Genetic Analysis of opaque 2 Modifier Loci in Quality Protein Maize
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ABSTRACT:
ORGANISM(S): Zea mays
PROVIDER: GSE10449 | GEO | 2008/02/08
SECONDARY ACCESSION(S): PRJNA108001
REPOSITORIES: GEO
Similar Datasets
Project description:Quality Protein Maize (QPM) was created by selecting for genetic modifiers that convert the starchy endosperm of an opaque2 (o2) mutant to a hard, vitreous phenotype. Genetic analysis has shown there are multiple, unlinked o2 modifiers (Opm), but their identity and mode of action are unknown. A microarray hybridization performed with RNA obtained from true breeding o2 progeny with vitreous and opaque kernel phenotypes identified a small group of differentially expressed genes, some of which map at or near the Opm QTLs. Compared 18 days after pollination endosperm transcript profiles in true breeding modified (vitreous; V) and non-modified (opaque; O) opaque 2 kernels. Used four vitreous biological reps (V1-V4) and four opaque biological reps (O1-O4). Each biological rep is a pool of 25 kernels representing 5 kernels form each of 5 uniform phenotype ears (vitreous or opaque). Four arrays used: Array 1= V1 vs O1, Array 2 = V2 vs O2, Array 3 = V3 vs O3, Array 4 = V4 vs O4
2010-05-26 | E-GEOD-10449 | biostudies-arrayexpress
Project description:Reduced prolamin (zein) accumulation and defective ER-body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and mucronate (Mc) whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. We used a LC-MS/MS proteomics approach to compare non-zein proteins of nearly isogenic opaque mutants. In total, 2762 proteins were identified that were enriched for biological processes such as protein transport and folding, amino acid biosynthesis, and proteolysis. Amino acid analysis of top proteins revealed qualitative changes in lysine abundance contributing to the overall lysine increase. Principal component analysis and pathway enrichment suggested that the mutants partition into three groups: Mc, DeB30, fl2 and o2; o1; and fl1. Indicator species analysis revealed mutant-specific proteins, and highlighted ER secretory pathway components that are enriched in selected groups of mutants, albeit with no common proteins across all mutants. Most significantly changed proteins were related to stress or defense and zein partitioning into the soluble fraction for Mc, DeB30, o1 and fl1 specifically. We suggest that ER stress is a universal trigger of opacity regardless of qualitative or quantitative changes in zein accumulation.
2016-01-05 | PXD002379 | Pride
Project description:Mutations in the Opaque2 (O2) gene of maize (Zea Mays L.) improve the nutritional value of maize by reducing the level of zeins in the kernel. The phenotype of o2 grain is controlled by many modifier genes and is therefore strongly dependent on the genetic background. We sought to distinguish between two hypotheses to explain differences in phenotypic severity: 1. Differences in phenotypic severity are due to genotype specific differentially expressed genes and 2. Differences in phenotypic severity are due to differences in the degree of differential expression of a set of differentially expressed genes. Eight pairs of inbred lines and their o2 counterparts were characterized for phenotypes controlled by o2 (lysine content, kernel density, seed weight and shoot to root ratio of seedlings). The inbred line B46 was identified as having severe o2 effects while the line M14 was identified as having minimal o2 effects. Transcripts that were differentially expressed between the wild-type and o2 versions of these two lines were identified by microarray hybridization. While genotype specific differentially expressed transcripts were identified, many transcripts were identified with reduced degree of differential expression in M14 relative to B46. Thus, a combination of genotype specific transcripts and degree of differential expression of transcripts can explain differences in phenotypic severity in these two genetic backgrounds. To identify the transcripts most likely to be differentially expressed in a given genetic background, we used RNA from eight genotype pools in microarray hybridization. By averaging across genotypes in this way, genotype-specific changes are minimized. Keywords: Genetic modification
2005-10-22 | GSE3490 | GEO
Project description:Development of the cereal endosperm involves cell differentiation processes that enable nutrient uptake from the maternal plant, accumulation of storage products and their utilization during germination. However, little is known about the regulatory mechanisms that link cell differentiation processes with those controlling storage product synthesis and deposition, including the activation of zein genes by the maize (Zea mays) bZIP transcription factor Opaque-2 (O2). In this study, we mapped in vivo binding sites of O2 in B73 endosperm, and compared the results with genes differentially expressed in B73 and B73o2. We identified 186 putative direct O2 targets and 1,677 indirect targets, encoding a broad set of gene functionalities. Examination of the temporal expression patterns of O2 targets using real-time RT-PCR experiments revealed at least two distinct modes of O2-mediated gene activation. We also showed that two O2-activated genes, bZIP17 and NAKED ENDOSPERM2 (NKD2) encoded transcription factors, which can in turn co-activate other O2-network genes with O2. NKD2 (with its paralog NKD1) was previously shown to be involved in regulation of aleurone development. Collectively, our results provide novel insights into the complexity of the O2-regulated network and its role in regulation of endosperm cell differentiation and function.
2018-09-14 | GSE114343 | GEO
Project description:The transcriptomic analysis of nkd1, nkd2 and o2 homozygous mutant set (including 1 WT, 3 single mutants, 3 double mutants and 1 triple mutant) at 8, 12 and 16 DAP revealed temporal regulatory landscape in endosperm grain-filling stage. The data also showed NKD1, NKD2 and O2 interactively regulate gene network overtime in several processes, such as hormone response, cell wall organization, nutrient storage and endoreduplication, etc.
2023-10-09 | GSE174059 | GEO
Project description:Endosperm is an absorptive structure that supports embryo development or seedling germination in angiosperms. The endosperm of cereals is a main source of food, feed, and industrial raw materials worldwide. However, the gene regulatory networks that control endosperm cell differentiation remain largely unclear. As a first step toward characterizing these networks, we profiled the mRNAs in five major cell types of the differentiating endosperm and in the embryo and four maternal compartments of the kernel. Comparisons of these mRNA populations revealed the diverged gene expression programs between filial and maternal compartments, and an unexpected close correlation between embryo and the aleurone layer of endosperm. Gene co-expression network analysis identified co-expression modules associated with single or multiple kernel compartments including modules for the endosperm cell types, some of which showed enrichment of previously identified temporally activated and/or imprinted genes. Detailed analyses of a co-expression module highly correlated with the basal endosperm transfer layer (BETL) identified a regulatory module activated by MRP-1, a regulator of BETL differentiation and function. These results provide a high-resolution atlas of gene activity in the compartments of the maize kernel and help to uncover the regulatory modules associated with the differentiation of the major endosperm cell types. RNAs from ten compartments of the maize kernel including the central starchy endosperm (CSE), conducting zone (CZ), aleurone (AL), basal endosperm transfer layer (BETL), embryo-surrounding region (ESR), nucellus (NU), pericarp (PE), placenta-chalazal region (PC), the vascular region of the pedicel (PED), and the embryo (EMB) were isolated at 8 days after pollination (DAP) using laser-capture microdissection and sequenced using an Illumina HiSeq 2000 platform.
2015-02-13 | E-GEOD-62778 | biostudies-arrayexpress
Project description:Kernel development is accompanied by complex gene networks. Expression quantitative trait loci (eQTL) analysis is an efficient way to detect the regulatory elements of genes, especially the trans-eQTLs help to construct the regulatory networks of genes and contribute to a better understanding of the intrinsic mechanisms of biological processes. Till now, the 15 DAP (day after pollination) eQTL has been elucidated in maize kernel, but little is known about the early stage. Here, we conduct eQTL analysis for 5 DAP maize kernel using 318 maize inbred lines. The results will provide insights into the genetic basis of early kernel development.
2019-10-01 | GSE110315 | GEO
Project description:Genetic Modifiers of Huntington's Disease
| PRJNA75833 | ENA