Project description:Cellular protein abundance results from the relative rates of protein synthesis and protein degradation. Through combining in vivo stable isotope labelling and in-depth quantitative proteomics, we created a protein turnover atlas of wheat grain proteins during grain development. Our data demonstrate that protein turnover rates for 1447 unique wheat grain protein groups have an apparent spatiotemporal pattern that aids explanation of the 60% of variation in protein abundances that are not attributable to gene expression. Protein synthesis rates of individual proteins vary over 100 fold and degradation rates over 20 fold. Storage proteins have both higher synthesis and degradation rates than the overarching average rates of grain proteins in other functional categories, while those proteins involved in photosynthesis, DNA synthesis and glycolysis, by contrast, are house-keeping proteins that show low synthesis and degradation rates at all times. Approximately 20% of total grain ATP production through respiration is used for grain proteome biogenesis and maintenance, and the grain invests nearly half of this budget in storage protein synthesis alone. Degradation of storage proteins as a class of grain proteins also consumed a significant amount of the total ATP allocated to protein degradation processes. This analysis suggests that 20% of newly synthesized storage proteins are turned over rather than stored suggesting that this process is not energetically optimal. This approach to measure protein turnover rates at the proteome scale shows how different functional categories of grain proteins accumulate, calculates the costs of futile cycling of protein turnover during wheat grain development and identifies the most and the least stable wheat grain proteins.
Project description:Wheat is the staple food of over 35% of the world’s population, accounts for 20% of all human calories, and its yield and quality improvement is a focus in the effort to meet new demands from population growth and changing diets. As the complexity of the wheat genome is unravelled, determining how it is used to build the protein machinery of wheat plants is a key next step in explaining detailed aspects of wheat growth and development. The specific functions of wheat organs during vegetative development and the role of metabolism, protein degradation and remobilisation in driving grain production are the foundations of crop performance and have recently become accessible through studies of the wheat proteome. With the aim of creating a resource complementary to current genome sequencing and assembly projects and to aid researchers in the specific analysis and measurement of wheat proteins of interest, we present a large scale, publicly accessible database of identified peptides and proteins derived from the proteome mapping of Triticum aestivum. This current dataset consists of twenty four organ and developmental samples in an online interactive resource allowing the selection, comparison and retrieval of proteomic data with rich biochemical annotation derived from multiple sources. Tissue specific sub-proteomes and ubiquitously expressed markers of the wheat proteome are identified alongside hierarchical assessment of protein functional classes and their presence in different tissues. The impact of wheat’s polyploid genome on proteome analysis and the effect on defining gene specific and protein family relationships is accounted for in the organisation of the data. The dataset will serve as a vehicle to build, refine and deposit confirmed targeted proteomic assays for wheat proteins and protein families to assess function.
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:Nuclear proteins of developing wheat grains collected during the cellularization, effective grain-filling and maturation phases of development were analysed.. Nuclear proteins were extracted and separated by two-dimensional gel electrophoresis. Image analysis revealed 371 and 299 reproducible spots in gels with first dimension separation along pH 4-7 and pH 6-11 isoelectric gradients, respectively. The relative abundance of 464 (67%) protein spots changed during grain development. Abundance profiles of these proteins clustered in six groups associated with the major phases and phase transitions of grain development. Using nano liquid chromatography-tandem mass spectrometry to analyse 387 variant and non-variant protein spots, 114 different proteins were identified that were classified into 16 functional classes. We noted that some proteins involved in the regulation of transcription, like HMG1/2-like protein and histone deacetylase HDAC2, were most abundant before the phase transition from cellularization to grain-filling, suggesting that major transcriptional changes occur during this key developmental phase. The maturation period was characterized by high relative abundance of proteins involved in ribosome biogenesis.
Project description:Purpose: The present study aimed to investigate the anthocyanin components and identify relevant regulatory genes in purple wheat grain by carrying out transcriptome analyses. Methods: The seeds of purple grain wheat and white grain wheat were collected 30 days after flowering, and three biological replicates were set. Total RNA was isolated and purified using TRIzol reagent (Invitrogen, Carlsbad, CA, USA) following the manufacturer's procedure. The RNA amount and purity of each sample was quantified using NanoDrop ND-1000. Then synthesizing the fragmented RNA into cDNA through the action of reverse transcriptase, and finally obtaining acDNA library. At last, we performed the 2×150bp paired-end sequencing (PE150) on an Illumina Novaseq™ 6000 following the vendor's recommended protocol. Results: A total of 10440 diferentially expressed genes were signifcantly enriched by RNA sequencing. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed signifcantly enriched flavonoid biosynthesis and anthocyanin biosynthesis in CW_S versus W_S. And the ANS and UFGT genes were predicted as core genes in anthocyanin biosynthesis. Conclusions: Our study represents the detailed analysis of wheat grain transcriptomes, with biologic replicates, generated by RNA-seq technology. Through this study, we speculated that ANS and UFGT genes are the core genes of anthocyanin biosynthesis.The significant differences of these genes affect the synthesis of anthocyanins in wheat grains, and thus affect the grain color of wheat.
Project description:The biological functions of circadian clock on growth and development have been well elucidated in model plants, while its regulatory roles in crop species, especially the roles on yield-related traits are poorly understood. Here, we characterize the core clock gene CCA1 homoeologs in wheat and studied their biological functions in seedling growth and spike development. TaCCA1 homoeologs exhibit typical diurnal expression patterns which are positively regulated by rhythmic histone modifications (H3K4me3, H3K9ac and H3k36me3). TaCCA1s are preferentially located in the nucleus and tend to form both homo- and heterodimers. TaCCA1 overexpression (TaCCA1-OE) transgenic wheat plants show disrupted circadian rhythmicity coupling with reduced chlorophyll and starch content, as well as biomass at seedling stage, also decreased spike length, grain number per spike and grain size at the ripening stage. Further studies using DNA affinity purification followed by deep sequencing (DAP-seq) indicates that TaCCA1 preferentially binds to sequences similar to “evening elements” (EE) motif in the wheat genome, particularly genes associated with photosynthesis, carbon utilization and auxin homeostasis, and decreased transcriptional levels of these target genes are observed in TaCCA1-OE transgenic wheat plants. Collectively, our study provides novel insights into a circadian-mediated mechanism of gene regulation to coordinate photo synthetic and metabolic activities in wheat, which is important for optimal plant growth and crop yield formation.
Project description:To better understand the regulatory mechanisms of water stress response in wheat, the transcript profiles in roots of two wheat genotypes, namely, drought tolerant 'Luohan No.2' (LH) and drought susceptible 'Chinese Spring' (CS) under water-stress were comparatively analyzed by using the Affymetrix wheat GeneChip®. A total of 3831 transcripts displayed 2-fold or more expression changes, 1593 transcripts were induced compared with 2238 transcripts were repressed, in LH under water-stress; Relatively fewer transcripts were drought responsive in CS, 1404 transcripts were induced and 1493 were repressed. Comparatively, 569 transcripts were commonly induced and 424 transcripts commonly repressed in LH and CS under water-stress. 689 transcripts (757 probe sets) identified from LH and 537 transcripts (575 probe sets) from CS were annotated and classified into 10 functional categories, and 74 transcripts derived from 80 probe sets displayed the change ratios no less than 16 in LH or CS. Several kinds of candidate genes were differentially expressed between the LH and CS, which could be responsible for the difference in drought tolerance of the two genotypes.
Project description:Based on EST-based in silico gene expression analysis a 15k oligonucleotid microarray has been developped in order to monitor environmental stress-dependent gene expression changes in the wheat caryopsis. Using this array, the effect of water withdrawal, with and and without additional heat stress, during the first five days of grain development (0-5 DAA) has been investigated on two wheat cultivars differing in their drought sensitivity. The combined effect of heat and drought (DH) on gene expression was much significant (8-10% of the investigated genes changed >2-fold) in contrast to drought alone (1.5%). Drought and heat stress resulted in the co-ordinated change of the expression of storage proteins, some enzymes involved in sugar/starch metabolism, cell division-related and histone proteins, certain transcription factors, heat shock proteins, proteases and aquaporins. The potential link between the observed gene expression changes and the parallel histological observations indicating the accelerated development of the stressed grains is discussed.
Project description:Background: MicroRNAs regulate various biological processes in plants. Considerable data are available on miRNAs involved in the development of rice, maize and barley. In contrast, little is known about miRNAs and their functions in the development of wheat. In this study, five small RNA (sRNA) libraries from wheat seedlings, flag leaves, and developing seeds were developed and sequenced to identify miRNAs and understand their functions in wheat development. Results: Twenty-four known miRNAs belonging to 15 miRNA families were identified from 18 MIRNA loci in wheat in the present study, including 15 (9 MIRNA loci) first identified in wheat, 13 miRNA families (16 MIRNA loci) being highly conserved and 2 (2 MIRNAs loci) moderately conserved. In addition, fifty-five novel miRNAs were also identified. The potential target genes for 15 known miRNAs and 37 novel miRNAs were predicted using strict criteria, and these target genes are involved in a wide range of biological functions. Four of the 15 known miRNA families and 22 of the 55 novel miRNAs were preferentially expressed in the developing seeds with logarithm of the fold change of 1.0~7.6, and half of them were seed-specific, suggesting that they participate in regulating wheat seed development and metabolism. From 5 days post-anthesis to 20 days post-anthesis, miR164 and miR160 increased in abundance in developing seeds, whereas miR169 decreased, suggesting their coordinating functions in the different developmental stages of wheat seed. Moreover, eight known miRNA families and 28 novel miRNAs exhibited tissue-biased expression in wheat flag leaves, with the logarithm of the fold changes of 0.5~5.2. The putative targets of these tissue-preferential miRNAs were involved in various metabolism and biological processes, suggesting complexity of the regulatory networks in different tissues. Our data also suggested that wheat flag leaves have more complicated regulatory networks of miRNAs than developing seeds. Conclusions: Our work identified and characterised wheat miRNAs, their targets and expression patterns. This study is the first to elucidate the regulatory networks of miRNAs involved in wheat flag leaves and developing seeds, and provided a foundation for future studies on specific functions of these miRNAs.