Project description:The differentiation and subsequent development of plant tissues or organs are tightly regulated at multiple levels, including the transcriptional, posttranscriptional, translational, and posttranslational levels. Transcriptomes define many of the tissue-specific gene expression patterns in maize, and some key genes and their regulatory networks have been established at the transcriptional level. In this study, the sequential window acquisition of all theoretical spectra-mass spectrometry technique was employed as a quantitative proteome assay of four representative maize tissues, and a set of high confidence proteins were identified. Integrated analysis of the proteome and transcriptome revealed that protein abundance was positively correlated with mRNA level with weak to moderate correlation coefficients, but the abundance of key proteins for function or architecture in a given tissue was closely tempo-spatially regulated at the transcription level. A subset of differentially expressed proteins, specifically tissue-specific proteins, were identified, e.g., reproductive structure and flower development-related proteins in tassel and ear, lipid and fatty acid biosynthetic process-related proteins in immature embryo, and inorganic substance and oxidation reduction responsive proteins in root, potentially revealing the physiology, morphology and function of each tissue. Furthermore, we found many new proteins in specific tissues that were highly correlated with their mRNA levels, in addition to known key factors. These proteome data provide new perspective for understanding many aspects of maize developmental biology.
Project description:Saha2011 - Genome-scale metabolic network of
Arabidopsis thaliana (iRS1597)
This model is described in the article:
Zea mays iRS1563: a
comprehensive genome-scale metabolic reconstruction of maize
metabolism.
Saha R, Suthers PF, Maranas
CD.
PLoS ONE 2011; 6(7): e21784
Abstract:
The scope and breadth of genome-scale metabolic
reconstructions have continued to expand over the last decade.
Herein, we introduce a genome-scale model for a plant with
direct applications to food and bioenergy production (i.e.,
maize). Maize annotation is still underway, which introduces
significant challenges in the association of metabolic
functions to genes. The developed model is designed to meet
rigorous standards on gene-protein-reaction (GPR) associations,
elementally and charged balanced reactions and a biomass
reaction abstracting the relative contribution of all biomass
constituents. The metabolic network contains 1,563 genes and
1,825 metabolites involved in 1,985 reactions from primary and
secondary maize metabolism. For approximately 42% of the
reactions direct literature evidence for the participation of
the reaction in maize was found. As many as 445 reactions and
369 metabolites are unique to the maize model compared to the
AraGEM model for A. thaliana. 674 metabolites and 893 reactions
are present in Zea mays iRS1563 that are not accounted for in
maize C4GEM. All reactions are elementally and charged balanced
and localized into six different compartments (i.e., cytoplasm,
mitochondrion, plastid, peroxisome, vacuole and extracellular).
GPR associations are also established based on the functional
annotation information and homology prediction accounting for
monofunctional, multifunctional and multimeric proteins,
isozymes and protein complexes. We describe results from
performing flux balance analysis under different physiological
conditions, (i.e., photosynthesis, photorespiration and
respiration) of a C4 plant and also explore model predictions
against experimental observations for two naturally occurring
mutants (i.e., bm1 and bm3). The developed model corresponds to
the largest and more complete to-date effort at cataloguing
metabolism for a plant species.
This model is hosted on
BioModels Database
and identified by:
MODEL1507180011.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Saha2011- Genome-scale metabolic network of
Zea mays (iRS1563)
This model is described in the article:
Zea mays iRS1563: a
comprehensive genome-scale metabolic reconstruction of maize
metabolism.
Saha R, Suthers PF, Maranas
CD.
PLoS ONE 2011; 6(7): e21784
Abstract:
The scope and breadth of genome-scale metabolic
reconstructions have continued to expand over the last decade.
Herein, we introduce a genome-scale model for a plant with
direct applications to food and bioenergy production (i.e.,
maize). Maize annotation is still underway, which introduces
significant challenges in the association of metabolic
functions to genes. The developed model is designed to meet
rigorous standards on gene-protein-reaction (GPR) associations,
elementally and charged balanced reactions and a biomass
reaction abstracting the relative contribution of all biomass
constituents. The metabolic network contains 1,563 genes and
1,825 metabolites involved in 1,985 reactions from primary and
secondary maize metabolism. For approximately 42% of the
reactions direct literature evidence for the participation of
the reaction in maize was found. As many as 445 reactions and
369 metabolites are unique to the maize model compared to the
AraGEM model for A. thaliana. 674 metabolites and 893 reactions
are present in Zea mays iRS1563 that are not accounted for in
maize C4GEM. All reactions are elementally and charged balanced
and localized into six different compartments (i.e., cytoplasm,
mitochondrion, plastid, peroxisome, vacuole and extracellular).
GPR associations are also established based on the functional
annotation information and homology prediction accounting for
monofunctional, multifunctional and multimeric proteins,
isozymes and protein complexes. We describe results from
performing flux balance analysis under different physiological
conditions, (i.e., photosynthesis, photorespiration and
respiration) of a C4 plant and also explore model predictions
against experimental observations for two naturally occurring
mutants (i.e., bm1 and bm3). The developed model corresponds to
the largest and more complete to-date effort at cataloguing
metabolism for a plant species.
This model is hosted on
BioModels Database
and identified by:
MODEL1507180064.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:The functional genome of agronomically important plant species remains largely unexplored, yet presents a virtually untapped resource for targeted crop improvement. Functional elements and regulatory DNA revealed through chromatin accessibility maps can be harnessed for manipulating gene expression to subtle phenotypic outputs that enhance productivity in specific environments. Here, we present a genome-wide view of accessible chromatin and nucleosome occupancy at a very early stage in the development of both pollen- and grain-bearing inflorescences of the important cereal crop maize (Zea mays), using an assay for differential sensitivity of chromatin to micrococcal nuclease (MNase) digestion. Results showed that in these largely undifferentiated tissues, approximately 1.5-4 percent of the genome is accessible, with the majority of MNase hypersensitive sites marking proximal promoters but also 3’ flanks of maize genes. This approach mapped regulatory elements to footprint-level resolution, and through integration of complementary transcriptome and transcription factor occupancy data, we annotated regulatory factors such as combinatorial motifs and long non-coding RNAs that potentially contribute to organogenesis in maize inflorescence development, including tissue-specific regulation between male and female structures. Finally, genome-wide association studies for inflorescence architecture traits based only on functional regions delineated by MNase hypersensitivity, revealed new SNP-trait associations in known regulators of inflorescence development. These analyses provide a first look into the cis-regulatory landscape during inflorescence differentiation in a major cereal crop, which ultimately shapes architecture and influences yield potential.
Project description:The extreme generalist two-spotted spider mite, Tetranychus urticae, which is documented to feed on more than 1100 plant hosts, is becoming an increasingly important agricultural pest. Historically, as studies of plant-herbivore interactions have focused largely on insects, considerably less research has investigated plant responses to spider mite herbivores, especially in grasses. To identify intraspecific differences in maize response to T. urticae, we collected RNA-seq data from three maize (Zea mays) inbred lines (B73, B75 and B49) as well as two F1 lines arising from crosses between B73 x B75 and B73 x B96. For each maize line, RNA-seq data was collected from uninfested leaves (control) and leaves infested with T. urticae for 24 hours.
Project description:Stalk borers are major pests for some of the most important crops in the world, such as maize or rice. Plant defense mechanisms against these herbivores have been poorly investigated. The maize´s stalk responds to insect feeding activating defense genes including hormone biosynthetic-related or proteinase inhibitor transcripts. The most outstanding conclusion is that cells in the maize´s stalk undergo cell wall fortification after corn borer tunneling. We performed a gene expression profiling to identify those genes differentially expressed in maize after infestation with the corn borer S. nonagrioides.
Project description:Ustilago maydis is a basidiomycete fungus that causes smut disease in maize. Most prominent symptoms of the disease are plant tumors, which can be induced by U. maydis on all aerial parts of the plant. We identified two linked genes, pit1 and pit2, which are specifically expressed during plant colonization. Deletion mutants for either pit1 or pit2 are unable to induce tumor development and elicit plant defense responses. We used the Affymetrix maize genome array to analyze the transcriptional responses of maize to deletion pit1 and pit2 mutants and found plant responses to both mutants being not significantly distinguishable. U. maydis infected parts of maize seedling leaves were dissected 4 days after inoculation with strain SG200Dpit1 and SG200Dpit2, respectively. We previously submitted data of maize leaves that were treated with the progenitor wild type strain SG200 as well as mock-infections under identical experimetal conditions (GEO: GSE10023, 4d mock and 4d SG200 Samples, equivalent record in Arrayexpress: E-GEOD-10023). These data served as controls for this experiment.
Project description:MicroRNAs (miRNAs) are small non-coding RNAs that play essential roles in plant growth and development. We conducted a genome-wide survey of maize miRNA genes, characterizing their structure, expression, and evolution. Computational approaches based on homology and secondary structure modeling identified 150 high-confidence genes within 26 miRNA families. For 25 families, expression was verified by deep-sequencing of small RNA libraries that were prepared from an assortment of maize tissues. PCR-RACE amplification of 68 miRNA transcript precursors, representing 18 families conserved across several plant species, showed that splice variation and the use of alternative transcriptional start and stop sites is common within this class of genes. Comparison of sequence variation data from diverse maize inbred lines versus teosinte accessions suggest that the mature miRNAs are under strong purifying selection while the flanking sequences evolve equivalently to other genes. Since maize is derived from an ancient tetraploid, the effect of whole-genome duplication on miRNA evolution was examined. We found that, like protein-coding genes, duplicated miRNA genes underwent extensive gene-loss, with ~35% of duplicate homeologous miRNA genes retained. This number is higher than that observed with protein-coding genes. A search for putative miRNA targets indicated a bias towards genes in regulatory and metabolic pathways. As maize is one of the principal models for plant growth and development, this study will serve as a foundation for future research into the functional roles of miRNA genes.