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Rice Genetics V
Book Available Rice as a reference genome and more The rice (Oryza sativa L.) genome has become the reference genome to which others are compared. Part of the reason for this is that rice has the lowest DNA content of the common cereals and its gene content and gene order are found in other grass species used for food. Having the genome sequence of rice, both japonica and indica, allows comparisons with regard to genomic structure, gene constitution, and gene expression. Map locations for single-copy genes, families of genes, and quantitative trait loci (QTLs) are often compared among species, usually with rice as the reference. Specialized databases have been developed to facilitate cross-species homology relationships relative to genome and EST sequencing, protein structure, gene function, and other useful aspects. The evolutionary relationship of rice and several other cereals such as maize (Zea mays L.) and sorghum is clearly observed when highlighting syntenic regions. The colinearity of rice and American wildrice (Zizania palustris) has been exploited to develop a molecular genetic map and to locate QTLs in wildrice. The goal of this paper is to illustrate the value of rice for comparative genome referencing. Keywords: comparative, duplication, map, polyploidy, synteny, QTLs, wildrice The complete rice genome sequence: a gold mine for future rice research The map-based complete rice genome sequence is now freely available to researchers worldwide, providing the most fundamental tool that should further accelerate efforts to improve the staple crop that feeds more than half the world’s population. The finished-quality sequence covers 95% of the 389-Mb genome, including virtually all of the euchromatin and two complete centromeres. A total of 37,544 non-transposable-element-related protein-coding genes were identified. The complete genetic information on rice will serve as a gold mine for genomic research in rice and other cereal species. It will facilitate the identification of many important genes by both forward and reverse genetics strategies, and clarify the relationships between sequence variation and phenotypes. The genome sequence derived from Oryza sativa subspecies japonica can be used as a reference sequence for comparative analysis among Oryza species that will help in understanding the major factors involved in speciation and searching for useful genetic resources. Furthermore, the completed sequence will also serve as a standard for cereal genome comparison and identification of rice orthologous genes in other cereal crops, thereby providing a platform for establishing the genomics of each cereal species. Keywords: rice, genome sequence, physical maps, tandem-arrayed genes, transposable elements Annotation of the rice genome A high-quality finished sequence of the rice genome was completed in 2005. However, to maximally use the sequences, quality annotation of the genes and genome features is necessary. The process of annotation is iterative in nature and requires the application and refinement of computational tools coupled with manual curation and evalutation. We are funded by the U.S. National Science Foundation to annotate the rice genome and have constructed pseudomolecules for the 12 Oryza sativa subspecies japonica var. Nipponbare chromosomes, which are publicly available through our project Web site (http://rice.tigr.org). We identified genes, gene models, and other annotation features in the rice genome. We expanded our annotation features to include a rice transcript assembly and its alignment with the rice genome, small noncoding RNAs, simple sequence repeats, as well as single nucleotide polymorphisms and insertions/deletions based on alignment with the indica subspecies. We updated our Oryza repeat database, which has allowed us to better quantify the repetitive sequences within the rice genome, which total 29% of the genome. To assist users in accessing the genome and our annotation, we expanded the content and functions of our Rice Genome Browser such that it supports 37 annotation tracks and data downloads of the underlying annotation data in various formats. Keywords: TIGR, annotation, transcript assembly, repetitive sequences, indels, noncoding RNAs Structural genomics and resources The Oryza map alignment project (OMAP): a new resource for comparative genomics studies within Oryza With the completion of a finished genome sequence, we must now functionally characterize the rice genome by a variety of methods, including comparative genomic analysis between cereal species and within the genus Oryza. Oryza contains two cultivated and 22 wild species that represent 10 distinct genome types. The wild species, in particular, contain an essentially untapped reservoir of agriculturally important genes that must be harnessed to enhance and sustain crop productivity. Keywords: Oryza, wild species, BAC libraries, map alignment, end sequences Analysis of oligo hybridization properties by high-resolution tiling microarrays in rice Rice genome sequencing and computational annotation provide a static map for understanding this model of Gramineae species. With the development of in situ oligonucleotide synthesis technology, tiling-path microarrays have become a dynamic and efficient way for monitoring large-scale transcriptional activities and detecting novel transcribed elements missed by software. Unlike conventional cDNA or oligonucleotide arrays, tiling-path platforms employ the full extent of oligos covering given genomic regions, and thus offer excellent experimental conditions in which to assay the properties of oligos in terms of their specificity and efficiency of hybridization to their corresponding targets. Here, we report a tiling-path microarray analysis of a 1-Mb region (10 to 11 Mb) in japonica rice chromosome 10, which was tiled by a 36-mer oligo set at a resolution of 5 bp. Our analysis focused on three major factors of oligo hybridization properties, including GC content, melting temperature (Tm), and the repetitiveness of oligo sequences. Keywords: Rice, genomics, tiling-path microarrays, transcriptome, hybridization Tissue culture–induced mutations and overexpression of full-length cDNAs as a tool for functional analysis of rice genes A collection of 50,000 Tos17-induced mutant rice lines carrying about 250,000 independent insertions was generated. DNA pools derived from 50,000 lines have been produced for polymerase chain reaction (PCR)–based reverse genetics screening. For in silico screening of mutants of genes of interest, a large-scale analysis of the mutants by sequencing the genomic DNA sequence flanking Tos17 insertions is in progress. To facilitate the functional analysis, the database on phenotypes covering all the mutant lines has been developed. About half of the mutant lines exhibited at least one phenotype. About 5–10% of the mutations were shown to be caused by insertion of Tos17, whereas the rest of the mutations were deletions, possibly caused by double-strand break repair and point mutations. These deletion mutations can be detected by the PCR-based screening method, providing a new resource for functional analysis of genes. Considering gene redundancy in rice and the availability of a large number of full-length cDNAs, we have begun producing a new type of activation tagged lines in which 15,000 independent normalized full-length cDNA are overexpressed under the control of the ubiquitin promoter. Keywords: insertional mutagenesis, Tos17, flanking sequence tag, activation tagging, full-length cDNA, forward genetics, reverse genetics Analysis of genome sequences from the maternal and paternal parents of an elite rice hybrid We have initiated a genome project in China, the Superhybrid Rice Genome Project (SRGP), to understand the molecular basis of hybrid vigor. The early phase of the project is to sequence 93-11 and PA64S, the paternal and maternal parents of the hybrid rice strain LYP9. Preliminary analysis on genomic sequences from the parental cultivars indicates that hybrid vigor may be more complex at the molecular level than previously proposed, which is shaped, through complex and meticulous breeding practices, by intricate genetic and functional complementation processes attributable largely to variations in protein-coding sequences, regulatory elements, epigenetics, and posttranslational modifications of gene products. We are in a process and collaborating with other research groups in rice biology to acquire, in a broad spectrum, transcriptomic and proteomic data of the triad from different tissues, at multiple developmental stages and with different methods. The study should yield useful candidate genes and genetic markers for further investigations in molecular and functional details. Based on the information acquired, the SRGP initiated at the Beijing Genomics Institute will continue to map domestication-related genes and loci, based on the rich diversity of resources available in rice. Keywords: superhybrid rice, genome sequence, hybrid vigor, gene expression Developmental biology and gene regulation T-DNA tagging for developmental biology We have generated 47,932 T-DNA tag lines in japonica rice using activation tagging vectors that contain tetramerized 35S enhancer sequences. To facilitate use of those lines, we isolated the genomic sequences flanking the inserted T-DNA via inverse polymerase chain reaction. For most of the lines, we performed four sets of amplifications using two different restriction enzymes toward both directions. In analyzing 41,234 lines, we obtained 27,621 flanking sequence tags (FSTs), among which 12,505 were integrated into genic regions and 15,116 into intergenic regions. Mapping of the FSTs on chromosomes revealed that T-DNA integration frequency was generally proportional to chromosome size. However, T-DNA insertions were nonuniformly distributed on each chromosome, that is, higher at the distal ends and lower in regions close to the centromeres. In addition, several regions showed extreme peaks and valleys of insertion frequency, suggesting hot and cold spots for T-DNA integration. The density of insertion events was somewhat correlated with the expressed, rather than the predicted, gene density along each chromosome. Analyses of expression patterns near the inserted enhancer showed that at least half the test lines displayed greater expression of the tagged genes. Although in most of the increased lines expression patterns after activation were similar to those in the wild type, thereby maintaining the endogenous patterns, the remaining lines showed changes in expression in the activation tagged lines. In this case, ectopic expression was most frequently observed in mature leaves. Currently, the database can be searched with the gene locus number or location on the chromosome at www.postech.ac.kr/life/pfg/risd. Upon request, seeds of the T1 or T2 plants will be provided to the scientific community. Keywords: activation tagging, database, flanking sequences, insertional mutation, T-DNA Novel insights into the genomics of rice root adaptive development Deciphering the genetic and molecular mechanisms controlling the development of the root system and its adaptive plasticity under adverse environments is of primary importance for the sustainable establishment of the rice crop. Rice displays a complex root structure comprising several root types mostly of postembryonic origin. The large natural variation in root architecture among cultivars reflects their adaptation to contrasting agro-environmental conditions. This article reviews the current knowledge on the organization and anatomy of the various types of roots of the fibrous root system of rice, the diversity and genetic basis of natural variation of root system architecture and performance, and the molecular mechanisms underlying constitutive and adaptive root development. This paper also throws light on how the integrated approach of new tools in high-resolution microscopy imaging, expression profiling, mutant screening, and reverse genetics could facilitate the rapid discovery and analysis of the key genes and regulatory networks involved in root architectural traits affecting plant performance under field conditions. Keywords: Functional genomics, molecular genetics, rice, root development Molecular signaling in disease resistance of rice Although impressive progress in the area of our understanding of molecular signaling in disease resistance of rice has been made recently, we still know relatively little about the molecular mechanisms of pathogen recognition and signal transduction leading to disease resistance. Increasing evidence indicates that Rac GTPase is an important molecular switch in disease resistance of rice. It activates the production of reactive oxygen species, defense gene expression, phytoalexin production, and lignin synthesis. Recent evidence suggests that it forms a protein complex with other factors involved in defense signaling. Two new technologies that are useful for the study of molecular signaling in defense responses in rice are discussed. Keywords: Rac GTPase, proteomics. effector, protein network, reactive oxygen species Applied genetics QTLs in rice breeding: examples for abiotic stresses Despite the status of rice as a model agricultural crop and hundreds of studies identifying quantitative trait loci (QTLs), the applications of these results in breeding have been limited. However, the success of plant breeders in developing varieties with high yield, excellent grain quality, and wide adaptation that are widely grown by farmers (i.e., mega varieties) has provided an opportunity to deploy the most useful QTLs for rice improvement. Marker-assisted backcrossing (MAB) facilitates the precise introgression of a desired trait into the original genetic background of such mega varieties. QTLs with a large effect are rare for complex agronomic traits like yield, but are more common for other traits such as resistance to abiotic stresses. Here we discuss the example of submergence tolerance. Much of the tolerance in varieties such as FR13A has been shown to be under the control of the Sub1 locus, which includes 2–3 tightly-linked putative transcription factors. Sub1 was transferred into the Indian cultivar Swarna, resulting in a new version of this mega variety with tolerance of submergence. Large QTLs also exist for tolerance of salinity, P deficiency, Al toxicity, and low temperature. With some modifications, this approach may be applicable for traits controlled by multiple smaller QTLs. However, strategies for transferring multiple QTLs into mega varieties need to be developed such that negative effects of the transferred segments (linkage drag) do not adversely affect the resulting varieties. Furthermore, strategies for reducing the costs associated with marker genotyping and efficient phenotyping also need to be developed and adopted in order to apply MAB on a larger scale. Keywords: quantitative trait loci, abiotic stress, rainfed lowland, marker-assisted selection, backcrossing Isolation of a QTL gene controlling grain number and QTL pyramiding to combine loci for grain number and plant height in rice Many agronomically important traits, including yield, are expressed in continuous phenotypic variation. These complex traits usually are governed by a number of genes known as quantitative trait loci (QTLs) derived from natural variations. Now, QTL analysis has been employed as a powerful approach to discover agronomically useful genes. Grain number and plant height are important traits that directly contribute to grain productivity. We aimed to identify genes of QTLs for grain number and plant height, not only to elucidate molecular mechanisms that regulate grain productivity but also to use these genes for breeding. We first identified that a QTL that increases grain productivity in rice, Gn1a, is a gene for cytokinin oxidase/dehydrogenase (OsCKX2), an enzyme that degrades the phytohormone cytokinin. Reduced expression of OsCKX2 causes cytokinin accumulation in inflorescence meristems and increases the number of reproductive organs, resulting in enhanced grain yield. QTL pyramiding to combine loci for grain number and plant height in the same genetic background generated lines exhibiting both beneficial traits. These results provide a strategy for tailor-made crop improvement. Discovering useful genes, improving agricultural traits hidden in the plant genome, and applying these findings to crop breeding will pave the way for a new green revolution. Keywords: cytokinin oxidase, grain number, plant height, QTL, QTL pyramiding
Flowering time (heading date) is a major determinant of regional and seasonal adaptation of cultivated rice. A large amount of variation is observed in heading date and photoperiodic response among rice cultivars and strains, including wild relatives. Quantitative trait locus (QTL) analyses of progeny derived from several cross combinations of rice cultivars suggest that more than 15 loci are involved in heading date. Map-based cloning has been performed on several QTLs for photoperiodic response. We have demonstrated that Heading date 1 (Hd1) is an ortholog of CONSTANS (CO) in Arabidopsis and is involved in the promotion of heading under short-day (SD) conditions and inhibition under long-day (LD) conditions. Hd6 is involved in inhibition under LD conditions and encodes the alpha-subunit of protein kinase CK2. Hd3a shows a high level of similarity to Arabidopsis FT (flowering time) and functions as a flowering inducer. Early heading date 1 (Ehd1) is involved in promotion under SD conditions and encodes a B-type response regulator. Hd5 is involved in inhibition under LD conditions and encodes a putative subunit of a CCAAT-box-binding protein. Late heading date 4 (Lhd4) is involved in inhibition under LD conditions and encodes a protein with a CCT motif. The combining of information from genetic and sequencing analyses reveals that the combination of natural alleles with loss or gain of function at particular QTLs, such as Hd1, Hd5, Hd6, Ehd1, and Lhd4, seems to generate a wide range of continuous variation in photoperiodic flowering in rice. These genetic and molecular analyses have allowed us to propose a pathway for the genetic control of photoperiodic flowering in rice, and analysis of the mRNA levels of genes in near-isogenic lines has clearly revealed their hierarchical relationship in the genetic control pathway. Identification and expression analyses of genes suggest the conservation and divergence of various features in the photoperiodic control of flowering in rice, an SD plant, and Arabidopsis, an LD plant. Keywords: Oryza sativa L., heading date, natural variation, QTL, map-based Understanding broad-spectrum durable resistance in rice A long-standing goal in rice disease control is to identify and incorporate broad-spectrum durable resistance (BSDR). Although quantitative resistance can potentially contribute to BSDR, neither the genes responsible for quantitative resistance nor the pathways or mechanisms by which they may function to contribute to BSDR are understood. Using varieties that show durable resistance historically, we have identified rice genes that are candidates for contributing to BSDR through co-localization with disease resistance QTLs in mapping studies. Several of these genes are known as disease defense response genes (e.g., oxalate oxidase, chitinase, PR1, etc.), whereas others are of unknown function. Genome-wide expression analyses at critical stages of host-pathogen interactions are also being used to reveal additional genes that may play a role in quantitative resistance. By combining chromosomal segments associated with five different candidate genes by marker-assisted selection, rice lines were produced that exhibited a high level of resistance to rice blast in multilocation trials. The current challenge is to understand if and how these candidate genes contribute to BSDR as well as the allelic variation that accounts for function in some lines but not in others. Targeted gene expression and functional analyses of candidate gene family members, for example, the oxalate oxidase gene families, are being used to focus on gene members involved in BSDR, and to determine what gene structural features are key to involvement. Sequence comparisons are providing clues as to critical allelic variation in rice germplasm. Finally, analysis of mutants exhibiting inappropriate activation of defense pathways is guiding the selection of candidate genes or genic regions. The integration of expression, mapping, and allelic diversity data is expected to unveil genes or gene interactions with significant phenotypic effects that can be used in breeding programs. Keywords: Rice, broad-spectrum durable resistance, candidate genes, Discovery and transfer of trait-enhancing alleles from wild species The approach demonstrated by this collaborative breeding project has had important implications for the use of exotic germplasm in wide crosses of rice. We demonstrated that AB-QTL analysis is capable of (1) successfully uncovering positive alleles that were not obvious based on the phenotype of the parent, (2) offering an estimation of the value of crosses between O. sativa and exotic or genetically distant germplasm, and (3) identifying molecular markers for numerous alleles of interest to aid in their incorporation into elite cultivars with a minimum of linkage drag. Keywords: Oryza rufipogon, AB-QTL analysis, population structure, exotic germplasm, gene cloning Genomics-based strategies for the development of “green super rice” Several challenges need to be met for sustainable rice production in China and to reduce the gap between potential yield and yield under large-scale production: (1) the increasingly severe occurrence of insects and diseases and the indiscriminate application of pesticides, (2) high pressure for a yield increase and overuse of fertilizers, and (3) the increasingly frequent occurrence of drought, resulting in water shortage. We have been using a combination of approaches based on recent advances in genomics research to address these challenges, with the long-term goal of developing rice cultivars referred to as “green super rice.” To obtain a yield increase and improve quality, green super rice should possess resistance to multiple insects and diseases, high nutrient efficiency and drought tolerance, and potential to greatly reduce the use of pesticides, chemical fertilizers, and water. Most current efforts have focused on identifying germplasm and discovering genes for improving rice cultivars for the following traits: resistance to diseases and insects, N and P efficiency, and drought tolerance. Approaches adopted include (1) screening of germplasm collections, (2) mapping and identifying QTLs, (3) screening of mutant libraries, (4) microarray analysis of genes differentially regulated, and (5) functional tests of candidate genes by transgenic analysis. Progress toward the development of “green super rice” currently made in our group is presented. Keywords: green super rice, genomics, candidate genes, gene identification, yield, biotic/abiotic stresses From gene to adaptation in rice The recent accumulation of information on plant genomes has enabled us to study adaptive traits at both the phenotypic and molecular levels. Genetic diversification is a consequence of the existence of a diverse set of environments. Plant breeding will accelerate the rate of micro-evolution in our changing world. To understand ongoing micro-evolutionary processes, genetic alterations in response to temperature, photoperiod, and biotic environments were investigated in wild and cultivated rice. These adaptive mechanisms were not well explained by a few major genes, suggesting that epistasis, genoype × environment (GE) interaction, and linked genes were involved in addition to genes with a small additive effect. Genetic diversity is affected both by current patterns of micro-evolutionary forces, such as gene flow and selection, and by phylogenetic history. Genealogies of agronomic genes provided insight into their history. Unexpectedly, the “Geen Revolution” gene (sd1) preexisted in the wild ancestor, showing that farmers selected it to obtain a high yield in response to altered practices in agriculture. In contrast, in the case of C, A, and wx genes, variants were generated from landraces through natural or artificial selection, suggesting that each of the genes may have its own history. Keywords: Genetic diversity, genealogy, adaptation, agronomic genes, Asian rice, wild rice Lessons from applying genomics to wheat and barley improvement On the surface, wheat and barley have little to offer the rice genomics research community. They have very large genomes without a physical map, making positional cloning complex, and they are difficult to transform, which hinders the functional analysis of genes and delivery of transgenic technologies. However, shifts in plant genomics research into understanding the basis of diversity and mechanisms involved in creating and maintaining genome complexity have shifted research from a model organism toward more complex species. Wheat and barley are becoming increasingly attractive organisms for many of the new genomics studies. Several key tools have been important for this change, including detailed and well-phenotyped populations, mapping of a large collection of ESTs, and studies of synteny with rice and maize. Keywords: Wheat, barley, synteny, genome, breeding, selection, abiotic stresses
Western civilization owes much of its foundation to pasta and bread wheat. These species are polyploidy, possessing multiple diploid sets of chromosomes. Pasta and bread wheats exist only because the Ph1 locus stabilizes the pairing of these multiple related chromosomes at meiosis. It provides a high level of fertility and seed set. This article reviews current knowledge of the biological effect of this important locus. It provides insights into how one might induce pairing between related chromosomes for breeding. Keywords: Ph1 locus, telomeres, centromeres, meiosis, chromosome pairing Functional genomics and rice improvement Functional genomics for gene discovery in abiotic stress response and tolerance Plants respond to abiotic stresses, such as drought, high salinity, and cold, to acquire stress tolerance. Molecular and genomic studies have shown that a number of genes with various functions are induced by abiotic stresses, and that various transcription factors are involved in the regulation of stress-inducible genes in Arabidopsis and rice. These gene products function not only in stress tolerance but also in stress response. In this review, recent progress in the analysis of complex cascades of gene expression in drought and cold stress responses is summarized. Various genes involved in stress tolerance are also discussed for their application to molecular breeding of drought, salinity, and/or cold stress tolerance. Keywords: Drought, cold stress, abscisic acid, gene expression, stress tolerance, signal transduction, microarray analysis Expression and functional analysis of rice genes involved in reproductive development and stress response The rice genome sequenced and annotated by the IRGSP has identified 37,544 protein-coding genes. In an effort to identify genes encoding transcription factors and signal transduction components, more than 7,000 genes belonging to 87 classes have been used to prepare a local database. Detailed analysis of genes for plant hormone response, CDPKs, C2H2 zinc-finger, and SET domain proteins unraveled interesting evolutionary aspects in relation to genes and the rice genome. A 51k microarray, SAGE analysis, and real-time polymerase chain reaction revealed differential expression of target genes during reproductive development and stress conditions. Several genes specific to reproductive floral organs and seed development have been identified. A large number of SAGE tags are observed from intergenic regions and antisense strands reflecting the unexplored transcription potential of the rice genome. Analysis of rice gene promoter activities has been undertaken in transgenic tobacco/Arabidopsis to demarcate regions conferring anther-/pollen-specific expression. OSISAP1, a gene coding for a stress-associated zinc-finger protein, and its promoter have been functionally validated in transgenic tobacco and rice. Genes for proteins interacting with OSISAP1 have also been found to be stress-inducible. Investigations on functional analysis of stress-responsive genes are in progress. Keywords: Functional genomics, microarray, phylogenetic analysis, reproductive Designing and constructing novel gene promoters to generate stress-tolerant plants without yield penalty Although genetic engineering has become an important practice in agricultural biotechnology, how to properly control the expression of transgenes in transgenic plants remains a challenging task. Strong constitutive promoters are routinely used in plant transformation, but sometimes their use leads to undesirable secondary effects and negatively affects the overall performance of transgenic plants. In order to maximize the benefits of transgenes and to avoid unexpected negative impact, tissue-specific stress-/ABA-inducible promoters have been designed and constructed based on knowledge learned from studies of native promoters. Microarray analysis and bioinformatics are also employed in an extensive search for stress-/ABA-inducible and tissue-specific promoters, and information obtained is used to broaden the foundation for constructing synthetic designer promoters. The efforts include (1) optimization of upstream ABA- /stress-responsive cis-acting elements such as AB responsive element (ABRE) and coupling element (CE), (2) a search for the most efficient minimal promoter and desirable introns, and (3) the addition of tissue-specific determinants. Various versions of synthetic stress-/ABA-inducible promoters have been constructed, and some of them have been tested in transgenic plants for the expression of beneficial genes in conferring stress tolerance. Although transgenic plants with either a strong constitutive promoter or synthetic stressinducible promoter acquire an elevated level of stress tolerance, only the latter display normal growth and development without any apparent yield penalty Keywords: genetic engineering, gene expression, tissue-specific inducible promoters, yield penality, transgene Rice: an emerging model for plant systems biology Proteomics has become a powerful technique to investigate cellular processes and network functions. This became possible as a result of major progress in the sensitivity of mass spectrometry instrumentation and data analysis software. As proteomics technologies are now becoming available to the wider scientific community, efforts are under way to identify complete proteomes. This information is used to improve genome annotation and to identify and confirm protein splice variants. Analysis of protein modifications and protein variants uses novel scoring and prediction tools independent of established protein databases. We discuss the proteomics tools and analysis pipelines that can be applied to rice in order to facilitate our understanding of rice genome structure and function. Keywords: Rice, proteomics, transcriptomics, metabolomics, TILING arrays, high throughput |
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Rice as a reference genome and more The complete rice genome sequence: a gold mine for future rice research The Oryza map alignment project (OMAP): a new resource for comparative genomics studies within Oryza Analysis of oligo hybridization properties by high-resolution tiling microarrays in rice Analysis of genome sequences from the maternal and paternal parents of an elite rice hybrid T-DNA tagging for developmental biology Novel insights into the genomics of rice root adaptive development QTLs in rice breeding: examples for abiotic stresses Genetic and molecular dissection of flowering time in rice Understanding broad-spectrum durable resistance in rice Discovery and transfer of trait-enhancing alleles from wild species Genomics-based strategies for the development of “green super rice” From gene to adaptation in rice Lessons from applying genomics to wheat and barley improvement The major chromosome pairing locus (Ph1) in hexaploid wheat: a prospective Functional genomics for gene discovery in abiotic stress response and tolerance Rice: an emerging model for plant systems biology
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