Project description:Title : Characterization of genes differentially expressed in roots of transgenic arabidopsis lines expressing the p25 protein of beet necrotic yellow vein virus. Biological question : 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. 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. 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. Experiment description: 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. Experiment 1 : 5 plates containing WT0A control plants and B0A transgenic plants. Experiment 2 : 5 plates containing WT1 control plants and B transgenic plants. 5 plates containing WT2 control plants and E transgenic plants. 5 plates containing WT3 control plants and T transgenic plants. 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: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:Purpose: The aim of this study is to investigate the role of H3K9 methylation in the development of syncytia induced by the beet cyst nematode (BCN, Heterodera schachtii). For this, ChIP-seq analysis was conducted in root tissues of Col-0 wild-type versus single suvh5 and suvh6 mutant plants and under BCN-infected and noninfected conditions. Methods: Methods: Col-0 wild-type and suvh5 and suvh6 mutant plants were grown and 10-day-old plants were inoculated with 100 second-stage juvenile (J2) H. schachtii at 10 days old. Five days post inoculation, root tissues were collected from infected and noninfected plants in triplicate. ChIP DNA was precipitated using the H3k9me2 antibody (Abcam) and prepared into libraries. Then, high throughput ChIP DNA sequencing was performed using the Illumina NovoSeq 6000. Raw reads were trimmed of adapter sequences and overrepresented reads. Then, high quality, paired-end reads were aligned to the Arabidopsis thaliana reference genome (TAIR10.28) using Bowtie2. Finally, histone peaks were called using MACS2 for the identification of genes associated with differentially dimethylated H3K9 in wild-type versus mutant roots under BCN-infected and noninfected conditions. Results and Conclusions: Under noninfected conditions, 511 and 143 H3K9me2 peaks were enriched in Col-0 compared to suvh5 and suvh6, respectively. The majority of these H3K9me2 peaks are located within TEs, which is consistent with previous findings that H3K9me2 corresponds to the repression of detrimental TEs. Our results suggest, however, that H3K9me2 adopts a new role in response to BCN. BCN-infected Col-0 had 791 H3K9me2 peaks compared to noninfected Col-0, 743 of which are located in the promoter or body of protein-coding genes. These peaks are associated with 1180 protein-coding genes. Similarly, suvh5 and suvh6 single mutants had 353 and 3106 H3K9me2 peaks compared to BCN-infected Col-0, respectively. The majority of these peaks are located in protein-coding genes and are associated with 558 and 4594 protein-coding genes, respectively. Interestingly, about 65% of peaks enriched in the BCN-infected wild type overlapped with peaks depleted in the suvh6 mutant, indicating that SUVH6 contributes to the majority of H3K9me2 during BCN parasitism.

Dataset Information

Beet

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure