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: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: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:We collected infected wheat leaf material at up to nine time points per Z. tritici isolate and conducted confocal microscopy analyses to select samples for RNA extraction and transcriptome sequencing based on the morphological infection stage. Thereby, we generated stage-specific RNA-seq datasets corresponding to the four core infection stages allowing us to compare the isolate-specific expression profiles at the same developmental stage of infection. Our final dataset comprises four stage-specific transcriptomes per isolate with two biological replicates per sample. Comparative transcriptome analyses reveal that the expression phenotypes of the three isolates differ significantly.
Project description:To get an overview of transcriptome characteristics of Wangshuibai during infection by Fg, a high-throughput RNA sequencing based on next generation sequencing (NGS) technology (Illumina) were performed. Each spike of 4 central spikelets was injected with 10 μl of conidial inoculant (105 macro conidia per milliliter) and covered with a plastic bag to maintain humidity until sampling. Both non-inoculated spikes and inoculated spikes at 12, 24, 48, 72 and 96 hours after inoculation (hai) were sampled. Inoculations and sampling were conducted at 7 a.m. except for the sample at 12 hai at 7 p.m. A total of 12 samples (one treatment, two genotypes and six time points) were prepared for RNA extraction. The samples for transcriptome analysis were the mixture of equal amount of RNA from non-inoculated spikes and spikes at 12, 24 and 48 hai of Wangshuibai. Transcriptome library with fragments between 200 to 700 bp was prepared following the Illuminaâs kits provided by manufacturer and sequenced on Illumina HiSeq⢠2000 using paired-end technology in a single run.
Project description:Fructans represent the major component of water soluble carbohydrates (WSCs) in the maturing stem of temperate cereals and are an important temporary carbon reserve for grain filling. Theoretically, genotypic variation in carbon reserve accumulation is determined by relative carbon availability and demand at the whole plant level. To evaluate the importance of source carbon availability in fructan accumulation and its associated molecular mechanisms, we performed comparative analyses of individual WSC components and the expression profiles of genes involved in major carbohydrate metabolism and photosynthesis in flag leaves of recombinant inbred lines derived from a cross between wheat cultivars Seri M82 and Babax (SB lines). High sucrose levels in the mature flag leaf (source carbon organ) were found to be positively associated with WSC and fructan concentrations in both the leaf and stem of SB lines in several field trials. Analysis of Affymetrix expression array data revealed that high leaf sucrose lines grown in abiotic-stress-prone environments had high expression levels of a number of genes in the leaf involved in the sucrose synthetic pathway and photosynthesis, such as Calvin cycle genes, antioxidant genes involved in the removal of chloroplast H2O2 and genes involved in energy dissipation. The expression of the majority of genes involved in fructan and starch synthetic pathways were positively correlated with sucrose levels in the leaves of these SB lines.