Project description:In this study, we analysed the proteomic response of 5mm sections of root tips to water-deficit stress in two contrasting genotypes of rice: IR64, a lowland, drought-susceptible, and shallow-rooting genotype; and Azucena, an upland, drought-tolerant, and deep-rooting genotype. Using a Partial Least Square Discriminant Analysis, we identified statistically significant differentially abundant proteins across genotypes and conditions. Analysis of biological processes led to the identification of novel proteins involved in root elongation with specific expression patterns in Azucena.
Project description:Rice (Oryza sativa L.) is one of the most important staple foods in the world, feeding more than 50% of the human population. One of its most damaging pathogens, with major impact on rice yield, is the migratory root rot nematode Hirschmanniella oryzae. In comparison with the existing knowledge on the infection process of dicots by sedentary nematodes, far less is known about the interaction between monocot plants and nematodes or plant interactions with migratory nematode species. Therefore, to gain deeper insight into the systemic transcriptional changes in rice after migratory root rot nematode infection we have performed mRNA-Seq on the shoots of root rot nematode infected rice plants. The observations were independently validated using qRT-PCR and biochemical analyses. This research reveals significant modifications in the metabolism of the plant, with a general suppression of chlorophyll biosynthesis, and primary metabolic processes involved in plant growth . Differential expression analysis between controls rice shoots and shoots from root rot nematode (H. oryzae) infected rice at two time points.
Project description:Biotrophic plant pathogens have evolved sophisticated strategies to manipulate their host. They derive all of their nutrients from living plant tissues, by making intimate contact with their host while avoiding a resistance response. Rice is one of the most important crop plants worldwide and an excellent model system for studying monocotyledonous plants. Estimates of annual yield losses due to plant-parasitic nematodes on this crop range from 10 to 25% worldwide. One of the agronomically most important nematodes attacking rice is the rice root knot nematode Meloidogyne graminicola. Attack of plant roots by sedentary plant parasitic nematodes, like the root knot nematodes (RKN; Meloidogyne spp.) involves the development of specialized feeding cells in the vascular tissue. The second stage juvenile of the RKN punctures selected vascular cells with its stylet, injects pharyngeal secretions, and this ultimately leads to the reorganisation of these cells into typical feeding structures called giant cells (GCs), from which the nematode feeds for the remainder of its sedentary life cycle (Gheysen & Mitchum, 2011). Morphological and physiological reprogramming of the initial feeding cell leads to nucleus enlargement, proliferation of mitochondria and plastids, metabolic activation, cell cycle alterations and cell wall changes (Gheysen and Mitchum, 2011). The hyperplasia and hypertrophy of the surrounding cells leads to the formation of a root gall, which is typically formed at the root tips in the case of the rice RKN M. graminicola. In comparison with other RKN, M. graminicola has a very fast life cycle, with swelling of the root tips observed as early as 1 day after infection (dai). At 3 dai, terminal hook-like galls are clearly visible (Bridge et al., 2005). After 3 moults the nematodes are mature, around 10 dai. The M. graminicola females lay their eggs inside the galls, while most other RKN deposit egg masses at the gall surface, and hatched juveniles can reinfect the same or adjacent roots. In well-drained soil at 22-29 degrees C the life cycle of M. graminicola is completed in 19 days. 2 biological replicates of nematode infected giant cells and control vascular cells were sampled at two time points: 7 and 14 dai
Project description:Histone lysine acylations are regulated by primary metabolism in animal cells. However, histone non-acetyl acylation is not yet studied in plants that have distinct primary metabolic pathways. In this work, we detected rice histone lysine butyrylation (Kbu) and crotonylation (Kcr) sites by mass spectrometry, and found both similar and specific acylation patterns compared with that in mammalian cells.
Project description:Rice is a critically important food source but yields worldwide are vulnerable to periods of drought. We exposed eight genotypes of upland and lowland rice (Oryza sativa L. ssp. japonica and indica) to drought stress at the late vegetative stage and harvested leaves for protein extraction and subsequent label-free shotgun proteomics. Gene ontology analysis revealed some differentially expressed proteins were induced by drought in all eight genotypes; we speculate that these play a universal role in drought tolerance. However, some highly genotype-specific patterns of response to drought suggest that some mechanisms of metabolic reprogramming are not universal. Such proteins had largely uncharacterized functions, making them biomarker candidates for drought tolerance screens.
Project description:In order to identify new miRNAs, NAT-siRNAs and possibly abiotic-stress regulated small RNAs in rice, three small RNA libraries were constructed from control rice seedlings and seedlings exposed to drought or salt stress, and then subjected to pyrosequencing. Totally three sets of small RNAs, which were obtained under normal condition as well as salt and drought stress conditions
Project description:Information about protein expression in rice grain across both pigmented and non-pigmented rice varieties is still relatively scarce. The data provided here represent proteomic data obtained from selected 6 Malaysian local rice varieties with varying pigmentations (black, red and white). The selected pigmented rice varieties such as black (BALI and Pulut hitam 9) and red rice (MRQ100 and MRM16) have shown high antioxidant activities and non-pigmented rice (MRQ76 and MR297) contain amino acid and micronutrient contents. This project aimed to obtain global protein expression profile as well as differential protein expression between the selected pigmented and non-pigmented rice varieties particularly proteins with their functions responsible for nutritional (i.e. antioxidant, folate and low glycaemic index) and quality (i.e. aromatic) traits. Integration of this proteomics dataset with other available in-house omics data could facilitate the identification of significant functional markers related to nutritional and quality traits. Total proteins were prepared from dehusked matured seeds harvested from three different rice plants of each variety (3 protein samples per variety). The proteins were trypsin digested before subjected to SWATH-MS proteomics analysis. Proteins were identified by matching tandem mass (MS/MS) spectra from both 1D and 2D IDA to Oryza sativa japonica and indica rice databases available at UniProt by using ProteinPilot software (v4.2) (AB Sciex). Quantification of proteins was carried out by determining protein peak areas extracted from SWATH analysis data sets using PeakView (v2.1) (AB Sciex) software. Differentially expressed protein between varieties were identified using T-test analysis with a set threshold for fold change ± 1.5 and p‐value < 0.05.
Project description:Endogenous small RNAs, including microRNAs (miRNAs) and short-interfering RNAs (siRNAs), function as posttranscriptional or transcriptional regulators in plants. miRNA function is essential for normal development and therefore likely to be important in the growth of the rice grain. To investigate the likely roles of miRNAs in rice grain development we carried out deep sequencing of the small RNA populations of rice grains. A total of 96,091 (including 23,867 reads from vegetative tissues) and 5,379,724 small RNA sequences that are longer than 17nt were generated. Approximately 94% of these small RNAs were 20-24nt in length. The majority of the small RNAs were singletons, indicating that rice genome has a very complex small RNA population, which is harder to be saturated. From these smal RNA sequences we found representatives of all 20 conserved plant miRNA families and evidence for changes in expression of miRNAs during rice grain development. Using an approach based on the presence of the miRNA and miRNA* sequences, we identified 51 novel, non-conserved rice miRNA families expressed in grains with functionally diverse predicted target genes. miRNA-guided cleavage was confirmed for a number of targets genes including ones with roles in sugar signalling and restoration of cytoplasmic male sterility. We identified a likely mirtron, indicating that plants can also use spliced introns as a source of miRNAs. Our sequencing results revealed four TAS3 loci; these all contain dual miR390 sites of which only the 3? site is cleaved. We also found a miRNA-like long hairpin generating phased 21nt small RNAs, strongly expressed in developing grains and show that these small RNAs act in trans to cleave target mRNAs. Keywords: high throughput pyrosequencing, small RNA, microRNA, grain development, rice Small RNA populations of shoots and roots of 7 days old seedlings, and 1-5 and 6-10 days after fertilization grains were determined using high throughput sequencing technology. The abundance of known miRNAs were compared based on the number of sequence reads. To give a whole picture of the rice small RNA populations and to reflect un-biasly the sequencing results, small RNAs that are longer than 17nt no matter whether or not they matched with the rice genome were included in this submitted dataset. The unmatched sequences may be derived from un-sequenced regions or sequencing errors.
Project description:Comparative functional genomics offers a powerful approach to study species evolution. To date, the majority of these studies have focused on the transcriptome in mammalian and yeast phylogenies. Here we present a novel multi-species proteomic dataset and a computational pipeline to compare the protein levels across multiple plant species systematically. Globally we find that protein levels diverge according to phylogenetic distance, but is more constrained than at the mRNA level. Module-level comparative analysis of groups of proteins shows that proteins that are more highly expressed tend to be more conserved. To interpret the evolutionary patterns of conservation and divergence, we develop a novel integrative analysis pipeline that combines publicly available transcriptomic datasets to define co-expression modules. Our analysis pipeline can be used to relate the changes in protein levels to different species-specific phenotypic traits. We present a case study with the rhizobia-legume symbiosis process that supports the important role of autophagy and redox management processes in this symbiotic association.