Project description:Transcriptome of Zea mays genotypes under control and stress conditions. Stress conditions include heat, cold, salt, and UV. We extracted and sequenced RNA from 14 day old seedlings of inbred lines B73, Mo17 and Oh43 grown using standard conditions as well as seedlings that had been subjected to cold (5°C for 16 hours), heat (50°C for 4 hours), high salt (watered with 300 mM NaCl 20 hours prior to collection) or UV stress (2 hours). For each stress the plants were sampled immediately following the stress treatment and there were no apparent morphological changes in these plants relative to control plants.
Project description:Gene transcription is an essential step of gene function and transcriptome variation is of agronomical, ecological and evolutionary importance. To explore global expression patterns and dissect the underlying genetic mechanisms are important scientific inquires which are still largely unknown, especially between a segregating population and the parents. In our study, we used RNA-Seq to profile the shoot apex transcriptome variation (including protein coding genes and non-coding genes) in maize IBM RIL population, to map eQTLs underlying the transcriptome variations and to utilize eQTLs to clone genes involved in maize shoot apices development. We revealed that: Much of the variation (the population mean, the coefficient of variation) of gene expression levels in RILs is reflective of differences present among the parents; These transcriptome variations could be explained by 30,774 eQTLs with 96 trans-eQTL hotspots; In many cases, the genes commonly regulated by a trans-eQTL hotspot are enriched for a specific function or act in the same genetic pathway; Structural variation within and near genes contributs to cis-regulatory variation. All of these results indicate Mendelian factors play as major contributors to the transcriptome variation. Meanwhile, non-Mendelian regulations were also observed as paramutation-like expression pattern for 145 genes, of which 88% genes were predicted to be potential targets of miRNAs or ta-siRNAs, and as unexpected presence/absence expression patterns for 210 genes. These genes with unexpected presence/absence expression patterns in the RILs likely include examples of functional genes as well as transposed gene fragments that may contribute to regulatory variation of their ancestral syntenic genes.
Project description:The prolamin-box binding factor-1 (pbf1) gene encodes a transcription factor that controls the expression of seed storage protein (zein) genes in maize. Prior studies show that pbf1 underwent selection during maize domestication, although how it affected trait change during domestication is unknown. To assay how pbf1 affects phenotypic differences between maize and teosinte, we compared isogenic lines (NILs) that differ for a maize vs.and teosinte alleles of pbf1. Kernel weight for the teosinte NIL (162 mg) is slightly and significantly greater than that for the maize NIL (156 mg). RNAseq data for developing kernels show that the teosinte allele of pbf1 is expressed at about twice the level of the maize allele. However, RNA and protein assays showed no difference in zein profiles between the two NILs. The lower expression for the maize pbf1 allele suggests that selection may have favored this change, however, how reduced pbf1 expression alters phenotype remains unknown. One possibility is that pbf1 regulates genes other than zeins and thereby a domestication trait. The observed drop in seed weight associated with the maize allele of pbf1 is counterintuitive, but could represent a negative pleiotropic effect of selection on some other aspect of kernel composition.
Project description:In this study a transcriptomic approach (RNA-sequencing) was utilized to elucidate molecular responses of maize (Zea mays L.) primary roots of the inbred line B73 to water deficit to gain a better understanding of the mechanisms underlying drought tolerance. Kernels of the maize inbred line B73 were germinated in paper rolls soaked with distilled water until seedlings had a primary root length of 2 to 4 cm. For mild and severe water deficit conditions, seedlings were transferred to PEG8000 solution with water potentials of -0.2 MPa and -0.8 MPa, respectively. Water deficit treatment was applied for 6 h and 24 h. Each treatment was performed in four biological replicates each consisting of 10 roots.
Project description:To discover the transcriptional dynamics during seed germination we have obtained the time course transcriptomes for embryonic shoot apical meristem (SAM) every six hours, starting from dry seeds to hour 72 (3 days).
Project description:In many eukaryotes, reproduction involves contributions of genetic material from two parents. At some genes there are parent-of-origin differences in the expression of the maternal and paternal alleles of a gene and this is referred to as imprinting. The analysis of allele-specific expression in several maize hybrids allowed the comprehensive detection of imprinted genes. By comparing allelic expression patterns in multiple crosses, it was possible to observe allelic variation for imprinting in maize. The comparison of genes subject to imprinting in multiple plant species reveals limited conservation for imprinting. The subset of genes that exhibit conserved imprinting in maize and rice may play important, dosage-dependent roles in regulation of seed development. In this study, deep sequencing of RNA isolated from 14 days-after-pollination (DAP) endosperm tissue of five reciprocal hybrid pairs was performed to identify imprinted genes.
Project description:Maize (Zea mays) is an excellent cereal model for research on seed development because of its relatively large size for both embryo and endosperm. Despite the importance of seed in agriculture, the genome-wide transcriptome pattern throughout seed development has not been well characterized. Using high-throughput RNA sequencing, we developed a spatiotemporal transcriptome atlas of B73 maize seed development based on 53 samples from fertilization to maturity for embryo, endosperm, and whole seed tissues.
Project description:Maize is one of the most important crops in the world and serves as an excellent model for seed development research. Despite the important role of the transcriptome in development, genome-wide expression throughout the process of maize seed development has not been characterized. Using RNA-seq, we developed a spatio-temporal transcriptome atlas of B73 maize seed development from fertilization to maturity for embryo, endosperm, and whole seed tissue.