Characterization of microRNAs of Beta macrocarpa and their responses to Beet necrotic yellow vein virus infection [miRNA-seq]
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ABSTRACT: Plant microRNAs (miRNAs) are a class of non-coding RNAs that play important regulatory roles in plant development, defense and abnormal disease symptom formation. Here, 547 known miRNAs, representing 129 miRNA families, and 282 potential novel miRNAs were identified in Beta macrocarpa using small RNA deep sequencing. Through a differential expression analysis, miRNAs responding to Beet necrotic yellow vein virus (BNYVV) infection were identified and confirmed using a microarray analysis. In total, 103 known miRNAs, representing 38 miRNA families, and 45 potential novel miRNAs were differentially regulated, with at least a two-fold change, in BNYVV-infected plants compared with the mock-inoculated control. These differentially expressed miRNAs were involved in hormone biosynthesis and signal transduction pathways, and enhanced axillary bud development and plant defenses. This work is the first to describe miRNAs of the plant genus Beta and may offer a reference for miRNA research in other species in the genus. It provides valuable information on the pathogenicity mechanisms of BNYVV.
Project description:Plant microRNAs (miRNAs) are a class of non-coding RNAs that play important regulatory roles in plant development, defense and abnormal disease symptom formation. Here, 547 known miRNAs, representing 129 miRNA families, and 282 potential novel miRNAs were identified in Beta macrocarpa using small RNA deep sequencing. Through a differential expression analysis, miRNAs responding to Beet necrotic yellow vein virus (BNYVV) infection were identified and confirmed using a microarray analysis. In total, 103 known miRNAs, representing 38 miRNA families, and 45 potential novel miRNAs were differentially regulated, with at least a two-fold change, in BNYVV-infected plants compared with the mock-inoculated control. These differentially expressed miRNAs were involved in hormone biosynthesis and signal transduction pathways, and enhanced axillary bud development and plant defenses. This work is the first to describe miRNAs of the plant genus Beta and may offer a reference for miRNA research in other species in the genus. It provides valuable information on the pathogenicity mechanisms of BNYVV.
Project description:Beet necrotic yellow vein virus (BNYVV) and Beet soil-borne mosaic virus (BSBMV) belong to the genus Benyvirus. Both viruses share a similar genome organization, but disease development induced in their major host plant sugar beet displays striking differences. BNYVV induces excessive lateral root (LR) formation by hijacking auxin-regulated pathways; whereas BSBMV infected roots appear asymptomatic. To elucidate transcriptomic changes associated with the virus-specific disease development of BNYVV and BSBMV, we performed a comparative transcriptome analysis of a virus infected susceptible sugar beet genotype.
Project description:Title : Characterization of genes differentially expressed in roots of transgenic arabidopsis lines expressing the p25 protein of beet necrotic yellow vein virus.<br> <br> Biological question : <br> Rhizomania ("crazy root") is a severe disease of sugar beet caused by beet necrotic yellow vein virus (BNYVV), which is transmitted by the soil-inhabiting fungus Polymyxa betae. Symptoms of virus infection are characterized by a constricted tap root and a massive proliferation of fine rootlets that often undergo necrosis. BNYVV RNA-3 encodes a 25 kDa (p25) which is an important determinant of leaf symptom phenotype. It also governs BNYVV invasion of the plant root system and induction of rootlet proliferation in sugar beet.<br> In order to obtain a better understanding of molecular aspects of disease development in roots and to characterize specific host genes involved in response to viral infection, transgenic Arabidopsis overexpressors of p25 viral protein was obtained and better characterized. It was shown that transgenic plants that efficiently expressed p25 protein produced more lateral roots. <br> Comparative analysis (microarray) was performed between wild type Arabidopsis roots and transgenic Arabidopsis roots expressing p25 protein, in order to identify Arabidopsis genes differentially expressed in response to p25 viral protein.<br> <br> Experiment description: <br> Seeds were surface sterilized, chilled at 4C for 4 days, and then germinated and grown on square Petri plates containing sterilized Murashige and Skoog (MS) medium with 1% sucrose. Such stock plates were arranged vertically in plastic racks and placed into growth chamber. After 5 days, plants were transferred carefully onto fresh MS medium big round plates. On each plate, 60 Wild Type (WT) plantlets were transferred on the half right of the plate, and 60 transgenic plantlets (B, E or T lines) were transferred on the half left of the plate. Plates were arranged horizontally and placed into growth chamber. <br> <br>Experiment 1 : 5 plates containing WT0A control plants and B0A transgenic plants. <br> <br>Experiment 2 : 5 plates containing WT1 control plants and B transgenic plants. <br>5 plates containing WT2 control plants and E transgenic plants. <br>5 plates containing WT3 control plants and T transgenic plants. <br> <br>Plants were harvested after 7 days (experiment 1) or 12 days (experiment 2), and WT roots or transgenic roots were pooled and conserved at -80C.
Project description:To facilitate the functional annotation of the pepper genome, analysis of miRNAs was performed for the sequenced data from five small RNA libraries described above, representing five different tissues. Starting with a set of 5,436 plant mature miRNA sequences available in miRBase, we annotated with high confidence 176 pepper miRNAs from 64 families, of which 30 families are computationally predicted to target TFs, suggesting important roles of these miRNA families in post-transcriptional gene regulation and transcription networks consistent with previous findings.
Project description:To identify known and novel miRNAs involved in the response and adaptation of sugar beet to short-term and long-term alkaline stress, miRNAs were identified by analysis of the deep sequencing of sRNA
Project description:Background: Sugar beet is an important root crop, accounting for 30 % of the sugar production worldwide. The long growing season make sugar beets exposed to a range of plant pathogens for longer periods than most other crops. Here, contrasting sugar beet genotypes were used for transcriptome analysis to reveal differential responses and new defense genes to Rhizoctonia solani, a soilborn fungal pathogen. Results: After curation of primary RNA-sequencing reads, 16,768 genes deriving from 36 samples composed of two susceptible and two resistant sugar beet genotypes, three time-points (0, two and five days post inoculation), each in three replicates were subjected for analysis. Among the elevated 217 transcripts at 2 dpi, three resistance-like genes (Bv4_088600_cumk, Bv8u_204980_frqg, and Bv_44840_iifo) were activated. By employing edgeR package statistics, 660 genes were significantly different (false discovery rate < 0.05) between resistant and susceptible genotypes in their response to R. solani inoculation. A combination of eukaryotic orthologous group assignments and gene ontology enrichment analyses, revealed three Bet v I/Major latex protein homologous genes (Bv7_162510_pymu, Bv7_162520_etow, Bv_27270_xeas) in the resistant genotypes after five days of fungal challenge. Co-expression network analysis of differentially expressed sugar beet genes further identified a MYB46 transcription factor, a plant disease resistance response protein (DRR206) and a flavonoid o-methyltransferase protein. MYB46 has a key function in secondary cell wall formation and exist as a singleton in the sugar beet genome. The genome of R. solani is enriched in cell wall degrading enzyme encoding genes and it is anticipated that they represent important virulence factors. Compared to Arabidopsis thaliana, sugar beet has 2.4-fold more carbohydrate esterases and particularly large numbers (26-fold) of auxiliary activity encoding genes whose function in cell wall biosynthesis is largely unknown. Conclusions: Based on components identified in this sugar beet transcript data set we conclude that defense responses to R. solani are attributed to a wide range of gene categories but functional information is missing to a large extent. This calls for careful integration to avoid negative side effects to obtain optimal combinations of these traits in order to reach the long-term goal of improved resistance in sugar beet.
Project description:MicroRNAs (miRNAs) are small non-coding RNAs that play essential roles in plant growth and development. We conducted a genome-wide survey of maize miRNA genes, characterizing their structure, expression, and evolution. Computational approaches based on homology and secondary structure modeling identified 150 high-confidence genes within 26 miRNA families. For 25 families, expression was verified by deep-sequencing of small RNA libraries that were prepared from an assortment of maize tissues. PCR-RACE amplification of 68 miRNA transcript precursors, representing 18 families conserved across several plant species, showed that splice variation and the use of alternative transcriptional start and stop sites is common within this class of genes. Comparison of sequence variation data from diverse maize inbred lines versus teosinte accessions suggest that the mature miRNAs are under strong purifying selection while the flanking sequences evolve equivalently to other genes. Since maize is derived from an ancient tetraploid, the effect of whole-genome duplication on miRNA evolution was examined. We found that, like protein-coding genes, duplicated miRNA genes underwent extensive gene-loss, with ~35% of duplicate homeologous miRNA genes retained. This number is higher than that observed with protein-coding genes. A search for putative miRNA targets indicated a bias towards genes in regulatory and metabolic pathways. As maize is one of the principal models for plant growth and development, this study will serve as a foundation for future research into the functional roles of miRNA genes.
Project description:Enzymatic degradation of plant biomass requires a complex mixture of many different enzymes. Like most fungi, thermophilic Myceliophthora species therefore have a large set of enzymes targeting different linkages in plant polysaccharides. The majority of these enzymes have not been functionally characterized and their role in plant biomass degradation is unknown. This study describes a strategy using sexual crossing and screening with the thermophilic fungus Myceliophthora heterothallica to identify specific enzymes associated with improved sugar beet pulp saccharification.Two genetically diverse M. heterothallica strains CBS 203.75 and CBS 663.74 were used to generate progenies with improved growth on sugar beet pulp. One progeny, named SBP.F1.2.11, had a different genetic pattern from the parental strains, and had improved saccharification activity after growth on 3% sugar beet pulp. Exo-proteome analysis of progeny and parental strains after 7 days growth on sugar beet pulp showed that only 17 of the 133 secreted CAZy enzymes were more abundant in progeny SBP.F1.2.11. Particularly one enzyme belonging to the carbohydrate esterase family 5 (CE5) was more present in SBP.F1.2.11. This CE5-CBM1 enzyme, named as Axe1, was phylogenetically related to acetyl xylan esterases.