Project description:High temperature stress results in yield loss and alterations to seed composition during seed filling in oilseed rape (Brassica napus). However, the mechanism underlying this heat response is poorly understood. In this study, we employed a microarray analysis with silique walls and seeds from the developing siliques (20 days after flowering) of Brassica napus that had undergone heat stress.
Project description:High temperature stress results in yield loss and alterations to seed composition during seed filling in oilseed rape (Brassica napus). However, the mechanism underlying this heat response is poorly understood. In this study, we employed a microarray analysis with silique walls and seeds from the developing siliques (20 days after flowering) of Brassica napus that had undergone heat stress. Two-condition experiment, control vs heat stress, 2 time points
Project description:The hemibiotrophic fungal pathogen Leptosphaeria maculans is the causal agent of blackleg disease in Brassica napus (canola, oilseed rape) and causes significant losses in crop yields worldwide. While genetic resistance has been used to mitigate the disease, little information about the genes and gene regulatory networks underlying blackleg resistance is currently available. High-throughput RNA sequencing and rigorous bioinformatics approaches revealed dynamic changes in the host transcriptome and identified plant defense pathways specific to the host-pathogen incompatible LepR1-AvrLepR1 interaction.
Project description:To identify oilseed rape genes with a potential role in N-remobilization during leaf senescence of developmentally old leaves in the lower canopy and young leaves in the upper canopy, transcriptomes of leaf number 4 and leaf number 8 of B. napus (cultivar Mozart) were analysed at different harvest time points under mild N deficiency and optimal N fertilization.
Project description:Glutathione (GSH) is a tripeptide involved in controlling heavy metal movement in plants. Our previous study demonstrated that GSH, applied to plant roots site-specifically, inhibited Cd translocation from roots to shoots in oilseed rape plants (Brassica napus) cultured hydroponically. One of the factors of this inhibitory effect was due to activation of Cd efflux from root cells. To investigate the molecular mechanism triggered by root applied GSH in more detail, the Cd movement was monitored non-invasively using a positron-emitting tracer imaging system (PETIS). The Cd absorption and efflux process in roots were visualized successfully. The effects of GSH on Cd efflux from root cells were estimated by analyzing obtained imaging data. Another image analysis suggested that Cd return was activated by GSH, applied to roots, at the shoot base. Cutting the shoot base of oilseed rape plants significantly inhibited Cd efflux from root cells. These experimental results demonstrated the shoot base is playing important roles in distributing Cd in the plant bodies. Furthermore, DNA microarray analysis revealed that over 300 genes in the roots of oilseed rape plants responded to root applied GSH. Among them, transporter proteins, related to heavy metal movement in plants, and proteins related to changing the structure of cell walls were involved.
Project description:The transcriptome of Leptosphaeria maculans was analyzed in mycelium and during oilseed rape (Brassica napus) leaf infection. The array probes were designed from gene models from the L. maculans whole genome annotation. One aim of this study was to verify the expression of the automatically annotated gene models in various conditions. Another goal was to monitor gene expression profiles during oilseed rape leaf infection and to highlight tissue-specific transcripts, e.g. in plant up-regulated transcripts, for further analyses. We performed 9 hybridizations (NimbleGen) with samples derived from mycelium and infected oilseed rape leaves. Samples from infected oilseed rape leaves were harvested 7 and 14 days post infection. Three replicates each. All samples were labeled with Cy3.
Project description:Oilseed rape is both an important oleaginous crop and agriculture sightseeing crop whereas has relatively scanty flower color. As natural flavonoids, Anthocyanin are responsible for the attractive red, purple, and blue colors of various tissues in higher plants, especially for the ornamental plants flower. One Brassica napus-Orychophragmus violaceus disomic addition line (M4) obtained previously exhibits red petals whichresult from anthocyanin biosynthesis. Transcriptome analysis of M4, B. napus (H3), natural individuals of O. violaceus with purple petals (OvP) and white petals (OvW) revealed that most of structural genes for the anthocyanin synthesis were up-regulated in both M4 and OvP, especially key gene ANS in the last step. Reads assembling and sequence alignment showed that the regulatory DEG PAP2 in M4 was from the transcript of O. violaceus. OvPAP2 was transformed into Arabidopsis thaliana and B. napus driven by the CaMV35S promoter and the rape petal-specific prompter XY355. Transgenic A. thaliana plants showed different levels of purple pigments in most of the organs, including the petals, and transgenic B. napus flowers exhibited restricted accumulation of anthocyanins in stamens when driven by CaMV35S promoter, but generated both red petals and anthers driven by the XY355 promoter. These results provided a platform for expounding the anthocyanin biosynthesis pathway in B. napus petals and give a successful case for flower color modification of the agriculture sightseeing rape.
Project description:Serial Analysis of Gene Expression (LongSAGE) was applied for gene expression profiling in seeds of oilseed rape (Brassica napus ssp. napus). The usefulness of this technique for detailed expression profiling in a non-model organism was demonstrated for the highly complex, neither fully sequenced nor annotated genome of B. napus by applying a tag-to-gene matching strategy based on Brassica ESTs and the annotated proteome of the closely related model crucifer A. thaliana. Transcripts from 3,094 genes were detected at two time-points of seed development, 23 days and 35 days after pollination (DAP). Differential expression in about 10 % of all matched genes, with a total abundance of 44 %, showed a shift from gene expression involved in diverse developmental processes including cell proliferation and seed coat formation at 23 DAP to more focussed metabolic processes including storage protein accumulation and lipid deposition at 35 DAP. The most abundant transcripts at 23 DAP were coding for diverse protease inhibitor proteins and proteases, including cysteine proteases involved in seed coat formation and a number of lipid transfer proteins involved in embryo pattern formation. At 35 DAP, transcripts encoding napin, cruciferin and oleosin storage proteins were most abundant. Over both time-points, 18.6 % of A. thaliana genes were matched by Brassica ESTs detected by LongSAGE tags in antisense orientation. This suggests a strong involvement of antisense transcript expression in regulatory processes during B. napus seed development. Seeds from 2 developmental stages of B. napus were used to construct 2 LongSAGE libraries, 23 days after pollination (23 DAP) and 35 days after pollination (35 DAP). Biological replicates and confirmation: Cloning of tag-amplified RT-PCR products, Real-time RT-PCR
Project description:MicroRNAs are multifunctional non-coding short nucleotide molecules. Nevertheless, the role of miRNAs in the interactions between plants and necrotrophic pathogens is largely unknown. Here, we report the identification of the miRNA repertoire of the economically important oil crop oilseed rape (Brassica napus) and those involved in interacting with its most devastating necrotrophic pathogen Sclerotinia sclerotiorum. We identified 280 B. napus miRNA candidates, including 53 novel candidates and 227 canonical members or variants of known miRNA families, by high-throughput deep sequencing of small RNAs from both normal and S. sclerotiorum-inoculated leaves. Target genes of 15 novel candidates and 222 known miRNAs were further identified by sequencing of degradomes from the two types of samples. MicroRNA microarray analysis revealed that 68 miRNAs were differentially expressed between S. sclerotiorum-inoculated and uninoculated leaves. A set of these miRNAs target genes involved in plant defense to S. sclerotiorum and/or other pathogens such as NBS-LRR R genes and nitric oxygen and reactive oxygen species related genes. Additionally, three miRNAs target AGO1 and AGO2, key components of post-transcriptional gene silencing (PTGS). Expression of several viral PTGS suppressors reduced resistance to S. sclerotiorum. Arabidopsis mutants of AGO1 and AGO2 exhibited reduced resistance while transgenic lines over-expressing AGO1 displayed increased resistance to S. sclerotiorum in an AGO1 expression level-dependent manner. Moreover, transient over-expression of miRNAs targeting AGO1 and AGO2 decreased resistance to S. sclerotiorum in oilseed rape. Our results demonstrate that the interactions between B. napus and S. sclerotiorum are tightly regulated at miRNA level and probably involve PTGS.
Project description:MicroRNAs are multifunctional non-coding short nucleotide molecules. Nevertheless, the role of miRNAs in the interactions between plants and necrotrophic pathogens is largely unknown. Here, we report the identification of the miRNA repertoire of the economically important oil crop oilseed rape (Brassica napus) and those involved in interacting with its most devastating necrotrophic pathogen Sclerotinia sclerotiorum. We identified 280 B. napus miRNA candidates, including 53 novel candidates and 227 canonical members or variants of known miRNA families, by high-throughput deep sequencing of small RNAs from both normal and S. sclerotiorum-inoculated leaves. Target genes of 15 novel candidates and 222 known miRNAs were further identified by sequencing of degradomes from the two types of samples. MicroRNA microarray analysis revealed that 68 miRNAs were differentially expressed between S. sclerotiorum-inoculated and uninoculated leaves. A set of these miRNAs target genes involved in plant defense to S. sclerotiorum and/or other pathogens such as NBS-LRR R genes and nitric oxygen and reactive oxygen species related genes. Additionally, three miRNAs target AGO1 and AGO2, key components of post-transcriptional gene silencing (PTGS). Expression of several viral PTGS suppressors reduced resistance to S. sclerotiorum. Arabidopsis mutants of AGO1 and AGO2 exhibited reduced resistance while transgenic lines over-expressing AGO1 displayed increased resistance to S. sclerotiorum in an AGO1 expression level-dependent manner. Moreover, transient over-expression of miRNAs targeting AGO1 and AGO2 decreased resistance to S. sclerotiorum in oilseed rape. Our results demonstrate that the interactions between B. napus and S. sclerotiorum are tightly regulated at miRNA level and probably involve PTGS.