Low-oxygen stress associated with natural phenomena such as waterlogging, results in widespread transcriptome changes and a metabolic switch from aerobic respiration to anaerobic fermentation. High-throughput sequencing of small RNA libraries obtained from low-oxygen stressed and control root tissue identified a total of 65 unique microRNA (miRNA) sequences from 46 families, and 14 trans-acting small interfering RNA (tasiRNA) from 3 families. Low-oxygen stress resulted in changes to the abundance of 46 miRNAs from 19 families, and all 3 tasiRNA families. Chemical inhibition of mitochondrial respiration caused similar changes in expression in a majority of the low-oxygen responsive small RNAs analysed. Our data indicate that miRNAs and tasiRNAs play a role in gene regulation and possibly developmental responses to low oxygen, and that a major signal for these responses is likely to be dependent on mitochondrial function. Keywords: Small RNA transcriptome analysis Overall design: Examination of root tissue under 2 different environments, control and low oxygen
Hypoxia-responsive microRNAs and trans-acting small interfering RNAs in Arabidopsis.
Age, Subject
View SamplesThe polycomb repressive complex 2 (PRC2) regulates epigenetic gene repression in eukaryotes. Mechanisms controlling its developmental specificity and signal-responsiveness are poorly understood. Here, we identify an oxygen-sensitive N-terminal (N-) degron in the plant PRC2 subunit VERNALIZATION(VRN)2, a homolog of animal Su(z)12, that promotes its degradation via the N-end rule pathway. We provide evidence that this N-degron arose early during angiosperm evolution via gene duplication and N-terminal truncation, facilitating expansion of PRC2 function in flowering plants. We show that proteolysis via the N-end rule pathway prevents ectopic VRN2 accumulation, and that hypoxia and long-term cold exposure lead to increased VRN2 abundance, which we propose may be due to inhibition of VRN2 turnover via its N-degron. Furthermore, we identify an overlap in the transcriptional responses to hypoxia and prolonged cold, and show that VRN2 promotes tolerance to hypoxia. Our work reveals a mechanism for post-translational regulation of VRN2 stability that could potentially link environmental inputs to the epigenetic control of plant development. Overall design: RNA was extracted from non-vernalized (0v; C) or 4 week vernalized (4v; V) seedlings. Three biological replicates for each treatment were used for subsequent RNA sequencing
Oxygen-dependent proteolysis regulates the stability of angiosperm polycomb repressive complex 2 subunit VERNALIZATION 2.
Specimen part, Treatment, Subject
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Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.
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View SamplesMicroarray analysis of gene expression patterns in immature ear, seedling, and embryo tissues from the maize inbred lines B73 and Mo17 identified numerous genes with variable expression. Some genes had detectable expression in only one of the two inbreds; most of these genes were detected in the genomic DNA of both inbreds, indicating that the expression differences are likely caused by differential regulation rather than by differences in gene content. Gene expression was also monitored in the reciprocal F1 hybrids B73xMo17 and Mo17xB73. The reciprocal F1 hybrid lines did not display parental effects on gene expression levels. Approximately 80% of the differentially expressed genes displayed additive expression patterns in the hybrids relative to the inbred parents. The approximately 20% of genes that display nonadditive expression patterns tend to be expressed at levels within the parental range, with minimal evidence for novel expression levels greater than the high parent or less than the low parent. Analysis of allele-specific expression patterns in the hybrid suggested that intraspecific variation in gene expression levels is largely attributable to cis-regulatory variation in maize. Collectively, our data suggest that allelic cis-regulatory variation between B73 and Mo17 dictates maintenance of inbred allelic expression levels in the F1 hybrid, resulting in additive expression patterns.
Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.
No sample metadata fields
View SamplesMicroarray analysis of gene expression patterns in immature ear, seedling, and embryo tissues from the maize inbred lines B73 and Mo17 identified numerous genes with variable expression. Some genes had detectable expression in only one of the two inbreds; most of these genes were detected in the genomic DNA of both inbreds, indicating that the expression differences are likely caused by differential regulation rather than by differences in gene content. Gene expression was also monitored in the reciprocal F1 hybrids B73xMo17 and Mo17xB73. The reciprocal F1 hybrid lines did not display parental effects on gene expression levels. Approximately 80% of the differentially expressed genes displayed additive expression patterns in the hybrids relative to the inbred parents. The approximately 20% of genes that display nonadditive expression patterns tend to be expressed at levels within the parental range, with minimal evidence for novel expression levels greater than the high parent or less than the low parent. Analysis of allele-specific expression patterns in the hybrid suggested that intraspecific variation in gene expression levels is largely attributable to cis-regulatory variation in maize. Collectively, our data suggest that allelic cis-regulatory variation between B73 and Mo17 dictates maintenance of inbred allelic expression levels in the F1 hybrid, resulting in additive expression patterns.
Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.
No sample metadata fields
View SamplesMicroarray analysis of gene expression patterns in immature ear, seedling, and embryo tissues from the maize inbred lines B73 and Mo17 identified numerous genes with variable expression. Some genes had detectable expression in only one of the two inbreds; most of these genes were detected in the genomic DNA of both inbreds, indicating that the expression differences are likely caused by differential regulation rather than by differences in gene content. Gene expression was also monitored in the reciprocal F1 hybrids B73xMo17 and Mo17xB73. The reciprocal F1 hybrid lines did not display parental effects on gene expression levels. Approximately 80% of the differentially expressed genes displayed additive expression patterns in the hybrids relative to the inbred parents. The approximately 20% of genes that display nonadditive expression patterns tend to be expressed at levels within the parental range, with minimal evidence for novel expression levels greater than the high parent or less than the low parent. Analysis of allele-specific expression patterns in the hybrid suggested that intraspecific variation in gene expression levels is largely attributable to cis-regulatory variation in maize. Collectively, our data suggest that allelic cis-regulatory variation between B73 and Mo17 dictates maintenance of inbred allelic expression levels in the F1 hybrid, resulting in additive expression patterns.
Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Nonadditive expression and parent-of-origin effects identified by microarray and allele-specific expression profiling of maize endosperm.
No sample metadata fields
View SamplesThe nuclear content of the plant endosperm is the result of the contribution two maternal genomes and a single paternal genome. This 2:1 dosage relationship provides a unique system for studying the additivity of gene expression levels in reciprocal hybrids. A combination of microarray profiling and allele-specific expression analysis was performed using RNA isolated from endosperm tissues of maize inbred lines B73 and Mo17 and their reciprocal hybrids at two developmental stages, 13 and 19 days after pollination. By assessing the relative levels of expression in the reciprocal hybrids it was possible to determine the prevalence of additive and non-additive expression patterns. While the majority of differentially expressed genes displayed additive expression patterns in the endosperm, approximately 10% of the genes displayed non-additive expression patterns including maternal-like, paternal-like, dominant high-parent, dominant low-parent and expression patterns outside the range of the inbreds. The frequency of hybrid expression patterns outside of the parental range in maize endosperm tissue is much higher than that observed for vegetative tissues. For a set of 90 genes allele-specific expression assays were employed to monitor allelic bias and regulatory variation. Eight of these genes exhibited evidence for maternally or paternally biased expression at multiple stages of endosperm development and are potential examples of differential imprinting. Collectively, our data indicate that parental effects on gene expression are much stronger in endosperm than in vegetative tissues, and that endosperm imprinting may be far more common than previously estimated.
Nonadditive expression and parent-of-origin effects identified by microarray and allele-specific expression profiling of maize endosperm.
No sample metadata fields
View SamplesThe nuclear content of the plant endosperm is the result of the contribution two maternal genomes and a single paternal genome. This 2:1 dosage relationship provides a unique system for studying the additivity of gene expression levels in reciprocal hybrids. A combination of microarray profiling and allele-specific expression analysis was performed using RNA isolated from endosperm tissues of maize inbred lines B73 and Mo17 and their reciprocal hybrids at two developmental stages, 13 and 19 days after pollination. By assessing the relative levels of expression in the reciprocal hybrids it was possible to determine the prevalence of additive and non-additive expression patterns. While the majority of differentially expressed genes displayed additive expression patterns in the endosperm, approximately 10% of the genes displayed non-additive expression patterns including maternal-like, paternal-like, dominant high-parent, dominant low-parent and expression patterns outside the range of the inbreds. The frequency of hybrid expression patterns outside of the parental range in maize endosperm tissue is much higher than that observed for vegetative tissues. For a set of 90 genes allele-specific expression assays were employed to monitor allelic bias and regulatory variation. Eight of these genes exhibited evidence for maternally or paternally biased expression at multiple stages of endosperm development and are potential examples of differential imprinting. Collectively, our data indicate that parental effects on gene expression are much stronger in endosperm than in vegetative tissues, and that endosperm imprinting may be far more common than previously estimated.
Nonadditive expression and parent-of-origin effects identified by microarray and allele-specific expression profiling of maize endosperm.
No sample metadata fields
View SamplesABSTRACT: BACKGROUND: While changes in chromosome number that result in aneuploidy are associated with phenotypic consequences such as Down syndrome and cancer, the molecular causes of specific phenotypes and genome-wide expression changes that occur in aneuploids are still being elucidated. RESULTS: We employed a segmental aneuploid condition in maize to study phenotypic and gene expression changes associated with aneuploidy. Maize plants that are trisomic for 90% of the short arm of chromosome 5 and monosomic for a small distal portion of the short arm of chromosome 6 exhibited a phenotypic syndrome that includes reduced stature, tassel morphology changes and the presence of knots on the leaves. The knotted-like homeobox gene knox10, which is located on the short arm of chromosome 5, was shown to be ectopically expressed in developing leaves of the aneuploid plants. Expression profiling revealed that ~40% of the expressed genes in the trisomic region exhibited the expected 1.5 fold increased transcript levels while the remaining 60% of genes did not show altered expression even with increased gene dosage. CONCLUSIONS: We found that the majority of genes with altered expression levels were located within the chromosomal regions affected by the segmental aneuploidy and exhibits dosage-dependent expression changes. A small number of genes exhibit higher levels of expression change not predicted by the dosage, or display altered expression even though they are not located in the aneuploid regions.
Profiling expression changes caused by a segmental aneuploid in maize.
No sample metadata fields
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