Project description:MicroRNAs and siRNAs are important regulators of plant development and seed formation, yet their population and abundance in the oil crop Brassica napus are still less understood, especially at different developmental stages and among cultivars with varied seed oil contents. Here, we systematically analyzed the small RNA expression profiles of Brassica napus seeds at early embryonic developmental stages in a high oil content and a low oil content Brassica napus cultivars, both cultured in two environments. A total of 50 conserved miRNAs and 11 new miRNAs were identified, together with some new miRNA targets. Expression analysis revealed some miRNAs with varied expression levels in different seed oil content cultivars or at different embryonic developmental stages. A large amount of 23-nt small RNAs with specific nucleotide composition preference were also identified, which may present new classes of functional small RNAs. Examination of small RNA profiles in 2 different seed oil content rapeseed culvitars at 2 locations.
Project description:Compared to ordinary rapeseed, high-oleic acid rapeseed has higher levels of monounsaturated fatty acids and lower levels of saturated fatty acid and polyunsaturated fatty acids, and thus is of high nutritional and health value. In addition, high-oleic acid rapeseed oil imparts cardiovascular protective effects. Based on these properties, high-oleic acid oil crops have been extensively investigated and cultivated. In this study, we employed a microarray analysis with high oleic acid line and low oleic acid line from the developing seeds (27 days after flowering) of Brassica napus.
Project description:C3-C4 intermediate Moricandia suffruticosa showed tolerance to drought and heat stresses, and high photosynthetic capacity under these abiotic stresses as comparing with C3 relative crop rapeseed (Brassica napus). In our study, systematic analysis was conducted to reveal photosynthetic difference between C3-C4 Moricandia suffruticosa and its relative C3 rapeseed from the same Brassiceae tribe. It was found that Moricandia leaf photosynthesis and anatomy were significantly changed compared to rapeseed under drought and heat stress conditions. De novo transcriptome of Moricandia was assembled by next generation sequencing, and unigenes were mapped to respective rapeseed gene locus. Then comparative transcriptome analysis was conducted in leaf tissues of Moricandia and rapeseed under both drought and heat stresses. Main pathways and candidate genes were revealed from this analysis, which may be associated with the stress induced change in Moricandia.
Project description:MicroRNAs (miRNAs) are a class of non-coding small RNAs (sRNAs) that play crucial regulatory roles in various developmental processes. Silique length indirectly influences seed yield in rapeseed (Brassica napus); however, the molecular roles of miRNAs in silique length are largely unknown. Here, backcross progenies of rapeseed with long siliques (LS) and short siliques (SS) were used to elucidate this role. Four small RNA libraries from early developing siliques were sequenced, and a total of 814 non-redundant miRNA precursors were identified, representing 65 known miRNAs, and 394 novel miRNAs. Expression analyses revealed 12 known miRNAs and 5 novel miRNAs that were differentially expressed in LS and SS lines. Furthermore, though two degradome sequencing, we annotated 522 cleavage events. An analysis of correlated expression between differentially expressed miRNAs and their targets demonstrated that some transcription factors might repress cell proliferation or auxin signal transduction to control silique length, and that a Pi/Cu deficiency might also restrict silique development. More significantly, the overexpression of miR160 in rapeseed may repress auxin response factors and result in increased silique length, illustrating that silique length could be regulated via an auxin-response pathway. These results will serve as a foundation for future research in B. napus.
Project description:Oil rapeseed (Brassica napus L.) is a typical winter biennial plant, with high cold tolerance during vegetative stage. In recent years, more and more early-maturing rapeseed varieties were planted across China. Unfortunately, the early-maturing rapeseed varieties with low cold tolerance have higher risk of freeze injury in cold winter and spring. Little is known about the molecular mechanisms for coping with different low-temperature stress conditions in rapeseed. In this study, we investigated 47,328 differentially expressed genes (DEGs) of two early-maturing rapeseed varieties with different cold tolerance treated with cold shock at chilling (4°C) and freezing (−4°C) temperatures, as well as chilling and freezing stress following cold acclimation or control conditions. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that two conserved (the primary metabolism and plant hormone signal transduction) and two novel (plant-pathogen interaction pathway and circadian rhythms pathway) signaling pathways were significantly enriched with differentially-expressed transcripts. Our results provided a foundation for understanding the low-temperature stress response mechanisms of rapeseed. We also propose new ideas and candidate genes for genetic improvement of rapeseed tolerance to cold stresses.
Project description:Among multiple factors, light plays a decisive role in the switch from heterotrophic to autotrophic growth. Under dark condition, the rapeseed hypocotyl extended quickly with an apical hook, yellow and folded cotyledon, and the glyoxysome assembling. Whereas under light, the hypocotyl extended slowly, the cotyledon unfolded and turned green. In this study, we performed proteome profiling analyses to show the differential molecular responses of Brassica napus cotyledons to light and dark and reveal metabolic adaptations in postgerminative seedling establishment. In both light and dark-grown conditions.
Project description:Transcription profiling of Brassica rapa, Brassica oleracea and Brassica napus I and II The nuclear genomes of the resynthesised B. napus lines should be identical but, as one (B. napus I) involved a cross of B. oleracea onto B. rapa, and the other (B. napus II) involved a cross of B rapa onto B. oleracea, they differ in cytoplasm, and hence contain different chloroplast and mitochondrial genomes.
Project description:A critical barrier for improving crops yield is the compensatory effect between seed weight (SW) and seed number (SN), which has been widely reported in several crops including Brassica napus. Despite the agronomic relevance of this issue, the molecular factors involved in the interaction between SW and SN are largely unknown in crops. In this work, we performed a detailed transcriptomic analysis of 48 seed samples obtained from two rapeseed spring genotypes subjected to different source-sink (S-S) ratios in order to modify the relationship between SW and SN under field conditions.
Project description:The rapeseed crop (Brassica napus) is valued mainly for animal feed, food oil and biofuel production. This plant is particularly susceptible to many pathogens like parasitic plants, fungi or animals attacking aerial or root parts. Conventional plant protection products, used intensively in agriculture, have a negative impact on the environment (air and water quality, biodiversity, etc.) as well as on human health. There is therefore a growing demand for the development of new, more planet-friendly alternative protection methods such as biocontrol compounds. Natural rhamnolipids (RLs) can be used as elicitors of plant defense mechanisms. Indeed, these glycolipids, from bacteria secretome, are biodegradable, non-toxic and they are known for their stimulating and protective effects, in particular on rapeseed against filamentous fungi. Characterizing the organ responsiveness to defense stimulating compounds like RLs is missing. This analysis is crucial in the frame of optimizing the effectiveness of RLs against various diseases. A TMT labeling of the proteins extracted from the shoots and roots of B. napus has been performed and showed a differential pattern of protein abundance between them. These results have allowed identifying several protein families possibly involved in the differential responses observed in shoots and roots of rapeseed upon RLs treatment. In particular, quantitative proteomic analysis highlighted differential accumulation of parietal and cytoplasmic defense or stress proteins in response to treatments with RLs with a clear effect of the type of application (foliar spraying or root absorption). These results must be considered for further use of RLs to fight specific rapeseed pathogens.