Temporal patterns of gene expression associated with tuberous root formation and development in sweetpotato (Ipomoea batatas)
ABSTRACT: Investigation of whole transcriptome gene expression level during tuberous root formation and development in sweetpotato (Ipomoea batatas) cv. Guangshu 87 Identification of transcription factors (TFs) during tuberous root formation and development in sweetpotato (Ipomoea batatas) cv. Guangshu 87 A total of 7 samples were analyzed using RNA isolated from sweetpotato roots at 10, 15, 20, 30, 60, 90, 120days after transplanting. Each sample had two biological replicates.
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:In this study, we analyzed the expression profiles of both mRNAs and miRNAs in tuberous roots at an early stage before cortex splitting (ES), cortex splitting stage (CSS), and secondary root thickening stage (RTS) in turnip based on high-throughput sequencing technology.
Project description:Mechanisms related to the development of cassava storage roots and starch accumulation remain largely unknown. To evaluate genome-wide expression patterns during cassava tuberization, a 60-mer oligonucleotide microarray representing 20,840 cassava genes was designed to identify differentially expressed transcripts in fibrous root, developing storage root and mature storage root. Using a random variance model and the traditional two-fold change method for statistical analysis, 912 and 3386 differentially expressed genes were identified related to the three different phases. Among 25 significant pathways identified, glycolysis/gluconeogenesis was the most important pathway signature due to its effects on other pathways. Rate-limiting enzymes were identified from each individual pathway, such as pectinesterase, enolase, L-lactate dehydrogenase and aldehyde dehydrogenase in glycolysis/gluconeogenesis, and ADP-glucose pyrophosphorylase, starch branching enzyme and glucan phosphorylase in sucrose and starch metabolism. This study revealed that dynamic changes in at least 16% of the transcriptome, including hundreds of transcription factors, oxidoreductases/transferases/hydrolases, hormone-related genes, and effectors of homeostasis, all of which highlight the complexity of this biological process. The reliability of differentially expressed genes in microarray analysis was further verified by quantitative real-time RT-PCR. The genome-wide transcription analysis facilitates our understanding of the formation of the storage root and deciphers key genes for further cassava improvement. Fibrous roots (FR), developing storage roots (DR) and mature storage roots (MR) were collected for RNA extractions from three independent healthy 4 month-old cassava (cultivar TMS60444) plants in the field .Two RNA samples extracted from stored storage root slices were used as technical repeats (TR) for quality control.
Project description:Focal cortical dysplasia (FCD), a focal brain malformation, is the most common cause of intractable epilepsy. One of the related disorders is tuberous sclerosis (TS). The dysplasia appears to result from a defect in cortical development, however, this disorder is heterogeneous, and FCD seizure therapy is non-specific and failure-prone. As a final recourse, patients may undergo multiple surgical resections to control seizures. Thus, there is a clinical need to characterize this disorder with respect to structural, molecular, and electrophysiological profiles, which will lead to development of animal models and pilot therapies that we will then apply to humans. Overall design: Total RNA obtained from brain epilepsy surgical isolate from 5 patients with Focal Cortical Dysplasia (FCD) and 3 patients with Tuberous Sclerosis (TS) compared to 3 normal brain tissue controls. Gene expression profiling was performed using Illumina bead array technology and HumanHT-12_v.4 chips.
Project description:A continuous gene expression profiling of roots was performed during nighttime at regular interval from transplanting until harvesting to characterize the transcriptional and physiological changes in the root system of rice throughout the entire growth under natural field conditions. Roots were sampled at nighttime (24:00) at 7-day intervals encompassing 14 different growth stages. All samples were obtained from rice plants grown in the field during the 2008 cultivation season.
Project description:A continuous gene expression profiling of roots was performed during daytime at regular interval from transplanting until harvesting to characterize the transcriptional and physiological changes in the root system of rice throughout the entire growth under natural field conditions. Roots were sampled at daytime (12:00) at 7-day intervals encompassing 14 different growth stages. All samples were obtained from rice plants grown in the field during the 2008 cultivation season.
Project description:Purpose: the technology of Solexa/Illumina (RNA-seq) is an attractive alternative to the transcriptome sequencing. The goals of this study are to investigate transcriptional changes in replanted R. glutinosa leaves and identify genes responding to the disease. Methods:Totally 6.01and 6.15 million raw tags were measured from leaves of the first year planted (L1) and the second year replanted R. glutinosa (L2) at the tuberous root expansion stage, respectively. mRNA profiles of leaves of the first year planted (L1) and the second year replanted R. glutinosa (L2) at the tuberous root expansion stage, were generated by deep sequencing (Illumina HiSeq™ 2000 system). qRT–PCR validation was performed using SYBR Green assays. Results: we obtained a total of 6.01 and 6.15 million total tags including 377,200 and 361,659 distinct tags from the L1 and L2 samples, respectively. Removal of low quality tags, 161,298 and 149,290 distinct clean tags were remained.With reference to the 94,544 non-redundant consensus sequences defined by the RNA-seq transcriptomic procedure, 60,574 genes had the diagnostic CATG site, which were taken as reference distinct sequences for DGE analysis. 47,458 of the L1 tag library and 42,247 of the L2 tag library were perfectly matched the reference sequences. we screened differentially expressed genes in the L1 and L2 libraries by digital gene expression (DGE) technique. Finally, a set of 1,954 genes may be in differential expression of L2. By bioinformatics and qRT-PCR, the 117 most strongly differentially expressed ones were considered to be prime candidates for responsible for replanting disease. Conclusions: The study provides an important resource for further investigating the cause of replanting disease and developing the methods to control or subtract its injury. Leaf mRNA profiles of L1 (The first year planted R. glutinosa leaves ) and L2 (the second year replanted R. glutinosa leaves) root expansion stage were generated by deep sequencing (using Illumina HiSeq™ 2000 system)
Project description:An overview of the expression pattern of all rice genes under natural field conditions based on microarray analysis of different organs and tissues at various stages of growth and development from transplanting to harvesting. A total of 48 samples representing organs/tissues at various stages of growth and development with 3 replicates each except for one anther sample with 2 replicates. Vegetative organs such as leaf blade, leaf sheath, root and stem were sampled during the vegetative, reproductive and ripening stages. Young inflorescence, anther, pistil, lemma, palea, ovary, embryo, and endosperm were sampled at various stages of development.
Project description:Somatic retrotranspositions of various mobile genetic elements take place in tumors, and L1 retroelements physiologically transpose in neural progenitor cells during neurogenesis. We sequenced whole genomes of the neural progenitor cell-derived subependymal giant cell astrocytomas that typically affect patients suffering from the neurodevelopmental disease Tuberous Sclerosis. Here we show an unprecedented increased L1 retrotransposition in these tumors, with tens of thousands new genomic insertions, that preferentially invade genes involved in neural activity, synaptic transmission and cancer. The prevalent insertions are short, nested in preexisting L1 repeats in the same orientation, trimmed in both the 5’ and 3’ ends, representing unorthodox retrotransposition”. Most somatic L1 inserts in the genomically stable astrocytomas are nested in preexisting L1 elements. This preferred nested integration may act as a “lightning rod” mechanism dampening the effects of massive retrotransposition. In contrast, the enhanced transposition found in genomically unstable breast tumors includes regions of high-density clustered insertion, transposminos. These clustered insertions are expected to be more detrimental, as many of them are non-nested and frequently invade genic and exonic sequences. Exaggerated L1 retrotransposition may be a common stochastic damaging pathway in neurological disorders and cancer. Overall design: four subependymal giant cell astrocytomas (SEGAs). Three out of four showed a massive number of Mobile Element Insertions (MEI), mainly L1 retrotranspositions(Hil1 samples ) , those are compared to the fourth without this high MEI element number (Lol1 sample )