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:Heavy rainfall causes flooding of natural ecosystems as well as farmland, negatively affecting crop performance and yield. While the response of the wild model organism Arabidopsis thaliana to such stress conditions is well understood, we hardly know anything about the response of its relative, the important oil crop plant Brassica napus. Here, we analyzed the molecular response of leaves of rapeseed seedlings to full submergence under illumination. RNAseq experiments revealed a strong carbon starvation response under submergence, but no indication for a low-oxygen response. We used two cultivars in this study, one Asian flooding-tolerant cultivar and one European hybrid cultivar, but those genotypes did not show strong differences in their responses to submergence.
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: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:Waterlogging is one major stress for crops and causes multiple problems for plants, for example low gas diffusion, reducing conditions in the soil and accumulation of toxic metabolites. Brassica napus is an important oil crop with high waterlogging sensitivity, which may cause severe yield losses. Its reactions to the stress are not fully understood. In this work the transcriptional response of rapeseed to one aspect of waterlogging, hypoxia in the root zone, was analyzed, including two rapeseed cultivars from different origin, Avatar from Europe and Zhongshuang 9 from Asia. Both cultivars showed a high number of differentially expressed genes in roots after 4 and 24 h of hypoxia. The response included many well-known hypoxia-induced genes such as genes coding for glycolytic and fermentative enzymes. Leaves hardly responded to the root stress after a 24-h-stress treatment, and photosynthesis seemed to be not affected by the stress applied to roots. There was no clear difference in either gene expression or tolerance to waterlogging between the two genotypes used in this study.
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:Global climate changes on one aspect of extreme temperature records would suddenly reset environmental growth conditions for field-grown crops, which severely affects agronomic and commercial traits. Taking the cold-season preferable crop rapeseed Brassica napus L. for example, low-temperature shocks change endogenous regulatory networks and cause phenotypic damages during most lifespan. Here we screened out two genetic breeding elites with different temperature-dependent germination rates, core germplasms with good germination performance and genetic loci and candidate genes potentially involved in low-temperature tolerant functions for the pre-breeding purpose of cold-tolerant germination. By using the phenotype of the germination index of 273 core germplasms under normal temperature and 10 transcriptomic datasets of cold-tolerant Jia You (JY) 1621 and cold-sensitive JY1605 elite cultivars on three timepoints during germination process, we successfully identified clustered genes of early and late temperature response germination (ETRG and LTRG) genes and several cold-tolerant (CDT) and temperature-insensitive (TPI) candidate regulators. This study performed comprehensive multi-omics research on potential cold-responsive genes for the rapeseed improvement of cold tolerance germination.
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.
Project description:The fullerenes, a kind of carbon nanoparticles, have potential for enhanced stress tolerance in plants. While the positive effects of polyhydroxy fullerene—fullerol on plants in response to drought at the physiological level have been documented, the molecular mechanism in Brassica napus are not entirely understood. In this study, exogenous fullerol was applied to the leaves of B. napus seedlings given drought. The leaves of B. napus seedlings in each treatment (sufficient water condition, drought, and drought combined with fullerol) were used to conduct the molecular mechanism using transcriptomic analysis.
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.