Project description:Transcriptional profiling of developing rice endosperm at seven days after flowering comparing aleurone layers with central starchy endosperm. Cereal productivity is dependent on the accumulation of storage compounds in the endosperm, a nutritive tissue that is composed of aleurone cells in the outermost regions and starchy endosperm in the inner region. The transcriptional analyses provides clues to the molecular basis for different metabolic pathways in response to the spatial and nutritional differences between rice aleurone cells and starchy endosperm.
Project description:Transcriptional profiling of developing rice endosperm at seven days after flowering comparing aleurone layers with central starchy endosperm. Cereal productivity is dependent on the accumulation of storage compounds in the endosperm, a nutritive tissue that is composed of aleurone cells in the outermost regions and starchy endosperm in the inner region. The transcriptional analyses provides clues to the molecular basis for different metabolic pathways in response to the spatial and nutritional differences between rice aleurone cells and starchy endosperm. Two-condition experiment, Aleurone layers vs. central starchy endosperm. 3 biological replicates with color swap for each biological replicate
Project description:This reports the transcript profiling of the aleurone and starchy endosperm layers of wheat seed over 3 time points critical in the development of the aleurone layer. Wheat is a critical food source globally. The aleurone layer develops from the starchy endosperm and is a concentrated source of vitamins and minerals, essential for the germination of the plant embryo. However the molecular mechanisms behind the development of this layer remain poorly understood. Here we present the first direct systematic comparison of the transcriptomes of the aleurone and starchy endosperm tissues of the wheat seed (Triticum aestivum) at time points critical to the development of the aleurone layer of 6, 9 and 14 days post anthesis. Gene expression patterns reflect the changing role of these tissues in seed development. Illumina sequencing gave 25 to 55 million sequence reads per tissue, of the trimmed reads, 70 – 81% mapped to reference expressed sequence transcripts. To quantify transcript abundance, RNA-Seq normalisation was performed to generate RPKM values, these were used in comparative analyses between the tissues at each time point using Kals Z-test. Sequences with significantly different RPKM values were categorised on the basis of tissue and time point expression and functionally annotated using standardised gene ontology vocabularies, revealing two very distinct tissues. In conclusion we show the relationships between and the fundamental biological reprogramming of the two major biologically and economically significant tissues of the wheat seed over time. Understanding these changes in gene expression profiles is essential to mining the potential these tissues hold for human nutrition and contributing to foundational and systems biology of this important crop. Examines the transcript profile of aleurone and starchy endoperm tissues at 6,9 and 14DPA. A minimum of 5 individual seeds from 3 separate spikes from three individual plants were pooled for each tissue preparation.
Project description:Starchy endosperm proteins determine wheat quality and exhibit, besides a quantitative protein gradient, a qualitative protein gradient from the outer to inner starchy endosperm. The goal was to investigate the relative differences in protein composition between the aleurone, sub-aleurone and inner endosperm. Using laser microdissection followed by nanoLC-MS/MS, an innovative method combining a high spatial specificity and analytical selectivity in sample-limited situations, 780 proteins were detected and classified by function. Relatively more gluten proteins were detected in the sub-aleurone compared to inner endosperm. Gluten composition-wise, the sub-aleurone is relatively more enriched in ω-gliadins, but impoverished in LMW-GS and γ-gliadins. While a basic set of albumins and globulins is detected across the entire endosperm, some proteins, like puroindoline-B, display an increasing (or decreasing) gradient. Histological origin and relative positioning of the endosperm cells are hypothesized to drive the protein gradient. Knowledge on this gradient provides major opportunities for the wheat manufacturing industry.
Project description:This reports the transcript profiling of the aleurone and starchy endosperm layers of wheat seed over 3 time points critical in the development of the aleurone layer. Wheat is a critical food source globally. The aleurone layer develops from the starchy endosperm and is a concentrated source of vitamins and minerals, essential for the germination of the plant embryo. However the molecular mechanisms behind the development of this layer remain poorly understood. Here we present the first direct systematic comparison of the transcriptomes of the aleurone and starchy endosperm tissues of the wheat seed (Triticum aestivum) at time points critical to the development of the aleurone layer of 6, 9 and 14 days post anthesis. Gene expression patterns reflect the changing role of these tissues in seed development. Illumina sequencing gave 25 to 55 million sequence reads per tissue, of the trimmed reads, 70 – 81% mapped to reference expressed sequence transcripts. To quantify transcript abundance, RNA-Seq normalisation was performed to generate RPKM values, these were used in comparative analyses between the tissues at each time point using Kals Z-test. Sequences with significantly different RPKM values were categorised on the basis of tissue and time point expression and functionally annotated using standardised gene ontology vocabularies, revealing two very distinct tissues. In conclusion we show the relationships between and the fundamental biological reprogramming of the two major biologically and economically significant tissues of the wheat seed over time. Understanding these changes in gene expression profiles is essential to mining the potential these tissues hold for human nutrition and contributing to foundational and systems biology of this important crop.
Project description:Transcriptome of starchy endosperm of hexaploid wheat var. Cadenza at 5 stages during grain-fill. This provides a reference set of all genes which are expressed in this single cell type during development which is of huge importance for human nutrition and for industrial uses of wheat grain. Here we focus on genes in glycosyl transferase and glycosyl hydrolase families which are responsible for the non-starch polysaccharide composition of wheat flour.
Project description:Heat stress occurrence during endosperm development and seed filling forms chalky portion in the limited zone of starchy endosperm of rice grains. In this study, isolation of aleurone, dorsal, central and lateral tissues of developing endosperm by laser-microdissection (LM) coupled with gene expression analysis of 44K microarray was performed to identify key regulatory genes involved in the formation of milky-white (MW) and white-back (WB) chalky grains during heat stress. Gene regulatory network analysis classified the genes changed under heat stress into five modules. the modules of genes changed in developing starchy endosperm corresponding to MW and WB portion under heat stress suggested different regulatory genes involved in each type of grain chalk. The most distinct expression pattern was observed in a M1 and M2 modules where most of the small heat shock proteins and cellular organisation genes being upregulated under heat stress in dorsal aleurone cells and dorsal starchy endosperm zones The histological observation supported the significant increase in cell number and size of dorsal aleurone cells in WB grains. With regard to the central zone of starchy endosperm, preferential downregulation of high molecular weight heat shock proteins (HMW HSPs) including a prominent member encoding for endoplasmic reticulum (ER) chaperones by heat stress were observed, while expression of starch-biosynthesis genes remained unaffected. Characterization of transgenic plants supressing endosperm lumenal binding protein (BiP1), an ER chaperone preferentially downregulated at MW portion under heat stress, showed an evidence of forming the chalky grains without disturbing the expression of starch-biosynthesis genes. The present LM-based comprehensive expression analyses provides novel inferences that HMW HSPs play important role in controlling the redox, nitrogen and amino aicd metabolism in endosperm leading to the formation of MW and WB chalky grains.Keywords ; developing endosperm, gene expression, grain chalkiness, heat stress, laser-microdissection, Oryza sativa.
Project description:The objective of the current study is to unravel the gene regulatory networks controlled by the nkd genes during maize endosperm development. We compared wild type (B73) vs. nkd mutant (introgressed into B73 background) transcriptomes in aleurone vs. starchy endosperm cell types captured by laser capture microdissection technology. We performed RNA seq analysis of mid-mature (15DAP) endosperm in two cell types [aleurone (A) and starchy endosperm (S)] of wild type B73 (B) and nkd mutant (N) kernels with three independent biological replicates.
Project description:The objective of the current study is to unravel the gene regulatory networks controlled by the nkd genes during maize endosperm developent. We compared wild type (B73) vs. nkd mutant (introgressed into B73 background) transcriptomes in aleurone vs. starchy endosperm cell types captured by laser capture microdissection technology.
Project description:Hordeum vulgare (barley) hordoindolines (HINs), HINa, HINb1 and HINb2, are orthologous proteins of wheat puroindolines (PINs) that are small, basic, cysteine-rich seed-specific proteins and responsible for grain hardness. Grain hardness, is, next to its protein content, a major quality trait. In barley, HINb is most highly expressed in the mid-stage developed endosperm and is associated with both major endosperm texture and grain hardness. However, data required tounderstand the spatio-temporal dynamics of HIN transcripts and HIN protein regulation during grain filling processes are missing. Using reverse transcription quantitative PCR (RT-qPCR) and proteomics we analyzed HIN transcript and HIN protein abundance from whole seeds (WSs) at four ((6 days after pollination (dap), 10 dap, 12 dap and ≥ 20 dap)) as well as from aleurone, subaleurone and starchy endosperm at two (12 dap and ≥ 20 dap) developmental stages. At the WS level, results from RT-qPCR, proteomics and western blot showed a continuous increase of HIN transcript and HIN protein abundance across these four developmental stages. Miroscopic studies revealed HIN localization mainly at the vacuolar membrane in the aleurone, at protein bodies (PBs) in subaleurone and at the periphery of starch granules in the starchy endosperm. Laser microdissetion (LMD) proteomic analyses identified HINb2 as the most prominent HIN protein in starchy endosperm at ≥ 20 dap. Additionally, our quantification data revealed a poor correlation between transcript and protein levels of HINs in subaleurone during development. Here, we correlated data achieved by RT-qPCR, proteomics and microscopy that reveal different expression and localization pattern of HINs in each layer during barley endosperm development. This indicats a contribution of each tissue to the regulation of HINs during grain filling. The effect of the high protein abundance of HINs in the starchy endosperm and their localization at the periphery of starch granules at late development stages at the high end-product quality is discussed. Understanding the spatio-temporal regulated HINs is essential to improve barley quality traits for high end-product quality, as hard texture of the barley grain is regulated by the ratio between HINb/HINa.