI were also observed in GM645.These results suggest that the protein-protein interactions for starch biosynthesis are modified in mutants,which provides insight into the mechanisms of starch biosynthesis,particularly in indica rice.
基金This work was financially supported in part by grants from National Science and Technology Support Project of China(2016YFD0101205)the Natural Science Foundation of Jiangsu Province,China(BK20160586)+1 种基金National Transgenic Major Project of China(2019ZX08010-004)as well as Six Talent Peaks Project of Jiangsu Province,China(NY-020).
文摘Endosperm mutants are critical to the studies on both starch synthesis and metabolism and genetic improvement of starch quality in maize.In the present study,a novel maize endosperm mutant A0178 of natural variation was used as the experimental material and identified and then characterized.Through phenotypic identification,genetic analysis,main ingredients measurement and embryo rescue,development of genetic mapping population from A0178,the endosperm mutant gene was located.The results showed that the mutant exhibited extremely low germination ability as attributed to the inhibited embryo development,and amounts of sugars were accumulated in the mutant seeds and more sugars content was detected at 23 days after pollination(DAP)in A0178 than B73.Employing genetic linkage analysis,the mutant trait was mapped in the bin 5.04 on chromosome 5.Sequence analysis showed that two sites of base transversion and insertion presented in the protein coding region and non-coding region of the mutant brittle-1(bt1),the adenylate translocator encoding gene involved in the starch synthesis.The single base insertion in the coding region cause frameshift mutation,early termination and lose of function of Brittle-1(BT1).All results suggested that bt1 is a novel allelic gene and the causal gene of this endosperm mutant,providing insights on the mechanism of endosperm formation in maize.
