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: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:Purpose: The goals of this study are studies the response of annual Zea mays ssp. mexicana L. under cold and drought stress Methods: The seedlings of zea may ssp. mexicana L. were generated by Illumina HiSeq2500 deep-sequencing. In order to generate a global overview of Zea mexicana transcriptome data, 3 of complement DNA (cDNA) libraries were prepared from RNA isolated from root, stem, and leave mixed tissues of Zea Mexicana from Control (24℃), Cold (4℃) and Drought (PEG2000, 20%) treatments and each teatment has two repetitions. The sequence reads that passed quality filters were merged and de novo to generate all transcripts set by Trinity with default parameter, which will be treated as reference genome. The number of paired-reads of each sample were mapped to reference genome by Bowtie software v1.1.1 and the number of mapped reads were calculated by RSEM. qRT-PCR validation was performed using BIO-RAD CFX96 sequence detection system and SYBR Green assays. Results: Using RNA-Seq technology with the Trinity assembled method, we generated a seedling plant transcriptome at a sequencing size of 51.78Gb of Zea mays ssp. mexicana L. from pooled RNA samples which included control (CK), cold (4℃) and drought (PEG2000, 20%) stressed plant samples. A total of 414,232,462 high quality clean reads were used to conduct de novo assembly and annotation of genes without reference genome information. All of these reads were assembled into 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp). A total of 3,504 up-regulated and 1,220 down-regulated genes were detected under cold stress and 532 up-regulated and 82 down-regulated genes were detected under drought stress. A Venn diagram indicated that 208 genes were affected by both cold and drought stresses. 3 cold stress pathways and 5 drought related pathways showed significant KEGG pathways. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and CBF6 gene of ICE1-CBF pathway may play important roles in the DEGs co-up-regulated by both stresses of Zea mays ssp. mexicana L. Conclusions: We analyzed transcriptome data and gene expression profile information from seedlings of Zea mays ssp. mexicana L. under cold and drought stresses. Together these data provides the most comprehensive sequence study available for Zea mays ssp. mexicana L. and provides some important functional genes and molecular mechanism information for improving the quality characteristic of maize in the future.
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 characterize plant heat stress-responsive genes and to clarify the heat stress-responsive transcription pathways, the transcriptome analysis of maize was conducted using microarray. Maize (Zea mays cv. B73) were grown in plastic pots filled with nutrient soil for 2 weeks with a 12 h light (28°C)/12 h dark (25°C) regimen (ca. 1500 μmol photons mâ2 sâ1) and were treated for 30 min at 42°C.
Project description:As a response to insect attack, maize (Zea mays) has inducible defenses that involve large changes in gene expression and metabolism. Piercing/sucking insects such as corn leaf aphids (Rhopalosiphum maidis) cause direct damage by acquiring phloem nutrients as well as indirect damage through the transmission of plant viruses. To elucidate the metabolic processes and gene expression changes involved in maize responses to aphid attack, leaves of inbred line B73 were infested with R. maidis for two to 96 hours.
Project description:The complexity of the maize (Zea mays) genome makes it an ideal system for the study of both genetics and epigenetics. Here, we generated the integrated maps of transcriptomes and epigenomes of shoots and roots of two maize inbred lines and their reciprocal hybrids, and globally surveyed the epigenetic variations and their relationships with transcriptional divergence between different tissues and different genotypes. We observed that whereas histone modifications vary both between tissues and between genotypes, DNA methylation patterns are more distinguishable between genotypes than between tissues. Histone modifications were associated with transcriptomic divergence between tissues and between hybrids and parents. Further, we show that genes up-regulated in both shoots and roots of hybrids were significantly enriched in the nucleosome assembly pathway. Interestingly, 22- and 24-nt siRNAs were shown to be derived from distinct transposable elements (TEs), and for different TEs in both shoots and roots, the differences in siRNA activity between hybrids and patents were primarily driven by different siRNA species. Together, our results suggest that despite of the variations in specific genes or genomic loci, similar mechanisms may account for the genome-wide epigenetic regulation of gene activity and transposon stability in different tissues of maize hybrids. Genome-wide integrated maps of mRNA and small RNA (sRNA) transcriptomes, DNA methylomes and genome-wide distribution of three representative histone modifications (H3K4me3, H3K9ac and H3K36me3) in the shoots and roots of 14 day old seedlings of two maize inbred lines (B73 and Mo17) and their reciprocal hybrids (B73 x Mo17 and Mo17 x B73).