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Guoying Wang - One of the best experts on this subject based on the ideXlab platform.
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increasing maize Seed Weight by enhancing the cytoplasmic adp glucose pyrophosphorylase activity in transgenic maize plants
Plant Cell Tissue and Organ Culture, 2007Co-Authors: Zhangying Wang, Xiaoping Chen, Jianhua Wang, Tingsong Liu, Yan Liu, Li Zhao, Guoying WangAbstract:ADP-glucose pyrophosphorylase (AGPase) plays a key role in regulating starch biosynthesis in cereal Seeds and is likely the most important determinant of Seed strength. The Escherichia coli mutant glgC gene (glgC16), which encodes a highly active and allosterically insensitive AGPase, was introduced into maize (Zea mays L.) under the control of an endosperm-specific promoter. Developing Seeds from transgenic maize plants showed up to 2–4-fold higher levels of AGPase activity in the presence of 5 mM inorganic phosphate (Pi). Transgenic plants with higher cytoplasmic AGPase activity under Pi-inhibitory conditions showed increases (13–25%) in Seed Weight over the untransformed control. In addition, in all transgenic maize plants, the Seeds were fully filled, and the Seed number of transgenic plants had no significant difference compared with that of untransformed control. These results indicate that increasing cytoplasmic AGPase activity has a marked effect on sink activity and, in turn, Seed Weight in transgenic maize plants.
Yongming Zhou - One of the best experts on this subject based on the ideXlab platform.
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identification of candidate genes of qtls for Seed Weight in brassica napus through comparative mapping among arabidopsis and brassica species
BMC Genetics, 2012Co-Authors: Guangqin Cai, Chuchuan Fan, Qingyong Yang, Qian Yang, Zhenxing Zhao, Hao Chen, Yongming ZhouAbstract:Map-based cloning of quantitative trait loci (QTLs) in polyploidy crop species remains a challenge due to the complexity of their genome structures. QTLs for Seed Weight in B. napus have been identified, but information on candidate genes for identified QTLs of this important trait is still rare. In this study, a whole genome genetic linkage map for B. napus was constructed using simple sequence repeat (SSR) markers that covered a genetic distance of 2,126.4 cM with an average distance of 5.36 cM between markers. A procedure was developed to establish colinearity of SSR loci on B. napus with its two progenitor diploid species B. rapa and B. oleracea through extensive bioinformatics analysis. With the aid of B. rapa and B. oleracea genome sequences, the 421 homologous colinear loci deduced from the SSR loci of B. napus were shown to correspond to 398 homologous loci in Arabidopsis thaliana. Through comparative mapping of Arabidopsis and the three Brassica species, 227 homologous genes for Seed size/Weight were mapped on the B. napus genetic map, establishing the genetic bases for the important agronomic trait in this amphidiploid species. Furthermore, 12 candidate genes underlying 8 QTLs for Seed Weight were identified, and a gene-specific marker for BnAP2 was developed through molecular cloning using the Seed Weight/size gene distribution map in B. napus. Our study showed that it is feasible to identify candidate genes of QTLs using a SSR-based B. napus genetic map through comparative mapping among Arabidopsis and B. napus and its two progenitor species B. rapa and B. oleracea. Identification of candidate genes for Seed Weight in amphidiploid B. napus will accelerate the process of isolating the mapped QTLs for this important trait, and this approach may be useful for QTL identification of other traits of agronomic significance.
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mapping of quantitative trait loci and development of allele specific markers for Seed Weight in brassica napus
Theoretical and Applied Genetics, 2010Co-Authors: Chuchuan Fan, Guangqin Cai, Jie Qin, Minggui Yang, Kede Liu, Yongming ZhouAbstract:Seed Weight is an important component of grain yield in oilSeed rape (Brassica napus L.), but the genetic basis for the important quantitative trait is still not clear. In order to identify the genes for Seed Weight in oilSeed rape, QTL mapping for thousand Seed Weight (TSW) was conducted with a doubled haploid (DH) population and an F2 population. A complete linkage map of the DH population was constructed using 297 simple sequence repeat (SSR) markers. Among nine TSW QTLs detected, two major QTLs, TSWA7a and TSWA7b, were stably identified across years and collectively explained 27.6–37.9% of the trait variation in the DH population. No significant epistatic interactions for TSW detected in the DH population indicate that the Seed Weight variation may be primarily attributed to additive effects. The stability and significance of TSWA7a and TSWA7b were further validated in the F2 population with different genetic backgrounds. By cloning BnMINI3a and BnTTG2a, two B. napus homologous genes to Arabidopsis thaliana, allele-specific markers were developed for TSWA5b and TSWA5c, two TSW QTLs on A5, respectively. The importance of the major and minor QTLs identified was further demonstrated by analysis of the allelic effects on TSW in the DH population.
Thomas W Okita - One of the best experts on this subject based on the ideXlab platform.
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engineering starch biosynthesis for increasing rice Seed Weight the role of the cytoplasmic adp glucose pyrophosphorylase
Plant Science, 2004Co-Authors: Chotipa Sakulsingharoj, Sangbong Choi, Seonkap Hwang, Gerald E Edwards, Jennifer Bork, Christopher R Meyer, Jack Preiss, Thomas W OkitaAbstract:ADP-glucose pyrophosphorylase (AGPase) controls a rate-limiting step in starch biosynthesis. In cereals, manipulation of this enzyme is a prime target to increase starch production during Seed development as a means to increase sink strength and, in turn, crop yields. The Escherichia coli glgC triple mutant (TM) gene, which encodes a highly active and allosterically insensitive AGPase, was introduced into rice and expressed during endosperm development. The mutated enzyme was targeted to either the amyloplast or cytoplasm to determine the relationship between intracellular location of ADP-glucose formation and starch synthesis. Transgenic rice Seeds expressing the amyloplast or cytoplasmic AGPase-TM showed up to 13-fold higher levels of AGPase activity compared to untransformed plants when assayed in the presence of inorganic phosphate to suppress the endogenous activity. Plants having elevated cytoplasmic AGPase activity under Pi-inhibitory conditions showed increases in 14C-sucrose labeling into starch and, in turn, increases (up to 11%) in Seed Weight over the wt. In contrast, transgenic plants expressing the amyloplast-targeted AGPase activity showed small to moderate increases in 14C-sucrose-labeling rates into starch and either a moderate increase in Seed Weight or, in several instances, a reduction in Seed Weight. Our results demonstrate that the intracellular location of AGPase has a marked effect on the capacity of the enzyme to increase starch synthesis and, in turn, Seed Weight.
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a single mutation that increases maize Seed Weight
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Michael J Giroux, Janine R Shaw, Gerard F Barry, B G Cobb, Thomas W Greene, Thomas W Okita, L C HannahAbstract:Abstract The maize endosperm-specific gene shrunken2 (Sh2) encodes the large subunit of the heterotetrameric starch synthetic enzyme adenosine diphosphoglucose pyrophosphorylase (AGP; EC 2.7.7.27). Here we exploit an in vivo, site-specific mutagenesis system to create short insertion mutations in a region of the gene known to be involved in the allosteric regulation of AGP. The site-specific mutagen is the transposable element dissociation (Ds). Approximately one-third (8 of 23) of the germinal revertants sequenced restored the wild-type sequence, whereas the remaining revertants contained insertions of 3 or 6 bp. All revertants retained the original reading frame 3' to the insertion site and involved the addition of tyrosine and/or serine. Each insertion revertant reduced total AGP activity and the amount of the SH2 protein. The revertant containing additional tyrosine and serine residues increased Seed Weight 11-18% without increasing or decreasing the percentage of starch. Other insertion revertants lacking an additional serine reduced Seed Weight. Reduced sensitivity to phosphate, a long-known inhibitor of AGP, was found in the high Seed-Weight revertant. This alteration is likely universally important since insertion of tyrosine and serine in the potato large subunit of AGP at the comparable position and expression in Escherichia coli also led to a phosphate-insensitive enzyme. These results show that single gene mutations giving rise to increased Seed Weight, and therefore perhaps yield, are clearly possible in a plant with a long history of intensive and successful breeding efforts.
Perry Cregan - One of the best experts on this subject based on the ideXlab platform.
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identification of qtl with large effect on Seed Weight in a selective population of soybean with genome wide association and fixation index analyses
BMC Genomics, 2017Co-Authors: Long Yan, Nicolle Hofmann, Marcio Elias Ferreira, Baohua Song, Guoliang Jiang, Shuxin Ren, Edward Fickus, Charles V Quigley, Perry CreganAbstract:Soybean Seed Weight is not only a yield component, but also a critical trait for various soybean food products such as sprouts, edamame, soy nuts, natto and miso. Linkage analysis and genome-wide association study (GWAS) are two complementary and powerful tools to connect phenotypic differences to the underlying contributing loci. Linkage analysis is based on progeny derived from two parents, given sufficient sample size and biological replication, it usually has high statistical power to map alleles with relatively small effect on phenotype, however, linkage analysis of the bi-parental population can’t detect quantitative trait loci (QTL) that are fixed in the two parents. Because of the small Seed Weight difference between the two parents in most families of previous studies, these populations are not suitable to detect QTL that have considerable effects on Seed Weight. GWAS is based on unrelated individuals to detect alleles associated with the trait under investigation. The ability of GWAS to capture major Seed Weight QTL depends on the frequency of the accessions with small and large Seed Weight in the population being investigated. Our objective was to identify QTL that had a pronounced effect on Seed Weight using a selective population of soybean germplasm accessions and the approach of GWAS and fixation index analysis. We selected 166 accessions from the USDA Soybean Germplasm Collection with either large or small Seed Weight and could typically grow in the same location. The accessions were evaluated for Seed Weight in the field for two years and genotyped with the SoySNP50K BeadChip containing >42,000 SNPs. Of the 17 SNPs on six chromosomes that were significantly associated with Seed Weight in two years based on a GWAS of the selective population, eight on chromosome 4 or chromosome 17 had significant Fst values between the large and small Seed Weight sub-populations. The Seed Weight difference of the two alleles of these eight significant SNPs varied from 8.1 g to 11.7 g/100 Seeds in two years. We also identified haplotypes in three haplotype blocks with significant effects on Seed Weight. These findings were validated in a panel with 3753 accessions from the USDA Soybean Germplasm Collection. This study highlighted the usefulness of selective genotyping populations coupled with GWAS and fixation index analysis for the identification of QTL with substantial effects on Seed Weight in soybean. This approach may help geneticists and breeders to more efficiently identify major QTL controlling other traits. The major regions and haplotypes we have identified that control Seed Weight differences in soybean will facilitate the identification of genes regulating this important trait.
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Identification of QTL with large effect on Seed Weight in a selective population of soybean with genome-wide association and fixation index analyses
BMC, 2017Co-Authors: Long Yan, Nicolle Hofmann, Marcio Elias Ferreira, Baohua Song, Guoliang Jiang, Shuxin Ren, Charles Quigley, Edward Fickus, Perry CreganAbstract:Abstract Background Soybean Seed Weight is not only a yield component, but also a critical trait for various soybean food products such as sprouts, edamame, soy nuts, natto and miso. Linkage analysis and genome-wide association study (GWAS) are two complementary and powerful tools to connect phenotypic differences to the underlying contributing loci. Linkage analysis is based on progeny derived from two parents, given sufficient sample size and biological replication, it usually has high statistical power to map alleles with relatively small effect on phenotype, however, linkage analysis of the bi-parental population can’t detect quantitative trait loci (QTL) that are fixed in the two parents. Because of the small Seed Weight difference between the two parents in most families of previous studies, these populations are not suitable to detect QTL that have considerable effects on Seed Weight. GWAS is based on unrelated individuals to detect alleles associated with the trait under investigation. The ability of GWAS to capture major Seed Weight QTL depends on the frequency of the accessions with small and large Seed Weight in the population being investigated. Our objective was to identify QTL that had a pronounced effect on Seed Weight using a selective population of soybean germplasm accessions and the approach of GWAS and fixation index analysis. Results We selected 166 accessions from the USDA Soybean Germplasm Collection with either large or small Seed Weight and could typically grow in the same location. The accessions were evaluated for Seed Weight in the field for two years and genotyped with the SoySNP50K BeadChip containing >42,000 SNPs. Of the 17 SNPs on six chromosomes that were significantly associated with Seed Weight in two years based on a GWAS of the selective population, eight on chromosome 4 or chromosome 17 had significant Fst values between the large and small Seed Weight sub-populations. The Seed Weight difference of the two alleles of these eight significant SNPs varied from 8.1 g to 11.7 g/100 Seeds in two years. We also identified haplotypes in three haplotype blocks with significant effects on Seed Weight. These findings were validated in a panel with 3753 accessions from the USDA Soybean Germplasm Collection. Conclusion This study highlighted the usefulness of selective genotyping populations coupled with GWAS and fixation index analysis for the identification of QTL with substantial effects on Seed Weight in soybean. This approach may help geneticists and breeders to more efficiently identify major QTL controlling other traits. The major regions and haplotypes we have identified that control Seed Weight differences in soybean will facilitate the identification of genes regulating this important trait
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genome wide association study genomic prediction and marker assisted selection for Seed Weight in soybean glycine max
Theoretical and Applied Genetics, 2016Co-Authors: Jiaoping Zhang, Qijian Song, Perry Cregan, Guoliang JiangAbstract:Twenty-two loci for soybean SW and candidate genes conditioning Seed development were identified; and prediction accuracies of GS and MAS were estimated through cross-validation and validation with unrelated populations. Soybean (Glycine max) is a major crop for plant protein and oil production, and Seed Weight (SW) is important for yield and quality in food/vegetable uses of soybean. However, our knowledge of genes controlling SW remains limited. To better understand the molecular mechanism underlying the trait and explore marker-based breeding approaches, we conducted a genome-wide association study in a population of 309 soybean germplasm accessions using 31,045 single nucleotide polymorphisms (SNPs), and estimated the prediction accuracy of genomic selection (GS) and marker-assisted selection (MAS) for SW. Twenty-two loci of minor effect associated with SW were identified, including hotspots on Gm04 and Gm19. The mixed model containing these loci explained 83.4 % of phenotypic variation. Candidate genes with Arabidopsis orthologs conditioning SW were also proposed. The prediction accuracies of GS and MAS by cross-validation were 0.75–0.87 and 0.62–0.75, respectively, depending on the number of SNPs used and the size of training population. GS also outperformed MAS when the validation was performed using unrelated panels across a wide range of maturities, with an average prediction accuracy of 0.74 versus 0.53. This study convincingly demonstrated that soybean SW is controlled by numerous minor-effect loci. It greatly enhances our understanding of the genetic basis of SW in soybean and facilitates the identification of genes controlling the trait. It also suggests that GS holds promise for accelerating soybean breeding progress. The results are helpful for genetic improvement and genomic prediction of yield in soybean.
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genetic mapping and confirmation of quantitative trait loci for Seed protein and oil contents and Seed Weight in soybean
Crop Science, 2013Co-Authors: Safiullah M Pathan, Jeongdong Lee, Perry Cregan, Grover J Shannon, Tri D Vuong, Kerry M Clark, Craig A Roberts, Mark R Ellersieck, J W Burton, David L HytenAbstract:Demand for soybean [Glycine max (L.) Merr.] meal has increased worldwide and soybean importers often offer premiums for soybean containing higher contents of protein and oil. objectives were to detect quantitative trait loci (QTL) associated with soybean Seed protein, oil, and Seed Weight in a soybean mapping population and confirm detected QTL across genetic backgrounds and environments. Two populations of 216 and 156 recombinant inbred lines were developed from Magellan × pI 438489B and Magellan × pI 567516C crosses, respectively, and grown in two Missouri environments in 2008. More than 900 simple sequence repeat (SSr) and single nucleotide polymorphism (SNp) markers were used for mapping in each population. Across environments and genetic backgrounds, we have identified seven QTL for protein, six for oil, and four for Seed Weight. Two QTL were detected in common for protein and oil, one on chromosome (Chr.) 5 and another on Chr. 6. Additionally, we have detected one new Seed Weight QTL on Chr. 6, in the same region of protein and oil QTL. Confirmed protein and oil QTL on Chrs. 5 and 6 may be important targets to find candidate genes involved in modification of protein and oil contents and Seed Weight using genetic and genomic approaches. Also, SSr and SNp markers closely associated with these QTL can be useful for marker-assisted selection. S.M. Pathan and J.G. Shannon, National Center for Soybean Biotechnology (NCSB) and Division of Plant Sciences, Univ. of Missouri Delta Research Center, Portageville, MO 63873; T. Vuong, K. Clark, H.T. Nguyen, and D.A. Sleper, NCSB and Division of Plant Sciences, Univ. of Missouri, Columbia, MO 65211; C.A. Roberts, Division of Plant Sciences, Univ. of Missouri, Columbia, MO 65211; M.R. Ellersieck, Division of Statistics, Univ. of Missouri, Columbia, MO 65211; J.W. Burton, Soybean and Nitrogen Fixation Research Unit, USDA-ARS, Raleigh, NC 27607; D.L. Hyten, Pioneer Hi-Bred International Inc., Johnston, IA 50131; P.B. Cregan, Soybean Genomics and Improvement Laboratory, USDA-ARS, Beltsville, MD 20705; J.-D. Lee, School of Applied Biosciences, Kyungpook National Univ., Daegu 702-701, Republic of Korea. S.M. Pathan and T. Vuong contributed equally to the article. Received 5 Mar. 2012. *Corresponding author (sleperd@missouri.edu). Abbreviations: BREC, Bradford Research and Extension Center; Chr., chromosome; DRC, Delta Research Center; H2, broad-sense heritability; LOD, logarithm of the odds; MPB, Magellan × PI 438489B; MPC, Magellan × PI 567516C; MQM, multiple-QTL method; MU, University of Missouri–Columbia; NIR, near-infrared reflectance; QTL, quantitative trait loci; RIL, recombinant inbred line; SBM, soybean meal; SCN, soybean cyst nematode; SNP, single nucleotide polymorphism; SSR, simple sequence repeat. Published in Crop Sci. 53:765–774 (2013). doi: 10.2135/cropsci2012.03.0153 © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher.
Hanzhong Wang - One of the best experts on this subject based on the ideXlab platform.
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maternal control of Seed Weight in rapeSeed brassica napus l the causal link between the size of pod mother source and Seed offspring sink
Plant Biotechnology Journal, 2019Co-Authors: Dongji Song, Xinfa Wang, Wei Peng, Jiepeng Zhan, Jiaqin Shi, Guihua Liu, Hanzhong WangAbstract:Seed size/Weight is one of the key traits related to plant domestication and crop improvement. In rapeSeed (Brassica napus L.) germplasm, Seed Weight shows extensive variation, but its regulatory mechanism is poorly understood. To identify the key mechanism of Seed Weight regulation, a systematic comparative study was performed. Genetic, morphological and cytological evidence showed that Seed Weight was controlled by maternal genotype, through the regulation of Seed size mainly via cell number. The physiological evidence indicated that differences in the pod length might result in differences in pod wall photosynthetic area, carbohydrates and the final Seed Weight. We also identified two pleiotropic major quantitative trait loci that acted indirectly on Seed Weight via their effects on pod length. RNA-seq results showed that genes related to pod development and hormones were significantly differentially expressed in the pod wall; genes related to development, cell division, nutrient reservoir and ribosomal proteins were all up-regulated in the Seeds of the large-Seed pool. Finally, we proposed a potential Seed Weight regulatory mechanism that is specific to rapeSeed and novel in plants. The results demonstrate a causal link between the size of the pod (mother, source) and the Seed (offspring, sink) in rapeSeed, which provides novel insight into the maternal control of Seed Weight and will open a new research field in plants.
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natural variation in arf18 gene simultaneously affects Seed Weight and silique length in polyploid rapeSeed
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Jing Liu, Xinfa Wang, Liang Zhang, Linbin Deng, Xingchao Sun, Wei Hua, Hongli Yang, Hanzhong WangAbstract:Seed Weight (SW), which is one of the three major factors influencing grain yield, has been widely accepted as a complex trait that is controlled by polygenes, particularly in polyploid crops. Brassica napus L., which is the second leading crop source for vegetable oil around the world, is a tetraploid (4×) species. In the present study, we identified a major quantitative trait locus (QTL) on chromosome A9 of rapeSeed in which the genes for SW and silique length (SL) were colocated. By fine mapping and association analysis, we uncovered a 165-bp deletion in the auxin-response factor 18 (ARF18) gene associated with increased SW and SL. ARF18 encodes an auxin-response factor and shows inhibitory activity on downstream auxin genes. This 55-aa deletion prevents ARF18 from forming homodimers, in turn resulting in the loss of binding activity. Furthermore, reciprocal crossing has shown that this QTL affects SW by maternal effects. Transcription analysis has shown that ARF18 regulates cell growth in the silique wall by acting via an auxin-response pathway. Together, our results suggest that ARF18 regulates silique wall development and determines SW via maternal regulation. In addition, our study reveals the first (to our knowledge) QTL in rapeSeed and may provide insights into gene cloning involving polyploid crops.
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a combined linkage and regional association mapping validation and fine mapping of two major pleiotropic qtls for Seed Weight and silique length in rapeSeed brassica napus l
BMC Plant Biology, 2014Co-Authors: Jiaqin Shi, Xinfa Wang, Guihua Liu, Hanzhong WangAbstract:Background Seed Weight (SW) and silique length (SL) are important determinants of the yield potential in rapeSeed (Brassica napus L.). However, the genetic basis of both traits is poorly understood. The main objectives of this study were to dissect the genetic basis of SW and SL in rapeSeed through the preliminary mapping of quantitative trait locus (QTL) by linkage analysis and fine mapping of the target major QTL by regional association analysis.
