Author
Devinder Sandhu
Other affiliations: University of Nebraska–Lincoln, Iowa State University, University of Wisconsin–Stevens Point ...read more
Bio: Devinder Sandhu is an academic researcher from Agricultural Research Service. The author has contributed to research in topics: Gene & Salinity. The author has an hindex of 23, co-authored 72 publications receiving 5502 citations. Previous affiliations of Devinder Sandhu include University of Nebraska–Lincoln & Iowa State University.
Topics: Gene, Salinity, Mutant, Genome, Expressed sequence tag
Papers published on a yearly basis
Papers
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Agricultural Research Service1, Purdue University2, University of North Carolina at Charlotte3, University of California, Berkeley4, University of Arizona5, University of Maryland, College Park6, University of Missouri7, Joint Genome Institute8, National Center for Genome Resources9, Iowa State University10, University of Wisconsin–Stevens Point11, University of Nebraska–Lincoln12
TL;DR: An accurate soybean genome sequence will facilitate the identification of the genetic basis of many soybean traits, and accelerate the creation of improved soybean varieties.
Abstract: Soybean (Glycine max) is one of the most important crop plants for seed protein and oil content, and for its capacity to fix atmospheric nitrogen through symbioses with soil-borne microorganisms. We sequenced the 1.1-gigabase genome by a whole-genome shotgun approach and integrated it with physical and high-density genetic maps to create a chromosome-scale draft sequence assembly. We predict 46,430 protein-coding genes, 70% more than Arabidopsis and similar to the poplar genome which, like soybean, is an ancient polyploid (palaeopolyploid). About 78% of the predicted genes occur in chromosome ends, which comprise less than one-half of the genome but account for nearly all of the genetic recombination. Genome duplications occurred at approximately 59 and 13 million years ago, resulting in a highly duplicated genome with nearly 75% of the genes present in multiple copies. The two duplication events were followed by gene diversification and loss, and numerous chromosome rearrangements. An accurate soybean genome sequence will facilitate the identification of the genetic basis of many soybean traits, and accelerate the creation of improved soybean varieties.
3,743 citations
Kansas State University1, United States Department of Agriculture2, University of California, Davis3, University of Arizona4, Cornell University5, Washington State University6, Iowa State University7, University of Missouri8, University of Minnesota9, North Dakota State University10, Colorado State University11, Texas Tech University12, North Carolina State University13, University of California, Riverside14
TL;DR: The chromosome bin map of ESTs is a unique resource for SNP analysis, comparative mapping, structural and functional analysis, and polyploid evolution, as well as providing a framework for constructing a sequence-ready, BAC-contig map of the wheat genome.
Abstract: Because of the huge size of the common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) genome of 17,300 Mb, sequencing and mapping of the expressed portion is a logical first step for gene discovery. Here we report mapping of 7104 expressed sequence tag (EST) unigenes by Southern hybridization into a chromosome bin map using a set of wheat aneuploids and deletion stocks. Each EST detected a mean of 4.8 restriction fragments and 2.8 loci. More loci were mapped in the B genome (5774) than in the A (5173) or D (5146) genomes. The EST density was significantly higher for the D genome than for the A or B. In general, EST density increased relative to the physical distance from the centromere. The majority of EST-dense regions are in the distal parts of chromosomes. Most of the agronomically important genes are located in EST-dense regions. The chromosome bin map of ESTs is a unique resource for SNP analysis, comparative mapping, structural and functional analysis, and polyploid evolution, as well as providing a framework for constructing a sequence-ready, BAC-contig map of the wheat genome.
411 citations
TL;DR: By physically mapping 3025 loci including 252 phenotypically characterized genes and 17 quantitative trait loci (QTLs) relative to 334 deletion breakpoints, the gene-containing fraction to 29% of the wheat genome present as 18 major and 30 minor gene-rich regions (GRRs).
Abstract: By physically mapping 3025 loci including 252 phenotypically characterized genes and 17 quantitative trait loci (QTLs) relative to 334 deletion breakpoints, we localized the gene-containing fraction to 29% of the wheat genome present as 18 major and 30 minor gene-rich regions (GRRs). The GRRs varied both in gene number and density. The five largest GRRs physically spanning <3% of the genome contained 26% of the wheat genes. Approximate size of the GRRs ranged from 3 to 71 Mb. Recombination mainly occurred in the GRRs. Various GRRs varied as much as 128-fold for gene density and 140-fold for recombination rates. Except for a general suppression in 25-40% of the chromosomal region around centromeres, no correlation of recombination was observed with the gene density, the size, or chromosomal location of GRRs. More than 30% of the wheat genes are in recombination-poor regions thus are inaccessible to map-based cloning.
207 citations
TL;DR: Comparisons of orthologous regions indicated that gene density in wheat is about one-half compared with rice, mainly because of amplification of the gene-poor regions, and insertional inactivation by adjoining retro-elements and selection seem to have played a major role in stabilizing genomes.
Abstract: Deletion line-based high-density physical maps revealed that the wheat (Triticum aestivum) genome is partitioned into gene-rich and -poor compartments. Available deletion lines have bracketed the gene-containing regions to about 10% of the genome. Emerging sequence data suggest that these may further be partitioned into "mini" gene-rich and gene-poor regions. An average of about 10% of each gene-rich region seem to contain genes. Sequence analyses in various species suggest that uneven distribution of genes may be a characteristic of all grasses and perhaps all higher organisms. Comparison of the physical maps with genetic linkage maps showed that recombination in wheat and barley (Hordeum vulgare) is confined to the gene-containing regions. Number of genes, gene density, and the extent of recombination vary greatly among the gene-rich regions. The gene order, relative region size, and recombination are highly conserved within the tribe Triticeae and moderately conserved within the family. Gene-poor regions are composed of retrotransposon-like non-transcribing repeats and pseudogenes. Direct comparisons of orthologous regions indicated that gene density in wheat is about one-half compared with rice (Oryza sativa). Genome size difference between wheat and rice is, therefore, mainly because of amplification of the gene-poor regions. Presence of species-, genera-, and family-specific repeats reveal a repeated invasion of the genomes by different retrotransposons over time. Preferential transposition to adjacent locations and presence of vital genes flanking a gene-rich region may have restricted retrotransposon amplification to gene-poor regions, resulting into tandem blocks of non-transcribing repeats. Insertional inactivation by adjoining retro-elements and selection seem to have played a major role in stabilizing genomes.
134 citations
TL;DR: This study physically localize gene-containing regions of the group 1 short arm, enrich these regions with markers, and study the distribution of genes and recombination of Triticeae homeologous group 1 chromosomes.
Abstract: The short arm of Triticeae homeologous group 1 chromosomes is known to contain many agronomically important genes. The objectives of this study were to physically localize gene-containing regions of the group 1 short arm, enrich these regions with markers, and study the distribution of genes and recombination. We focused on the major gene-rich region ("1S0.8 region") and identified 75 useful genes along with 93 RFLP markers by comparing 35 different maps of Poaceae species. The RFLP markers were tested by gel blot DNA analysis of wheat group 1 nullisomic-tetrasomic lines, ditelosomic lines, and four single-break deletion lines for chromosome arm 1BS. Seventy-three of the 93 markers mapped to group 1 and detected 91 loci on chromosome 1B. Fifty-one of these markers mapped to two major gene-rich regions physically encompassing 14% of the short arm. Forty-one marker loci mapped to the 1S0.8 region and 10 to 1S0.5 region. Two cDNA markers mapped in the centromeric region and the remaining 24 loci were on the long arm. About 82% of short arm recombination was observed in the 1S0.8 region and 17% in the 1S0.5 region. Less than 1% recombination was observed for the remaining 85% of the physical arm length.
114 citations
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TL;DR: Phytozome provides a view of the evolutionary history of every plant gene at the level of sequence, gene structure, gene family and genome organization, while at the same time providing access to the sequences and functional annotations of a growing number of complete plant genomes.
Abstract: The number of sequenced plant genomes and associated genomic resources is growing rapidly with the advent of both an increased focus on plant genomics from funding agencies, and the application of inexpensive next generation sequencing. To interact with this increasing body of data, we have developed Phytozome (http://www.phytozome.net), a comparative hub for plant genome and gene family data and analysis. Phytozome provides a view of the evolutionary history of every plant gene at the level of sequence, gene structure, gene family and genome organization, while at the same time providing access to the sequences and functional annotations of a growing number (currently 25) of complete plant genomes, including all the land plants and selected algae sequenced at the Joint Genome Institute, as well as selected species sequenced elsewhere. Through a comprehensive plant genome database and web portal, these data and analyses are available to the broader plant science research community, providing powerful comparative genomics tools that help to link model systems with other plants of economic and ecological importance.
3,728 citations
TL;DR: The MCScanX toolkit implements an adjusted MCScan algorithm for detection of synteny and collinearity that extends the original software by incorporating 14 utility programs for visualization of results and additional downstream analyses.
Abstract: MCScan is an algorithm able to scan multiple genomes or subgenomes in order to identify putative homologous chromosomal regions, and align these regions using genes as anchors. The MCScanX toolkit implements an adjusted MCScan algorithm for detection of synteny and collinearity that extends the original software by incorporating 14 utility programs for visualization of results and additional downstream analyses. Applications of MCScanX to several sequenced plant genomes and gene families are shown as examples. MCScanX can be used to effectively analyze chromosome structural changes, and reveal the history of gene family expansions that might contribute to the adaptation of lineages and taxa. An integrated view of various modes of gene duplication can supplement the traditional gene tree analysis in specific families. The source code and documentation of MCScanX are freely available at http://chibba.pgml.uga.edu/mcscan2/.
3,388 citations
TL;DR: It is becoming clear that a single WRKY transcription factor might be involved in regulating several seemingly disparate processes, and that members of the family play roles in both the repression and de-repression of important plant processes.
1,967 citations
University of Évry Val d'Essonne1, Crops Research Institute2, Agriculture and Agri-Food Canada3, J. Craig Venter Institute4, Fujian Agriculture and Forestry University5, Plant Genome Mapping Laboratory6, University of Giessen7, French Alternative Energies and Atomic Energy Commission8, Institut national de la recherche agronomique9, National Research Council10, Australian Centre for Plant Functional Genomics11, University of Cologne12, Purdue University13, University of California, Berkeley14, University of British Columbia15, Fondation Jean Dausset Centre d'Etude du Polymorphisme Humain16, Huazhong Agricultural University17, Hunan Agricultural University18, Chungnam National University19, University of Arizona20, University of York21, University of Missouri22, Southern Cross University23, University of Western Australia24, Centre national de la recherche scientifique25
TL;DR: The polyploid genome of Brassica napus, which originated from a recent combination of two distinct genomes approximately 7500 years ago and gave rise to the crops of rape oilseed, is sequenced.
Abstract: Oilseed rape (Brassica napus L.) was formed ~7500 years ago by hybridization between B. rapa and B. oleracea, followed by chromosome doubling, a process known as allopolyploidy. Together with more ancient polyploidizations, this conferred an aggregate 72× genome multiplication since the origin of angiosperms and high gene content. We examined the B. napus genome and the consequences of its recent duplication. The constituent An and Cn subgenomes are engaged in subtle structural, functional, and epigenetic cross-talk, with abundant homeologous exchanges. Incipient gene loss and expression divergence have begun. Selection in B. napus oilseed types has accelerated the loss of glucosinolate genes, while preserving expansion of oil biosynthesis genes. These processes provide insights into allopolyploid evolution and its relationship with crop domestication and improvement.
1,743 citations
Agricultural Research Service1, Oregon State University2, University of California, Berkeley3, John Innes Centre4, United States Department of Energy5, United States Department of Agriculture6, University of California, Davis7, University of Silesia in Katowice8, China Agricultural University9, Iowa State University10, Washington State University11, University of Florida12, University of Massachusetts Amherst13, University of Wisconsin-Madison14, Technische Universität München15, Cornell University16, University of Zurich17, University of Helsinki18, Universidade Federal de Pelotas19, Purdue University20, University of Texas at Arlington21, National Center for Genome Resources22, University of Delaware23, Joint BioEnergy Institute24, University of Copenhagen25, Kyung Hee University26, Ghent University27, Centre national de la recherche scientifique28, Oak Ridge National Laboratory29, Ohio State University30, Institut national de la recherche agronomique31, University of Picardie Jules Verne32, Illinois State University33, Sabancı University34, Donald Danforth Plant Science Center35
TL;DR: The high-quality genome sequence will help Brachypodium reach its potential as an important model system for developing new energy and food crops and establishes a template for analysis of the large genomes of economically important pooid grasses such as wheat.
Abstract: Three subfamilies of grasses, the Ehrhartoideae, Panicoideae and Pooideae, provide the bulk of human nutrition and are poised to become major sources of renewable energy. Here we describe the genome sequence of the wild grass Brachypodium distachyon (Brachypodium), which is, to our knowledge, the first member of the Pooideae subfamily to be sequenced. Comparison of the Brachypodium, rice and sorghum genomes shows a precise history of genome evolution across a broad diversity of the grasses, and establishes a template for analysis of the large genomes of economically important pooid grasses such as wheat. The high-quality genome sequence, coupled with ease of cultivation and transformation, small size and rapid life cycle, will help Brachypodium reach its potential as an important model system for developing new energy and food crops.
1,603 citations