Digital Gene Expression Analysis Based on Integrated De Novo Transcriptome Assembly of Sweet Potato [Ipomoea batatas (L.) Lam.]
Ontology highlight
ABSTRACT: More than 3.5 million raw DGE tags were obtained in each library. The clean tags in each sample ranged from 3.35 to 3.63 million, and the distinct clean tags ranged from 93,593 to 139,389. The 21 bp DGE clean tags were mapped to sweet potato transcripts. Then, we compared 7 libraries pair-wisely so that 21 pairs of comparisons were implemented. Among these comparisons, we found that 4,721 to 12,151 transcripts had significant changes in expression, and the average number was 9,657. We also observed a large number of specifically expressed transcripts between each two libraries. The expression profiles of those genes involved in root development and carbohydrates accumulation were characterized. Moreover, other genes of interest, such as potentially abiotic stress tolerance and insect resistance, were also characterized. 7 samples are examined: young leaves, mature leaves, stems, fibrous roots, initial tuberous roots, expanding tuberous roots and harvest tuberous roots.
Project description:In the present study, we compared transcriptional response to salinity between male and female individuals of Populus yunnanensis. We found that several functional groups of genes involved in important pathways were differentially expressed, including photosynthesis-related genes which were mainly up-regulated in males but down-regulated in females. This gene expression pattern is consistent with physiological observation that salinity inhibited photosynthetic capacity more in females than in males. In conclusion, our study provided molecular evidence of sexual differences in poplar salinity tolerance. Identified sex-related genes in salinity tolerance and their functional groups will enhance our understanding of sexual differences to salinity stress at the transcription level. 4 samples examined: males without salinity stress, males exposed to salinity stress, females without salinity stress and females exposed to salinity stress. Nine plants of each sex were exposed to each treatment, and RNA samples from the 9 individuals were pooled with equal proportion.
Project description:Recently, we found a dioecious plant Populus cathayana males possess a greater tolerance to enhanced UV-B radiation than do females. To carry this work forward, comparative transcriptome analyses were carried out. Similar to previous studies, a set of conserved functions and pathways related to UV-B stress were detected in males and females, regardless of the sex. In addition, sex-specific responses via transcriptome remodeling were also detected as shown in the changes of sex-related gene expression occurred in some pathways. For example, a lot of differentially expressed genes (DEGs) involved in amino acid metabolism were mainly up-regulated in males, but down-regulated in females. Moreover, we found some DEGs expressed predominantly or exclusively in one sex, which may directly contribute to sex-related physiological responses. 4 samples examined: (i) males exposure to decreased solar UV-B radiation (MC); (ii) females exposure to decreased solar UV-B radiation (FC); (iii) males exposure to ambient solar UV-B radiation (MU); and (iv) females exposure to ambient solar UV-B radiation (FU). Nine plants of each sex were exposed to each treatment, and RNA samples from the 9 individuals were pooled with equal proportion.
Project description:The present study profiled and analyzed gene expression of the maize ear at four key developmental stages. Based on genome-wide profile analysis, we detected differential mRNA of maize genes. Some of the differentially expressed genes (DEGs) were predicted to be potential candidates of maize ear development. Several well-known genes were found with reported mutants analyses, such as, compact plant2 (ct2), zea AGAMOUS homolog1 (zag1), bearded ear (bde), and silky1 (si1). MicroRNAs such as microRNA156 were predicted to target genes involved in maize ear development. Antisense transcripts were widespread throughout all the four stages, and are suspected to play important roles in maize ear development. Thus, identification and characterization of important genes and regulators at all the four developmental stages will contribute to an improved understanding of the molecular mechanisms responsible for maize ear development. Seeds of the maize inbred line 18-599 (Maize Research Institute, Sichuan Agricultural University, Chengdu, China) were grown in a growth chamber at 24°C/18°C (day/night) with 12 h illumination per day. Ears were collected as described previously [10] at four developmental stages: the growth point elongation, spikelet differentiation, floret primordium differentiation, and the floret organ differentiation phases. In brief, ears were manually collected at the four developmental stages. All the samples were harvested and immediately frozen in liquid nitrogen, and stored at -80°C until used for RNA isolation.
Project description:Cassava (Manihot esculenta) is one of the most important staple food crops worldwide. Its starchy tuberous roots supply over 800 million people with carbohydrates. Yet, surprisingly little is known about the processes involved in filling of those vital storage organs. A better understanding of cassava carbohydrate allocation and starch storage is key to improve storage root yield. In this work, we studied cassava morphology and phloem sap flow from source to sink using transgenic pAtSUC2::GFP plants, the phloem tracers esculin and 5(6)-carboxyfluorescein diacetate (CFDA), as well as several staining techniques. We show that cassava performs apoplasmic phloem loading in source leaves and symplasmic unloading into phloem parenchyma cells of tuberous roots. We demonstrate that vascular rays play an important role in radial transport from the phloem to xylem parenchyma cells in tuberous roots. Furthermore, enzymatic and proteomic measurements of storage root tissues confirmed high abundance and activity of enzymes involved in the sucrose synthase-mediated pathway and indicated that starch is stored most efficiently in the outer xylem layers of tuberous roots. Our findings represent a first basis for biotechnological approaches aimed at improved phloem loading and enhanced carbohydrate allocation and storage in order to increase tuberous root yield of cassava.
Project description:Our proteomic and metabolic profile analysis of sweetpotato roots stored at low temperature reveal that the antioxidant enzymes activities, proline and especially soluble sugar content were significantly increased. Most of the DEPs were implicated in phenylpropanoids and followed by starch and sucrose metabolism. Glucosinolate biosynthesis played a leading role in metabolic pathways of sweetpotao roots. More importantly, leucine, tryptophan, tyrosine, isoleucine and valine were all significantly up-regulated in glucosinolate biosynthesis.
Project description:Versatile roles of REVOLUTA (REV), a Class III homeodomain-leucine zipper (HD-ZIP III) transcription factor, have been mainly depicted in Arabidopsis and Populus. In this study, we investigated the functions of its tomato homolog, namely SlREV. Over-expression of a microRNA166-resistant version of SlREV (35S::REVRis) not only resulted in vegetative abnormities such as curly leaves and fasciated stems, but also caused dramatic reproductive alterations including continuous production of flowers at pedicel abscission zone (AZ) and ectopic fruit formation on receptacles. Microscopic analysis showed that meristem-like structures continuously emerged out from the exodermises of pedicel AZs and ectopic carpels formed between the first and the second whorl of floral buds in 35S::REVRis plants. Therefore, we performed Illumina’s digital gene expression (DGE) system, a tag-based transcriptome sequencing methodTranscriptional data to dicover differential expressed genes in early buds (1-2 mm floral buds at stage 6-8) of overexpression line SlREVRis-1. The result suggests that SlREV may regulate genes related to meristem maintenance and cell differentiation in the development of flower pedicel abscission zone, and modulate genes in homodomain and MADS-box families and hormone pathways during fruit formation. These results reveal important roles of SlREV in tomato. 1-2 mm floral buds at stage 6-8 were sampled from three individual plants of 35S::REVRis-1 and corresponding WT control. Three aliquots of RNA from transgenic or WT plants were pooled. Then, the digital expression profile were generated by Illumina Cluster Station and Illumina HiSeq™ 2000 System (BGI Inc.).
Project description:Obese and lean pig show breed-specific traits in muscle growth and meat quality. However, the mechanisms underlying remains unclear. Here, we reported the first genome-wide muscle development research from embryonic to 6 months old between Lantang (obese) and Landrace (lean) using Solexa/Illumina’s Genome Analyzer. We obtained 4.22±0.9×107 total reads per sample with approximately 5×106 distinct tags. Filtered adaptor tags, empty reads, low quality tags and tags of copy number =1, we obtained 3.84±0.9×107 clean total tags with 1.5±0.5×106 clean distinct tags. 20 libraries of longissimus muscle samples were sequenced in Lantang and Landrace at days 35, 49, 63, 77, 91 prenatal and 2, 28, 90, 120, 180 postnatal days.
Project description:To screen genes related to the development of sweet potato tuberous roots, the high throughput sequencing of different stages of sweet potato tuberous roots was performed. The fibrous roots (FR; roots at 20 dap), developing tuberous roots (DR; roots at 60 dap) and mature tuberous roots (MR; roots at 120 dap) of Ipomoea batatas (L.) Taizhong 6 and MBP3 overexpressed lines were used for transcriptome analysis. Totally, we identified 5488 differentially expressed genes between different stage tuberous roots of Taizhong6 and 14312 differentially expressed genes between the tuberous roots of Taizhong6 and MBP3 overexpressed lines, by calculating the gene FPKM in each sample and conducting differential gene analysis. This study provides a foundation for the mechanism analysis of sweet potato tuberous root development.
Project description:We report the application of digital gene expression analysis for high-throughput profiling the different gene expression of WT and gi mutant under control and drought conditions. Examination gene expression of WT and gi under control and drought conditions
Project description:The feather follicle is a “professional” regenerative organ that undergoes natural cycling and, regeneration after wound plucking. Similar to mammalian hair follicle, dermal papilla (DP) controls feather regeneration, shape, size, and axis. Here we report gene expression profiling for feather DP at different growth stages. For growth phase, we compared gene expression of DP, the ramogenic zone of feather branching epithelium (Erz) and the mesenchymal pulp (Pp). We also compared gene expression of DP at resting phase. To characterize the feather regeneration process, we further profiled gene expression at Day-2 and Day-4 post wound. Our results provide a resource for investigating feather growth and regeneration. Examination of gene expression in dermal papilla (DP) at growth phase and resting phase feather follicle, and during feather regeneration.