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Sample records for brassica napus phosphatidylinositol-phospholipase

  1. Over-expression of Brassica napus phosphatidylinositol-phospholipase C2 in canola induces significant changes in gene expression and phytohormone distribution patterns, enhances drought tolerance and promotes early flowering and maturation.

    PubMed

    Georges, Fawzy; DAS, Shankar; Ray, Heather; Bock, Cheryl; Nokhrina, Kateryna; Kolla, Venkat Apparao; Keller, Wilf

    2009-12-01

    Phosphatidylinositol-specific phospholipase C (PtdIns-PLC2) plays a central role in the phosphatidylinositol-specific signal transduction pathway. It catalyses the hydrolysis of membrane-bound phosphatidylinositol 4,5-bisphosphate to produce two second messengers, sn-1,2-diacylglycerol and inositol 1,4,5-trisphosphate. The former is a membrane activator of protein kinase C in mammalian systems, and the latter is a Ca(2+) modulator which induces distinctive oscillating bursts of cytosolic Ca(2+), resulting in regulation of gene expression and activation of proteins. Sustained over-expression of BnPtdIns-PLC2 in transgenic Brassica napus lines brought about an early shift from vegetative to reproductive phases, and shorter maturation periods, accompanied by notable alterations in hormonal distribution patterns in various tissues. The photosynthetic rate increased, while stomata were partly closed. Numerous gene expression changes that included induction of stress-related genes such as glutathione S-transferase, hormone-regulated and regulatory genes, in addition to a number of kinases, calcium-regulated factors and transcription factors, were observed. Other changes included increased phytic acid levels and phytohormone organization patterns. These results suggest the importance of PtdIns-PLC2 as an elicitor of a battery of events that systematically control hormone regulation, and plant growth and development in what may be a preprogrammed mode.

  2. Brassica oleracea and B. napus.

    PubMed

    Sparrow, Penny A C Hundleby Née; Irwin, Judith A

    2015-01-01

    With the accelerating advances in genetics and genomics research in Arabidopsis and Brassica, transformation technologies are now routinely being exploited to elucidate gene function as well as contributing to the development of novel enhanced crops. When a researcher's desired goal is simply to modify or introduce candidate genes into a Brassica, the availability of easy-to-follow protocols and knowledge of readily transformable genotypes becomes a valuable resource. In this chapter we outline a basic A. tumefaciens-mediated transformation method, using 4-day-old cotyledonary explants, that has been successfully applied to a range of different B. oleracea and B. napus genotypes. For demonstration purposes, we focus primarily on the diploid species B. oleracea using a model doubled haploid genotype, AG DH1012. After only 3-4 weeks on kanamycin selection the first transgenic shoots can be isolated. Transformation efficiencies are typically in the region of 15-25 % (based on 15-25 PCR-positive independent shoots from 100 inoculated explants). Most explants will produce multiple shoots (1-3+ per explant) and so the total number of transgenic shoots produced will exceed 15-25 per 100 explant experiment. The protocol is also applicable to B. napus and modifications specific to this species are highlighted accordingly. For researchers wishing to use their own plant genotype, tissue culture phenotypes that are conducive to efficient transformation are also highlighted within this chapter.

  3. Genetic enhancement of Brassica napus seed quality.

    PubMed

    Hannoufa, Abdelali; Pillai, Bhinu V S; Chellamma, Sreekala

    2014-02-01

    The ultimate value of the Brassica napus (canola) seed is derived from the oil fraction, which has long been recognized for its premium dietary attributes, including its low level of saturated fatty acids, high content of monounsaturated fatty acids, and favorable omega-3 fatty acid profile. However, the protein (meal) portion of the seed has also received favorable attention for its essential amino acids, including abundance of sulfur-containing amino acids, such that B. napus protein is being contemplated for large scale use in livestock and fish feed formulations. Efforts to optimize the composition of B. napus oil and protein fractions are well documented; therefore, this article will review research concerned with optimizing secondary metabolites that affect the quality of seed oil and meal, from undesirable anti-nutritional factors to highl value beneficial products. The biological, agronomic, and economic values attributed to secondary metabolites have brought much needed attention to those in Brassica oilseeds and other crops. This review focuses on increasing levels of beneficial endogenous secondary metabolites (such as carotenoids, choline and tochopherols) and decreasing undesirable antinutritional factors (glucosinolates, sinapine and phytate). Molecular genetic approaches are given emphasis relative to classical breeding.

  4. Agrobacterium-mediated transformation of Brassica napus and Brassica oleracea.

    PubMed

    Bhalla, Prem L; Singh, Mohan B

    2008-01-01

    Agrobacterium-mediated transformation is widely used for gene delivery in plants. However, commercial cultivars of crop plants are often recalcitrant to transformation because the protocols established for model varieties are not directly applicable to them. The genus Brassica includes the oil seed crop, canola (B. napus), and vegetable crop varieties of Brassica oleracea, including cauliflower, broccoli and cabbage. Here, we describe an efficient protocol for Agrobacterium-mediated transformation using seedling explants that is applicable to various Brassica varieties; this protocol has been used to genetically engineer commercial cultivars of canola and cauliflower in our laboratory. Young seedling explants are inoculated with Agrobacterium on the day of explant preparation. Explants are grown for 1 week in the absence of a selective agent before being transferred to a selective medium to recover transgenic shoots. Transgenic shoots are subjected to an additional round of selection on medium containing higher levels of the selective agent and a low-carbohydrate source; this helps to eliminate false-positive plants. Use of seedling explants offers flexible experiment planning and a convenient explant source. Using this protocol, transgenic plants can be obtained in 2.5 to 3.5 months.

  5. Characterization of Brassica napus Flavonol Synthase Involved in Flavonol Biosynthesis in Brassica napus L.

    PubMed

    Vu, Tien Thanh; Jeong, Chan Young; Nguyen, Hoai Nguyen; Lee, Dongho; Lee, Sang A; Kim, Ji Hye; Hong, Suk-Whan; Lee, Hojoung

    2015-09-01

    Recently, Brassica napus has become a very important crop for plant oil production. Flavonols, an uncolored flavonoid subclass, have a high antioxidative effect and are known to have antiproliferative, antiangiogenic, and neuropharmacological properties. In B. napus, some flavonoid structural genes have been identified, such as, BnF3H-1, BnCHS, and BnC4H-1. However, no studies on FLS genes in B. napus have been conducted. Thus, in this study, we cloned and characterized the function of BnFLS gene B. napus. By overexpression of the BnFLS gene, flavonol (kaempferol and quercetin) levels were recovered in the Arabidopsis atfls1-ko mutant. In addition, we found that the higher endogenous flavonol levels of BnFLS-ox in vitro shoots correlated with slightly higher ROS scavenging activities. Thus, our results indicate that the BnFLS gene encodes for a BnFLS enzyme that can be manipulated to specifically increase flavonol accumulation in oilseed plants and other species such as Arabidopsis.

  6. Chalazal seed coat development in Brassica napus.

    PubMed

    Millar, Jenna L; Khan, Deirdre; Becker, Michael G; Chan, Ainsley; Dufresne, André; Sumner, Michael; Belmonte, Mark F

    2015-12-01

    The chalazal seed coat (CZSC) is a maternal subregion adjacent to the funiculus which serves as the first point of entry into the developing seed. This subregion is of particular interest in Brassica napus (canola) because of its location within the seed and its putative contribution to seed filling processes. In this study, the CZSC of canola was characterized at an anatomical and molecular level to (i) describe the cellular and subcellular features of the CZSC throughout seed development, (ii) reveal cellular features of the CZSC that relate to transport processes, (iii) study gene activity of transporters and transcriptional regulators in the CZSC subregion over developmental time, and (iv) briefly investigate the contribution of the A and C constituent genomes to B. napus CZSC gene activity. We found that the CZSC contains terminating ends of xylem and phloem as well as a mosaic of endomembrane and plasmodesmatal connections, suggesting that this subregion is likely involved in the transport of material and information from the maternal tissues of the plant to other regions of the seed. Laser microdissection coupled with quantitative RT-PCR identified the relative abundance of sugar, water, auxin and amino acid transporter homologs inherited from the constituent genomes of this complex polyploid. We also studied the expression of three transcription factors that were shown to co-express with these biological processes providing a preliminary framework for the regulatory networks responsible for seed filling in canola and discuss the relationship of the CZSC to other regions and subregions of the seed and its role in seed development.

  7. Gene expression profiles associated with intersubgenomic heterosis in Brassica napus.

    PubMed

    Chen, Xin; Li, Maoteng; Shi, Jiaqin; Fu, Donghui; Qian, Wei; Zou, Jun; Zhang, Chunyu; Meng, Jinling

    2008-11-01

    In order to understand the genetic mechanism of heterosis that has been observed in hybrids between Brassica napus and partial new-type B. napus which had exotic genome components from relative species, this study focused on the difference in gene expression patterns among partial new-typed B. napus lines, B. napus cultivars and their hybrids using the cDNA amplified fragment length polymorphism technique (cDNA-AFLP) technique. First, three partial new-type B. napus lines were compared with their original parents. One new line contained the exotic genomic components from B. rapa, and the other two new lines were obtained by the introgression of genomic components from B. rapa and B. carinata. The experimental results showed that the introgression of A(r) and C(c) genome components from B. rapa and B. carinata led to considerable differences in the gene expression profiles of the partial new-type lines when compared with their parents. Secondly, the gene expression profiles of nine cross-combinations between three partial new-type lines and three B. napus cultivars were compared. Twenty transcript-derived fragments (TDFs) associated with intersubgenomic heterosis were randomly selected and converted into PCR-based molecular markers. Some of them were mapped in the confidence intervals of quantitative trait loci (QTLs) for yield and yield-related traits in three segregative populations of B. napus. These results suggested that a proportion of the heterosis-associated TDFs were really responsible for fluctuating seed yield in rapeseed.

  8. Low probability of chloroplast movement from oilseed rape (Brassica napus) into wild Brassica rapa.

    PubMed

    Scott, S E; Wilkinson, M J

    1999-04-01

    Pollen-mediated movement of transgenes from transplastomic oilseed rape (Brassica napus) into wild relatives will be avoided if chloroplasts are maternally transmitted. We assess the probability of chloroplast exchange between conventional oilseed rape and wild Brassica rapa to model the future behavior of transplastomic cultivars. Primers specific to cpDNA were used to demonstrate maternal inheritance of chloroplasts in 47 natural hybrids between cultivated B. napus and wild B. rapa. We conclude that there will be no or negligible pollen-mediated chloroplast dispersal from oilseed rape. Transgene introgression could still occur in mixed populations, however, if B. napus acted as the recurrent female parent. Rate of transfer would then depend on the abundance of mixed populations, their persistence as mixtures, and hybridization frequency within stands. A low incidence of sympatry (0.6-0.7%) between wild B. rapa and cultivated B. napus along the river Thames, UK, in 1997 and 1998, suggests mixed stands will form only rarely. Eighteen feral populations of B. napus also showed a strong tendency toward rapid decline in plant number, seed return, and ultimately, extinction within 3 years. Conversely, hybrid production is significant in mixed stands, and the absence of control practices means that oilseed rape will have slightly greater persistence. We infer that some introgression from transplastomic B. napus into B. rapa is inevitable in mixed populations even though such populations will occur infrequently and will tend to lose B. napus plants relatively quickly. Chloroplast exchange will be extremely rare and scattered.

  9. Fatty acid breakdown in developing embryos of Brassica napus L.

    PubMed

    Chia, T; Rawsthorne, S

    2000-12-01

    Developing Brassica napus embryos are primarily concerned with the accumulation of storage products, namely oil, starch and protein. The presence of fatty acid catabolic pathways in the background of this biosynthetic activity was investigated. Enzymes involved in the process of lipid mobilization, such as malate synthase and isocitrate lyase, are detectable towards the late stages of embryo development. [(14)C]Acetate feeding experiments also reveal that fatty acid catabolism becomes increasingly functional as the embryo matures.

  10. Structural and functional comparative mapping between the Brassica A genomes in allotetraploid Brassica napus and diploid Brassica rapa.

    PubMed

    Jiang, Congcong; Ramchiary, Nirala; Ma, Yongbiao; Jin, Mina; Feng, Ji; Li, Ruiyuan; Wang, Hao; Long, Yan; Choi, Su Ryun; Zhang, Chunyu; Cowling, Wallace A; Park, Beom Seok; Lim, Yong Pyo; Meng, Jinling

    2011-10-01

    Brassica napus (AACC genome) is an important oilseed crop that was formed by the fusion of the diploids B. rapa (AA) and B. oleracea (CC). The complete genomic sequence of the Brassica A genome will be available soon from the B. rapa genome sequencing project, but it is not clear how informative the A genome sequence in B. rapa (A(r)) will be for predicting the structure and function of the A subgenome in the allotetraploid Brassica species B. napus (A(n)). In this paper, we report the results of structural and functional comparative mapping between the A subgenomes of B. napus and B. rapa based on genetic maps that were anchored with bacterial artificial chromosomes (BACs)-sequence of B. rapa. We identified segmental conservation that represented by syntenic blocks in over one third of the A genome; meanwhile, comparative mapping of quantitative trait loci for seed quality traits identified a dozen homologous regions with conserved function in the A genome of the two species. However, several genomic rearrangement events, such as inversions, intra- and inter-chromosomal translocations, were also observed, covering totally at least 5% of the A genome, between allotetraploid B. napus and diploid B. rapa. Based on these results, the A genomes of B. rapa and B. napus are mostly functionally conserved, but caution will be necessary in applying the full sequence data from B. rapa to the B. napus as a result of genomic rearrangements in the A genome between the two species.

  11. Pairing and recombination at meiosis of Brassica rapa (AA) x Brassica napus (AACC) hybrids.

    PubMed

    Leflon, M; Eber, F; Letanneur, J C; Chelysheva, L; Coriton, O; Huteau, V; Ryder, C D; Barker, G; Jenczewski, E; Chèvre, A M

    2006-11-01

    Interspecific crosses contribute significantly to plant evolution enabling gene exchanges between species. The efficiency of interspecific crosses depends on the similarity between the implicated genomes as high levels of genome similarity are required to ensure appropriate chromosome pairing and genetic recombination. Brassica napus (AACC) is an allopolyploid, resulting from natural hybridization between Brassica rapa (AA) and Brassica oleracea (CC), both being diploid species derived from a common ancestor. To study the relationships between genomes of these Brassica species, we have determined simultaneously the pairing and recombination pattern of A and C chromosomes during meiosis of AAC triploid hybrids, which result from the interspecific cross between natural B. napus and B. rapa. Different AAC triploid hybrids and their progenies have been analysed using cytogenetic, BAC-FISH, and molecular techniques. In 71% of the pollen mother cells, homologous A chromosomes paired regularly, and usually one chromosome of each pair was transmitted to the progeny. C chromosomes remained mainly univalent, but were involved in homoeologous pairing in 21.5% of the cells, and 13% of the transmitted C chromosomes were either recombined or broken. The rate of transmission of C chromosomes depended on the identity of the particular chromosome and on the way the hybrid was crossed, as the male or as the female parent, to B. napus or to B. rapa. Gene transfers in triploid hybrids are favoured between A genomes of B. rapa and B. napus, but also occur between A and C genomes though at lower rates.

  12. Citric acid assisted phytoremediation of copper by Brassica napus L.

    PubMed

    Zaheer, Ihsan Elahi; Ali, Shafaqat; Rizwan, Muhammad; Farid, Mujahid; Shakoor, Muhammad Bilal; Gill, Rafaqa Ali; Najeeb, Ullah; Iqbal, Naeem; Ahmad, Rehan

    2015-10-01

    Use of organic acids for promoting heavy metals phytoextraction is gaining worldwide attention. The present study investigated the influence of citric acid (CA) in enhancing copper (Cu) uptake by Brassica napus L. seedlings. 6 Weeks old B. napus seedlings were exposed to different levels of copper (Cu, 0, 50 and 100µM) alone or with CA (2.5mM) in a nutrient medium for 40 days. Exposure to elevated Cu levels (50 and 100µM) significantly reduced the growth, biomass production, chlorophyll content, gas exchange attributes and soluble proteins of B. napus seedlings. In addition, Cu toxicity increased the production of hydrogen peroxide (H2O2), malondialdehyde (MDA) and electrolyte leakage (EL) in leaf and root tissues of B. napus. Activities of antioxidant enzymes such as guaiacol peroxidase (POD), superoxide dismutase (SOD), catalases (CAT), ascorbate peroxidase (APX) in root and shoot tissues of B. napus were increased in response to lower Cu concentration (50µM) but increased under higher Cu concentration (100µM). Addition of CA into nutrient medium significantly alleviated Cu toxicity effects on B. napus seedlings by improving photosynthetic capacity and ultimately plant growth. Increased activities of antioxidant enzymes in CA-treated plants seems to play a role in capturing of stress-induced reactive oxygen species as was evident from lower level of H2O2, MDA and EL in CA-treated plants. Increasing Cu concentration in the nutrient medium significantly increased Cu concentration in in B. napus tissues. Cu uptake was further increased by CA application. These results suggested that CA might be a useful strategy for increasing phytoextraction of Cu from contaminated soils.

  13. Citric acid assisted phytoremediation of copper by Brassica napus L.

    PubMed

    Zaheer, Ihsan Elahi; Ali, Shafaqat; Rizwan, Muhammad; Farid, Mujahid; Shakoor, Muhammad Bilal; Gill, Rafaqa Ali; Najeeb, Ullah; Iqbal, Naeem; Ahmad, Rehan

    2015-10-01

    Use of organic acids for promoting heavy metals phytoextraction is gaining worldwide attention. The present study investigated the influence of citric acid (CA) in enhancing copper (Cu) uptake by Brassica napus L. seedlings. 6 Weeks old B. napus seedlings were exposed to different levels of copper (Cu, 0, 50 and 100µM) alone or with CA (2.5mM) in a nutrient medium for 40 days. Exposure to elevated Cu levels (50 and 100µM) significantly reduced the growth, biomass production, chlorophyll content, gas exchange attributes and soluble proteins of B. napus seedlings. In addition, Cu toxicity increased the production of hydrogen peroxide (H2O2), malondialdehyde (MDA) and electrolyte leakage (EL) in leaf and root tissues of B. napus. Activities of antioxidant enzymes such as guaiacol peroxidase (POD), superoxide dismutase (SOD), catalases (CAT), ascorbate peroxidase (APX) in root and shoot tissues of B. napus were increased in response to lower Cu concentration (50µM) but increased under higher Cu concentration (100µM). Addition of CA into nutrient medium significantly alleviated Cu toxicity effects on B. napus seedlings by improving photosynthetic capacity and ultimately plant growth. Increased activities of antioxidant enzymes in CA-treated plants seems to play a role in capturing of stress-induced reactive oxygen species as was evident from lower level of H2O2, MDA and EL in CA-treated plants. Increasing Cu concentration in the nutrient medium significantly increased Cu concentration in in B. napus tissues. Cu uptake was further increased by CA application. These results suggested that CA might be a useful strategy for increasing phytoextraction of Cu from contaminated soils. PMID:26099461

  14. Microarray expression analysis of the main inflorescence in Brassica napus.

    PubMed

    Huang, Yi; Shi, Jiaqin; Tao, Zhangsheng; Zhang, Lida; Liu, Qiong; Wang, Xinfa; Yang, Qing; Liu, Guihua; Wang, Hanzhong

    2014-01-01

    The effect of the number of pods on the main inflorescence (NPMI) on seed yield in Brassica napus plants grown at high density is a topic of great economic and scientific interest. Here, we sought to identify patterns of gene expression that determine the NPMI during inflorescence differentiation. We monitored gene expression profiles in the main inflorescence of two B. napus F6 RIL pools, each composed of nine lines with a low or high NPMI, and their parental lines, Zhongshuang 11 (ZS11) and 73290, using a Brassica 90K elements oligonucleotide array. We identified 4,805 genes that were differentially expressed (≥1.5 fold-change) between the low- and high-NPMI samples. Of these, 82.8% had been annotated and 17.2% shared no significant homology with any known genes. About 31 enriched GO clusters were identified amongst the differentially expressed genes (DEGs), including those involved in hormone responses, development regulation, carbohydrate metabolism, signal transduction, and transcription regulation. Furthermore, 92.8% of the DEGs mapped to chromosomes that originated from B. rapa and B. oleracea, and 1.6% of the DEGs co-localized with two QTL intervals (PMI10 and PMI11) known to be associated with the NPMI. Overexpression of BnTPI, which co-localized with PMI10, in Arabidopsis suggested that this gene increases the NPMI. This study provides insight into the molecular factors underlying inflorescence architecture, NPMI determination and, consequently, seed yield in B. napus.

  15. Microarray expression analysis of the main inflorescence in Brassica napus.

    PubMed

    Huang, Yi; Shi, Jiaqin; Tao, Zhangsheng; Zhang, Lida; Liu, Qiong; Wang, Xinfa; Yang, Qing; Liu, Guihua; Wang, Hanzhong

    2014-01-01

    The effect of the number of pods on the main inflorescence (NPMI) on seed yield in Brassica napus plants grown at high density is a topic of great economic and scientific interest. Here, we sought to identify patterns of gene expression that determine the NPMI during inflorescence differentiation. We monitored gene expression profiles in the main inflorescence of two B. napus F6 RIL pools, each composed of nine lines with a low or high NPMI, and their parental lines, Zhongshuang 11 (ZS11) and 73290, using a Brassica 90K elements oligonucleotide array. We identified 4,805 genes that were differentially expressed (≥1.5 fold-change) between the low- and high-NPMI samples. Of these, 82.8% had been annotated and 17.2% shared no significant homology with any known genes. About 31 enriched GO clusters were identified amongst the differentially expressed genes (DEGs), including those involved in hormone responses, development regulation, carbohydrate metabolism, signal transduction, and transcription regulation. Furthermore, 92.8% of the DEGs mapped to chromosomes that originated from B. rapa and B. oleracea, and 1.6% of the DEGs co-localized with two QTL intervals (PMI10 and PMI11) known to be associated with the NPMI. Overexpression of BnTPI, which co-localized with PMI10, in Arabidopsis suggested that this gene increases the NPMI. This study provides insight into the molecular factors underlying inflorescence architecture, NPMI determination and, consequently, seed yield in B. napus. PMID:25007212

  16. Progressive introgression between Brassica napus (oilseed rape) and B. rapa.

    PubMed

    Hansen, L B; Siegismund, H R; Jørgensen, R B

    2003-09-01

    We have earlier shown extensive introgression between oilseed rape (Brassica napus) and B. rapa in a weedy population using AFLP markers specific for the nuclear genomes. In order to describe the progress of this introgression, we examined 117 offspring from 12 maternal plants from the introgressed population with the same AFLP-markers; AFLP data were supported by chromosome counting. We also analysed the offspring with a species-specific chloroplast marker and finally evaluated the reproductive system in selected maternal plants. Our results indicated a high outcrossing rate of the introgressed maternal plants. It seemed that B. rapa most often functioned as the maternal plant in the introgression process and that the amount of oilseed rape DNA was highly diminished in the offspring compared to their introgressed maternal plants. However, our analysis of plants from the weedy population indicated that introgression can lead to both (1) exchange of chloroplast DNA between species producing B. rapa-like plants with B. napus chloroplasts and (2) incorporation of B. napus C-genome DNA into the B. rapa genome. Therefore, we question whether it can be regarded as containment to position transgenes in the chloroplast or in specific parts of the nuclear genome of B. napus.

  17. Phytochelatin systhesis and cadmium uptake of Brassica napus.

    PubMed

    Selvam, A; Wong, J W C

    2008-07-01

    Soil contamination with cadmium (Cd) poses risk to human health. Metal hyperaccumulator plants play an important role in phytoextraction of heavy metals from such contaminated sites. Accumulation of Cd and its influence on the induction of phytochelatins in Brassica napus was investigated. Brassica napus plants were grown in nutrient culture with 1 and 5 microM Cd for 10 days. The biomass negatively correlates with Cd concentration in the nutrient solution and the reduction in dry weight was significantly higher for the root than the shoot. Cadmium accumulation positively correlates with the Cd concentration in the nutrient solution and the Cd accumulation in root is significantly higher than the shoot. High-performance liquid chromatography (HPLC) analysis revealed the induction of PC2, PC3 and PC4 in response to Cd in B. napus and their concentrations vary with the Cd level in the external solution. In 1 microM Cd treated plants; PC2 was the dominant thiol fraction in the root, followed by PC3 and PC4, whereas in the shoot, PC3 is the dominant species followed by PC4 and PC2. In 5 microM Cd treated plants, the concentration of both PC3 and PC4 are higher than that of PC2 in the roots. In the shoot, the concentration of PC3 and PC4 was higher than the PC2 irrespective of the quantity of Cd uptake, implying that the detoxification of Cd involves higher molecular weight thiol complexes in the shoot. Considering the high aboveground biomass and Cd accumulation in the shoot, B. napus can be a potential candidate for the phytoextraction of Cd. PMID:18697518

  18. Cloning and characterization of boron transporters in Brassica napus.

    PubMed

    Sun, Jinhua; Shi, Lei; Zhang, Chunyu; Xu, Fangsen

    2012-02-01

    Six full-length cDNA encoding boron transporters (BOR) were isolated from Brassica napus (AACC) by rapid amplification of cDNA ends (RACE). The phylogenic analysis revealed that the six BORs were the orthologues of AtBOR1, which formed companying with the triplication and allotetra-ploidization process of B. napus, and were divided into three groups in B. napus. Each group was comprised of two members, one of which was originated from Brassica rapa (AA) and the other from Brassica oleracea (CC). Based on the phylogenetic relationships, the six genes were named as BnBOR1;1a, BnBOR1;1c, BnBOR1;2a, BnBOR1;2c, BnBOR1;3a and BnBOR1;3c, respectively. The deduced BnBOR1 s had extensive similarity with other plant BORs, with the identity of 74-96.8% in amino acid sequence. The BnBOR1;3a and BnBOR1;3c resembled AtBOR1 in number and positions of the 11 introns, but the others only have 9 introns. After the gene duplication, there was evidence of purifying selection under a divergent selective pressure. The expression patterns of the six BnBOR1 s were detected by semi-quantitative RT-PCR. The BnBOR1;3a and BnBOR1;3c showed a ubiquitous expression in all of the investigated tissues, whereas the other four genes showed similar tissue-specific expression profile. Unlike the non-transcriptional regulation of AtBOR1, the expression of BnBOR1;1c and BnBOR1;2a were obviously induced by boron deficiency. This study suggested that the BOR1 s had undergone a divergent expression pattern in the genome of B. napus after that the B. napus diverged from Arabidopsis thaliana.

  19. Intersubgenomic heterosis in seed yield potential observed in a new type of Brassica napus introgressed with partial Brassica rapa genome.

    PubMed

    Qian, W; Chen, X; Fu, D; Zou, J; Meng, J

    2005-05-01

    This paper reports the observation on the intersubgenomic heterosis for seed yield among hybrids between natural Brassica napus (A(n)A(n)C(n)C(n)) and a new type of B. napus with introgressions of genomic components of Brassica rapa (A(r)A(r)). This B. napus was selected from the progeny of B. napus x B. rapa and (B. napus x B. rapa) x B. rapa based on extensive phenotypic and cytological observation. Among the 129 studied partial intersubgenomic hybrids, which were obtained by randomly crossing 13 lines of the new type of B. napus in F(3) or BC(1)F(3) to 27 cultivars of B. napus from different regions as tester lines, about 90% of combinations exceeded the yield of their respective tester lines, whereas about 75% and 25% of combinations surpassed two elite Chinese cultivars, respectively. This strong heterosis was further confirmed by reevaluating 2 out of the 129 combinations in a successive year and by surveying hybrids between 20 lines of the new type of B. napus in BC(1)F(5) and its parental B. napus in two locations. Some DNA segments from B. rapa were identified with significant effects on seed yield and yield components of the new type of B. napus in BC(1)F(5) and intersubgenomic hybrids in positive or negative direction. It seems that the genomic components introgressed from B. rapa contributed to improvement of seed yield of rapeseed.

  20. Extensive tRNA gene changes in synthetic Brassica napus.

    PubMed

    Wei, Lijuan; An, Zeshan; Mason, Annaliese S; Xiao, Meili; Guo, Ying; Yin, Jiaming; Li, Jiana; Fu, Donghui

    2014-01-01

    Allopolyploidization, where two species come together to form a new species, plays a major role in speciation and genome evolution. Transfer RNAs (abbreviated tRNA) are typically 73-94 nucleotides in length, and are indispensable in protein synthesis, transferring amino acids to the cell protein synthesis machinery (ribosome). To date, the regularity and function of tRNA gene sequence variation during the process of allopolyploidization have not been well understood. In this study, the inter-tRNA gene corresponding to tRNA amplification polymorphism method was used to detect changes in tRNA gene sequences in the progeny of interspecific hybrids between Brassica rapa and B. oleracea, mimicking the original B. napus (canola) species formation event. Cluster analysis showed that tRNA gene variation during allopolyploidization did not appear to have a genotypic basis. Significant variation occurred in the early generations of synthetic B. napus (F1 and F2 generations), but fewer alterations were observed in the later generation (F3). The variation-prone tRNA genes tended to be located in AT-rich regions. BlastN analysis of novel tRNA gene variants against a Brassica genome sequence database showed that the variation of these tRNA-gene-associated sequences in allopolyploidization might result in variation of gene structure and function, e.g., metabolic process and transport.

  1. NMR metabolomics of ripened and developing oilseed rape (Brassica napus) and turnip rape (Brassica rapa).

    PubMed

    Kortesniemi, Maaria; Vuorinen, Anssi L; Sinkkonen, Jari; Yang, Baoru; Rajala, Ari; Kallio, Heikki

    2015-04-01

    The oilseeds of the commercially important oilseed rape (Brassica napus) and turnip rape (Brassica rapa) were investigated with (1)H NMR metabolomics. The compositions of ripened (cultivated in field trials) and developing seeds (cultivated in controlled conditions) were compared in multivariate models using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA). Differences in the major lipids and the minor metabolites between the two species were found. A higher content of polyunsaturated fatty acids and sucrose were observed in turnip rape, while the overall oil content and sinapine levels were higher in oilseed rape. The genotype traits were negligible compared to the effect of the growing site and concomitant conditions on the oilseed metabolome. This study demonstrates the applicability of NMR-based analysis in determining the species, geographical origin, developmental stage, and quality of oilseed Brassicas.

  2. Transgenic Bt-producing Brassica napus: Plutella xylostella selection pressure and fitness of weedy relatives.

    PubMed

    Mason, Peter; Braun, Lorraine; Warwick, Suzanne I; Zhu, Bin; Stewart, C Neal

    2003-01-01

    Release of transgenic insect-resistant crops creates the potential not only for the insect pest to evolve resistance but for the escape of transgenes that may confer novel or enhanced fitness-related traits through hybridization with their wild relatives. The differential response of diamondback moth (Plutella xylostella) populations in eastern and western Canada to Bt-producing (GT) Brassica napus and the potential for enhanced fitness of GT B. napus and weedy GT Brassica rapa x B. napus hybrid populations (F1, BC1, BC2) were studied. Comparative bioassays using neonates and 4th instars showed that GT B. napus and GT B. rapa x B. napus hybrids are lethal to larvae from both populations. No measurable plant fitness advantage (reproductive dry weight) was observed for GT B. napus (crop) and GT B. rapa x B. napus hybrid populations at low insect pressure (1 larva per leaf). At high insect densities (>10 larvae per leaf), vegetative plant weight was not significantly different for GT B. napus and non-GT B. napus, whereas reproductive plant weight and proportion of reproductive material were significantly higher in GT B. napus. Establishment of the Bt trait in wild B. rapa populations may also increase its competitive advantage under high insect pressure.

  3. Storage lipid biosynthesis in microspore-derived Brassica napus embryos

    SciTech Connect

    Taylor, D.C.; Underhill, E.W.; Weber, N. ); Pomeroy, M.K. ); Edwards, L. )

    1989-04-01

    Erucic acid, a fatty acid which is confined to the neutral lipids in developing seed cotyledons or rape, was chosen as a marker to study triacylglycerol (TAG) biosynthesis in a Brassica napus L. cv Reston microspore-derived embryo culture system. Accumulation and changes in acyl composition of TAGs during embryogenesis strongly paralleled that observed during seed development. Homogenates of 29-day cultured embryos were examined for the ability to incorporate erucoyl moieties into storage lipids. In the presence of {sup 14}C erucoyl CoA and various acceptors, including glycerol-3-phosphate (G3P), {sup 14}C erucic acid was rapidly incorporated into the TAG fraction. However, in contrast to studies with {sup 14}C oleoyl CoA, there was no measurable radioactivity in any Kennedy Pathway intermediates or within membrane lipid components. Analysis of the radiolabelled TAG species suggested that erucoyl moieties were incorporated into the sn-3 position by a highly active diacylglyercol acyltransferase.

  4. Protein composition of oil bodies from mature Brassica napus seeds.

    PubMed

    Jolivet, Pascale; Boulard, Céline; Bellamy, Annick; Larré, Colette; Barre, Marion; Rogniaux, Hélène; d'Andréa, Sabine; Chardot, Thierry; Nesi, Nathalie

    2009-06-01

    Seed oil bodies (OBs) are intracellular particles storing lipids as food or biofuel reserves in oleaginous plants. Since Brassica napus OBs could be easily contaminated with protein bodies and/or myrosin cells, they must be purified step by step using floatation technique in order to remove non-specifically trapped proteins. An exhaustive description of the protein composition of rapeseed OBs from two double-zero varieties was achieved by a combination of proteomic and genomic tools. Genomic analysis led to the identification of sequences coding for major seed oil body proteins, including 19 oleosins, 5 steroleosins and 9 caleosins. Most of these proteins were also identified through proteomic analysis and displayed a high level of sequence conservation with their Arabidopsis thaliana counterparts. Two rapeseed oleosin orthologs appeared acetylated on their N-terminal alanine residue and both caleosins and steroleosins displayed a low level of phosphorylation.

  5. Immunocytochemical localization of myrosinase in Brassica napus L.

    PubMed

    Thangstad, O P; Iversen, T H; Slupphaug, G; Bones, A

    1990-01-01

    The cytological and intracellular localization of myrosinase (EC 3.2.3.1) has been studied by immunochemical techniques using paraffin-embedded sections of radicles and cotyledons from seeds of Brassica napus L. cv. Niklas. For immunolabelling, sections were sequentially incubated with a monoclonal anti-myrosinase antibody and with peroxidase-and fluorescein-isothiocyanate-conjugated secondary antibodies. Enzyme and fluorescence label was present in typical myrosin cells both in radicles and in cotyledons. With higher magnification, fluorescence label revealed that the intracellular localization of myrosinase was associated with the tonoplast-like membrane surrounding the myrosin grains in the myrosin cells. The results also indicate that a large proportion of the positive myrosin cells are located in the second-outermost cell layer of the peripheral cortex region of the radicles. PMID:24201952

  6. Protein composition of oil bodies from mature Brassica napus seeds.

    PubMed

    Jolivet, Pascale; Boulard, Céline; Bellamy, Annick; Larré, Colette; Barre, Marion; Rogniaux, Hélène; d'Andréa, Sabine; Chardot, Thierry; Nesi, Nathalie

    2009-06-01

    Seed oil bodies (OBs) are intracellular particles storing lipids as food or biofuel reserves in oleaginous plants. Since Brassica napus OBs could be easily contaminated with protein bodies and/or myrosin cells, they must be purified step by step using floatation technique in order to remove non-specifically trapped proteins. An exhaustive description of the protein composition of rapeseed OBs from two double-zero varieties was achieved by a combination of proteomic and genomic tools. Genomic analysis led to the identification of sequences coding for major seed oil body proteins, including 19 oleosins, 5 steroleosins and 9 caleosins. Most of these proteins were also identified through proteomic analysis and displayed a high level of sequence conservation with their Arabidopsis thaliana counterparts. Two rapeseed oleosin orthologs appeared acetylated on their N-terminal alanine residue and both caleosins and steroleosins displayed a low level of phosphorylation. PMID:19562800

  7. RFLP mapping of Brassica napus using doubled haploid lines.

    PubMed

    Ferreira, M E; Williams, P H; Osborn, T C

    1994-11-01

    The combined use of doubled haploid lines and molecular markers can provide new genetic information for use in breeding programs. An F1-derived doubled haploid (DH) population of Brassica napus obtained from a cross between an annual canola cultivar ('Stellar') and a biennial rapeseed ('Major') was used to construct a linkage map of 132 restriction fragment length polymorphism loci. The marker loci were arranged into 22 linkage groups and six pairs of linked loci covering 1016 cM. The DH map was compared to a partial map constructed with a common set of markers for an F2 population derived from the same F1 plant, and the overall maps were not significantly different. Comparisons of maps in Brassica species suggest that less recombination occurs in B. napus (n = 19) than expected from the combined map distances of the two hypothesized diploid progenitors, B. oleracea (n = 9) and B. rapa (n=10). A high percentage (32%) of segregating marker loci were duplicated in the DH map, and conserved linkage arrangements of some duplicated loci indicated possible intergenome homoeology in the amphidiploid or intragenome duplications from the diploid progenitors. Deviation from Mendelian segregation ratios (P < 0.05) was observed for 30% of the marker loci in the DH population and for 24% in the F2 population. Deviation towards each parent occurred at equal frequencies in both populations and marker loci that showed deviation clustered in specific linkage groups. The DH lines and molecular marker map generated for this study can be used to map loci for agronomic traits segregating in this population.

  8. Novel flowering time variation in the resynthesized polyploid Brassica napus.

    PubMed

    Schranz, M E; Osborn, T C

    2000-01-01

    Recent molecular data using resynthesized polyploids of Brassica napus established that genome changes can occur rapidly after polyploid formation. In this study we present data that de novo phenotypic variation for flowering time also occurs rapidly after polyploidization. Two initial polyploid plants were developed by reciprocal crosses of B. rapa and B. oleracea followed by chromosome doubling to establish two lineages, each of which was expected to be homozygous and homogeneous. Several sublineages of each lineage were advanced by self-pollination. The range in days to flower of the sixth generation plants was 39-75 and 43-64 for the two lineages. Analysis of seventh generation progeny indicated that the variation was heritable. Lines were selected and self-pollinated to the eighth generation and also testcrossed to a natural B. napus cultivar; the testcross plants were then self-pollinated. Differences in flowering time were also inherited in these advanced generations. Days to flower was significantly correlated with leaf number in each generation. The rapid evolution of new phenotypic variation, like that observed in this model system, may have contributed to the success and diversification of natural polyploid organisms.

  9. Physiological and proteomic analyses on artificially aged Brassica napus seed

    PubMed Central

    Yin, Xiaojian; He, Dongli; Gupta, Ravi; Yang, Pingfang

    2015-01-01

    Plant seeds lose their viability when they are exposed to long term storage or controlled deterioration treatments, by a process known as seed aging. Based on previous studies, artificially aging treatments have been developed to accelerate the process of seed aging in order to understand its underlying mechanisms. In this study, we used Brassica napus seeds to investigate the mechanisms of aging initiation. B. napus seeds were exposed to artificially aging treatment (40°C and 90% relative humidity) and their physio-biochemical characteristics were analyzed. Although the treatment delayed germination, it did not increase the concentration of cellular reactive oxygen species (ROS). Comparative proteomic analysis was conducted among the control and treated seeds at different stages of germination. The proteins responded to the treatment were mainly involved in metabolism, protein modification and destination, stress response, development, and miscellaneous enzymes. Except for peroxiredoxin, no changes were observed in the accumulation of other antioxidant enzymes in the artificially aged seeds. Increased content of abscisic acid (ABA) was observed in the artificially treated seeds which might be involved in the inhibition of germination. Taken together, our results highlight the involvement of ABA in the initiation of seed aging in addition to the ROS which was previously reported to mediate the seed aging process. PMID:25763006

  10. Expression, mapping, and genetic variability of Brassica napus disease resistance gene analogues.

    PubMed

    Fourmann, M; Chariot, F; Froger, N; Delourme, R; Brunel, D

    2001-12-01

    Numerous sequences analogous to resistance (R) genes exist in plant genomes and could be involved in resistance traits. The aim of this study was to identify a large number of Brassica napus sequences related to R genes and also to test the adequacy of specific PCR-based tools for studying them. Different consensus primers were compared for their efficiency in amplifying resistance-gene analogues (RGAs) related to the nucleotide-binding-site subgroup of R genes. Specific primers were subsequently designed to fine-study the different RGAs and we tested their efficiency in three species related to B. napus: Brassica oleracea, Brassica rapa, and Arabidopsis thaliana. Forty-four B. napus RGAs were identified. Among 29 examined, at least one-third were expressed. Eighteen RGAs were mapped on 10 of the 19 B. napus linkage groups. The high variability within these sequences permitted discrimination of each genotype within a B. napus collection. The RGA-specific primers amplified RGAs in the B. oleracea and B. rapa genomes, but the sequences appear to be poorly conserved in A. thaliana. Specific RGA primers are a precise tool for studying known-sequence RGAs. These sequences represent interesting markers that could be correlated with resistance traits in B. napus or related Brassica genomes.

  11. Conserved patterns of chromosome pairing and recombination in Brassica napus crosses.

    PubMed

    Parkin, I A; Lydiate, D J

    1997-08-01

    The patterns of chromosome pairing and recombination in two contrasting Brassica napus F1 hybrids were deduced. One hybrid was from a winter oilseed rape (WOSR) x spring oilseed rape cross, the other from a resynthesized B. napus x WOSR cross. Segregation at 211 equivalent loci assayed in the population derived from each hybrid produced two collinear genetic maps. Alignment of the maps indicated that B. napus chromosomes behaved reproducibly as 19 homologous pairs and that the 19 distinct chromosomes of B. napus each recombined with unique chromosomes from the interspecific hybrid between Brassica rapa and Brassica oleracea. This result indicated that the genomes of the diploid progenitors of amphidiploid B. napus have remained essentially unaltered since the formation of the species and that the progenitor genomes were similar to those of modern-day B. rapa and B. oleracea. The frequency and distribution of crossovers were almost indistinguishable in the two populations, suggesting that the recombination machinery of B. napus could cope easily with different degrees of genetic divergence between homologous chromosomes. Efficient recombination in wide crosses will facilitate the introgression of novel alleles into oilseed rape from B. rapa and B. oleracea (via resynthesized B. napus) and reduce linkage drag.

  12. Identification, evolution, and expression partitioning of miRNAs in allopolyploid Brassica napus.

    PubMed

    Shen, Enhui; Zou, Jun; Hubertus Behrens, Falk; Chen, Li; Ye, Chuyu; Dai, Shutao; Li, Ruiyan; Ni, Meng; Jiang, Xiaoxue; Qiu, Jie; Liu, Yang; Wang, Weidi; Zhu, Qian-Hao; Chalhoub, Boulos; Bancroft, Ian; Meng, Jinling; Cai, Daguang; Fan, Longjiang

    2015-12-01

    The recently published genome of Brassica napus offers for the first time the opportunity to gain insights into the genomic organization and the evolution of miRNAs in oilseed rape. In this study, 12 small RNA libraries from two B. napus cultivars (Tapidor and Ningyou7) and their four double-haploid lines were sequenced, employing the newly sequenced B. napus genome, together with genomes of its progenitors Brassica rapa and Brassica oleracea. A total of 645 miRNAs including 280 conserved and 365 novel miRNAs were identified. Comparative analysis revealed a high level of genomic conservation of MIRNAs (75.9%) between the subgenomes of B. napus and its two progenitors' genomes, and MIRNA lost/gain events (133) occurred in B. napus after its speciation. Furthermore, significant partitioning of miRNA expressions between the two subgenomes in B. napus was detected. The data of degradome sequencing, miRNA-mediated cleavage, and expression analyses support specific interactions between miRNAs and their targets in the modulation of diverse physiological processes in roots and leaves, as well as in biosynthesis of, for example, glucosinolates and lipids in oilseed rape. These data provide a first genome-wide view on the origin, evolution, and genomic organization of B. napus MIRNAs.

  13. Identification, evolution, and expression partitioning of miRNAs in allopolyploid Brassica napus.

    PubMed

    Shen, Enhui; Zou, Jun; Hubertus Behrens, Falk; Chen, Li; Ye, Chuyu; Dai, Shutao; Li, Ruiyan; Ni, Meng; Jiang, Xiaoxue; Qiu, Jie; Liu, Yang; Wang, Weidi; Zhu, Qian-Hao; Chalhoub, Boulos; Bancroft, Ian; Meng, Jinling; Cai, Daguang; Fan, Longjiang

    2015-12-01

    The recently published genome of Brassica napus offers for the first time the opportunity to gain insights into the genomic organization and the evolution of miRNAs in oilseed rape. In this study, 12 small RNA libraries from two B. napus cultivars (Tapidor and Ningyou7) and their four double-haploid lines were sequenced, employing the newly sequenced B. napus genome, together with genomes of its progenitors Brassica rapa and Brassica oleracea. A total of 645 miRNAs including 280 conserved and 365 novel miRNAs were identified. Comparative analysis revealed a high level of genomic conservation of MIRNAs (75.9%) between the subgenomes of B. napus and its two progenitors' genomes, and MIRNA lost/gain events (133) occurred in B. napus after its speciation. Furthermore, significant partitioning of miRNA expressions between the two subgenomes in B. napus was detected. The data of degradome sequencing, miRNA-mediated cleavage, and expression analyses support specific interactions between miRNAs and their targets in the modulation of diverse physiological processes in roots and leaves, as well as in biosynthesis of, for example, glucosinolates and lipids in oilseed rape. These data provide a first genome-wide view on the origin, evolution, and genomic organization of B. napus MIRNAs. PMID:26357884

  14. Identification, evolution, and expression partitioning of miRNAs in allopolyploid Brassica napus

    PubMed Central

    Shen, Enhui; Zou, Jun; Hubertus Behrens, Falk; Chen, Li; Ye, Chuyu; Dai, Shutao; Li, Ruiyan; Ni, Meng; Jiang, Xiaoxue; Qiu, Jie; Liu, Yang; Wang, Weidi; Zhu, Qian-Hao; Chalhoub, Boulos; Bancroft, Ian; Meng, Jinling; Cai, Daguang; Fan, Longjiang

    2015-01-01

    The recently published genome of Brassica napus offers for the first time the opportunity to gain insights into the genomic organization and the evolution of miRNAs in oilseed rape. In this study, 12 small RNA libraries from two B. napus cultivars (Tapidor and Ningyou7) and their four double-haploid lines were sequenced, employing the newly sequenced B. napus genome, together with genomes of its progenitors Brassica rapa and Brassica oleracea. A total of 645 miRNAs including 280 conserved and 365 novel miRNAs were identified. Comparative analysis revealed a high level of genomic conservation of MIRNAs (75.9%) between the subgenomes of B. napus and its two progenitors’ genomes, and MIRNA lost/gain events (133) occurred in B. napus after its speciation. Furthermore, significant partitioning of miRNA expressions between the two subgenomes in B. napus was detected. The data of degradome sequencing, miRNA-mediated cleavage, and expression analyses support specific interactions between miRNAs and their targets in the modulation of diverse physiological processes in roots and leaves, as well as in biosynthesis of, for example, glucosinolates and lipids in oilseed rape. These data provide a first genome-wide view on the origin, evolution, and genomic organization of B. napus MIRNAs. PMID:26357884

  15. Integration of Brassica A genome genetic linkage map between Brassica napus and B. rapa.

    PubMed

    Suwabe, Keita; Morgan, Colin; Bancroft, Ian

    2008-03-01

    An integrated linkage map between B. napus and B. rapa was constructed based on a total of 44 common markers comprising 41 SSR (33 BRMS, 6 Saskatoon, and 2 BBSRC) and 3 SNP/indel markers. Between 3 and 7 common markers were mapped onto each of the linkage groups A1 to A10. The position and order of most common markers revealed a high level of colinearity between species, although two small regions on A4, A5, and A10 revealed apparent local inversions between them. These results indicate that the A genome of Brassica has retained a high degree of colinearity between species, despite each species having evolved independently after the integration of the A and C genomes in the amphidiploid state. Our results provide a genetic integration of the Brassica A genome between B. napus and B. rapa. As the analysis employed sequence-based molecular markers, the information will accelerate the exploitation of the B. rapa genome sequence for the improvement of oilseed rape.

  16. Secondary product glycosyltransferases in seeds of Brassica napus.

    PubMed

    Mittasch, Juliane; Strack, Dieter; Milkowski, Carsten

    2007-01-01

    This study describes a systematic screen for secondary product UDP-glycosyltransferases (UGTs; EC 2.4.1) involved in seed development of oilseed rape (Brassica napus) and was aimed at identifying genes related to UGT84A9 encoding UDP-glucose:sinapate glucosyltransferase (EC 2.4.1.120), a proven target for molecular breeding approaches to reduce the content of anti-nutritive sinapate esters. By RT-PCR with primers recognizing the conserved signature motif of UGTs, 13 distinct ESTs could be generated from seed RNA. Sequence analysis allowed to assign the isolated ESTs to groups B, D, E, and L of the UGT family. In an alternative approach, two open reading frames related to UGT84A9 were cloned from the B. napus genome and designated as UGT84A10 and UGT84A11, respectively. Functional expression of UGT84A10 revealed that the encoded enzyme catalyzes the formation of 1-O-acylglucosides (beta-acetal esters) with several hydroxycinnamates whereas, in our hands, the recombinant UGT84A11 did not display this enzymatic activity. Semi-quantitative RT-PCR confirmed that the majority of potential UGTs specified by the isolated ESTs is differentially expressed. A pronounced transcriptional up-regulation during seed development was evident for UGT84A9 and one EST (BnGT3) clustering in group E of UGTs. UGT84A10 was highly induced in flowers and expressed to a moderate level in late seed maturation indicating a possible involvement in seed-specific sinapate ester biosynthesis. PMID:16909288

  17. Spontaneous gene flow from rapeseed (Brassica napus) to wild Brassica oleracea.

    PubMed

    Ford, Caroline S; Allainguillaume, Joël; Grilli-Chantler, Phil; Cuccato, Giulia; Allender, Charlotte J; Wilkinson, Mike J

    2006-12-22

    Research on the environmental risks of gene flow from genetically modified (GM) crops to wild relatives has traditionally emphasized recipients yielding most hybrids. For GM rapeseed (Brassica napus), interest has centred on the 'frequently hybridizing' Brassica rapa over relatives such as Brassica oleracea, where spontaneous hybrids are unreported in the wild. In two sites, where rapeseed and wild B. oleracea grow together, we used flow cytometry and crop-specific microsatellite markers to identify one triploid F1 hybrid, together with nine diploid and two near triploid introgressants. Given the newly discovered capacity for spontaneous introgression into B. oleracea, we then surveyed associated flora and fauna to evaluate the capacity of both recipients to harm cohabitant species with acknowledged conservational importance. Only B. oleracea occupies rich communities containing species afforded legislative protection; these include one rare micromoth species that feeds on B. oleracea and warrants further assessment. We conclude that increased attention should now focus on B. oleracea and similar species that yield few crop-hybrids, but possess scope to affect rare or endangered associates.

  18. Differential Expression of miRNAs in Brassica napus Root following Infection with Plasmodiophora brassicae

    PubMed Central

    Verma, Shiv S.; Rahman, Muhammad H.; Deyholos, Michael K.; Basu, Urmila; Kav, Nat N. V.

    2014-01-01

    Canola (oilseed rape, Brassica napus L.) is susceptible to infection by the biotrophic protist Plasmodiophora brassicae, the causal agent of clubroot. To understand the roles of microRNAs (miRNAs) during the post-transcriptional regulation of disease initiation and progression, we have characterized the changes in miRNA expression profiles in canola roots during clubroot disease development and have compared these to uninfected roots. Two different stages of clubroot development were targeted in this miRNA profiling study: an early time of 10-dpi for disease initiation and a later 20-dpi, by which time the pathogen had colonized the roots (as evident by visible gall formation and histological observations). P. brassicae responsive miRNAs were identified and validated by qRT-PCR of miRNAs and the subsequent validation of the target mRNAs through starBase degradome analysis, and through 5′ RLM-RACE. This study identifies putative miRNA-regulated genes with roles during clubroot disease initiation and development. Putative target genes identified in this study included: transcription factors (TFs), hormone-related genes, as well as genes associated with plant stress response regulation such as cytokinin, auxin/ethylene response elements. The results of our study may assist in elucidating the role of miRNAs in post-transcriptional regulation of target genes during disease development and may contribute to the development of strategies to engineer durable resistance to this important phytopathogen. PMID:24497962

  19. Comparison of flowering time genes in Brassica rapa, B. napus and Arabidopsis thaliana.

    PubMed

    Osborn, T C; Kole, C; Parkin, I A; Sharpe, A G; Kuiper, M; Lydiate, D J; Trick, M

    1997-07-01

    The major difference between annual and biennial cultivars of oilseed Brassica napus and B. rapa is conferred by genes controlling vernalization-responsive flowering time. These genes were compared between the species by aligning the map positions of flowering time quantitative trait loci (QTLs) detected in a segregating population of each species. The results suggest that two major QTLs identified in B. rapa correspond to two major QTLs identified in B. napus. Since B. rapa is one of the hypothesized diploid parents of the amphidiploid B. napus, the vernalization requirement of B. napus probably originated from B. rapa. Brassica genes also were compared to flowering time genes in Arabidopsis thaliana by mapping RFLP loci with the same probes in both B. napus and Arabidopsis. The region containing one pair of Brassica QTLs was collinear with the top of chromosome 5 in A. thaliana where flowering time genes FLC, FY and CO are located. The region containing the second pair of QTLs showed fractured collinearity with several regions of the Arabidopsis genome, including the top of chromosome 4 where FRI is located. Thus, these Brassica genes may correspond to two genes (FLC and FRI) that regulate flowering time in the latest flowering ecotypes of Arabidopsis.

  20. Metabolically engineered male sterility in rapeseed (Brassica napus L.).

    PubMed

    Engelke, Thomas; Hirsche, J; Roitsch, T

    2011-01-01

    Male sterility is of special interest as a mechanism allowing hybrid breeding, especially in important crops such as rapeseed (Brassica napus). Male sterile plants are also suggested to be used as a biological safety method to prevent the spread of transgenes, a risk that is high in the case of rapeseed due to the mode of pollination, out-crossing by wind or insects, and the presence of related, cross-pollinating species in the surrounding ecosystem in Europe. Different natural occurring male sterilities and alloplasmic forms have been tried to be used in rapeseed with more or less success. Due to the difficulties and limitations with these systems, we present a biotechnological alternative: a metabolically engineered male sterility caused by interference with anther-specific cell wall-bound invertase. This is an essential enzyme for carbohydrate supply of the symplastically isolated pollen. The activity of this enzyme is reduced either by antisense interference or by expressing an invertase inhibitor under control of the anther-specific promoter of the invertase with the consequence of a strong decrease of pollen germination ability. PMID:20821307

  1. Oxalic acid-mediated stress responses in Brassica napus L.

    PubMed

    Liang, Yue; Strelkov, Stephen E; Kav, Nat N V

    2009-06-01

    Oxalic acid (OA) occurs extensively in nature and plays diverse roles, especially in pathogenic processes involving various plant pathogens. However, proteome changes and modifications of signaling and oxidative network of plants in response to OA are not well understood. In order to investigate the responses of Brassica napus toward OA, a proteome analysis was conducted employing 2-DE with MS/MS. A total of 37 proteins were identified as responding to OA stress, of which 13 were up-regulated and 24 were down-regulated. These proteins were categorized into several functional groups including protein processing, RNA processing, photosynthesis, signal transduction, stress response, and redox homeostasis. Investigation of the effect of OA on phytohormone signaling and oxidative responses revealed that jasmonic acid-, ethylene-, and abscisic acid-mediated signaling pathways appear to increase at later time points, whereas those pathways mediated by salicylic acid appear to be suppressed. Moreover, the activities of the antioxidant enzymes catalase, peroxidase, superoxide dismutase and oxalic acid oxidase, but not NADPH oxidase, were suppressed by OA stress. Our findings are discussed within the context of the proposed role(s) of OA during infection by Sclerotinia sclerotiorum and subsequent disease progression. PMID:19526549

  2. Peroxidases from cell suspension cultures of Brassica napus.

    PubMed

    Agostini, E; de Forchetti, S M; Tigier, H A

    2000-08-01

    Cell suspension cultures of Brassica napus were obtained under different hormonal conditions, using 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin as growth regulators. They were analyzed as a culture system for peroxidase production in vitro to avoid many of the problems that affect the production from field-grown roots. Total peroxidase specific activities reached a maximum at the end of exponential growth phase of the cultures. Cultures obtained with 4 mg/l of 2,4-D an without kinetin or with 1 mg/l of 2,4-D and the same amount of kinetin produced twice the total activity of root extracts and, in addition, they released peroxidases to the culture medium, which would be advantageous for the commercial production of the enzyme. Peroxidase patterns, obtained by isoelectric focusing of cell extracts and of culture medium of cell suspension cultures, differed from those of root crude extracts from field-grown plants with additional bands of higher isoelectric points. These cultures showed interesting properties and could be considered an alternative source of peroxidases for commercial production and/or to be applied as a model for physiological research. PMID:10979611

  3. Storage oil breakdown during embryo development of Brassica napus (L.).

    PubMed

    Chia, Tansy Y P; Pike, Marilyn J; Rawsthorne, Stephen

    2005-05-01

    In this study it is shown that at least 10% of the major storage product of developing embryos of Brassica napus (L.), triacylglycerol, is lost during the desiccation phase of seed development. The metabolism of this lipid was studied by measurements of the fate of label from [1-(14)C]decanoate supplied to isolated embryos, and by measurements of the activities of enzymes of fatty acid catabolism. Measurements on desiccating embryos have been compared with those made on embryos during lipid accumulation and on germinating seedlings. Enzymes of beta-oxidation and the glyoxylate cycle, and phosphoenolpyruvate carboxykinase were present in embryos during oil accumulation, and increased in activity and abundance as the seeds matured and became desiccated. Although the activities were less than those measured during germination, they were at least comparable to the in vivo rate of fatty acid synthesis in the embryo during development. The pattern of labelling, following metabolism of decanoate by isolated embryos, indicated a much greater involvement of the glyoxylate cycle during desiccation than earlier in oil accumulation, and showed that much of the (14)C-label from decanoate was released as CO(2) at both stages. Sucrose was not a product of decanoate metabolism during embryo development, and therefore lipid degradation was not associated with net gluconeogenic activity. These observations are discussed in the context of seed development, oil yield, and the synthesis of novel fatty acids in plants.

  4. Lipid composition and metabolism in embryos of Brassica napus

    SciTech Connect

    Sparace, S.A. ); Pomroy, M.K. )

    1990-05-01

    Seven and 14-day old microspore-derived developing embryos of the low-erucate Brassica napus L. (cv. Topas) were analyzed for their acyl lipid composition and capacity to incorporate ({sup 14}C)acetate into lipid. The most significant changes in the lipid compositions of these ages of embryos are (1) increased total lipid from 2 to 5% of fresh weight; (2) increased proportion of TAG from 31 to 74%, and shifts in the fatty acid composition of TAG from 25 to 50% 18:1; 28 to 23% 18:2; and 24 to 13% 18:3. Lipids of 7-day embryos also consist of primarily 8% DAG, 2% MG, 12% FFA, 10% DGDG, 15% PA and approximately 5% each of PC, PE and PG. The levels of these lipids generally decrease as the embryos mature and accumulate TAG. ({sup 14}C)Acetate is incorporated into all lipids and fatty acids except 18:2 or 18:3. As much as 39, 59 and 34% of the fatty acid radioactivity of Mg was recovered in 20:0, 22:0 and 24:0, respectively.

  5. Purification and properties of recombinant Brassica napus diacylglycerol acyltransferase 1.

    PubMed

    Caldo, Kristian Mark P; Greer, Michael S; Chen, Guanqun; Lemieux, M Joanne; Weselake, Randall J

    2015-03-12

    Diacylglycerol acyltransferase 1 (DGAT1) catalyzes the final step in the acyl-CoA-dependent triacylglycerol biosynthesis. Although the first DGAT1 gene was identified many years ago and the encoded enzyme catalyzes a key step in lipid biosynthesis, no detailed structure-function information is available on the enzyme due to difficulties associated with its purification. This study describes the purification of recombinant Brassica napus DGAT1 (BnaC.DGAT1.a) in active form through solubilization in n-dodecyl-β-D-maltopyranoside, cobalt affinity chromatography, and size-exclusion chromatography. Different BnaC.DGAT1.a oligomers in detergent micelles were resolved during the size-exclusion process. BnaC.DGAT1.a was purified 126-fold over the solubilized fraction and exhibited a specific activity of 26 nmol TAG/min/mg protein. The purified enzyme exhibited substrate preference for α-linolenoyl-CoA>oleoyl-CoA=palmitoyl-CoA>linoleoyl-CoA>stearoyl-CoA.

  6. Transfer of hygromycin resistance into Brassica napus using total DNA of a transgenic B. nigra line.

    PubMed

    Golz, C; Köhler, F; Schieder, O

    1990-09-01

    The successful transfer of a marker gene (hpt gene) from Brassica nigra into B. napus via direct gene transfer was demonstrated. Total DNA was isolated from a hygromycin-resistant callus line, which contained three to five copies of the hpt gene. This line had been produced via direct gene transfer with the hygromycin resistance-conferring plasmid pGL2. The treatment of B. napus protoplasts with genomic DNA of B. nigra (HygR) resulted in relative transformation frequencies of 0.1-0.4%. Similar transformation rates were obtained in direct gene transfer experiments using B. napus protoplasts and plasmid pGL2.

  7. Karyotype and identification of all homoeologous chromosomes of allopolyploid Brassica napus and its diploid progenitors.

    PubMed

    Xiong, Zhiyong; Pires, J Chris

    2011-01-01

    Investigating recombination of homoeologous chromosomes in allopolyploid species is central to understanding plant breeding and evolution. However, examining chromosome pairing in the allotetraploid Brassica napus has been hampered by the lack of chromosome-specific molecular probes. In this study, we establish the identification of all homoeologous chromosomes of allopolyploid B. napus by using robust molecular cytogenetic karyotypes developed for the progenitor species Brassica rapa (A genome) and Brassica oleracea (C genome). The identification of every chromosome among these three Brassica species utilized genetically mapped bacterial artificial chromosomes (BACs) from B. rapa as probes for fluorescent in situ hybridization (FISH). With this BAC-FISH data, a second karyotype was developed using two BACs that contained repetitive DNA sequences and the ubiquitous ribosomal and pericentromere repeats. Using this diagnostic probe mix and a BAC that contained a C-genome repeat in two successive hybridizations allowed for routine identification of the corresponding homoeologous chromosomes between the A and C genomes of B. napus. When applied to the B. napus cultivar Stellar, we detected one chromosomal rearrangement relative to the parental karyotypes. This robust novel chromosomal painting technique will have biological applications for the understanding of chromosome pairing, homoeologous recombination, and genome evolution in the genus Brassica and will facilitate new applied breeding technologies that rely upon identification of chromosomes.

  8. Destiny of a transgene escape from Brassica napus into Brassica rapa.

    PubMed

    Lu, M.; Kato, M.; Kakihara, F.

    2002-07-01

    Transgenic Brassica napus can be easily crossed with wild Brassica rapa. The spread of the transgene to wild species has aroused the general concern about its effect on ecological and agricultural systems. This paper was designated, by means of population genetics, to study the fate of a transgene escape from B. napus to B. rapa. Three models were proposed to survey the change in gene frequency during successive backcross processes by considering selection pressures against aneuploids, against herbicide-susceptible individuals, and by considering A-C intergenomic recombination and the effect of genetic drift. The transmission rate of an A-chromosome gene through an individual to the next generation was 50%, irrespective of the chromosome number; while that of a C-chromosome transgene varied from 8.7% to 39.9%, depending on the chromosome number of the individual used in the backcross. Without spraying herbicide, the frequency of an A-chromosome gene was 50% in the BC(1) generation, and decreased by 50% with the advance of each backcross generation; that of a C-chromosome gene was around 39.9% in BC(1), 7.7% in BC(2), 1.2% in BC(3) and 0.1% in the BC(4) generation. Under the selection pressure against herbicide-susceptible individuals, the frequency of a transgene reached a stable value of about 5.5% within six generations of successive backcrossings. The effect of genetic drift and intergenomic exchange on gene transmission rate was discussed. It is suggested that the transgene integrated on a C-chromosome (or better on a cytoplasm genome) is safer than that on an A-chromosome. The transgenic cultivars should be cultivated rotationally by year(s) with other non-transgenic varieties in order to reduce the transfer of the transgene to wild B. rapa species.

  9. Gene transferability from transgenic Brassica napus L. to various subspecies and varieties of Brassica rapa.

    PubMed

    Xiao, Ling; Lu, Changming; Zhang, Bing; Bo, Huijie; Wu, Yuhua; Wu, Gang; Cao, Yinglong; Yu, Deyue

    2009-10-01

    Gene transferability from transgenic rapeseed to various subspecies and varieties of Brassica rapa was assessed in this study. Artificial crossability was studied in 118 cultivars of 7 B. rapa subspecies and varieties with the transgenic rapeseed GT73 (Brassica napus) as the pollen donor. On average 5.7 seeds were obtained per pollination, with a range from 0.05 to 19.4. The heading type of B. rapa L. showed significantly higher crossability than non-heading types of B. rapa. The spontaneous outcrossing rate between B. rapa (female) and the transgenic rapeseed Ms8 x Rf3 (B. napus) (male) ranged from 0.039 to 0.406%, with an average of 0.19%. The fertilization process and the development of the hybrid seeds as shown by fluorescent staining techniques indicated that the number of adhered pollens on the stigma was reduced by 80%, the number of pollen tubes in the style was reduced by 2/3 and the fertilization time was delayed by over 20 h when pollinated with the transgenic rapeseed Ms8 x Rf3 in comparison with the bud self-pollination of B. rapa as control. About 10-70% of the interspecific hybrid embryos were aborted in the course of development. Some seeds looked cracked in mature pods, which showed germination abilities lower than 10%. The spontaneous outcrossing rates were much lower than the artificial crossability, and their survival fitness of the interspecific hybrid was very low, indicating that it should be possible to keep the adventitious presence of the off-plants under the allowed threshold, if proper measures are taken.

  10. Effects of Fe deficiency on the protein profile of Brassica napus phloem sap

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this work was to study the effect of Fe deficiency on the protein profile of phloem sap exudates from Brassica napus using 2-DE (IEF-SDS PAGE). The experiment was repeated thrice and two technical replicates per treatment were done. Two hundred sixty-three spots were consistently detected...

  11. Physical Localization and Genetic Mapping of Fertility Restoration Gene Rfo in Canola (Brassica napus L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Ogu cytoplasm for male fertility and its fertility restorer gene Rfo in canola (Brassica napus L.) were originally introgressed from radish (Raphanus sativus L.) and have been widely used for canola hybrid production and breeding. The objective of this study was to determine the physical locati...

  12. Selection against hybrids in mixed populations of Brassica rapa and Brassica napus: model and synthesis.

    PubMed

    de Jong, Tom J; Hesse, Elze

    2012-06-01

    Pollen of the crop oilseed rape (Brassica napus, AACC) can cross-fertilize ovules of Brassica rapa (AA), which leads to an influx of unpaired C-chromosomes into wild B. rapa populations. The presence of such extra chromosomes is thought to be an indicator of introgression. Backcrosses and F(1) hybrids were found in Danish populations but, surprisingly, only F(1) hybrids were found in the UK and the Netherlands. Here, a model tests how the level of selection and biased vs unbiased transmission affect the population frequency of C-chromosomes. In the biased-transmission scenario the experimental results of the first backcross are extrapolated to estimate survival of gametes with different numbers of C-chromosomes from all crosses in the population. With biased transmission, the frequency of C-chromosomes always rapidly declines to zero. With unbiased transmission, the continued presence of plants with extra C-chromosomes depends on selection in the adult stage and we argue that this is the most realistic option for modeling populations. We suggest that selection in the field against plants with unpaired C-chromosomes is strong in Dutch and UK populations. The model highlights what we do not know and makes suggestions for further research on introgression.

  13. Citric acid assisted phytoremediation of cadmium by Brassica napus L.

    PubMed

    Ehsan, Sana; Ali, Shafaqat; Noureen, Shamaila; Mahmood, Khalid; Farid, Mujahid; Ishaque, Wajid; Shakoor, Muhammad Bilal; Rizwan, Muhammad

    2014-08-01

    Phytoextraction is an eco-friendly and cost-effective technique for removal of toxins, especially heavy metals and metalloids from contaminated soils by the roots of high biomass producing plant species with subsequent transport to aerial parts. Lower metal bioavailability often limits the phytoextraction. Organic chelators can help to improve this biological technique by increasing metal solubility. The aim of the present study was to investigate the possibility of improving the phytoextraction of Cd by the application of citric acid. For this purpose, plants were grown in hydroponics under controlled conditions. Results indicated that Cd supply significantly decreased the plant growth, biomass, pigments, photosynthetic characteristics and protein contents which were accompanied by a significant increase in Cd concentration, hydrogen peroxide (H₂O₂), electrolyte leakage, malondialdehyde (MDA) accumulation and decrease in antioxidant capacity. The effects were dose dependent with obvious effects at higher Cd concentration. Application of CA significantly enhanced Cd uptake and its accumulation in plant roots, stems and leaves. Citric acid alleviated Cd toxicity by increasing plant biomass and photosynthetic and growth parameters alone and in combination with Cd and by reducing oxidative stress as observed by reduction in MDA and H₂O₂ production and decreased electrolyte leakage induced by Cd stress. Application of CA also enhanced the antioxidant enzymes activity alone and under Cd stress. Thus, the data indicate that exogenous CA application can increase Cd uptake and minimize Cd stress in plants and may be beneficial in accelerating the phytoextraction of Cd through hyper-accumulating plants such as Brassica napus L.

  14. Haplotype hitchhiking promotes trait coselection in Brassica napus.

    PubMed

    Qian, Lunwen; Qian, Wei; Snowdon, Rod J

    2016-07-01

    Local haplotype patterns surrounding densely spaced DNA markers with significant trait associations can reveal information on selective sweeps and genome diversity associated with important crop traits. Relationships between haplotype and phenotype diversity, coupled with analysis of gene content in conserved haplotype blocks, can provide insight into coselection for nonrelated traits. We performed genome-wide analysis of haplotypes associated with the important physiological and agronomic traits leaf chlorophyll and seed glucosinolate content, respectively, in the major oilseed crop species Brassica napus. A locus on chromosome A01 showed opposite effects on leaf chlorophyll content and seed glucosinolate content, attributed to strong linkage disequilibrium (LD) between orthologues of the chlorophyll biosynthesis genes EARLY LIGHT-INDUCED PROTEIN and CHLOROPHYLL SYNTHASE, and the glucosinolate synthesis gene ATP SULFURYLASE 1. Another conserved haplotype block, on chromosome A02, contained a number of chlorophyll-related genes in LD with orthologues of the key glucosinolate biosynthesis genes METHYLTHIOALKYMALATE SYNTHASE-LIKE 1 and 3. Multigene haplogroups were found to have a significantly greater contribution to variation for chlorophyll content than haplotypes for any single gene, suggesting positive effects of additive locus accumulation. Detailed reanalysis of population substructure revealed a clade of ten related accessions exhibiting high leaf chlorophyll and low seed glucosinolate content. These accessions each carried one of the above-mentioned haplotypes from A01 or A02, generally in combination with further chlorophyll-associated haplotypes from chromosomes A05 and/or C05. The phenotypic rather than pleiotropic correlations between leaf chlorophyll content index and seed GSL suggest that LD may have led to inadvertent coselection for these two traits. PMID:26800855

  15. Comparative analysis between homoeologous genome segments of Brassica napus and its progenitor species reveals extensive sequence-level divergence.

    PubMed

    Cheung, Foo; Trick, Martin; Drou, Nizar; Lim, Yong Pyo; Park, Jee-Young; Kwon, Soo-Jin; Kim, Jin-A; Scott, Rod; Pires, J Chris; Paterson, Andrew H; Town, Chris; Bancroft, Ian

    2009-07-01

    Homoeologous regions of Brassica genomes were analyzed at the sequence level. These represent segments of the Brassica A genome as found in Brassica rapa and Brassica napus and the corresponding segments of the Brassica C genome as found in Brassica oleracea and B. napus. Analysis of synonymous base substitution rates within modeled genes revealed a relatively broad range of times (0.12 to 1.37 million years ago) since the divergence of orthologous genome segments as represented in B. napus and the diploid species. Similar, and consistent, ranges were also identified for single nucleotide polymorphism and insertion-deletion variation. Genes conserved across the Brassica genomes and the homoeologous segments of the genome of Arabidopsis thaliana showed almost perfect collinearity. Numerous examples of apparent transduplication of gene fragments, as previously reported in B. oleracea, were observed in B. rapa and B. napus, indicating that this phenomenon is widespread in Brassica species. In the majority of the regions studied, the C genome segments were expanded in size relative to their A genome counterparts. The considerable variation that we observed, even between the different versions of the same Brassica genome, for gene fragments and annotated putative genes suggest that the concept of the pan-genome might be particularly appropriate when considering Brassica genomes.

  16. Synthetic Brassica napus L.: development and studies on morphological characters, yield attributes, and yield.

    PubMed

    Malek, M A; Ismail, M R; Rafii, M Y; Rahman, M

    2012-01-01

    Brassica napus was synthesized by hybridization between its diploid progenitor species B. rapa and B. oleracea followed by chromosome doubling. Cross with B. rapa as a female parent was only successful. Among three colchicine treatments (0.10, 0.15, and 0.20%), 0.15% gave the highest success (86%) of chromosome doubling in the hybrids (AC; 2n = 19). Synthetic B. napus (AACC, 2n = 38) was identified with bigger petals, fertile pollens and seed setting. Synthetic B. napus had increased growth over parents and exhibited wider ranges with higher coefficients of variations than parents for morphological and yield contributing characters, and yield per plant. Siliqua length as well as beak length in synthetic B. napus was longer than those of the parents. Number of seeds per siliqua, 1000-seed weight and seed yield per plant in synthetic B. napus were higher than those of the parents. Although flowering time in synthetic B. napus was earlier than both parents, however the days to maturity was little higher over early maturing B. rapa parent. The synthesized B. napus has great potential to produce higher seed yield. Further screening and evaluation is needed for selection of desirable genotypes having improved yield contributing characters and higher seed yield.

  17. Synthetic Brassica napus L.: Development and Studies on Morphological Characters, Yield Attributes, and Yield

    PubMed Central

    Malek, M. A.; Ismail, M. R.; Rafii, M. Y.; Rahman, M.

    2012-01-01

    Brassica napus was synthesized by hybridization between its diploid progenitor species B. rapa and B. oleracea followed by chromosome doubling. Cross with B. rapa as a female parent was only successful. Among three colchicine treatments (0.10, 0.15, and 0.20%), 0.15% gave the highest success (86%) of chromosome doubling in the hybrids (AC; 2n = 19). Synthetic B. napus (AACC, 2n = 38) was identified with bigger petals, fertile pollens and seed setting. Synthetic B. napus had increased growth over parents and exhibited wider ranges with higher coefficients of variations than parents for morphological and yield contributing characters, and yield per plant. Siliqua length as well as beak length in synthetic B. napus was longer than those of the parents. Number of seeds per siliqua, 1000-seed weight and seed yield per plant in synthetic B. napus were higher than those of the parents. Although flowering time in synthetic B. napus was earlier than both parents, however the days to maturity was little higher over early maturing B. rapa parent. The synthesized B. napus has great potential to produce higher seed yield. Further screening and evaluation is needed for selection of desirable genotypes having improved yield contributing characters and higher seed yield. PMID:22701356

  18. Characteristics Analysis of F1 Hybrids between Genetically Modified Brassica napus and B. rapa

    PubMed Central

    Sohn, Soo-In; Oh, Young-Ju; Lee, Kyeong-Ryeol; Ko, Ho-Cheol; Cho, Hyun-Suk; Lee, Yeon-Hee; Chang, Ancheol

    2016-01-01

    A number of studies have been conducted on hybridization between transgenic Brassica napus and B. rapa or backcross of F1 hybrid to their parents. However, trait changes must be analyzed to evaluate hybrid sustainability in nature. In the present study, B. rapa and transgenic (BrAGL20) B. napus were hybridized to verify the early flowering phenomenon of F1 hybrids, and F1 hybrid traits were analyzed to predict their impact on sustainability. Flowering of F1 hybrid has been induced slightly later than that of the transgenic B. napus, but flowering was available in the greenhouse without low temperature treatment to young plant, similar to the transgenic B. napus. It is because the BrAGL20 gene has been transferred from transgenic B. napus to F1 hybrid. The size of F1 hybrid seeds was intermediate between those of B. rapa and transgenic B. napus, and ~40% of F1 pollen exhibited abnormal size and morphology. The form of the F1 stomata was also intermediate between that of B. rapa and transgenic B. napus, and the number of stomata was close to the parental mean. Among various fatty acids, the content of erucic acid exhibited the greatest change, owing to the polymorphism of parental FATTY ACID ELONGASE 1 alleles. Furthermore, F2 hybrids could not be obtained. However, BC1 progeny were obtained by hand pollination of B. rapa with F1 hybrid pollen, with an outcrossing rate of 50%. PMID:27632286

  19. Characteristics Analysis of F1 Hybrids between Genetically Modified Brassica napus and B. rapa.

    PubMed

    Sohn, Soo-In; Oh, Young-Ju; Lee, Kyeong-Ryeol; Ko, Ho-Cheol; Cho, Hyun-Suk; Lee, Yeon-Hee; Chang, Ancheol

    2016-01-01

    A number of studies have been conducted on hybridization between transgenic Brassica napus and B. rapa or backcross of F1 hybrid to their parents. However, trait changes must be analyzed to evaluate hybrid sustainability in nature. In the present study, B. rapa and transgenic (BrAGL20) B. napus were hybridized to verify the early flowering phenomenon of F1 hybrids, and F1 hybrid traits were analyzed to predict their impact on sustainability. Flowering of F1 hybrid has been induced slightly later than that of the transgenic B. napus, but flowering was available in the greenhouse without low temperature treatment to young plant, similar to the transgenic B. napus. It is because the BrAGL20 gene has been transferred from transgenic B. napus to F1 hybrid. The size of F1 hybrid seeds was intermediate between those of B. rapa and transgenic B. napus, and ~40% of F1 pollen exhibited abnormal size and morphology. The form of the F1 stomata was also intermediate between that of B. rapa and transgenic B. napus, and the number of stomata was close to the parental mean. Among various fatty acids, the content of erucic acid exhibited the greatest change, owing to the polymorphism of parental FATTY ACID ELONGASE 1 alleles. Furthermore, F2 hybrids could not be obtained. However, BC1 progeny were obtained by hand pollination of B. rapa with F1 hybrid pollen, with an outcrossing rate of 50%.

  20. Characteristics Analysis of F1 Hybrids between Genetically Modified Brassica napus and B. rapa.

    PubMed

    Sohn, Soo-In; Oh, Young-Ju; Lee, Kyeong-Ryeol; Ko, Ho-Cheol; Cho, Hyun-Suk; Lee, Yeon-Hee; Chang, Ancheol

    2016-01-01

    A number of studies have been conducted on hybridization between transgenic Brassica napus and B. rapa or backcross of F1 hybrid to their parents. However, trait changes must be analyzed to evaluate hybrid sustainability in nature. In the present study, B. rapa and transgenic (BrAGL20) B. napus were hybridized to verify the early flowering phenomenon of F1 hybrids, and F1 hybrid traits were analyzed to predict their impact on sustainability. Flowering of F1 hybrid has been induced slightly later than that of the transgenic B. napus, but flowering was available in the greenhouse without low temperature treatment to young plant, similar to the transgenic B. napus. It is because the BrAGL20 gene has been transferred from transgenic B. napus to F1 hybrid. The size of F1 hybrid seeds was intermediate between those of B. rapa and transgenic B. napus, and ~40% of F1 pollen exhibited abnormal size and morphology. The form of the F1 stomata was also intermediate between that of B. rapa and transgenic B. napus, and the number of stomata was close to the parental mean. Among various fatty acids, the content of erucic acid exhibited the greatest change, owing to the polymorphism of parental FATTY ACID ELONGASE 1 alleles. Furthermore, F2 hybrids could not be obtained. However, BC1 progeny were obtained by hand pollination of B. rapa with F1 hybrid pollen, with an outcrossing rate of 50%. PMID:27632286

  1. Population genomic analysis reveals differential evolutionary histories and patterns of diversity across subgenomes and subpopulations of Brassica napus L.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brassica napus (L.) is a crop of major economic importance that produces canola oil (seed), vegetables, fodder and animal meal. Characterizing the genetic diversity present in the extant germplasm pool of B. napus is fundamental to better conserve, manage and utilize the genetic resources of this s...

  2. Effect of microwave treatment on the efficacy of expeller pressing of Brassica napus rapeseed and Brassica juncea mustard seeds.

    PubMed

    Niu, Yanxing; Rogiewicz, Anna; Wan, Chuyun; Guo, Mian; Huang, Fenghong; Slominski, Bogdan A

    2015-04-01

    A study was conducted to evaluate the effect of microwave heating on the efficacy of expeller pressing of rapeseed and mustard seed and the composition of expeller meals in two types of Brassica napus rapeseed (intermediate- and low-glucosinolate) and in Brassica juncea mustard (high-glucosinolate). Following microwave treatment, the microstructure of rapeseed using transmission electron microscopy showed a significant disappearance of oil bodies and myrosin cells. After 6 min of microwave heating (400 g, 800 W), the oil content of rapeseed expeller meal decreased from 44.9 to 13.5% for intermediate-glucosinolate B. napus rapeseed, from 42.6 to 11.3% for low-glucosinolate B. napus rapeseed, and from 44.4 to 14.1% for B. juncea mustard. The latter values were much lower than the oil contents of the corresponding expeller meals derived from the unheated seeds (i.e., 26.6, 22.6, and 29.8%, respectively). Neutral detergent fiber (NDF) contents showed no differences except for the expeller meal from the intermediate-glucosinolate B. napus rapeseed, which increased from 22.7 to 29.2% after 6 min of microwave heating. Microwave treatment for 4 and 5 min effectively inactivated myrosinase enzyme of intermediate-glucosinolate B. napus rapeseed and B. juncea mustard seed, respectively. In low-glucosinolate B. napus rapeseed the enzyme appeared to be more heat stable, with some activity being present after 6 min of microwave heating. Myrosinase enzyme inactivation had a profound effect on the glucosinolate content of expeller meals and prevented their hydrolysis to toxic breakdown products during the expelling process. It appeared evident from this study that microwave heating for 6 min was an effective method of producing expeller meal without toxic glucosinolate breakdown products while at the same time facilitating high yield of oil during the expelling process. PMID:25765856

  3. Effect of microwave treatment on the efficacy of expeller pressing of Brassica napus rapeseed and Brassica juncea mustard seeds.

    PubMed

    Niu, Yanxing; Rogiewicz, Anna; Wan, Chuyun; Guo, Mian; Huang, Fenghong; Slominski, Bogdan A

    2015-04-01

    A study was conducted to evaluate the effect of microwave heating on the efficacy of expeller pressing of rapeseed and mustard seed and the composition of expeller meals in two types of Brassica napus rapeseed (intermediate- and low-glucosinolate) and in Brassica juncea mustard (high-glucosinolate). Following microwave treatment, the microstructure of rapeseed using transmission electron microscopy showed a significant disappearance of oil bodies and myrosin cells. After 6 min of microwave heating (400 g, 800 W), the oil content of rapeseed expeller meal decreased from 44.9 to 13.5% for intermediate-glucosinolate B. napus rapeseed, from 42.6 to 11.3% for low-glucosinolate B. napus rapeseed, and from 44.4 to 14.1% for B. juncea mustard. The latter values were much lower than the oil contents of the corresponding expeller meals derived from the unheated seeds (i.e., 26.6, 22.6, and 29.8%, respectively). Neutral detergent fiber (NDF) contents showed no differences except for the expeller meal from the intermediate-glucosinolate B. napus rapeseed, which increased from 22.7 to 29.2% after 6 min of microwave heating. Microwave treatment for 4 and 5 min effectively inactivated myrosinase enzyme of intermediate-glucosinolate B. napus rapeseed and B. juncea mustard seed, respectively. In low-glucosinolate B. napus rapeseed the enzyme appeared to be more heat stable, with some activity being present after 6 min of microwave heating. Myrosinase enzyme inactivation had a profound effect on the glucosinolate content of expeller meals and prevented their hydrolysis to toxic breakdown products during the expelling process. It appeared evident from this study that microwave heating for 6 min was an effective method of producing expeller meal without toxic glucosinolate breakdown products while at the same time facilitating high yield of oil during the expelling process.

  4. Genome-Wide Delineation of Natural Variation for Pod Shatter Resistance in Brassica napus

    PubMed Central

    Raman, Harsh; Raman, Rosy; Kilian, Andrzej; Detering, Frank; Carling, Jason; Coombes, Neil; Diffey, Simon; Kadkol, Gururaj; Edwards, David; McCully, Margaret; Ruperao, Pradeep; Parkin, Isobel A. P.; Batley, Jacqueline; Luckett, David J.; Wratten, Neil

    2014-01-01

    Resistance to pod shattering (shatter resistance) is a target trait for global rapeseed (canola, Brassica napus L.), improvement programs to minimise grain loss in the mature standing crop, and during windrowing and mechanical harvest. We describe the genetic basis of natural variation for shatter resistance in B. napus and show that several quantitative trait loci (QTL) control this trait. To identify loci underlying shatter resistance, we used a novel genotyping-by-sequencing approach DArT-Seq. QTL analysis detected a total of 12 significant QTL on chromosomes A03, A07, A09, C03, C04, C06, and C08; which jointly account for approximately 57% of the genotypic variation in shatter resistance. Through Genome-Wide Association Studies, we show that a large number of loci, including those that are involved in shattering in Arabidopsis, account for variation in shatter resistance in diverse B. napus germplasm. Our results indicate that genetic diversity for shatter resistance genes in B. napus is limited; many of the genes that might control this trait were not included during the natural creation of this species, or were not retained during the domestication and selection process. We speculate that valuable diversity for this trait was lost during the natural creation of B. napus. To improve shatter resistance, breeders will need to target the introduction of useful alleles especially from genotypes of other related species of Brassica, such as those that we have identified. PMID:25006804

  5. Biodiversity of nematofauna of oilseed rape (Brassica napus L.).

    PubMed

    Manachini, B; Landi, S; Tomasini, V

    2005-01-01

    Few data is available on the nematodes found in Brassicaceae, except for the most important plant parasite. However, studying the structure of nematofauna could be an important database for the soil quality and in order to assess the effects of future disturbance. This is particularly important considering that the diffusion of the canola crop in the world is increasing because of its use as a bio-diesel. Very diffused is also the Bt variety of oil seed rape, and, in this case, the study of the impact on the soil health and on bio-diversity is essential. In this research we have analyzed the nematode community, used as a bio-indicator of the soil condition. The nematofauna found in canola (Brassica napus var. oleifera) fields located in Southern Italy (Metaponto - MT) was investigated. The nematode community was studied considering its abundance, genus composition and trophic structure. Maturity and biodiversity indices were also calculated. A total of 5286 nematodes were extracted. They belong to 14 families and 24 genera. Bacterial and fungal feeders, 50.18% and 42.90% of the total respectively, dominated the trophic structure. Aphelencus is the most abundant genus (23.71%) followed by Acrobeloides (20.49%) and Aphelencoides (19.18%). Among plant feeders (6.59%), Pratylenchus is the dominant genus (2.20%) and Tylenchidae the main family (3.54%). No infestation of Meloidogyne, Heterodera or Naboccus, important plant-parasitic nematodes of canola crops, was recorded. Other important phytophagous were Helycotylenchus (0.5%), Trichotylenchus (0.5%) and Filenchus (0.9%). All of them had an abundance level below injury level. The indices of biodiversity are rather low (H'=0.93, J'=0.67), as is typical for agro ecosystems. However, the nematofauna community is quite well structured (N2=6.31, D=0.16) and the maturity index rather high (EMI=1.94). These values demonstrate that oilseed rape has a lower impact on the soil compared to other crop systems and that it could be

  6. Pleiotropy in Triazine-Resistant Brassica napus1

    PubMed Central

    Dekker, Jack H.; Burmester, Ronald G.

    1992-01-01

    Studies were conducted that supported the hypothesis that the mutation to the psbA plastid gene that confers S-triazine resistance (R) in Brassica napus also results in an altered diurnal pattern of photosynthetic carbon assimilation (A) relative to that of the susceptible (S) wild type, and that these patterns change over the ontogeny of a plant. Photosynthetic photon flux density, under closely controlled environmental conditions, was incrementally increased and decreased on either side of the midday maxima of 1150 to 1300 μmol quanta m−2 s−1. In all experiments, A approximately tracked the increasing and decreasing diurnal light levels. Younger (3- to 4-leaf) R plants had greater photosynthetic rates early and late in the diurnal light period, whereas those of S plants were greater during midday as well as during the photoperiod as a whole. These relative photosynthetic characteristics of R and S plants changed in several ways with ontogeny. As the plants aged during the vegetative phase of development, S plants gradually assimilated more carbon in the early, and then in the late, part of the day. At the end of the vegetative phase of development, R plant carbon assimilation was less relative to S plants at most times of the day, and was never greater. This relationship between the two biotypes dramatically changed with the onset of the reproductive phase (8½ to 9½ leaf) of plant development: R plants assimilated more carbon than S plants during all periods of the diurnal light period with the exception of the late part of the day. In addition to these differences in A, R plant stomatal function differed from that in S plants. R plant leaves were always cooler than S plant leaves under the same environmental and diurnal conditions. Correlated with this difference in leaf temperature were equal or greater total conductances to water vapor and intercellular CO2 partial pressures in R compared to S leaves in most instances. These studies indicate a more

  7. Self-compatibility in Brassica napus is caused by independent mutations in S-locus genes.

    PubMed

    Okamoto, Shunsuke; Odashima, Masashi; Fujimoto, Ryo; Sato, Yutaka; Kitashiba, Hiroyasu; Nishio, Takeshi

    2007-05-01

    Brassica napus is an amphidiploid species with the A genome from Brassica rapa and the C genome from Brassica oleracea. Although B. rapa, B. oleracea and artificially synthesized amphidiploids with the AC genome are self-incompatible, B. napus is self-compatible. Six S genotypes were identified in B. napus, five of which had class I S haplotypes from one species and a class II S haplotype from the other species, and mutations causing self-compatibility were identified in three of these S genotypes. The most predominant S genotype (BnS-1;BnS-6), which is that of cv. 'Westar', had a class I S haplotype similar to B. rapa S-47 (BrS-47) and a class II S haplotype similar to B. oleracea S-15 (BoS-15). The stigmas of 'Westar' rejected the pollen grains of both BrS-47 and BoS-15, while reciprocal crossings were compatible. Insertion of a DNA fragment of about 3.6 kb was found in the promoter region of the SP11/SCR allele of BnS-1, and transcripts of SP11/SCR were not detected in 'Westar'. The nucleotide sequence of the SP11 genomic DNA of BnS-6 was 100% identical to that of SP11 of BoS-15. Class I SP11 alleles from one species showed dominance over class II SP11 alleles from the other species in artificially synthesized B. napus lines, suggesting that the non-functional dominant SP11 allele suppressed the expression of the recessive SP11 allele in 'Westar'. Two other S genotypes in B. napus also had non-functional class I S haplotypes together with recessive BnS-6. These observations suggest independent origins of self-compatibility in B. napus.

  8. Multiple Evolutionary Events Involved in Maintaining Homologs of Resistance to Powdery Mildew 8 in Brassica napus.

    PubMed

    Li, Qin; Li, Jing; Sun, Jin-Long; Ma, Xian-Feng; Wang, Ting-Ting; Berkey, Robert; Yang, Hui; Niu, Ying-Ze; Fan, Jing; Li, Yan; Xiao, Shunyuan; Wang, Wen-Ming

    2016-01-01

    The Resistance to Powdery Mildew 8 (RPW8) locus confers broad-spectrum resistance to powdery mildew in Arabidopsis thaliana. There are four Homologous to RPW8s (BrHRs) in Brassica rapa and three in Brassica oleracea (BoHRs). Brassica napus (Bn) is derived from diploidization of a hybrid between B. rapa and B. oleracea, thus should have seven homologs of RPW8 (BnHRs). It is unclear whether these genes are still maintained or lost in B. napus after diploidization and how they might have been evolved. Here, we reported the identification and sequence polymorphisms of BnHRs from a set of B. napus accessions. Our data indicated that while the BoHR copy from B. oleracea is highly conserved, the BrHR copy from B. rapa is relatively variable in the B. napus genome owing to multiple evolutionary events, such as gene loss, point mutation, insertion, deletion, and intragenic recombination. Given the overall high sequence homology of BnHR genes, it is not surprising that both intragenic recombination between two orthologs and two paralogs were detected in B. napus, which may explain the loss of BoHR genes in some B. napus accessions. When ectopically expressed in Arabidopsis, a C-terminally truncated version of BnHRa and BnHRb, as well as the full length BnHRd fused with YFP at their C-termini could trigger cell death in the absence of pathogens and enhanced resistance to powdery mildew disease. Moreover, subcellular localization analysis showed that both BnHRa-YFP and BnHRb-YFP were mainly localized to the extra-haustorial membrane encasing the haustorium of powdery mildew. Taken together, our data suggest that the duplicated BnHR genes might have been subjected to differential selection and at least some may play a role in defense and could serve as resistance resource in engineering disease-resistant plants.

  9. Multiple Evolutionary Events Involved in Maintaining Homologs of Resistance to Powdery Mildew 8 in Brassica napus.

    PubMed

    Li, Qin; Li, Jing; Sun, Jin-Long; Ma, Xian-Feng; Wang, Ting-Ting; Berkey, Robert; Yang, Hui; Niu, Ying-Ze; Fan, Jing; Li, Yan; Xiao, Shunyuan; Wang, Wen-Ming

    2016-01-01

    The Resistance to Powdery Mildew 8 (RPW8) locus confers broad-spectrum resistance to powdery mildew in Arabidopsis thaliana. There are four Homologous to RPW8s (BrHRs) in Brassica rapa and three in Brassica oleracea (BoHRs). Brassica napus (Bn) is derived from diploidization of a hybrid between B. rapa and B. oleracea, thus should have seven homologs of RPW8 (BnHRs). It is unclear whether these genes are still maintained or lost in B. napus after diploidization and how they might have been evolved. Here, we reported the identification and sequence polymorphisms of BnHRs from a set of B. napus accessions. Our data indicated that while the BoHR copy from B. oleracea is highly conserved, the BrHR copy from B. rapa is relatively variable in the B. napus genome owing to multiple evolutionary events, such as gene loss, point mutation, insertion, deletion, and intragenic recombination. Given the overall high sequence homology of BnHR genes, it is not surprising that both intragenic recombination between two orthologs and two paralogs were detected in B. napus, which may explain the loss of BoHR genes in some B. napus accessions. When ectopically expressed in Arabidopsis, a C-terminally truncated version of BnHRa and BnHRb, as well as the full length BnHRd fused with YFP at their C-termini could trigger cell death in the absence of pathogens and enhanced resistance to powdery mildew disease. Moreover, subcellular localization analysis showed that both BnHRa-YFP and BnHRb-YFP were mainly localized to the extra-haustorial membrane encasing the haustorium of powdery mildew. Taken together, our data suggest that the duplicated BnHR genes might have been subjected to differential selection and at least some may play a role in defense and could serve as resistance resource in engineering disease-resistant plants. PMID:27493652

  10. Multiple Evolutionary Events Involved in Maintaining Homologs of Resistance to Powdery Mildew 8 in Brassica napus

    PubMed Central

    Li, Qin; Li, Jing; Sun, Jin-Long; Ma, Xian-Feng; Wang, Ting-Ting; Berkey, Robert; Yang, Hui; Niu, Ying-Ze; Fan, Jing; Li, Yan; Xiao, Shunyuan; Wang, Wen-Ming

    2016-01-01

    The Resistance to Powdery Mildew 8 (RPW8) locus confers broad-spectrum resistance to powdery mildew in Arabidopsis thaliana. There are four Homologous to RPW8s (BrHRs) in Brassica rapa and three in Brassica oleracea (BoHRs). Brassica napus (Bn) is derived from diploidization of a hybrid between B. rapa and B. oleracea, thus should have seven homologs of RPW8 (BnHRs). It is unclear whether these genes are still maintained or lost in B. napus after diploidization and how they might have been evolved. Here, we reported the identification and sequence polymorphisms of BnHRs from a set of B. napus accessions. Our data indicated that while the BoHR copy from B. oleracea is highly conserved, the BrHR copy from B. rapa is relatively variable in the B. napus genome owing to multiple evolutionary events, such as gene loss, point mutation, insertion, deletion, and intragenic recombination. Given the overall high sequence homology of BnHR genes, it is not surprising that both intragenic recombination between two orthologs and two paralogs were detected in B. napus, which may explain the loss of BoHR genes in some B. napus accessions. When ectopically expressed in Arabidopsis, a C-terminally truncated version of BnHRa and BnHRb, as well as the full length BnHRd fused with YFP at their C-termini could trigger cell death in the absence of pathogens and enhanced resistance to powdery mildew disease. Moreover, subcellular localization analysis showed that both BnHRa-YFP and BnHRb-YFP were mainly localized to the extra-haustorial membrane encasing the haustorium of powdery mildew. Taken together, our data suggest that the duplicated BnHR genes might have been subjected to differential selection and at least some may play a role in defense and could serve as resistance resource in engineering disease-resistant plants. PMID:27493652

  11. Comparative quantitative trait loci for silique length and seed weight in Brassica napus.

    PubMed

    Fu, Ying; Wei, Dayong; Dong, Hongli; He, Yajun; Cui, Yixin; Mei, Jiaqin; Wan, Huafang; Li, Jiana; Snowdon, Rod; Friedt, Wolfgang; Li, Xiaorong; Qian, Wei

    2015-09-23

    Silique length (SL) and seed weight (SW) are important yield-associated traits in rapeseed (Brassica napus). Although many quantitative trait loci (QTL) for SL and SW have been identified in B. napus, comparative analysis for those QTL is seldom performed. In the present study, 20 and 21 QTL for SL and SW were identified in doubled haploid (DH) and DH-derived reconstructed F2 populations in rapeseed, explaining 55.1-74.3% and 24.4-62.9% of the phenotypic variation across three years, respectively. Of which, 17 QTL with partially or completely overlapped confidence interval on chromosome A09, were homologous with two overlapped QTL on chromosome C08 by aligning QTL confidence intervals with the reference genomes of Brassica crops. By high density selective genotyping of DH lines with extreme phenotypes, using a Brassica single-nucleotide polymorphism (SNP) array, the QTL on chromosome A09 was narrowed, and aligned into 1.14-Mb region from 30.84 to 31.98 Mb on chromosome R09 of B. rapa and 1.05-Mb region from 27.21 to 28.26 Mb on chromosome A09 of B. napus. The alignment of QTL with Brassica reference genomes revealed homologous QTL on A09 and C08 for SL. The narrowed QTL region provides clues for gene cloning and breeding cultivars by marker-assisted selection.

  12. Comparative quantitative trait loci for silique length and seed weight in Brassica napus

    PubMed Central

    Fu, Ying; Wei, Dayong; Dong, Hongli; He, Yajun; Cui, Yixin; Mei, Jiaqin; Wan, Huafang; Li, Jiana; Snowdon, Rod; Friedt, Wolfgang; Li, Xiaorong; Qian, Wei

    2015-01-01

    Silique length (SL) and seed weight (SW) are important yield-associated traits in rapeseed (Brassica napus). Although many quantitative trait loci (QTL) for SL and SW have been identified in B. napus, comparative analysis for those QTL is seldom performed. In the present study, 20 and 21 QTL for SL and SW were identified in doubled haploid (DH) and DH-derived reconstructed F2 populations in rapeseed, explaining 55.1–74.3% and 24.4–62.9% of the phenotypic variation across three years, respectively. Of which, 17 QTL with partially or completely overlapped confidence interval on chromosome A09, were homologous with two overlapped QTL on chromosome C08 by aligning QTL confidence intervals with the reference genomes of Brassica crops. By high density selective genotyping of DH lines with extreme phenotypes, using a Brassica single-nucleotide polymorphism (SNP) array, the QTL on chromosome A09 was narrowed, and aligned into 1.14-Mb region from 30.84 to 31.98 Mb on chromosome R09 of B. rapa and 1.05-Mb region from 27.21 to 28.26 Mb on chromosome A09 of B. napus. The alignment of QTL with Brassica reference genomes revealed homologous QTL on A09 and C08 for SL. The narrowed QTL region provides clues for gene cloning and breeding cultivars by marker-assisted selection. PMID:26394547

  13. Functional analysis and tissue-differential expression of four FAD2 genes in amphidiploid Brassica napus derived from Brassica rapa and Brassica oleracea.

    PubMed

    Lee, Kyeong-Ryeol; In Sohn, Soo; Jung, Jin Hee; Kim, Sun Hee; Roh, Kyung Hee; Kim, Jong-Bum; Suh, Mi Chung; Kim, Hyun Uk

    2013-12-01

    Fatty acid desaturase 2 (FAD2), which resides in the endoplasmic reticulum (ER), plays a crucial role in producing linoleic acid (18:2) through catalyzing the desaturation of oleic acid (18:1) by double bond formation at the delta 12 position. FAD2 catalyzes the first step needed for the production of polyunsaturated fatty acids found in the glycerolipids of cell membranes and the triacylglycerols in seeds. In this study, four FAD2 genes from amphidiploid Brassica napus genome were isolated by PCR amplification, with their enzymatic functions predicted by sequence analysis of the cDNAs. Fatty acid analysis of budding yeast transformed with each of the FAD2 genes showed that whereas BnFAD2-1, BnFAD2-2, and BnFAD2-4 are functional enzymes, and BnFAD2-3 is nonfunctional. The four FAD2 genes of B. napus originated from synthetic hybridization of its diploid progenitors Brassica rapa and Brassica oleracea, each of which has two FAD2 genes identical to those of B. napus. The BnFAD2-3 gene of B. napus, a nonfunctional pseudogene mutated by multiple nucleotide deletions and insertions, was inherited from B. rapa. All BnFAD2 isozymes except BnFAD2-3 localized to the ER. Nonfunctional BnFAD2-3 localized to the nucleus and chloroplasts. Four BnFAD2 genes can be classified on the basis of their expression patterns. PMID:24029080

  14. Functional analysis and tissue-differential expression of four FAD2 genes in amphidiploid Brassica napus derived from Brassica rapa and Brassica oleracea.

    PubMed

    Lee, Kyeong-Ryeol; In Sohn, Soo; Jung, Jin Hee; Kim, Sun Hee; Roh, Kyung Hee; Kim, Jong-Bum; Suh, Mi Chung; Kim, Hyun Uk

    2013-12-01

    Fatty acid desaturase 2 (FAD2), which resides in the endoplasmic reticulum (ER), plays a crucial role in producing linoleic acid (18:2) through catalyzing the desaturation of oleic acid (18:1) by double bond formation at the delta 12 position. FAD2 catalyzes the first step needed for the production of polyunsaturated fatty acids found in the glycerolipids of cell membranes and the triacylglycerols in seeds. In this study, four FAD2 genes from amphidiploid Brassica napus genome were isolated by PCR amplification, with their enzymatic functions predicted by sequence analysis of the cDNAs. Fatty acid analysis of budding yeast transformed with each of the FAD2 genes showed that whereas BnFAD2-1, BnFAD2-2, and BnFAD2-4 are functional enzymes, and BnFAD2-3 is nonfunctional. The four FAD2 genes of B. napus originated from synthetic hybridization of its diploid progenitors Brassica rapa and Brassica oleracea, each of which has two FAD2 genes identical to those of B. napus. The BnFAD2-3 gene of B. napus, a nonfunctional pseudogene mutated by multiple nucleotide deletions and insertions, was inherited from B. rapa. All BnFAD2 isozymes except BnFAD2-3 localized to the ER. Nonfunctional BnFAD2-3 localized to the nucleus and chloroplasts. Four BnFAD2 genes can be classified on the basis of their expression patterns.

  15. Transcriptome Analysis of Stem and Globally Comparison with Other Tissues in Brassica napus

    PubMed Central

    Miao, Liyun; Zhang, Libin; Raboanatahiry, Nadia; Lu, Guangyuan; Zhang, Xuekun; Xiang, Jun; Gan, Jianping; Fu, Chunhua; Li, Maoteng

    2016-01-01

    Brassica napus is one of the most important oilseed crops in the world. However, there is currently no enough stem transcriptome information and comparative transcriptome analysis of different tissues, which impedes further functional genomics research on B. napus. In this study, the stem transcriptome of B. napus was characterized by RNA-seq technology. Approximately 13.4 Gb high-quality clean reads with an average length of 100 bp were generated and used for comparative transcriptome analysis with the existing transcriptome sequencing data of roots, leaves, flower buds, and immature embryos of B. napus. All the transcripts were annotated against GO and KEGG databases. The common genes in five tissues, differentially expressed genes (DEGs) of the common genes between stems and other tissues, and tissue-specific genes were detected, and the main biochemical activities and pathways implying the common genes, DEGs and tissue-specific genes were investigated. Accordingly, the common transcription factors (TFs) in the five tissues and tissue-specific TFs were identified, and a TFs-based regulation network between TFs and the target genes involved in ‘Phenylpropanoid biosynthesis’ pathway were constructed to show several important TFs and key nodes in the regulation process. Collectively, this study not only provided an available stem transcriptome resource in B. napus, but also revealed valuable comparative transcriptome information of five tissues of B. napus for future investigation on specific processes, functions and pathways. PMID:27708656

  16. Expression divergence of FRUITFULL homeologs enhanced pod shatter resistance in Brassica napus.

    PubMed

    Peng, P F; Li, Y C; Mei, D S; Colasanti, J; Fu, L; Liu, J; Chen, Y F; Hu, Q

    2015-02-02

    To improve pod shatter resistance in the important oilseed crop Brassica napus, the phenotypic diversity of B. napus was tested using 80 B. napus varieties for pod shatter resistance by a random impact test. Among these varieties, R1-1 was identified as resistant, while R2, 8908B was susceptible to shatter. To understand the molecular basis for this phenotypic difference based on the candidate gene approach, B. napus FRUITFULL (FUL) homologs were identified and characterized. Two FUL loci in the A and C genomes of B. napus were identified. In the susceptible variety, both BnaA.FUL and BnaC.FUL were expressed in the same tissues. However, the expression level of BnaC.FUL differed in varieties with different pod shatter resistance. In the most resistant variety, R1-1, only BnaA.FUL was expressed, while BnaC.FUL was silenced. Therefore, the functional divergence and differing expression of BnaX.FUL homeologs may significantly affect phenotypic variation, which is an important consequence of allopolyploid evolution. This expression level divergence may be useful for selecting pod shatter resistant lines through marker-assisted selection in B. napus-breeding programs.

  17. Expression divergence of FRUITFULL homeologs enhanced pod shatter resistance in Brassica napus.

    PubMed

    Peng, P F; Li, Y C; Mei, D S; Colasanti, J; Fu, L; Liu, J; Chen, Y F; Hu, Q

    2015-01-01

    To improve pod shatter resistance in the important oilseed crop Brassica napus, the phenotypic diversity of B. napus was tested using 80 B. napus varieties for pod shatter resistance by a random impact test. Among these varieties, R1-1 was identified as resistant, while R2, 8908B was susceptible to shatter. To understand the molecular basis for this phenotypic difference based on the candidate gene approach, B. napus FRUITFULL (FUL) homologs were identified and characterized. Two FUL loci in the A and C genomes of B. napus were identified. In the susceptible variety, both BnaA.FUL and BnaC.FUL were expressed in the same tissues. However, the expression level of BnaC.FUL differed in varieties with different pod shatter resistance. In the most resistant variety, R1-1, only BnaA.FUL was expressed, while BnaC.FUL was silenced. Therefore, the functional divergence and differing expression of BnaX.FUL homeologs may significantly affect phenotypic variation, which is an important consequence of allopolyploid evolution. This expression level divergence may be useful for selecting pod shatter resistant lines through marker-assisted selection in B. napus-breeding programs. PMID:25730026

  18. Restoring enzyme activity in nonfunctional low erucic acid Brassica napus fatty acid elongase 1 by a single amino acid substitution.

    PubMed

    Katavic, Vesna; Mietkiewska, Elzbieta; Barton, Dennis L; Giblin, E Michael; Reed, Darwin W; Taylor, David C

    2002-11-01

    Genomic fatty acid elongation 1 (FAE1) clones from high erucic acid (HEA) Brassica napus, Brassica rapa and Brassica oleracea, and low erucic acid (LEA) B. napus cv. Westar, were amplified by PCR and expressed in yeast cells under the control of the strong galactose-inducible promoter. As expected, yeast cells expressing the FAE1 genes from HEA Brassica spp. synthesized very long chain monounsaturated fatty acids that are not normally found in yeast, while fatty acid profiles of yeast cells expressing the FAE1 gene from LEA B. napus were identical to control yeast samples. In agreement with published findings regarding different HEA and LEA B. napus cultivars, comparison of FAE1 protein sequences from HEA and LEA Brassicaceae revealed one crucial amino acid difference: the serine residue at position 282 of the HEA FAE1 sequences is substituted by phenylalanine in LEA B. napus cv. Westar. Using site directed mutagenesis, the phenylalanine 282 residue was substituted with a serine residue in the FAE1 polypeptide from B. napus cv. Westar, the mutated gene was expressed in yeast and GC analysis revealed the presence of very long chain monounsaturated fatty acids (VLCMFAs), indicating that the elongase activity was restored in the LEA FAE1 enzyme by the single amino acid substitution. Thus, for the first time, the low erucic acid trait in canola B. napus can be attributed to a single amino acid substitution which prevents the biosynthesis of the eicosenoic and erucic acids.

  19. Identifying Conserved and Novel MicroRNAs in Developing Seeds of Brassica napus Using Deep Sequencing

    PubMed Central

    Körbes, Ana Paula; Machado, Ronei Dorneles; Guzman, Frank; Almerão, Mauricio Pereira; de Oliveira, Luiz Felipe Valter; Loss-Morais, Guilherme; Turchetto-Zolet, Andreia Carina; Cagliari, Alexandro; dos Santos Maraschin, Felipe; Margis-Pinheiro, Marcia; Margis, Rogerio

    2012-01-01

    MicroRNAs (miRNAs) are important post-transcriptional regulators of plant development and seed formation. In Brassica napus, an important edible oil crop, valuable lipids are synthesized and stored in specific seed tissues during embryogenesis. The miRNA transcriptome of B. napus is currently poorly characterized, especially at different seed developmental stages. This work aims to describe the miRNAome of developing seeds of B. napus by identifying plant-conserved and novel miRNAs and comparing miRNA abundance in mature versus developing seeds. Members of 59 miRNA families were detected through a computational analysis of a large number of reads obtained from deep sequencing two small RNA and two RNA-seq libraries of (i) pooled immature developing stages and (ii) mature B. napus seeds. Among these miRNA families, 17 families are currently known to exist in B. napus; additionally 29 families not reported in B. napus but conserved in other plant species were identified by alignment with known plant mature miRNAs. Assembled mRNA-seq contigs allowed for a search of putative new precursors and led to the identification of 13 novel miRNA families. Analysis of miRNA population between libraries reveals that several miRNAs and isomiRNAs have different abundance in developing stages compared to mature seeds. The predicted miRNA target genes encode a broad range of proteins related to seed development and energy storage. This work presents a comparative study of the miRNA transcriptome of mature and developing B. napus seeds and provides a basis for future research on individual miRNAs and their functions in embryogenesis, seed maturation and lipid accumulation in B. napus. PMID:23226347

  20. A high-throughput SNP array in the amphidiploid species Brassica napus shows diversity in resistance genes.

    PubMed

    Dalton-Morgan, Jessica; Hayward, Alice; Alamery, Salman; Tollenaere, Reece; Mason, Annaliese S; Campbell, Emma; Patel, Dhwani; Lorenc, Michał T; Yi, Bin; Long, Yan; Meng, Jinling; Raman, Rosy; Raman, Harsh; Lawley, Cindy; Edwards, David; Batley, Jacqueline

    2014-12-01

    Single-nucleotide polymorphisms (SNPs)are molecular markers based on nucleotide variation and can be used for genotyping assays across populations and to track genomic inheritance. SNPs offer a comprehensive genotyping alternative to whole-genome sequencing for both agricultural and research purposes including molecular breeding and diagnostics, genome evolution and genetic diversity analyses, genetic mapping, and trait association studies. Here genomic SNPs were discovered between four cultivars of the important amphidiploid oilseed species Brassica napus and used to develop a B. napus Infinium™ array containing 5,306 SNPs randomly dispersed across the genome. Assay success was high, with >94 % of these producing a reproducible, polymorphic genotype in the 1,070 samples screened. Although the assay was designed to B. napus, successful SNP amplification was achieved in the B. napus progenitor species, Brassica rapa and Brassica oleracea, and to a lesser extent in the related species Brassica nigra. Phylogenetic analysis was consistent with the expected relationships between B. napus individuals. This study presents an efficient custom SNP assay development pipeline in the complex polyploid Brassica genome and demonstrates the utility of the array for high-throughput genotyping in a number of related Brassica species. It also demonstrates the utility of this assay in genotyping resistance genes on chromosome A7, which segregate amongst the 1,070 samples.

  1. A high-throughput SNP array in the amphidiploid species Brassica napus shows diversity in resistance genes.

    PubMed

    Dalton-Morgan, Jessica; Hayward, Alice; Alamery, Salman; Tollenaere, Reece; Mason, Annaliese S; Campbell, Emma; Patel, Dhwani; Lorenc, Michał T; Yi, Bin; Long, Yan; Meng, Jinling; Raman, Rosy; Raman, Harsh; Lawley, Cindy; Edwards, David; Batley, Jacqueline

    2014-12-01

    Single-nucleotide polymorphisms (SNPs)are molecular markers based on nucleotide variation and can be used for genotyping assays across populations and to track genomic inheritance. SNPs offer a comprehensive genotyping alternative to whole-genome sequencing for both agricultural and research purposes including molecular breeding and diagnostics, genome evolution and genetic diversity analyses, genetic mapping, and trait association studies. Here genomic SNPs were discovered between four cultivars of the important amphidiploid oilseed species Brassica napus and used to develop a B. napus Infinium™ array containing 5,306 SNPs randomly dispersed across the genome. Assay success was high, with >94 % of these producing a reproducible, polymorphic genotype in the 1,070 samples screened. Although the assay was designed to B. napus, successful SNP amplification was achieved in the B. napus progenitor species, Brassica rapa and Brassica oleracea, and to a lesser extent in the related species Brassica nigra. Phylogenetic analysis was consistent with the expected relationships between B. napus individuals. This study presents an efficient custom SNP assay development pipeline in the complex polyploid Brassica genome and demonstrates the utility of the array for high-throughput genotyping in a number of related Brassica species. It also demonstrates the utility of this assay in genotyping resistance genes on chromosome A7, which segregate amongst the 1,070 samples. PMID:25147024

  2. Plant genetics. Early allopolyploid evolution in the post-Neolithic Brassica napus oilseed genome.

    PubMed

    Chalhoub, Boulos; Denoeud, France; Liu, Shengyi; Parkin, Isobel A P; Tang, Haibao; Wang, Xiyin; Chiquet, Julien; Belcram, Harry; Tong, Chaobo; Samans, Birgit; Corréa, Margot; Da Silva, Corinne; Just, Jérémy; Falentin, Cyril; Koh, Chu Shin; Le Clainche, Isabelle; Bernard, Maria; Bento, Pascal; Noel, Benjamin; Labadie, Karine; Alberti, Adriana; Charles, Mathieu; Arnaud, Dominique; Guo, Hui; Daviaud, Christian; Alamery, Salman; Jabbari, Kamel; Zhao, Meixia; Edger, Patrick P; Chelaifa, Houda; Tack, David; Lassalle, Gilles; Mestiri, Imen; Schnel, Nicolas; Le Paslier, Marie-Christine; Fan, Guangyi; Renault, Victor; Bayer, Philippe E; Golicz, Agnieszka A; Manoli, Sahana; Lee, Tae-Ho; Thi, Vinh Ha Dinh; Chalabi, Smahane; Hu, Qiong; Fan, Chuchuan; Tollenaere, Reece; Lu, Yunhai; Battail, Christophe; Shen, Jinxiong; Sidebottom, Christine H D; Wang, Xinfa; Canaguier, Aurélie; Chauveau, Aurélie; Bérard, Aurélie; Deniot, Gwenaëlle; Guan, Mei; Liu, Zhongsong; Sun, Fengming; Lim, Yong Pyo; Lyons, Eric; Town, Christopher D; Bancroft, Ian; Wang, Xiaowu; Meng, Jinling; Ma, Jianxin; Pires, J Chris; King, Graham J; Brunel, Dominique; Delourme, Régine; Renard, Michel; Aury, Jean-Marc; Adams, Keith L; Batley, Jacqueline; Snowdon, Rod J; Tost, Jorg; Edwards, David; Zhou, Yongming; Hua, Wei; Sharpe, Andrew G; Paterson, Andrew H; Guan, Chunyun; Wincker, Patrick

    2014-08-22

    Oilseed rape (Brassica napus L.) was formed ~7500 years ago by hybridization between B. rapa and B. oleracea, followed by chromosome doubling, a process known as allopolyploidy. Together with more ancient polyploidizations, this conferred an aggregate 72× genome multiplication since the origin of angiosperms and high gene content. We examined the B. napus genome and the consequences of its recent duplication. The constituent An and Cn subgenomes are engaged in subtle structural, functional, and epigenetic cross-talk, with abundant homeologous exchanges. Incipient gene loss and expression divergence have begun. Selection in B. napus oilseed types has accelerated the loss of glucosinolate genes, while preserving expansion of oil biosynthesis genes. These processes provide insights into allopolyploid evolution and its relationship with crop domestication and improvement.

  3. Plant genetics. Early allopolyploid evolution in the post-Neolithic Brassica napus oilseed genome.

    PubMed

    Chalhoub, Boulos; Denoeud, France; Liu, Shengyi; Parkin, Isobel A P; Tang, Haibao; Wang, Xiyin; Chiquet, Julien; Belcram, Harry; Tong, Chaobo; Samans, Birgit; Corréa, Margot; Da Silva, Corinne; Just, Jérémy; Falentin, Cyril; Koh, Chu Shin; Le Clainche, Isabelle; Bernard, Maria; Bento, Pascal; Noel, Benjamin; Labadie, Karine; Alberti, Adriana; Charles, Mathieu; Arnaud, Dominique; Guo, Hui; Daviaud, Christian; Alamery, Salman; Jabbari, Kamel; Zhao, Meixia; Edger, Patrick P; Chelaifa, Houda; Tack, David; Lassalle, Gilles; Mestiri, Imen; Schnel, Nicolas; Le Paslier, Marie-Christine; Fan, Guangyi; Renault, Victor; Bayer, Philippe E; Golicz, Agnieszka A; Manoli, Sahana; Lee, Tae-Ho; Thi, Vinh Ha Dinh; Chalabi, Smahane; Hu, Qiong; Fan, Chuchuan; Tollenaere, Reece; Lu, Yunhai; Battail, Christophe; Shen, Jinxiong; Sidebottom, Christine H D; Wang, Xinfa; Canaguier, Aurélie; Chauveau, Aurélie; Bérard, Aurélie; Deniot, Gwenaëlle; Guan, Mei; Liu, Zhongsong; Sun, Fengming; Lim, Yong Pyo; Lyons, Eric; Town, Christopher D; Bancroft, Ian; Wang, Xiaowu; Meng, Jinling; Ma, Jianxin; Pires, J Chris; King, Graham J; Brunel, Dominique; Delourme, Régine; Renard, Michel; Aury, Jean-Marc; Adams, Keith L; Batley, Jacqueline; Snowdon, Rod J; Tost, Jorg; Edwards, David; Zhou, Yongming; Hua, Wei; Sharpe, Andrew G; Paterson, Andrew H; Guan, Chunyun; Wincker, Patrick

    2014-08-22

    Oilseed rape (Brassica napus L.) was formed ~7500 years ago by hybridization between B. rapa and B. oleracea, followed by chromosome doubling, a process known as allopolyploidy. Together with more ancient polyploidizations, this conferred an aggregate 72× genome multiplication since the origin of angiosperms and high gene content. We examined the B. napus genome and the consequences of its recent duplication. The constituent An and Cn subgenomes are engaged in subtle structural, functional, and epigenetic cross-talk, with abundant homeologous exchanges. Incipient gene loss and expression divergence have begun. Selection in B. napus oilseed types has accelerated the loss of glucosinolate genes, while preserving expansion of oil biosynthesis genes. These processes provide insights into allopolyploid evolution and its relationship with crop domestication and improvement. PMID:25146293

  4. Conservation of the microstructure of genome segments in Brassica napus and its diploid relatives.

    PubMed

    Rana, Debashis; van den Boogaart, Tom; O'Neill, Carmel M; Hynes, Llewelyn; Bent, Elisabeth; Macpherson, Lee; Park, Jee Young; Lim, Yong Pyo; Bancroft, Ian

    2004-12-01

    The cultivated Brassica species are the group of crops most closely related to Arabidopsis thaliana (Arabidopsis). They represent models for the application in crops of genomic information gained in Arabidopsis and provide an opportunity for the investigation of polyploid genome formation and evolution. The scientific literature contains contradictory evidence for the dynamics of the evolution of polyploid genomes. We aimed at overcoming the inherent complexity of Brassica genomes and clarify the effects of polyploidy on the evolution of genome microstructure in specific segments of the genome. To do this, we have constructed bacterial artificial chromosome (BAC) libraries from genomic DNA of B. rapa subspecies trilocularis (JBr) and B. napus var Tapidor (JBnB) to supplement an existing BAC library from B. oleracea. These allowed us to analyse both recent polyploidization (under 10,000 years in B. napus) and more ancient polyploidization events (ca. 20 Myr for B. rapa and B. oleracea relative to Arabidopsis), with an analysis of the events occurring on an intermediate time scale (over the ca. 4 Myr since the divergence of the B. rapa and B. oleracea lineages). Using the Arabidopsis genome sequence and clones from the JBr library, we have analysed aspects of gene conservation and microsynteny between six regions of the genome of B. rapa with the homoeologous regions of the genomes of B. oleracea and Arabidopsis. Extensive divergence of gene content was observed between the B. rapa paralogous segments and their homoeologous segments within the genome of Arabidopsis. A pattern of interspersed gene loss was identified that is similar, but not identical, to that observed in B. oleracea. The conserved genes show highly conserved collinearity with their orthologues across genomes, but a small number of species-specific rearrangements were identified. Thus the evolution of genome microstructure is an ongoing process. Brassica napus is a recently formed polyploid resulting

  5. Conservation of the microstructure of genome segments in Brassica napus and its diploid relatives.

    PubMed

    Rana, Debashis; van den Boogaart, Tom; O'Neill, Carmel M; Hynes, Llewelyn; Bent, Elisabeth; Macpherson, Lee; Park, Jee Young; Lim, Yong Pyo; Bancroft, Ian

    2004-12-01

    The cultivated Brassica species are the group of crops most closely related to Arabidopsis thaliana (Arabidopsis). They represent models for the application in crops of genomic information gained in Arabidopsis and provide an opportunity for the investigation of polyploid genome formation and evolution. The scientific literature contains contradictory evidence for the dynamics of the evolution of polyploid genomes. We aimed at overcoming the inherent complexity of Brassica genomes and clarify the effects of polyploidy on the evolution of genome microstructure in specific segments of the genome. To do this, we have constructed bacterial artificial chromosome (BAC) libraries from genomic DNA of B. rapa subspecies trilocularis (JBr) and B. napus var Tapidor (JBnB) to supplement an existing BAC library from B. oleracea. These allowed us to analyse both recent polyploidization (under 10,000 years in B. napus) and more ancient polyploidization events (ca. 20 Myr for B. rapa and B. oleracea relative to Arabidopsis), with an analysis of the events occurring on an intermediate time scale (over the ca. 4 Myr since the divergence of the B. rapa and B. oleracea lineages). Using the Arabidopsis genome sequence and clones from the JBr library, we have analysed aspects of gene conservation and microsynteny between six regions of the genome of B. rapa with the homoeologous regions of the genomes of B. oleracea and Arabidopsis. Extensive divergence of gene content was observed between the B. rapa paralogous segments and their homoeologous segments within the genome of Arabidopsis. A pattern of interspersed gene loss was identified that is similar, but not identical, to that observed in B. oleracea. The conserved genes show highly conserved collinearity with their orthologues across genomes, but a small number of species-specific rearrangements were identified. Thus the evolution of genome microstructure is an ongoing process. Brassica napus is a recently formed polyploid resulting

  6. Analysis of B-Genome Chromosome Introgression in Interspecific Hybrids of Brassica napus × B. carinata

    PubMed Central

    Navabi, Zahra K.; Stead, Kiersten E.; Pires, J. Chris; Xiong, Zhiyong; Sharpe, Andrew G.; Parkin, Isobel A. P.; Rahman, M. Habibur; Good, Allen G.

    2011-01-01

    Brassica carinata, an allotetraploid with B and C genomes, has a number of traits that would be valuable to introgress into B. napus. Interspecific hybrids were created between B. carinata (BBCC) and B. napus (AACC), using an advanced backcross approach to identify and introgress traits of agronomic interest from the B. carinata genome and to study the genetic changes that occur during the introgression process. We mapped the B and C genomes of B. carinata with SSR markers and observed their introgression into B. napus through a number of backcross generations, focusing on a BC3 and BC3S1 sibling family. There was close colinearity between the C genomes of B. carinata and B. napus and we provide evidence that B. carinata C chromosomes pair and recombine normally with those of B. napus, suggesting that similar to other Brassica allotetraploids no major chromosomal rearrangements have taken place since the formation of B. carinata. There was no evidence of introgression of the B chromosomes into the A or C chromosomes of B. napus; instead they were inherited as whole linkage groups with the occasional loss of terminal segments and several of the B-genome chromosomes were retained across generations. Several BC3S1 families were analyzed using SSR markers, genomic in situ hybridization (GISH) assays, and chromosome counts to study the inheritance of the B-genome chromosome(s) and their association with morphological traits. Our work provides an analysis of the behavior of chromosomes in an interspecific cross and reinforces the challenges of introgressing novel traits into crop plants. PMID:21196520

  7. Computational Prediction of acyl-coA Binding Proteins Structure in Brassica napus.

    PubMed

    Raboanatahiry, Nadia Haingotiana; Lu, Guangyuan; Li, Maoteng

    2015-01-01

    Acyl-coA binding proteins could transport acyl-coA esters from plastid to endoplasmic reticulum, prior to fatty acid biosynthesis, leading to the formation of triacylglycerol. The structure and the subcellular localization of acyl-coA binding proteins (ACBP) in Brassica napus were computationally predicted in this study. Earlier, the structure analysis of ACBPs was limited to the small ACBPs, the current study focused on all four classes of ACBPs. Physicochemical parameters including the size and the length, the intron-exon structure, the isoelectric point, the hydrophobicity, and the amino acid composition were studied. Furthermore, identification of conserved residues and conserved domains were carried out. Secondary structure and tertiary structure of ACBPs were also studied. Finally, subcellular localization of ACBPs was predicted. The findings indicated that the physicochemical parameters and subcellular localizations of ACBPs in Brassica napus were identical to Arabidopsis thaliana. Conserved domain analysis indicated that ACBPs contain two or three kelch domains that belong to different families. Identical residues in acyl-coA binding domains corresponded to eight amino acid residues in all ACBPs of B. napus. However, conserved residues of common ACBPs in all species of animal, plant, bacteria and fungi were only inclusive in small ACBPs. Alpha-helixes were displayed and conserved in all the acyl-coA binding domains, representing almost the half of the protein structure. The findings confirm high similarities in ACBPs between A. thaliana and B. napus, they might share the same functions but loss or gain might be possible.

  8. Identification of Putative Candidate Genes for Water Stress Tolerance in Canola (Brassica napus)

    PubMed Central

    Zhang, Jing; Mason, Annaliese S.; Wu, Jian; Liu, Sheng; Zhang, Xuechen; Luo, Tao; Redden, Robert; Batley, Jacqueline; Hu, Liyong; Yan, Guijun

    2015-01-01

    Drought stress can directly inhibit seedling establishment in canola (Brassica napus), resulting in lower plant densities and reduced yields. To dissect this complex trait, 140 B. napus accessions were phenotyped under normal (0.0 MPa, S0) and water-stressed conditions simulated by polyethylene glycol (PEG) 6000 (−0.5 MPa, S5) in a hydroponic system. Phenotypic variation and heritability indicated that the root to shoot length ratio was a reliable indicator for water stress tolerance. Thereafter, 66 accessions (16 water stress tolerant, 34 moderate and 16 sensitive lines) were genotyped using 25,495 Brassica single nucleotide polymorphisms (SNPs). Genome-wide association studies (GWAS) identified 16 loci significantly associated with water stress response. Two B. napus accessions were used for RNA sequencing, with differentially-expressed genes under normal and water-stressed conditions examined. By combining differentially-expressed genes detected by RNA sequencing with significantly associated loci from GWAS, 79 candidate genes were identified, of which eight were putatively associated with drought tolerance based on gene ontology of Arabidopsis. Functional validation of these genes may confirm key drought-related genes for selection and breeding in B. napus. Our results provide insight into the genetic basis of water stress tolerance in canola. PMID:26640475

  9. Identification of Putative Candidate Genes for Water Stress Tolerance in Canola (Brassica napus).

    PubMed

    Zhang, Jing; Mason, Annaliese S; Wu, Jian; Liu, Sheng; Zhang, Xuechen; Luo, Tao; Redden, Robert; Batley, Jacqueline; Hu, Liyong; Yan, Guijun

    2015-01-01

    Drought stress can directly inhibit seedling establishment in canola (Brassica napus), resulting in lower plant densities and reduced yields. To dissect this complex trait, 140 B. napus accessions were phenotyped under normal (0.0 MPa, S0) and water-stressed conditions simulated by polyethylene glycol (PEG) 6000 (-0.5 MPa, S5) in a hydroponic system. Phenotypic variation and heritability indicated that the root to shoot length ratio was a reliable indicator for water stress tolerance. Thereafter, 66 accessions (16 water stress tolerant, 34 moderate and 16 sensitive lines) were genotyped using 25,495 Brassica single nucleotide polymorphisms (SNPs). Genome-wide association studies (GWAS) identified 16 loci significantly associated with water stress response. Two B. napus accessions were used for RNA sequencing, with differentially-expressed genes under normal and water-stressed conditions examined. By combining differentially-expressed genes detected by RNA sequencing with significantly associated loci from GWAS, 79 candidate genes were identified, of which eight were putatively associated with drought tolerance based on gene ontology of Arabidopsis. Functional validation of these genes may confirm key drought-related genes for selection and breeding in B. napus. Our results provide insight into the genetic basis of water stress tolerance in canola. PMID:26640475

  10. Differential expression of duplicated peroxidase genes in the allotetraploid Brassica napus.

    PubMed

    Zhao, Jianwei; Buchwaldt, Lone; Rimmer, S Roger; Brkic, Myrtle; Bekkaoui, Diana; Hegedus, Dwayne

    2009-07-01

    Gene redundancy due to polyploidization provides a selective advantage for plant adaptation. We examined the expression patterns of two peroxidase genes (BnPOX1 and BnPOX2) in the natural allotetraploid Brassica napus and the model diploid progenitors Brassica rapa (Br) and Brassica oleracea (Bo) in response to the fungal pathogen Sclerotinia sclerotiorum. We demonstrated that the Bo homeolog of BnPOX1 was up-regulated after infection, while both BnPOX2 homeologs were down-regulated. A bias toward reciprocal expression of the homeologs of BnPOX1 in different organs in the natural allotetraploid of B. napus was also observed. These results suggest that subfunctionalization of the duplicated BnPOX genes after B. napus polyploidization as well as subneofunctionalization of the homeologs in response to this specific biotic stress has occurred. Retention of expression patterns in the diploid progenitors and the natural allotetraploid in some organs indicates that the function of peroxidase genes has been conserved during evolution.

  11. Latent S alleles are widespread in cultivated self-compatible Brassica napus.

    PubMed

    Ekuere, U U; Parkin, I A P; Bowman, C; Marshall, D; Lydiate, D J

    2004-04-01

    The genetic control of self-incompatibility in Brassica napus was investigated using crosses between resynthesized lines of B. napus and cultivars of oilseed rape. These crosses introduced eight C-genome S alleles from Brassica oleracea (S16, S22, S23, S25, S29, S35, S60, and S63) and one A-genome S allele from Brassica rapa (SRM29) into winter oilseed rape. The inheritance of S alleles was monitored using genetic markers and S phenotypes were determined in the F1, F2, first backcross (B1), and testcross (T1) generations. Two different F1 hybrids were used to develop populations of doubled haploid lines that were subjected to genetic mapping and scored for S phenotype. These investigations identified a latent S allele in at least two oilseed rape cultivars and indicated that the S phenotype of these latent alleles was masked by a suppressor system common to oilseed rape. These latent S alleles may be widespread in oilseed rape varieties and are possibly associated with the highly conserved C-genome S locus of these crop types. Segregation for S phenotype in subpopulations uniform for S genotype suggests the existence of suppressor loci that influenced the expression of the S phenotype. These suppressor loci were not linked to the S loci and possessed suppressing alleles in oilseed rape and non-suppressing alleles in the diploid parents of resynthesized B. napus lines.

  12. Phytotoxicity evaluation of some commonly used shampoos using Brassica napus L.

    PubMed

    Naeem, Faiqa; Ahmed, Faiza; Kanwal, Memoona; Murad, Waheed; Azizullah, Azizullah

    2015-10-01

    Hair shampoos are among the most commonly used chemicals in everyday life. Since shampoos are a major component of domestic and municipal wastewater, they may affect plants when irrigated with wastewater. However, their effects on plants have never been investigated in detail. The present study was aimed to evaluate the effect of some commonly used hair shampoos on seed germination and seedling vigor of Brassica napus. Seeds of Brassica napus were exposed to different concentrations of hair shampoos, i.e., 0 (control), 0.001, 0.01, 0.1, 1.0, and 10 %. The obtained results revealed that germination was not very sensitive to shampoo stress and was significantly inhibited only at the highest tested concentration (10 %) of shampoo except in the case of one shampoo where it was inhibited at concentration of 1 % or above. The other tested parameters of Brassica napus were comparatively more sensitive than germination to shampoo stress. However, at lower concentrations of shampoos, stimulatory effects were also observed in some cases. Although no exact data is available on shampoo concentration in wastewater used for irrigation, it is unlikely that shampoo concentration in irrigation water reach so high and pose adversity to plants.

  13. Differential expression of duplicated peroxidase genes in the allotetraploid Brassica napus.

    PubMed

    Zhao, Jianwei; Buchwaldt, Lone; Rimmer, S Roger; Brkic, Myrtle; Bekkaoui, Diana; Hegedus, Dwayne

    2009-07-01

    Gene redundancy due to polyploidization provides a selective advantage for plant adaptation. We examined the expression patterns of two peroxidase genes (BnPOX1 and BnPOX2) in the natural allotetraploid Brassica napus and the model diploid progenitors Brassica rapa (Br) and Brassica oleracea (Bo) in response to the fungal pathogen Sclerotinia sclerotiorum. We demonstrated that the Bo homeolog of BnPOX1 was up-regulated after infection, while both BnPOX2 homeologs were down-regulated. A bias toward reciprocal expression of the homeologs of BnPOX1 in different organs in the natural allotetraploid of B. napus was also observed. These results suggest that subfunctionalization of the duplicated BnPOX genes after B. napus polyploidization as well as subneofunctionalization of the homeologs in response to this specific biotic stress has occurred. Retention of expression patterns in the diploid progenitors and the natural allotetraploid in some organs indicates that the function of peroxidase genes has been conserved during evolution. PMID:19345111

  14. Proteome Dynamics and Physiological Responses to Short-Term Salt Stress in Brassica napus Leaves.

    PubMed

    Jia, Huan; Shao, Mingquan; He, Yongjun; Guan, Rongzhan; Chu, Pu; Jiang, Haidong

    2015-01-01

    Salt stress limits plant growth and crop productivity and is an increasing threat to agriculture worldwide. In this study, proteomic and physiological responses of Brassica napus leaves under salt stress were investigated. Seedlings under salt treatment showed growth inhibition and photosynthesis reduction. A comparative proteomic analysis of seedling leaves exposed to 200 mM NaCl for 24 h, 48 h and 72 h was conducted. Forty-four protein spots were differentially accumulated upon NaCl treatment and 42 of them were identified, including several novel salt-responsive proteins. To determine the functional roles of these proteins in salt adaptation, their dynamic changes in abundance were analyzed. The results suggested that the up-accumulated proteins, which were associated with protein metabolism, damage repair and defense response, might contribute to the alleviation of the deleterious effect of salt stress on chlorophyll biosynthesis, photosynthesis, energy synthesis and respiration in Brassica napus leaves. This study will lead to a better understanding of the molecular basis of salt stress adaptation in Brassica napus and provides a basis for genetic engineering of plants with improved salt tolerance in the future. PMID:26691228

  15. Proteome Dynamics and Physiological Responses to Short-Term Salt Stress in Brassica napus Leaves

    PubMed Central

    He, Yongjun; Guan, Rongzhan; Chu, Pu; Jiang, Haidong

    2015-01-01

    Salt stress limits plant growth and crop productivity and is an increasing threat to agriculture worldwide. In this study, proteomic and physiological responses of Brassica napus leaves under salt stress were investigated. Seedlings under salt treatment showed growth inhibition and photosynthesis reduction. A comparative proteomic analysis of seedling leaves exposed to 200 mM NaCl for 24 h, 48 h and 72 h was conducted. Forty-four protein spots were differentially accumulated upon NaCl treatment and 42 of them were identified, including several novel salt-responsive proteins. To determine the functional roles of these proteins in salt adaptation, their dynamic changes in abundance were analyzed. The results suggested that the up-accumulated proteins, which were associated with protein metabolism, damage repair and defense response, might contribute to the alleviation of the deleterious effect of salt stress on chlorophyll biosynthesis, photosynthesis, energy synthesis and respiration in Brassica napus leaves. This study will lead to a better understanding of the molecular basis of salt stress adaptation in Brassica napus and provides a basis for genetic engineering of plants with improved salt tolerance in the future. PMID:26691228

  16. Phytotoxicity evaluation of some commonly used shampoos using Brassica napus L.

    PubMed

    Naeem, Faiqa; Ahmed, Faiza; Kanwal, Memoona; Murad, Waheed; Azizullah, Azizullah

    2015-10-01

    Hair shampoos are among the most commonly used chemicals in everyday life. Since shampoos are a major component of domestic and municipal wastewater, they may affect plants when irrigated with wastewater. However, their effects on plants have never been investigated in detail. The present study was aimed to evaluate the effect of some commonly used hair shampoos on seed germination and seedling vigor of Brassica napus. Seeds of Brassica napus were exposed to different concentrations of hair shampoos, i.e., 0 (control), 0.001, 0.01, 0.1, 1.0, and 10 %. The obtained results revealed that germination was not very sensitive to shampoo stress and was significantly inhibited only at the highest tested concentration (10 %) of shampoo except in the case of one shampoo where it was inhibited at concentration of 1 % or above. The other tested parameters of Brassica napus were comparatively more sensitive than germination to shampoo stress. However, at lower concentrations of shampoos, stimulatory effects were also observed in some cases. Although no exact data is available on shampoo concentration in wastewater used for irrigation, it is unlikely that shampoo concentration in irrigation water reach so high and pose adversity to plants. PMID:26201659

  17. Comparing the effects of excess copper in the leaves of Brassica juncea (L. Czern) and Brassica napus (L.) seedlings: Growth inhibition, oxidative stress and photosynthetic damage.

    PubMed

    Feigl, Gábor; Kumar, Devanand; Lehotai, Nóra; Pető, Andrea; Molnár, Árpád; Rácz, Éva; Ördög, Attila; Erdei, László; Kolbert, Zsuzsanna; Laskay, Gábor

    2015-06-01

    Hydroponic experiments were conducted to compare the effects of excess copper (Cu) on growth and photosynthesis in young Indian mustard (Brassica juncea) and oilseed rape (Brassica napus). We compared the effects of excess Cu on the two Brassica species at different physiological levels from antioxidant levels to photosynthetic activity. Nine-day-old plants were treated with Cu (10, 25 and 50 μM CuSO4) for 7 and 14 days. Both species took up Cu from the external solution to a similar degree but showed slight root-to-shoot translocation. Furthermore, after seven days of treatment, excess Cu significantly decreased other microelement content, such as iron (Fe) and manganese (Mn), especially in the shoots of B. napus. As a consequence, the leaves of young Brassica napus plants showed decreased concentrations of photosynthetic pigments and more intense growth inhibition; however, accumulation of highly reactive oxygen species (hROS) were not detected. After 14 days of Cu exposure the reduction of Fe and Mn contents and shoot growth proved to be comparable in the two species. Moreover, a significant Cu-induced hROS accumulation was observed in both Brassica species. The diminution in pigment contents and photosynthetic efficiency were more pronounced in B. napus during prolonged Cu exposure. Based on all the parameters, B. juncea appears to be more resistant to excess Cu than B. napus, rendering it a species with higher potential for phytoremediation.

  18. Comparing the effects of excess copper in the leaves of Brassica juncea (L. Czern) and Brassica napus (L.) seedlings: Growth inhibition, oxidative stress and photosynthetic damage.

    PubMed

    Feigl, Gábor; Kumar, Devanand; Lehotai, Nóra; Pető, Andrea; Molnár, Árpád; Rácz, Éva; Ördög, Attila; Erdei, László; Kolbert, Zsuzsanna; Laskay, Gábor

    2015-06-01

    Hydroponic experiments were conducted to compare the effects of excess copper (Cu) on growth and photosynthesis in young Indian mustard (Brassica juncea) and oilseed rape (Brassica napus). We compared the effects of excess Cu on the two Brassica species at different physiological levels from antioxidant levels to photosynthetic activity. Nine-day-old plants were treated with Cu (10, 25 and 50 μM CuSO4) for 7 and 14 days. Both species took up Cu from the external solution to a similar degree but showed slight root-to-shoot translocation. Furthermore, after seven days of treatment, excess Cu significantly decreased other microelement content, such as iron (Fe) and manganese (Mn), especially in the shoots of B. napus. As a consequence, the leaves of young Brassica napus plants showed decreased concentrations of photosynthetic pigments and more intense growth inhibition; however, accumulation of highly reactive oxygen species (hROS) were not detected. After 14 days of Cu exposure the reduction of Fe and Mn contents and shoot growth proved to be comparable in the two species. Moreover, a significant Cu-induced hROS accumulation was observed in both Brassica species. The diminution in pigment contents and photosynthetic efficiency were more pronounced in B. napus during prolonged Cu exposure. Based on all the parameters, B. juncea appears to be more resistant to excess Cu than B. napus, rendering it a species with higher potential for phytoremediation. PMID:26081276

  19. High-throughput multiplex cpDNA resequencing clarifies the genetic diversity and genetic relationships among Brassica napus, Brassica rapa and Brassica oleracea.

    PubMed

    Qiao, Jiangwei; Cai, Mengxian; Yan, Guixin; Wang, Nian; Li, Feng; Chen, Binyun; Gao, Guizhen; Xu, Kun; Li, Jun; Wu, Xiaoming

    2016-01-01

    Brassica napus (rapeseed) is a recent allotetraploid plant and the second most important oilseed crop worldwide. The origin of B. napus and the genetic relationships with its diploid ancestor species remain largely unresolved. Here, chloroplast DNA (cpDNA) from 488 B. napus accessions of global origin, 139 B. rapa accessions and 49 B. oleracea accessions were populationally resequenced using Illumina Solexa sequencing technologies. The intraspecific cpDNA variants and their allelic frequencies were called genomewide and further validated via EcoTILLING analyses of the rpo region. The cpDNA of the current global B. napus population comprises more than 400 variants (SNPs and short InDels) and maintains one predominant haplotype (Bncp1). Whole-genome resequencing of the cpDNA of Bncp1 haplotype eliminated its direct inheritance from any accession of the B. rapa or B. oleracea species. The distribution of the polymorphism information content (PIC) values for each variant demonstrated that B. napus has much lower cpDNA diversity than B. rapa; however, a vast majority of the wild and cultivated B. oleracea specimens appeared to share one same distinct cpDNA haplotype, in contrast to its wild C-genome relatives. This finding suggests that the cpDNA of the three Brassica species is well differentiated. The predominant B. napus cpDNA haplotype may have originated from uninvestigated relatives or from interactions between cpDNA mutations and natural/artificial selection during speciation and evolution. These exhaustive data on variation in cpDNA would provide fundamental data for research on cpDNA and chloroplasts.

  20. High-throughput multiplex cpDNA resequencing clarifies the genetic diversity and genetic relationships among Brassica napus, Brassica rapa and Brassica oleracea.

    PubMed

    Qiao, Jiangwei; Cai, Mengxian; Yan, Guixin; Wang, Nian; Li, Feng; Chen, Binyun; Gao, Guizhen; Xu, Kun; Li, Jun; Wu, Xiaoming

    2016-01-01

    Brassica napus (rapeseed) is a recent allotetraploid plant and the second most important oilseed crop worldwide. The origin of B. napus and the genetic relationships with its diploid ancestor species remain largely unresolved. Here, chloroplast DNA (cpDNA) from 488 B. napus accessions of global origin, 139 B. rapa accessions and 49 B. oleracea accessions were populationally resequenced using Illumina Solexa sequencing technologies. The intraspecific cpDNA variants and their allelic frequencies were called genomewide and further validated via EcoTILLING analyses of the rpo region. The cpDNA of the current global B. napus population comprises more than 400 variants (SNPs and short InDels) and maintains one predominant haplotype (Bncp1). Whole-genome resequencing of the cpDNA of Bncp1 haplotype eliminated its direct inheritance from any accession of the B. rapa or B. oleracea species. The distribution of the polymorphism information content (PIC) values for each variant demonstrated that B. napus has much lower cpDNA diversity than B. rapa; however, a vast majority of the wild and cultivated B. oleracea specimens appeared to share one same distinct cpDNA haplotype, in contrast to its wild C-genome relatives. This finding suggests that the cpDNA of the three Brassica species is well differentiated. The predominant B. napus cpDNA haplotype may have originated from uninvestigated relatives or from interactions between cpDNA mutations and natural/artificial selection during speciation and evolution. These exhaustive data on variation in cpDNA would provide fundamental data for research on cpDNA and chloroplasts. PMID:26031705

  1. Novel flowering and fatty acid characters in rapid cycling Brassica napus L. resynthesized by protoplast fusion.

    PubMed

    Hansen, L N; Earle, E D

    1994-12-01

    Novel rapid cycling Brassica napus lines have been produced by protoplast fusion between rapid cycling B. oleracea and rapid cycling B. rapa. Fusion products were selected based on iodoacetate inactivation and regeneration ability. A total of 36 plants was recovered from 3 regenerating calli. All were confirmed as somatic hybrids by morphological features, flow cytometric estimation of nuclear DNA content, RAPD analysis and/or DNA hybridization. Plants from two of the calli contained chloroplasts from B. rapa, and plants from the third contained B. oleracea chloroplasts. Some plants flowered in vitro, but on average flowering was initiated 22 days after transfer to soil. Although seed set was fairly low after self pollination, more seeds were obtained from pollination of open flowers than from pollination of buds. Seeds of the somatic hybrid B. napus showed novel fatty acid compositions, different from the mean of the two parental lines. Flowering was monitored in plants grown from seeds of the somatic hybrids, rapid cycling B. napus (CrGC 5-1) and the two diploid parental genotypes. Progeny of the somatic hybrids flowered faster and were more vigorous than rapid cycling B. napus (CrGC 5-1). The improved lines contain chloroplasts from B. rapa, unlike rapid cycling B. napus (CrGC 5-1), which has B. oleracea chloroplasts. The somatic hybrid lines produced may be useful for genetic studies or further in vitro manipulations.

  2. Genetic regulation of meiotic cross-overs between related genomes in Brassica napus haploids and hybrids.

    PubMed

    Nicolas, Stéphane D; Leflon, Martine; Monod, Hervé; Eber, Frédérique; Coriton, Olivier; Huteau, Virginie; Chèvre, Anne-Marie; Jenczewski, Eric

    2009-02-01

    Although the genetic regulation of recombination in allopolyploid species plays a pivotal role in evolution and plant breeding, it has received little recent attention, except in wheat (Triticum aestivum). PrBn is the main locus that determines the number of nonhomologous associations during meiosis of microspore cultured Brassica napus haploids (AC; 19 chromosomes). In this study, we examined the role played by PrBn in recombination. We generated two haploid x euploid populations using two B. napus haploids with differing PrBn (and interacting genes) activity. We analyzed molecular marker transmission in these two populations to compare genetic changes, which have arisen during meiosis. We found that cross-over number in these two genotypes was significantly different but that cross-overs between nonhomologous chromosomes showed roughly the same distribution pattern. We then examined genetic recombination along a pair of A chromosomes during meiosis of B. rapa x B. napus AAC and AACC hybrids that were produced with the same two B. napus genotypes. We observed significant genotypic variation in cross-over rates between the two AAC hybrids but no difference between the two AACC hybrids. Overall, our results show that PrBn changes the rate of recombination between nonhomologous chromosomes during meiosis of B. napus haploids and also affects homologous recombination with an effect that depends on plant karyotype.

  3. The self-compatibility mechanism in Brassica napus L. is applicable to F1 hybrid breeding.

    PubMed

    Tochigi, Takahiro; Udagawa, Hisashi; Li, Feng; Kitashiba, Hiroyasu; Nishio, Takeshi

    2011-08-01

    Brassica napus, an allopolyploid species having the A genome of B. rapa and the C genome of B. oleracea, is self-compatible, although both B. rapa and B. oleracea are self-incompatible. We have previously reported that SP11/SCR alleles are not expressed in anthers, while SRK alleles are functional in the stigma in B. napus cv. 'Westar', which has BnS-1 similar to B. rapa S-47 and BnS-6 similar to B. oleracea S-15. This genotype is the most frequent S genotype in B. napus, and we hypothesized that the loss of the function of SP11 is the primary cause of the self-compatibility of 'Westar'. To verify this hypothesis, we transformed 'Westar' plants with the SP11 allele of B. rapa S-47. All the transgenic plants and their progeny were completely self-incompatible, demonstrating self-compatibility to be due to the S haplotype having the non-functional SP11 allele in the A genome, which suppresses a functional recessive SP11 allele in the C genome. An artificially synthesized B. napus line having two recessive SP11 alleles was developed by interspecific hybridization between B. rapa and B. oleracea. This line was self-incompatible, but F(1) hybrids between this line and 'Westar' were self-compatible. These results suggest that the self-compatibility mechanism of 'Westar' is applicable to F(1) seed production in B. napus.

  4. Identification of the A and C genomes of amphidiploid Brassica napus (oilseed rape).

    PubMed

    Parkin, I A; Sharpe, A G; Keith, D J; Lydiate, D J

    1995-12-01

    A genetic linkage map consisting of 399 RFLP-defined loci was generated from a cross between resynthesized Brassica napus (an interspecific B. rapa x B. oleracea hybrid) and "natural" oilseed rape. The majority of loci exhibited disomic inheritance of parental alleles demonstrating that B. rapa chromosomes were each pairing exclusively with recognisable A-genome homologues in B. napus and that B. oleracea chromosomes were pairing similarly with C-genome homologues. This behaviour identified the 10 A genome and 9 C genome linkage groups of B. napus and demonstrated that the nuclear genomes of B. napus, B. rapa, and B. oleracea have remained essentially unaltered since the formation of the amphidiploid species, B. napus. A range of unusual marker patterns, which could be explained by aneuploidy and nonreciprocal translocations, were observed in the mapping population. These chromosome abnormalities were probably caused by associations between homoeologous chromosomes at meiosis in the resynthesized parent and the F1 plant leading to nondisjunction and homoeologous recombination.

  5. Barriers to gene flow from oilseed rape (Brassica napus) into populations of Sinapis arvensis.

    PubMed

    Moyes, C L; Lilley, J M; Casais, C A; Cole, S G; Haeger, P D; Dale, P J

    2002-01-01

    One concern over growing herbicide-tolerant crops is that herbicide-tolerance genes may be transferred into the weeds they are designed to control. Brassica napus (oilseed rape) has a number of wild relatives that cause weed problems and the most widespread of these is Sinapis arvensis (charlock). Sinapis arvensis seed was collected from 102 populations across the UK, within and outside B. napus-growing areas. These populations were tested for sexual compatibility with B. napus and it was found that none of them hybridized readily in the glasshouse. In contrast to previous studies, we have found that hybrids can be formed naturally with S. arvensis as the maternal parent. Six diverse B. napus cultivars (Capricorn, Drakkar, Falcon, Galaxy, Hobson and Regent) were tested for their compatibility with S. arvensis but no cultivar hybridized readily in the glasshouse. We were unable to detect gene transfer from B. napus to S. arvensis in the field, confirming the extremely low probability of hybridization predicted from the glasshouse work. PMID:11903908

  6. Mining expressed sequence tags of rapeseed (Brassica napus L.) to predict the drought responsive regulatory network.

    PubMed

    Shamloo-Dashtpagerdi, Roohollah; Razi, Hooman; Ebrahimie, Esmaeil

    2015-07-01

    It is of great significance to understand the regulatory mechanisms by which plants deal with drought stress. Two EST libraries derived from rapeseed (Brassica napus) leaves in non-stressed and drought stress conditions were analyzed in order to obtain the transcriptomic landscape of drought-exposed B. napus plants, and also to identify and characterize significant drought responsive regulatory genes and microRNAs. The functional ontology analysis revealed a substantial shift in the B. napus transcriptome to govern cellular drought responsiveness via different stress-activated mechanisms. The activity of transcription factor and protein kinase modules generally increased in response to drought stress. The 26 regulatory genes consisting of 17 transcription factor genes, eight protein kinase genes and one protein phosphatase gene were identified showing significant alterations in their expressions in response to drought stress. We also found the six microRNAs which were differentially expressed during drought stress supporting the involvement of a post-transcriptional level of regulation for B. napus drought response. The drought responsive regulatory network shed light on the significance of some regulatory components involved in biosynthesis and signaling of various plant hormones (abscisic acid, auxin and brassinosteroids), ubiquitin proteasome system, and signaling through Reactive Oxygen Species (ROS). Our findings suggested a complex and multi-level regulatory system modulating response to drought stress in B. napus. PMID:26261397

  7. Sequence-level comparative analysis of the Brassica napus genome around two stearoyl-ACP desaturase loci.

    PubMed

    Cho, Kwangsoo; O'Neill, Carmel M; Kwon, Soo-Jin; Yang, Tae-Jin; Smooker, Andrew M; Fraser, Fiona; Bancroft, Ian

    2010-02-01

    We conducted a sequence-level comparative analyses, at the scale of complete bacterial artificial chromosome (BAC) clones, between the genome of the most economically important Brassica species, Brassica napus (oilseed rape), and those of Brassica rapa, the genome of which is currently being sequenced, and Arabidopsis thaliana. We constructed a new B. napus BAC library and identified and sequenced clones that contain homoeologous regions of the genome including stearoyl-ACP desaturase-encoding genes. We sequenced the orthologous region of the genome of B. rapa and conducted comparative analyses between the Brassica sequences and those of the orthologous region of the genome of A. thaliana. The proportion of genes conserved (approximately 56%) is lower than has been reported previously between A. thaliana and Brassica (approximately 66%). The gene models for sets of conserved genes were used to determine the extent of nucleotide conservation of coding regions. This was found to be 84.2 +/- 3.9% and 85.8 +/- 3.7% between the B. napus A and C genomes, respectively, and that of A. thaliana, which is consistent with previous results for other Brassica species, and 97.5 +/- 3.1% between the B. napus A genome and B. rapa, and 93.1 +/- 4.9% between the B. napus C genome and B. rapa. The divergence of the B. napus genes from the A genome and the B. rapa genes was greater than anticipated and indicates that the A genome ancestor of the B. napus cultivar studied was relatively distantly related to the cultivar of B. rapa selected for genome sequencing.

  8. Functional Analysis of the Brassica napus L. Phytoene Synthase (PSY) Gene Family

    PubMed Central

    López-Emparán, Ada; Quezada-Martinez, Daniela; Zúñiga-Bustos, Matías; Cifuentes, Víctor; Iñiguez-Luy, Federico; Federico, María Laura

    2014-01-01

    Phytoene synthase (PSY) has been shown to catalyze the first committed and rate-limiting step of carotenogenesis in several crop species, including Brassica napus L. Due to its pivotal role, PSY has been a prime target for breeding and metabolic engineering the carotenoid content of seeds, tubers, fruits and flowers. In Arabidopsis thaliana, PSY is encoded by a single copy gene but small PSY gene families have been described in monocot and dicotyledonous species. We have recently shown that PSY genes have been retained in a triplicated state in the A- and C-Brassica genomes, with each paralogue mapping to syntenic locations in each of the three “Arabidopsis-like” subgenomes. Most importantly, we have shown that in B. napus all six members are expressed, exhibiting overlapping redundancy and signs of subfunctionalization among photosynthetic and non photosynthetic tissues. The question of whether this large PSY family actually encodes six functional enzymes remained to be answered. Therefore, the objectives of this study were to: (i) isolate, characterize and compare the complete protein coding sequences (CDS) of the six B. napus PSY genes; (ii) model their predicted tridimensional enzyme structures; (iii) test their phytoene synthase activity in a heterologous complementation system and (iv) evaluate their individual expression patterns during seed development. This study further confirmed that the six B. napus PSY genes encode proteins with high sequence identity, which have evolved under functional constraint. Structural modeling demonstrated that they share similar tridimensional protein structures with a putative PSY active site. Significantly, all six B. napus PSY enzymes were found to be functional. Taking into account the specific patterns of expression exhibited by these PSY genes during seed development and recent knowledge of PSY suborganellar localization, the selection of transgene candidates for metabolic engineering the carotenoid content of

  9. Functional analysis of the Brassica napus L. phytoene synthase (PSY) gene family.

    PubMed

    López-Emparán, Ada; Quezada-Martinez, Daniela; Zúñiga-Bustos, Matías; Cifuentes, Víctor; Iñiguez-Luy, Federico; Federico, María Laura

    2014-01-01

    Phytoene synthase (PSY) has been shown to catalyze the first committed and rate-limiting step of carotenogenesis in several crop species, including Brassica napus L. Due to its pivotal role, PSY has been a prime target for breeding and metabolic engineering the carotenoid content of seeds, tubers, fruits and flowers. In Arabidopsis thaliana, PSY is encoded by a single copy gene but small PSY gene families have been described in monocot and dicotyledonous species. We have recently shown that PSY genes have been retained in a triplicated state in the A- and C-Brassica genomes, with each paralogue mapping to syntenic locations in each of the three "Arabidopsis-like" subgenomes. Most importantly, we have shown that in B. napus all six members are expressed, exhibiting overlapping redundancy and signs of subfunctionalization among photosynthetic and non photosynthetic tissues. The question of whether this large PSY family actually encodes six functional enzymes remained to be answered. Therefore, the objectives of this study were to: (i) isolate, characterize and compare the complete protein coding sequences (CDS) of the six B. napus PSY genes; (ii) model their predicted tridimensional enzyme structures; (iii) test their phytoene synthase activity in a heterologous complementation system and (iv) evaluate their individual expression patterns during seed development. This study further confirmed that the six B. napus PSY genes encode proteins with high sequence identity, which have evolved under functional constraint. Structural modeling demonstrated that they share similar tridimensional protein structures with a putative PSY active site. Significantly, all six B. napus PSY enzymes were found to be functional. Taking into account the specific patterns of expression exhibited by these PSY genes during seed development and recent knowledge of PSY suborganellar localization, the selection of transgene candidates for metabolic engineering the carotenoid content of oilseeds

  10. SNP markers-based map construction and genome-wide linkage analysis in Brassica napus.

    PubMed

    Raman, Harsh; Dalton-Morgan, Jessica; Diffey, Simon; Raman, Rosy; Alamery, Salman; Edwards, David; Batley, Jacqueline

    2014-09-01

    An Illumina Infinium array comprising 5306 single nucleotide polymorphism (SNP) markers was used to genotype 175 individuals of a doubled haploid population derived from a cross between Skipton and Ag-Spectrum, two Australian cultivars of rapeseed (Brassica napus L.). A genetic linkage map based on 613 SNP and 228 non-SNP (DArT, SSR, SRAP and candidate gene markers) covering 2514.8 cM was constructed and further utilized to identify loci associated with flowering time and resistance to blackleg, a disease caused by the fungus Leptosphaeria maculans. Comparison between genetic map positions of SNP markers and the sequenced Brassica rapa (A) and Brassica oleracea (C) genome scaffolds showed several genomic rearrangements in the B. napus genome. A major locus controlling resistance to L. maculans was identified at both seedling and adult plant stages on chromosome A07. QTL analyses revealed that up to 40.2% of genetic variation for flowering time was accounted for by loci having quantitative effects. Comparative mapping showed Arabidopsis and Brassica flowering genes such as Phytochrome A/D, Flowering Locus C and agamous-Like MADS box gene AGL1 map within marker intervals associated with flowering time in a DH population from Skipton/Ag-Spectrum. Genomic regions associated with flowering time and resistance to L. maculans had several SNP markers mapped within 10 cM. Our results suggest that SNP markers will be suitable for various applications such as trait introgression, comparative mapping and high-resolution mapping of loci in B. napus.

  11. Brassica napus hairy roots and rhizobacteria for phenolic compounds removal.

    PubMed

    González, Paola S; Ontañon, Ornella M; Armendariz, Ana L; Talano, Melina A; Paisio, Cintia E; Agostini, Elizabeth

    2013-03-01

    Phenolic compounds are contaminants frequently found in water and soils. In the last years, some technologies such as phytoremediation have emerged to remediate contaminated sites. Plants alone are unable to completely degrade some pollutants; therefore, their association with rhizospheric bacteria has been proposed to increase phytoremediation potential, an approach called rhizoremediation. In this work, the ability of two rhizobacteria, Burkholderia kururiensis KP 23 and Agrobacterium rhizogenes LBA 9402, to tolerate and degrade phenolic compounds was evaluated. Both microorganisms were capable of tolerating high concentrations of phenol, 2,4-dichlorophenol (2,4-DCP), guaiacol, or pentachlorophenol (PCP), and degrading different concentrations of phenol and 2,4-DCP. Association of these bacterial strains with B. napus hairy roots, as model plant system, showed that the presence of both rhizospheric microorganisms, along with B. napus hairy roots, enhanced phenol degradation compared to B. napus hairy roots alone. These findings are interesting for future applications of these strains in phenol rhizoremediation processes, with whole plants, providing an efficient, economic, and sustainable remediation technology. PMID:22961561

  12. From Arabidopsis thaliana to Brassica napus: development of amplified consensus genetic markers (ACGM) for construction of a gene map.

    PubMed

    Fourmann, M.; Barret, P.; Froger, N.; Baron, C.; Charlot, F.; Delourme, R.; Brunel, D.

    2002-12-01

    The evolution of genomes can be studied by comparing maps of homologous genes which show changes in nucleic acid sequences and chromosome rearrangements. In this study, we developed a set of 32 amplified consensus gene markers (ACGMs) that amplified gene sequences from Arabidopsis thaliana and Brassica napus. Our methodology, based on PCR, facilitated the rapid sequencing of homologous genes from various species of the same phylogenetic family and the detection of intragenic polymorphism. We found that such polymorphism principally concerned intron sequences and we used it to attribute a Brassica oleracea or Brassica rapa origin to the B. napus sequences and to map 43 rapeseed genes. We confirm that the genetic position of homologous genes varied between B. napus and A. thaliana. ACGMs are a useful tool for genome evolution studies and for the further development of single nucleotide polymorphism suitable for use in genetic mapping and genetic diversity analyses.

  13. Frequency-dependent fitness of hybrids between oilseed rape (Brassica napus) and weedy B. rapa (Brassicaceae).

    PubMed

    Hauser, Thure P; Damgaard, Christian; Jørgensen, Rikke B

    2003-04-01

    Fitness of interspecific hybrids is sometimes high relative to their parents, despite the conventional belief that they are mostly unfit. F(1) hybrids between oilseed rape (Brassica napus) and weedy B. rapa can be significantly more fit than their weedy parents under some conditions; however, under other conditions they are less fit. To understand the reasons, we measured the seed production of B. napus, B. rapa, and different generations of hybrid plants at three different densities and in mixtures of different frequencies (including pure stands). Brassica napus, B. rapa, and backcross plants (F(1) ♀ × B. rapa) produced many more seeds per plant in pure plots than in mixtures and more seeds in plots when each was present at high frequency. The opposite was true for F(1) plants that produced many more seeds than B. rapa in mixtures, but fewer in pure stands. Both vegetative and reproductive interactions may be responsible for these effects. Our results show that the fitness of both parents and hybrids is strongly frequency-dependent and that the likelihood of introgression of genes between the species thus may depend on the numbers and densities of parents and their various hybrid offspring in the population.

  14. Construction of an oilseed rape (Brassica napus L.) genetic map with SSR markers.

    PubMed

    Piquemal, J; Cinquin, E; Couton, F; Rondeau, C; Seignoret, E; Doucet, I; Perret, D; Villeger, M-J; Vincourt, P; Blanchard, P

    2005-11-01

    We constructed a Brassica napus genetic map with 240 simple sequence repeats (SSR) primer pairs from private and public origins. SSR, or microsatellites, are highly polymorphic and efficient markers for the analysis of plant genomes. Our selection of primer pairs corresponded to 305 genetic loci that we were able to map. In addition, we also used 52 sequence-characterized amplified region primer pairs corresponding to 58 loci that were developed in our lab. Genotyping was performed on six F2 populations, corresponding to a total of 574 F2 individual plants, obtained according to an unbalanced diallel cross design involving six parental lines. The resulting consensus map presented 19 linkage groups ranging from 46.2 to 276.5 cM, which we were able to name after the B. napus map available at http://ukcrop.net/perl/ace/search/BrassicaDB , thus enabling the identification of the A genome linkage groups originating from the B. rapa ancestor and the C genome linkage groups originating from the B. oleracea ancestor in the amphidiploid genome of B. napus. Some homologous regions were identified between the A and the C genomes. This map could be used to identify more markers, which would eventually be linked to genes controlling important agronomic characters in rapeseed. Furthermore, considering the good genome coverage we obtained, together with an observed homogenous distribution of the loci across the genome, this map is a powerful tool to be used in marker-assisted breeding.

  15. Diversity array technology markers: genetic diversity analyses and linkage map construction in rapeseed (Brassica napus L.).

    PubMed

    Raman, Harsh; Raman, Rosy; Nelson, Matthew N; Aslam, M N; Rajasekaran, Ravikesavan; Wratten, Neil; Cowling, Wallace A; Kilian, A; Sharpe, Andrew G; Schondelmaier, Joerg

    2012-01-01

    We developed Diversity Array Technology (DArT) markers for application in genetic studies of Brassica napus and other Brassica species with A or C genomes. Genomic representation from 107 diverse genotypes of B. napus L. var. oleifera (rapeseed, AACC genomes) and B. rapa (AA genome) was used to develop a DArT array comprising 11 520 clones generated using PstI/BanII and PstI/BstN1 complexity reduction methods. In total, 1547 polymorphic DArT markers of high technical quality were identified and used to assess molecular diversity among 89 accessions of B. napus, B. rapa, B. juncea, and B. carinata collected from different parts of the world. Hierarchical cluster and principal component analyses based on genetic distance matrices identified distinct populations clustering mainly according to their origin/pedigrees. DArT markers were also mapped in a new doubled haploid population comprising 131 lines from a cross between spring rapeseed lines 'Lynx-037DH' and 'Monty-028DH'. Linkage groups were assigned on the basis of previously mapped simple sequence repeat (SSRs), intron polymorphism (IP), and gene-based markers. The map consisted of 437 DArT, 135 SSR, 6 IP, and 6 gene-based markers and spanned 2288 cM. Our results demonstrate that DArT markers are suitable for genetic diversity analysis and linkage map construction in rapeseed.

  16. Identification and characterization of improved nitrogen efficiency in interspecific hybridized new-type Brassica napus

    PubMed Central

    Wang, Gaili; Ding, Guangda; Li, Ling; Cai, Hongmei; Ye, Xiangsheng; Zou, Jun; Xu, Fangsen

    2014-01-01

    Background and Aims Oilseed rape (Brassica napus) is an important oil crop worldwide. The aim of this study was to identify the variation in nitrogen (N) efficiency of new-type B. napus (genome ArArCcCc) genotypes, and to characterize some critical physiological and molecular mechanisms in response to N limitation. Methods Two genotypes with contrasting N efficiency (D4-15 and D1-1) were identified from 150 new-type B. napus lines, and hydroponic and pot experiments were conducted. Root morphology, plant biomass, N uptake parameters and seed yield of D4-15 and D1-1 were investigated. Two traditional B. napus (genome AnAnCnCn) genotypes, QY10 and NY7, were also cultivated. Introgression of exotic genomic components in D4-15 and D1-1 was evaluated with molecular markers. Key Results Large genetic variation existed among traits contributing to the N efficiency of new-type B. napus. Under low N levels at the seedling stage, the N-efficient new-type D4-15 showed higher values than the N-inefficient D1-1 line and the traditional B. napus QY10 and NY7 genotypes with respect to several traits, including root and shoot biomass, root morphology, N accumulation, N utilization efficiency (NutE), N uptake efficiency (NupE), activities of nitrate reductase (NR) and glutamine synthetase (GS), and expression levels of N transporter genes and genes that are involved in N assimilation. Higher yield was produced by the N-efficient D4-15 line compared with the N-inefficient D1-1 at maturity. More exotic genome components were introgressed into the genome of D4-15 (64·97 %) compared with D1-1 (32·23 %). Conclusions The N-efficient new-type B. napus identified in this research had higher N efficiency (and tolerance to low-N stress) than traditional B. napus cultivars, and thus could have important potential for use in breeding N-efficient B. napus cultivars in the field. PMID:24989788

  17. Rapid alterations of gene expression and cytosine methylation in newly synthesized Brassica napus allopolyploids.

    PubMed

    Xu, Yanhao; Zhong, Lan; Wu, Xiaoming; Fang, Xiaoping; Wang, Jianbo

    2009-02-01

    Allopolyploidy is an important speciation mechanism and is ubiquitous among plants. Brassica napus is a model system for studying the consequences of hybridization and polyploidization on allopolyploid genome. In this research, two sets of plant materials were used to investigate the transcriptomic and epigenetic changes in the early stages of allopolyploid formation. The first comparison was between a synthetic B. napus allotetraploid and its diploid progenitors, B. rapa (AA genome) and B. oleracea (CC genome). Using cDNA-amplified fragment length polymorphism (cDNA-AFLP) and methylation-sensitive amplification polymorphism (MSAP) approaches, ~4.09 and 6.84% of the sequences showed changes in gene expression and DNA methylation in synthesized B. napus compared to its diploid progenitors. The proportions of C-genome-specific gene silencing and DNA methylation alterations were significantly greater than those of A-genome-specific alterations. The second comparison was between amphihaploid and amphidiploid B. napus organs grown on synthesized dimorphic plants. About 0.73% of the cDNA-AFLP fragments and 1.94% of the MSAP fragments showed changes in gene expression and DNA methylation. We sequenced 103 fragments that differed in the synthetic/parental or the amphihaploid/amphidiploid cDNA-AFLP and MSAP comparisons. Sequence analysis revealed these fragments were involved in various biological pathways. Our results provided evidence for genome-wide changes in gene expression and DNA methylation occurring immediately after hybridization and polyploidization in synthetic B. napus. Moreover, this study contributed to the elucidation of genome doubling effects on responses of transcriptome and epigenetics in B. napus.

  18. Comparative Analysis of the Brassica napus Root and Leaf Transcript Profiling in Response to Drought Stress.

    PubMed

    Liu, Chunqing; Zhang, Xuekun; Zhang, Ka; An, Hong; Hu, Kaining; Wen, Jing; Shen, Jinxiong; Ma, Chaozhi; Yi, Bin; Tu, Jinxing; Fu, Tingdong

    2015-08-11

    Drought stress is one of the major abiotic factors affecting Brassica napus (B. napus) productivity. In order to identify genes of potential importance to drought stress and obtain a deeper understanding of the molecular mechanisms regarding the responses of B. napus to dehydration stress, we performed large-scale transcriptome sequencing of B. napus plants under dehydration stress using the Illumina sequencing technology. In this work, a relatively drought tolerant B. napus line, Q2, identified in our previous study, was used. Four cDNA libraries constructed from mRNAs of control and dehydration-treated root and leaf were sequenced by Illumina technology. A total of 6018 and 5377 differentially expressed genes (DEGs) were identified in root and leaf. In addition, 1745 genes exhibited a coordinated expression profile between the two tissues under drought stress, 1289 (approximately 74%) of which showed an inverse relationship, demonstrating different regulation patterns between the root and leaf. The gene ontology (GO) enrichment test indicated that up-regulated genes in root were mostly involved in "stimulus" "stress" biological process, and activated genes in leaf mainly functioned in "cell" "cell part" components. Furthermore, a comparative network related to plant hormone signal transduction and AREB/ABF, AP2/EREBP, NAC, WRKY and MYC/MYB transcription factors (TFs) provided a view of different stress tolerance mechanisms between root and leaf. Some of the DEGs identified may be candidates for future research aimed at detecting drought-responsive genes and will be useful for understanding the molecular mechanisms of drought tolerance in root and leaf of B. napus.

  19. Comparative Analysis of the Brassica napus Root and Leaf Transcript Profiling in Response to Drought Stress.

    PubMed

    Liu, Chunqing; Zhang, Xuekun; Zhang, Ka; An, Hong; Hu, Kaining; Wen, Jing; Shen, Jinxiong; Ma, Chaozhi; Yi, Bin; Tu, Jinxing; Fu, Tingdong

    2015-01-01

    Drought stress is one of the major abiotic factors affecting Brassica napus (B. napus) productivity. In order to identify genes of potential importance to drought stress and obtain a deeper understanding of the molecular mechanisms regarding the responses of B. napus to dehydration stress, we performed large-scale transcriptome sequencing of B. napus plants under dehydration stress using the Illumina sequencing technology. In this work, a relatively drought tolerant B. napus line, Q2, identified in our previous study, was used. Four cDNA libraries constructed from mRNAs of control and dehydration-treated root and leaf were sequenced by Illumina technology. A total of 6018 and 5377 differentially expressed genes (DEGs) were identified in root and leaf. In addition, 1745 genes exhibited a coordinated expression profile between the two tissues under drought stress, 1289 (approximately 74%) of which showed an inverse relationship, demonstrating different regulation patterns between the root and leaf. The gene ontology (GO) enrichment test indicated that up-regulated genes in root were mostly involved in "stimulus" "stress" biological process, and activated genes in leaf mainly functioned in "cell" "cell part" components. Furthermore, a comparative network related to plant hormone signal transduction and AREB/ABF, AP2/EREBP, NAC, WRKY and MYC/MYB transcription factors (TFs) provided a view of different stress tolerance mechanisms between root and leaf. Some of the DEGs identified may be candidates for future research aimed at detecting drought-responsive genes and will be useful for understanding the molecular mechanisms of drought tolerance in root and leaf of B. napus. PMID:26270661

  20. Hybridisation and introgression between Brassica napus and B. rapa in the Netherlands.

    PubMed

    Luijten, S H; Schidlo, N S; Meirmans, P G; de Jong, T J

    2015-01-01

    We used flow cytometry, chromosome counting and AFLP markers to investigate gene flow from the crop plant oilseed rape, Brassica napus (AACC) to wild B. rapa (AA) in the Netherlands. From 89 B. napus source populations investigated, all near cropping fields or at transhipment sites, only 19 contained a B. rapa population within a 2.5-km radius. During our survey we found only three populations with F1 hybrids (AAC), as recognized by their nine extra chromosomes and by flow cytometry. These hybrids were all collected in mixed populations where the two species grew in close proximity. Populations with F1 hybrids were not close to crops, but instead were located on road verges with highly disturbed soils, in which both species were probably recruited from the soil seed bank. Many plants in the F2, BC1 or higher backcrosses are expected to carry one to eight C chromosomes. However, these plants were not observed among the hybrids. We further investigated introgression with molecular markers (AFLP) and compared sympatric B. rapa populations (near populations of B. napus) with control populations of B. rapa (no B. napus within at least 7 km). We found no difference between sympatric and control populations in the number of C markers in B. rapa, nor did we find that these sympatric populations closely resembled B. napus. Our data show that hybrids occur but also suggest no recent introgression of alleles from the crop plant B. napus into wild B. rapa in the Dutch populations studied.

  1. Comparative Analysis of the Brassica napus Root and Leaf Transcript Profiling in Response to Drought Stress

    PubMed Central

    Liu, Chunqing; Zhang, Xuekun; Zhang, Ka; An, Hong; Hu, Kaining; Wen, Jing; Shen, Jinxiong; Ma, Chaozhi; Yi, Bin; Tu, Jinxing; Fu, Tingdong

    2015-01-01

    Drought stress is one of the major abiotic factors affecting Brassica napus (B. napus) productivity. In order to identify genes of potential importance to drought stress and obtain a deeper understanding of the molecular mechanisms regarding the responses of B. napus to dehydration stress, we performed large-scale transcriptome sequencing of B. napus plants under dehydration stress using the Illumina sequencing technology. In this work, a relatively drought tolerant B. napus line, Q2, identified in our previous study, was used. Four cDNA libraries constructed from mRNAs of control and dehydration-treated root and leaf were sequenced by Illumina technology. A total of 6018 and 5377 differentially expressed genes (DEGs) were identified in root and leaf. In addition, 1745 genes exhibited a coordinated expression profile between the two tissues under drought stress, 1289 (approximately 74%) of which showed an inverse relationship, demonstrating different regulation patterns between the root and leaf. The gene ontology (GO) enrichment test indicated that up-regulated genes in root were mostly involved in “stimulus” “stress” biological process, and activated genes in leaf mainly functioned in “cell” “cell part” components. Furthermore, a comparative network related to plant hormone signal transduction and AREB/ABF, AP2/EREBP, NAC, WRKY and MYC/MYB transcription factors (TFs) provided a view of different stress tolerance mechanisms between root and leaf. Some of the DEGs identified may be candidates for future research aimed at detecting drought-responsive genes and will be useful for understanding the molecular mechanisms of drought tolerance in root and leaf of B. napus. PMID:26270661

  2. Hybridisation and introgression between Brassica napus and B. rapa in the Netherlands.

    PubMed

    Luijten, S H; Schidlo, N S; Meirmans, P G; de Jong, T J

    2015-01-01

    We used flow cytometry, chromosome counting and AFLP markers to investigate gene flow from the crop plant oilseed rape, Brassica napus (AACC) to wild B. rapa (AA) in the Netherlands. From 89 B. napus source populations investigated, all near cropping fields or at transhipment sites, only 19 contained a B. rapa population within a 2.5-km radius. During our survey we found only three populations with F1 hybrids (AAC), as recognized by their nine extra chromosomes and by flow cytometry. These hybrids were all collected in mixed populations where the two species grew in close proximity. Populations with F1 hybrids were not close to crops, but instead were located on road verges with highly disturbed soils, in which both species were probably recruited from the soil seed bank. Many plants in the F2, BC1 or higher backcrosses are expected to carry one to eight C chromosomes. However, these plants were not observed among the hybrids. We further investigated introgression with molecular markers (AFLP) and compared sympatric B. rapa populations (near populations of B. napus) with control populations of B. rapa (no B. napus within at least 7 km). We found no difference between sympatric and control populations in the number of C markers in B. rapa, nor did we find that these sympatric populations closely resembled B. napus. Our data show that hybrids occur but also suggest no recent introgression of alleles from the crop plant B. napus into wild B. rapa in the Dutch populations studied. PMID:24889091

  3. Possibilities of direct introgression from Brassica napus to B. juncea and indirect introgression from B. napus to related Brassicaceae through B. juncea.

    PubMed

    Tsuda, Mai; Ohsawa, Ryo; Tabei, Yutaka

    2014-05-01

    The impact of genetically modified canola (Brassica napus) on biodiversity has been examined since its initial stage of commercialization. Various research groups have extensively investigated crossability and introgression among species of Brassicaceae. B. rapa and B. juncea are ranked first and second as the recipients of cross-pollination and introgression from B. napus, respectively. Crossability between B. napus and B. rapa has been examined, specifically in terms of introgression from B. napus to B. rapa, which is mainly considered a weed in America and European countries. On the other hand, knowledge on introgression from B. napus to B. juncea is insufficient, although B. juncea is recognized as the main Brassicaceae weed species in Asia. It is therefore essential to gather information regarding the direct introgression of B. napus into B. juncea and indirect introgression of B. napus into other species of Brassicaceae through B. juncea to evaluate the influence of genetically modified canola on biodiversity. We review information on crossability and introgression between B. juncea and other related Brassicaseae in this report.

  4. A large-scale introgression of genomic components of Brassica rapa into B. napus by the bridge of hexaploid derived from hybridization between B. napus and B. oleracea.

    PubMed

    Li, Qinfei; Mei, Jiaqin; Zhang, Yongjing; Li, Jiana; Ge, Xianhong; Li, Zaiyun; Qian, Wei

    2013-08-01

    Brassica rapa (AA) has been used to widen the genetic basis of B. napus (AACC), which is a new but important oilseed crop worldwide. In the present study, we have proposed a strategy to develop new type B. napus carrying genomic components of B. rapa by crossing B. rapa with hexaploid (AACCCC) derived from B. napus and B. oleracea (CC). The hexaploid exhibited large flowers and high frequency of normal chromosome segregation, resulting in good seed set (average of 4.48 and 12.53 seeds per pod by self and open pollination, respectively) and high pollen fertility (average of 87.05 %). It was easy to develop new type B. napus by crossing the hexaploid with 142 lines of B. rapa from three ecotype groups, with the average crossability of 9.24 seeds per pod. The genetic variation of new type B. napus was diverse from that of current B. napus, especially in the A subgenome, revealed by genome-specific simple sequence repeat markers. Our data suggest that the strategy proposed here is a large-scale and highly efficient method to introgress genomic components of B. rapa into B. napus. PMID:23699961

  5. A large-scale introgression of genomic components of Brassica rapa into B. napus by the bridge of hexaploid derived from hybridization between B. napus and B. oleracea.

    PubMed

    Li, Qinfei; Mei, Jiaqin; Zhang, Yongjing; Li, Jiana; Ge, Xianhong; Li, Zaiyun; Qian, Wei

    2013-08-01

    Brassica rapa (AA) has been used to widen the genetic basis of B. napus (AACC), which is a new but important oilseed crop worldwide. In the present study, we have proposed a strategy to develop new type B. napus carrying genomic components of B. rapa by crossing B. rapa with hexaploid (AACCCC) derived from B. napus and B. oleracea (CC). The hexaploid exhibited large flowers and high frequency of normal chromosome segregation, resulting in good seed set (average of 4.48 and 12.53 seeds per pod by self and open pollination, respectively) and high pollen fertility (average of 87.05 %). It was easy to develop new type B. napus by crossing the hexaploid with 142 lines of B. rapa from three ecotype groups, with the average crossability of 9.24 seeds per pod. The genetic variation of new type B. napus was diverse from that of current B. napus, especially in the A subgenome, revealed by genome-specific simple sequence repeat markers. Our data suggest that the strategy proposed here is a large-scale and highly efficient method to introgress genomic components of B. rapa into B. napus.

  6. Possibilities of direct introgression from Brassica napus to B. juncea and indirect introgression from B. napus to related Brassicaceae through B. juncea

    PubMed Central

    Tsuda, Mai; Ohsawa, Ryo; Tabei, Yutaka

    2014-01-01

    The impact of genetically modified canola (Brassica napus) on biodiversity has been examined since its initial stage of commercialization. Various research groups have extensively investigated crossability and introgression among species of Brassicaceae. B. rapa and B. juncea are ranked first and second as the recipients of cross-pollination and introgression from B. napus, respectively. Crossability between B. napus and B. rapa has been examined, specifically in terms of introgression from B. napus to B. rapa, which is mainly considered a weed in America and European countries. On the other hand, knowledge on introgression from B. napus to B. juncea is insufficient, although B. juncea is recognized as the main Brassicaceae weed species in Asia. It is therefore essential to gather information regarding the direct introgression of B. napus into B. juncea and indirect introgression of B. napus into other species of Brassicaceae through B. juncea to evaluate the influence of genetically modified canola on biodiversity. We review information on crossability and introgression between B. juncea and other related Brassicaseae in this report. PMID:24987292

  7. Possibilities of direct introgression from Brassica napus to B. juncea and indirect introgression from B. napus to related Brassicaceae through B. juncea.

    PubMed

    Tsuda, Mai; Ohsawa, Ryo; Tabei, Yutaka

    2014-05-01

    The impact of genetically modified canola (Brassica napus) on biodiversity has been examined since its initial stage of commercialization. Various research groups have extensively investigated crossability and introgression among species of Brassicaceae. B. rapa and B. juncea are ranked first and second as the recipients of cross-pollination and introgression from B. napus, respectively. Crossability between B. napus and B. rapa has been examined, specifically in terms of introgression from B. napus to B. rapa, which is mainly considered a weed in America and European countries. On the other hand, knowledge on introgression from B. napus to B. juncea is insufficient, although B. juncea is recognized as the main Brassicaceae weed species in Asia. It is therefore essential to gather information regarding the direct introgression of B. napus into B. juncea and indirect introgression of B. napus into other species of Brassicaceae through B. juncea to evaluate the influence of genetically modified canola on biodiversity. We review information on crossability and introgression between B. juncea and other related Brassicaseae in this report. PMID:24987292

  8. Development of a core set of single-locus SSR markers for allotetraploid rapeseed (Brassica napus L.).

    PubMed

    Li, Haitao; Younas, Muhammad; Wang, Xiaofeng; Li, Xuemin; Chen, Lin; Zhao, Bo; Chen, Xun; Xu, Jinsong; Hou, Fan; Hong, Baohua; Liu, Gang; Zhao, Hongyang; Wu, Xueli; Du, Hongzhi; Wu, Jiangsheng; Liu, Kede

    2013-04-01

    Brassica napus (AACC) is a recent allotetraploid species evolved through hybridization between two diploids, B. rapa (AA) and B. oleracea (CC). Due to extensive genome duplication and homoeology within and between the A and C genomes of B. napus, most SSR markers display multiple fragments or loci, which limit their application in genetics and breeding studies of this economically important crop. In this study, we collected 3,890 SSR markers from previous studies and also developed 5,968 SSR markers from genomic sequences of B. rapa, B. oleracea and B. napus. Of these, 2,701 markers that produced single amplicons were putative single-locus markers in the B. napus genome. Finally, a set of 230 high-quality single-locus SSR markers were established and assigned to the 19 linkage groups of B. napus using a segregating population with 154 DH individuals. A subset of 78 selected single-locus SSR markers was proved to be highly stable and could successfully discriminate each of the 45 inbred lines and hybrids. In addition, most of the 230 SSR markers showed the single-locus nature in at least one of the Brassica species of the U's triangle besides B. napus. These results indicated that this set of single-locus SSR markers has a wide range of coverage with excellent stability and would be useful for gene tagging, sequence scaffold assignment, comparative mapping, diversity analysis, variety identification and association mapping in Brassica species.

  9. Identification of miRNAs and their targets from Brassica napus by high-throughput sequencing and degradome analysis

    PubMed Central

    2012-01-01

    Background MicroRNAs (miRNAs) are endogenous regulators of a broad range of physiological processes and act by either degrading mRNA or blocking its translation. Oilseed rape (Brassica napus) is one of the most important crops in China, Europe and other Asian countries with publicly available expressed sequence tags (ESTs) and genomic survey sequence (GSS) databases, but little is known about its miRNAs and their targets. To date, only 46 miRNAs have been identified in B. napus. Results Forty-one conserved and 62 brassica-specific candidate B. napus miRNAs, including 20 miRNA* sequences, were identified using Solexa sequencing technology. Furthermore, 33 non-redundant mRNA targets of conserved brassica miRNAs and 19 new non-redundant mRNA targets of novel brassica-specific miRNAs were identified by genome-scale sequencing of mRNA degradome. Conclusions This study describes large scale cloning and characterization of B. napus miRNAs and their potential targets, providing the foundation for further characterization of miRNA function in the regulation of diverse physiological processes in B. napus. PMID:22920854

  10. Identification of Candidate Genes for Seed Glucosinolate Content Using Association Mapping in Brassica napus L.

    PubMed Central

    Qu, Cun-Min; Li, Shi-Meng; Duan, Xiu-Jian; Fan, Jin-Hua; Jia, Le-Dong; Zhao, Hui-Yan; Lu, Kun; Li, Jia-Na; Xu, Xin-Fu; Wang, Rui

    2015-01-01

    Rapeseed contains glucosinolates, a toxic group of sulfur-containing glucosides, which play critical roles in defense against herbivores and microbes. However, the presence of glucosinolates in rapeseed reduces the value of the meal as feed for livestock. We performed association mapping of seed glucosinolate (GS) content using the 60K Brassica Infinium single nucleotide polymorphism (SNP) array in 520 oilseed rape accessions. A total of 11 peak SNPs significantly associated with GS content were detected in growing seasons of 2013 and 2014 and were located on B. napus chromosomes A08, A09, C03, and C09, respectively. Two associated regions of GS content covered by these markers were further verified, and three B. napus homologous genes involved in the biosynthesis and accumulation of GS were identified. These genes were multigene family members and were distributed on different chromosomes. Moreover, two genes (BnGRT2 and BnMYB28) associated with GS content were validated by the qRT-PCR analysis of their expression profiles. The further identification and functionalization of these genes will provide useful insight into the mechanism underlying GS biosynthesis and allocation in B. napus, and the associated SNPs markers could be helpful for molecular maker-assisted breeding for low seed GS in B. napus. PMID:26593950

  11. Comparative transcriptomic analysis uncovers the complex genetic network for resistance to Sclerotinia sclerotiorum in Brassica napus

    PubMed Central

    Wu, Jian; Zhao, Qing; Yang, Qingyong; Liu, Han; Li, Qingyuan; Yi, Xinqi; Cheng, Yan; Guo, Liang; Fan, Chuchuan; Zhou, Yongming

    2016-01-01

    Sclerotinia stem rot caused by Sclerotinia sclerotiorum is one of the most devastating diseases in many important crops including Brassica napus worldwide. Quantitative resistance is the only source for genetic improvement of Sclerotinia-resistance in B. napus, but the molecular basis for such a resistance is largely unknown. Here, we performed dynamic transcriptomic analyses to understand the differential defense response to S. sclerotiorum in a resistant line (R-line) and a susceptible line (S-line) of B. napus at 24, 48 and 96 h post-inoculation. Both the numbers of and fold changes in differentially expressed genes in the R-line were larger than those in the S-line. We identified 9001 relative differentially expressed genes in the R-line compared with the S-line. The differences between susceptibility and resistance were associated with the magnitude of expression changes in a set of genes involved in pathogen recognition, MAPK signaling cascade, WRKY transcription regulation, jasmonic acid/ethylene signaling pathways, and biosynthesis of defense-related protein and indolic glucosinolate. The results were supported by quantitation of defense-related enzyme activity and glucosinolate contents. Our results provide insights into the complex molecular mechanism of the defense response to S. sclerotiorum in B. napus and for development of effective strategies in Sclerotinia-resistance breeding. PMID:26743436

  12. Detection, introgression and localization of genes conferring specific resistance to Leptosphaeria maculans from Brassica rapa into B. napus.

    PubMed

    Leflon, M; Brun, H; Eber, F; Delourme, R; Lucas, M O; Vallée, P; Ermel, M; Balesdent, M H; Chèvre, A M

    2007-11-01

    Blackleg (stem canker) caused by the fungus Leptosphaeria maculans is one of the most damaging diseases of oilseed rape (Brassica napus). Crop relatives represent a valuable source of "new" resistance genes that could be used to diversify cultivar resistance. B. rapa, one of the progenitors of B. napus, is a potential source of new resistance genes. However, most of the accessions are heterozygous so it is impossible to directly detect the plant genes conferring specific resistance due to the complex patterns of avirulence genes in L. maculans isolates. We developed a strategy to simultaneously characterize and introgress resistance genes from B. rapa, by homologous recombination, into B. napus. One B. rapa plant resistant to one L. maculans isolate was used to produce B. rapa backcross progeny and a resynthesized B. napus plant from which a population of doubled haploid lines was derived after crossing with natural B. napus. We then used molecular analyses and resistance tests on these populations to identify and map the resistance genes and to characterize their introgression from B. rapa into B. napus. Three specific genes conferring resistance to L. maculans (Rlm1, Rlm2 and Rlm7) were identified in B. rapa. Comparisons of genetic maps showed that two of these genes were located on the R7 linkage group, in a region homologous to the region on linkage group N7 in B. napus, where these genes have been reported previously. The results of our study offer new perspectives for gene introgression and cloning in Brassicas.

  13. Glyphosate-drift but not herbivory alters the rate of transgene flow from single and stacked trait transgenic canola (Brassica napus) to nontransgenic B. napus and B. rapa.

    PubMed

    Londo, Jason P; Bollman, Michael A; Sagers, Cynthia L; Lee, E Henry; Watrud, Lidia S

    2011-08-01

    • Transgenic plants can offer agricultural benefits, but the escape of transgenes is an environmental concern. In this study we tested the hypothesis that glyphosate drift and herbivory selective pressures can change the rate of transgene flow between the crop Brassica napus (canola), and weedy species and contribute to the potential for increased transgene escape risk and persistence outside of cultivation. • We constructed plant communities containing single transgenic B. napus genotypes expressing glyphosate herbicide resistance (CP4 EPSPS), lepidopteran insect resistance (Cry1Ac), or both traits ('stacked'), plus nontransgenic B. napus, Brassica rapa and Brassica nigra. Two different selective pressures, a sublethal glyphosate dose and lepidopteran herbivores (Plutella xylostella), were applied and rates of transgene flow and transgenic seed production were measured. • Selective treatments differed in the degree in which they affected gene flow and production of transgenic hybrid seed. Most notably, glyphosate-drift increased the incidence of transgenic seeds on nontransgenic B. napus by altering flowering phenology and reproductive function. • The findings of this study indicate that transgenic traits may be transmitted to wild populations and may increase in frequency in weedy populations through the direct and indirect effects of selection pressures on gene flow.

  14. Development of a chloroplast DNA marker for monitoring of transgene introgression in Brassica napus L.

    PubMed

    Woo, Hee-Jong; Lim, Myung-Ho; Shin, Kong-Sik; Martins, Bianca; Lee, Bum-Kyu; Cho, Hyun-Suk; Mallory-Smith, Carol A

    2013-09-01

    Chloroplast molecular markers can provide useful information for high-resolution analysis of inter- and intra-specific variation in Brassicaceae and for differentiation between its species. Combining data generated from nuclear and chloroplast markers enables the study of seed and pollen movement, and assists in the assessment of gene-flow from genetically modified (GM) plants through hybridization studies. To develop chloroplast DNA markers for monitoring of transgene introgression in Brassica napus L., we searched for sequence variations in the chloroplast (cp) genome, and developed a simple cpDNA marker that is reliable, time-saving, and easily discriminates among 4 species (B. napus, B. rapa, Raphanus sativus, and Sinapis alba) based on PCR-product length polymorphism. This marker will be useful to identify maternal lineages and to estimate transgene movement of GM canola.

  15. Phytoextraction of Cd and Zn as single or mixed pollutants from soil by rape (Brassica napus).

    PubMed

    Cojocaru, Paula; Gusiatin, Zygmunt Mariusz; Cretescu, Igor

    2016-06-01

    This paper analyses the capacity of the rape (Brassica napus) to extract Cd and Zn from the soil and the effect of these metals on the morphometric parameters of the plant (length, weight, surface area, fractal dimension of leaves). Rape plants were mostly affected by the combined toxicity of the Cd and Zn mixture that caused a significant reduction in the rate of seed germination, the plant biomass quantity and the fractal dimension. In the case of Cd soil pollution, the bioaccumulation factor (BAF), bioaccumulation coefficient (BAC) as well as the heavy metal root-to-stalk translocation factor (TF) were determined. The results showed that B. napus had a great potential as a cadmium hyperaccumulator but not as an accumulator of Zn or Cd + Zn mixture. The efficiency of phytoextraction rape was 0.8-1.22 % for a soil heavily polluted with cadmium. PMID:26884243

  16. Computational Prediction of acyl-coA Binding Proteins Structure in Brassica napus

    PubMed Central

    Raboanatahiry, Nadia Haingotiana; Lu, Guangyuan; Li, Maoteng

    2015-01-01

    Acyl-coA binding proteins could transport acyl-coA esters from plastid to endoplasmic reticulum, prior to fatty acid biosynthesis, leading to the formation of triacylglycerol. The structure and the subcellular localization of acyl-coA binding proteins (ACBP) in Brassica napus were computationally predicted in this study. Earlier, the structure analysis of ACBPs was limited to the small ACBPs, the current study focused on all four classes of ACBPs. Physicochemical parameters including the size and the length, the intron-exon structure, the isoelectric point, the hydrophobicity, and the amino acid composition were studied. Furthermore, identification of conserved residues and conserved domains were carried out. Secondary structure and tertiary structure of ACBPs were also studied. Finally, subcellular localization of ACBPs was predicted. The findings indicated that the physicochemical parameters and subcellular localizations of ACBPs in Brassica napus were identical to Arabidopsis thaliana. Conserved domain analysis indicated that ACBPs contain two or three kelch domains that belong to different families. Identical residues in acyl-coA binding domains corresponded to eight amino acid residues in all ACBPs of B. napus. However, conserved residues of common ACBPs in all species of animal, plant, bacteria and fungi were only inclusive in small ACBPs. Alpha-helixes were displayed and conserved in all the acyl-coA binding domains, representing almost the half of the protein structure. The findings confirm high similarities in ACBPs between A. thaliana and B. napus, they might share the same functions but loss or gain might be possible. PMID:26065422

  17. Physical localization and genetic mapping of the fertility restoration gene Rfo in canola (Brassica napus L.).

    PubMed

    Feng, Jiuhuan; Primomo, Valerio; Li, Zenglu; Zhang, Yongping; Jan, Chao-Chien; Tulsieram, Lomas; Xu, Steven S

    2009-04-01

    The Ogu cytoplasm for male sterility and its fertility restorer gene Rfo in canola (Brassica napus L.) were originally introgressed from radish (Raphanus sativus L.) and have been widely used for canola hybrid production and breeding. The objective of this study was to determine the physical location of the Rfo locus in the canola genome using fluorescence in situ hybridization and genetic mapping. For physical localization of the Rfo gene, two bacterial artificial chromosome (BAC) clones, G62 and B420, which were closely linked to the Rfo gene, were used as probes to hybridize with the somatic metaphase chromosomes of a canola hybrid variety, PHI-46 (46H02), containing the Rfo fragment. The results showed that both clones were physically located at the end of one large metacentric chromosome. By simultaneous use of two BAC clones and 45S rDNA repeated sequences as the probes, we demonstrated that the large metacentric chromosome probed with the two BAC clones did not carry 45S rDNA repeated sequences. The chromosome was 3.65 +/- 0.74 microm in average length (20 cells) and ranked second in size among the chromosomes without 45S rDNAs. The centromere index of the chromosome (20 cells) was calculated as 43.74 +/- 4.19. A comparison with previously reported putative karyotypes of B. napus (AACC) and its diploid ancestors Brassica rapa L. (AA) and Brassica oleracea L. (CC) suggests that the chromosome carrying the Rfo fragment might belong to one of three large metacentric chromosomes of the C genome. Genetic mapping has confirmed the localization of the Rfo fragment to the distal region of linkage group N19, which corresponds to the C genome in B. napus. This study has provided the evidence of the location of the Rfo gene on canola chromosomes and established a basic framework for further physical mapping and manipulation of the gene.

  18. Bioremediation of pesticide wastes in soil using two plant species, Kochia Scoparia and Brassica Napus

    SciTech Connect

    Kruger, E.L.; Anderson, T.A.; Coats, J.R.

    1995-12-31

    Radiotracer studies were conducted to determine the fate of atrazine and metolachlor, applied as a mixture, in soils taken from pesticide-contaminated sites. Samples taken from nonvegetated areas and from the rhizosphere of Kochia scoparia were treated with {sup 14}C-atrazine and unlabeled metolachlor (50 {mu}g/g each) and incubated for 30, 60 or 135 d. A mass balance of the {sup 14}C applied revealed significant differences between the two soil types in soil bound residues, {sup 14}CO{sub 2}, and the extractable organic fraction (p<0.05). After 135-d incubation, 28% of the applied {sup 14}C was mineralized in Kochia rhizosphere soil, compared to 4% in soil taken from a nonvegetated area. A greater amount of {sup 14}C was extractable from the nonvegetated soil compared to the rhizosphere soil (64% and 22%, respectively). The half-life of atrazine based on extractable {sup 14}C-atrazine was 193 d in nonvegetated soil and 50 d in Kochia rhizosphere soil. Additional subsamples of nonvegetated soils treated with a mixture of {sup 14}C-atrazine and metolachlor were allowed to age for 135 d, and then were either planted with Brassica napus, Kochia scoparia, or left unvegetated. Incubations were carried out in enclosed chambers under controlled conditions. After 30 additional days, a subset of samples was extracted and analyzed using thin-layer chromatography, soil and plant combustion, and liquid scintillation spectroscopy. The percent of applied {sup 14}C-atrazine remaining as atrazine in soil which was nonvegetated, or planted with Brassica napus or Kochia scoparia was 9.3, 6.5, and 4.2%, respectively. Combustion of plants revealed that 11% of the applied radioactivity was taken up in Kochia scoparia, while less than 1% was taken up in Brassica napus plants. The potential for vegetation to aid in bioremediating pesticide wastes in soil is promising.

  19. RFLP and AFLP analysis of inter- and intraspecific variation of Brassica rapa and B. napus shows that B. rapa is an important genetic resource for B. napus improvement.

    PubMed

    Liu, Ren-Hu; Meng, Jin-Ling

    2006-09-01

    Fingerprinting of 29 accessions of oilseed rape, including seven accessions of Brassica napus, and 22 accessions of B. rapa (B. campestris) from Europe, North America, and China was analyzed using RFLP and AFLP markers. In total, 1,477 polymorphic RFLP bands and 183 polymorphic AFLP bands from 166 enzyme-probe combinations and two pairs of AFLP primers, respectively, were scored for the 29 accessions. On average, RFLP analysis showed that the Arabidopsis EST probe detected more polymorphic bands in Brassica than the random genomic probe performed. More polymorphic RFLP markers were detected with the digestion of EcoR I or BamH I than HindIII. According to the number of bands amplified from each accession, the copy numbers of each gene in the genomes of B. rapa and B. napus were estimated. The average copy numbers in B. rapa of China, B. rapa of Europe, and B. napus, were 3.2, 3.1, and 2.9, respectively. Genetic distance based on the AFLP data was well correlated with that based on the RFLP data (r = 0.72, P<0.001), but 0.39 smaller on average. Genetic diversity analysis showed that Chinese B. rapa was more polymorphic than Chinese B. napus and European materials. Some European B. napus accessions were clustered into European B. rapa, which were distinctly different from Chinese B. napus. The larger variations of Chinese accessions of B. rapa suggest that they are valuable in oilseed rape breeding. Novel strategies to use intersubgenomic heterosis between genome of B. rapa (A(r)A(r)) and genome of B. napus (A(n)A(n)C(n)C(n)) were elucidated.

  20. Field tolerance to fungal pathogens of Brassica napus constitutively expressing a chimeric chitinase gene

    SciTech Connect

    Grison, R.; Grezes-Besset, B.; Lucante, N.

    1996-05-01

    Constitutive overexpression of a protein involved in plant defense mechanisms to disease is one of the strategies proposed to increase plant tolerance to fungal pathogens. A hybrid endochitinase gene under a constitutive promoter was introduced by Agrobacterium-mediated transformation into a winter-type oilseed rape (Brassica napus var. oleifera) inbred line. Progeny from transformed plants was challenged using three different fungal pathogens (Cylindrosporium concentricum, Phoma lingam, Sclerotinia sclerotiorum) in field trials at two different geographical locations. These plants exhibited an increased tolerance to disease as compared with the nontransgenic parental plants. 31 refs., 1 fig., 2 tabs.

  1. Construction of novel Brassica napus genotypes through chromosomal substitution and elimination using interploid species hybridization.

    PubMed

    Li, Maoteng; Qian, Wei; Meng, Jinling; Li, Zongyun

    2004-01-01

    A synthetic Brassica napus rapeseed with genome composition of A(r)A(r)C(c)C(c), made by combining A(r) from B. rapa (A(r)A(r)) and C(c) from B. carinata (B(c)B(c)C(c)C(c)), is valuable for making new genes available to breeders and gaining heterosis in crosses. An intergenomic hybrid A(n)A(r)C(n)C(c) was made from a hybrid between natural Brassica napus (A(n)A(n)C(n)C(n)) and a synthetic rapeseed. To construct the synthetic Brassica napus, hexaploid plants (2n=54, A(r)A(r)B(c)B(c)C(c)C(c)) were first obtained through chromosome doubling of trigenomic hybrids (2n=27, A(r)B(c)C(c)) between Brassica carinata (2n=34) and B. rapa (2n=20). Pentaploid hybrids (2n=46, A(r)A(n)B(c)C(c)C(n)) were then produced by crossing the hexaploid with the pollen of natural B. napus (2n=38). Chromosomes with dual and single B(c) genomes were observed in somatic cells of hexaploid and pentaploid plants. About 80% of pollen mother cells of pentaploid hybrids had 19 or more bivalents, indicating that the bivalents from A(r)/A(n) and C(c)/C(n) chromosomes were normally formed. The occurrence of trivalents and quadrivalents at diakinesis suggested that B(c), A(n) and A(r) or B(c), C(n) and C(c) homologous pairing and exchange might happen. The variable number of laggards, 3 and 4 in most cases, were observed in the majority of PMCs at anaphase. Results from genomic in situ hybridization showed that the laggards belonged mainly to the B(c) genome, suggesting that the B(c) genome could be eliminated in the gametes of pentaploid hybrids. 16.15% of seeds derived from self-pollinated pentaploids have 38 chromosomes, and 90% of 38-chromosome seeds were completely excluded B(c) genome. The cytological results of this experiment suggested that it is possible to obtain new materials with genome composition of A(r)A(r)C(c)C(c) for rapeseed breeding.

  2. Ultrastructural changes in shoot apical meristem of canola (Brassica napus cv. Symbol) treated with sodium chloride.

    PubMed

    Mahmoodzadeh, Homa

    2008-04-15

    In the present research, structure and ultrastructure of shoot apical meristem of canola (Brassica napus cv. Symbol) under salinity conditions were investigated. The experiments were conducted in five groups (0, 3, 6, 9, 12 dS m(-1)) under greenhouse conditions. Sampling of apical meristem and TEM tissue preparation procedure were carried out. Semithin and ultrathin sections were prepared and viewed in light and electron microscopy, respectively. The results included reduction of meristem size, disorders in meristem structure. Also formation of autophagic vacuoles was observed that is probably one of the plant responses to salt stress for more water storage in these vacuoles and decreasing of cell water requirements.

  3. Comparison of winter and summer canola (Brassica napus) genotypes in Turkey.

    PubMed

    Maltas, E; Vural, H C

    2013-01-01

    We examined genetic relationships between canola (Brassica napus) genotypes cultivated in winter and spring in Turkey. Genomic DNA was isolated from the seeds by two modified CTAB protocols: EZ1 nucleic acid isolation method and a commercial kit (Dneasy Plant Mini Kit, Qiagen). Diversity and genetic relationships in the genotypes were analyzed with RAPD markers; 156 reliable bands were found for both genotypes, of which 24% were polymorphic. Fifteen primers gave at least one consistent polymorphic band. The dendogram developed by pooling data of RAPD analysis of summer and winter genotypes had similar patterns. This technique allowed us to examine the relationship between canola genotypes.

  4. BnNAC485 is involved in abiotic stress responses and flowering time in Brassica napus.

    PubMed

    Ying, Lu; Chen, Haiying; Cai, Weiming

    2014-06-01

    NAC domain proteins are plant-specific transcription factors that play important roles in plant growth and development. In this present study, we isolated BnNAC485 from Brassica napus L. (cv. HuYou15) and found that it showed high homology (84% at the amino acid level) with a NAC protein called AtRD26/ANAC072. BnNAC485 was specifically expressed in cotyledons and leaves of young seedlings, and expression was induced by abiotic stress and abscisic acid (ABA) treatment. The BnNAC485 protein localized to the nucleus. Over-expression of BnNAC485 enhanced tolerance to abiotic stress compared with wild-type plants in both B. napus and Arabidopsis thaliana. Furthermore, under exogenous ABA stress, BnNAC485 over-expression lines showed hypersensitivity to this treatment compared with wild-type B. napus and A. thaliana plants. Moreover, exogenous ABA treatment enhanced stomatal closing in B. napus plants over-expressing BnNAC485. Real-time RT-PCR assays showed that some abiotic- or ABA-responsive genes were up-regulated in A. thaliana plants over-expressing BnNAC485. Additionally, the transgenic lines flowered earlier than the wild-type B. napus and A. thaliana plants and the expression patterns of certain circadian clock genes were found to have changed. These results suggest that BnNAC485 acts in response to abiotic stress in plants via an ABA-mediated pathway and this gene can also alter plant flowering time.

  5. Type 1 diacylglycerol acyltransferases of Brassica napus preferentially incorporate oleic acid into triacylglycerol

    PubMed Central

    Aznar-Moreno, Jose; Denolf, Peter; Van Audenhove, Katrien; De Bodt, Stefanie; Engelen, Steven; Fahy, Deirdre; Wallis, James G.; Browse, John

    2015-01-01

    DGAT1 enzymes (acyl-CoA:diacylglycerol acyltransferase 1, EC 2.3.1.20) catalyse the formation of triacylglycerols (TAGs), the most abundant lipids in vegetable oils. Thorough understanding of the enzymology of oil accumulation is critical to the goal of modifying oilseeds for improved vegetable oil production. Four isoforms of BnDGAT1, the final and rate-limiting step in triacylglycerol synthesis, were characterized from Brassica napus, one of the world’s most important oilseed crops. Transcriptional profiling of developing B. napus seeds indicated two genes, BnDGAT1-1 and BnDGAT1-2, with high expression and two, BnDGAT1-3 and BnDGAT1-4, with low expression. The activities of each BnDGAT1 isozyme were characterized following expression in a strain of yeast deficient in TAG synthesis. TAG from B. napus seeds contain only 10% palmitic acid (16:0) at the sn-3 position, so it was surprising that all four BnDGAT1 isozymes exhibited strong (4- to 7-fold) specificity for 16:0 over oleic acid (18:1) as the acyl-CoA substrate. However, the ratio of 18:1-CoA to 16:0-CoA in B. napus seeds during the peak period of TAG synthesis is 3:1. When substrate selectivity assays were conducted with 18:1-CoA and 16:0-CoA in a 3:1 ratio, the four isozymes incorporated 18:1 in amounts 2- to 5-fold higher than 16:0. This strong sensitivity of the BnDGAT1 isozymes to the relative concentrations of acyl-CoA substrates substantially explains the observed fatty acid composition of B. napus seed oil. Understanding these enzymes that are critical for triacylglycerol synthesis will facilitate genetic and biotechnological manipulations to improve this oilseed crop. PMID:26195728

  6. Type 1 diacylglycerol acyltransferases of Brassica napus preferentially incorporate oleic acid into triacylglycerol.

    PubMed

    Aznar-Moreno, Jose; Denolf, Peter; Van Audenhove, Katrien; De Bodt, Stefanie; Engelen, Steven; Fahy, Deirdre; Wallis, James G; Browse, John

    2015-10-01

    DGAT1 enzymes (acyl-CoA:diacylglycerol acyltransferase 1, EC 2.3.1.20) catalyse the formation of triacylglycerols (TAGs), the most abundant lipids in vegetable oils. Thorough understanding of the enzymology of oil accumulation is critical to the goal of modifying oilseeds for improved vegetable oil production. Four isoforms of BnDGAT1, the final and rate-limiting step in triacylglycerol synthesis, were characterized from Brassica napus, one of the world's most important oilseed crops. Transcriptional profiling of developing B. napus seeds indicated two genes, BnDGAT1-1 and BnDGAT1-2, with high expression and two, BnDGAT1-3 and BnDGAT1-4, with low expression. The activities of each BnDGAT1 isozyme were characterized following expression in a strain of yeast deficient in TAG synthesis. TAG from B. napus seeds contain only 10% palmitic acid (16:0) at the sn-3 position, so it was surprising that all four BnDGAT1 isozymes exhibited strong (4- to 7-fold) specificity for 16:0 over oleic acid (18:1) as the acyl-CoA substrate. However, the ratio of 18:1-CoA to 16:0-CoA in B. napus seeds during the peak period of TAG synthesis is 3:1. When substrate selectivity assays were conducted with 18:1-CoA and 16:0-CoA in a 3:1 ratio, the four isozymes incorporated 18:1 in amounts 2- to 5-fold higher than 16:0. This strong sensitivity of the BnDGAT1 isozymes to the relative concentrations of acyl-CoA substrates substantially explains the observed fatty acid composition of B. napus seed oil. Understanding these enzymes that are critical for triacylglycerol synthesis will facilitate genetic and biotechnological manipulations to improve this oilseed crop.

  7. Glyphostate-drift but not herbivory alters the rate of transgene flow from single and stacked trait transgenic canola (Brassica napus L.) to non-transgenic B. napus and B. rapa

    EPA Science Inventory

    While transgenic plants can offer agricultural benefits, the escape of transgenes out of crop fields is a major environmental concern. Escape of transgenic herbicide resistance has occurred between transgenic Brassica napus (canola) and weedy species in numerous locations. In t...

  8. Production of asymmetric hybrids between Arabidopsis thaliana and Brassica napus utilizing an efficient protoplast culture system.

    PubMed

    Yamagishi, H.; Landgren, M.; Forsberg, J.; Glimelius, K.

    2002-05-01

    Application of the protoplast culture method developed for Brassica protoplasts to protoplasts of Arabidopsis thaliana has increased the opportunities for interspecific hybridizations involving Arabidopsis. A more-efficient and much-simpler method was established compared to the earlier-reported protocol developed for A. thaliana protoplasts in which alginate beads were utilized. Mesophyll protoplasts of A. thaliana (ecotypes 'Landsberg erecta' and 'Wassilewskija') were cultured in the modified 8p liquid medium, which had been developed for Brassica protoplasts. For comparison, protoplasts were cultured in sodium alginate beads supplied with B5 medium according to the protocol for A. thaliana. The protoplasts divided with high frequencies in the 8p medium, and calli proliferated more rapidly than in the sodium alginate beads. High frequencies of shoot differentiation and regeneration were observed in calli of both ecotypes, from about 30% in the ecotype 'Wassilewskija' to about 60% for 'Landsberg erecta'. The more-rapidly the calli developed, the higher the regeneration frequencies were. Asymmetric hybrids between A. thaliana and Brassica napus were obtained by treating the protoplasts of A. thaliana with iodoacetamide (IOA) and B. napus protoplasts with UV-irradiation before fusion with polyethylene glycol (PEG). By using the culture procedure developed for Brassica protoplasts, calli developed and plants were regenerated. Although most of the plants regenerated after cell fusion were A. thaliana-like and were judged to be escapes from IOA treatment, more than ten plants showed hybrid features of both morphological and molecular characters. Among the hybrids that have flowered so far, both male-fertile and male-sterile plants have been obtained. Back-crossings to A. thaliana are now in progress as is morphological and molecular characterization of the plants.

  9. Identification and characterization of candidate Rlm4 blackleg resistance genes in Brassica napus using next-generation sequencing.

    PubMed

    Tollenaere, Reece; Hayward, Alice; Dalton-Morgan, Jessica; Campbell, Emma; Lee, Joanne R M; Lorenc, Michal T; Manoli, Sahana; Stiller, Jiri; Raman, Rosy; Raman, Harsh; Edwards, David; Batley, Jacqueline

    2012-08-01

    A thorough understanding of the relationships between plants and pathogens is essential if we are to continue to meet the agricultural needs of the world's growing population. The identification of genes underlying important quantitative trait loci is extremely challenging in complex genomes such as Brassica napus (canola, oilseed rape or rapeseed). However, recent advances in next-generation sequencing (NGS) enable much quicker identification of candidate genes for traits of interest. Here, we demonstrate this with the identification of candidate disease resistance genes from B. napus for its most devastating fungal pathogen, Leptosphaeria maculans (blackleg fungus). These two species are locked in an evolutionary arms race whereby a gene-for-gene interaction confers either resistance or susceptibility in the plant depending on the genotype of the plant and pathogen. Preliminary analysis of the complete genome sequence of Brassica rapa, the diploid progenitor of B. napus, identified numerous candidate genes with disease resistance characteristics, several of which were clustered around a region syntenic with a major locus (Rlm4) for blackleg resistance on A7 of B. napus. Molecular analyses of the candidate genes using B. napus NGS data are presented, and the difficulties associated with identifying functional gene copies within the highly duplicated Brassica genome are discussed.

  10. [Creation and analysis of Brassica napus + Arabidopsis thaliana somatic hybrids possessing maize Spm/dSpm heterologous transposable system].

    PubMed

    Ovcharenko, O O; Komarnyts'kyĭ, I K; Cherep, M M; Hleba, Iu Iu; Kuchuk, M V

    2005-01-01

    Functionally asymmetric somatic hybrids possessing heterologous transposable element Spm/dSpm were obtained following intertribal somatic hybridization between Brassica napus and transgenic Arabidopsis thaliana. Mobile genetic elements actively transposed in the hybrid genomes. Complete elimination of A. thaliana genome was not observed.

  11. Chemical variation for leaf cuticular waxes and their levels revealed in a diverse panel of Brassica napus L.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brassica napus L. is one of the most important oilseed crops in the world, providing oil and protein used for food, fuel, and industrial purposes. Despite high oil yields and desirable agronomic traits, its geographical range is mainly limited to temperate climates, and oil yields and quality are ne...

  12. Production and characterization of asymmetric somatic hybrids between Arabidopsis thaliana and Brassica napus.

    PubMed

    Bauer-Weston, B; Keller, W; Webb, J; Gleddie, S

    1993-04-01

    Cell suspension-derived protoplasts of a chlorsulfuron-resistant (GH50) strain of Arabidopsis thaliana cv Columbia were X-irradiated at 60 or 90 krad, to facilitate the elimination of GH50 donor chromosomes in fusion products. Irradiated GH50 protoplasts were fused, with polyethylene glycol, to protoplasts derived from stem epidermal strips of Brassica napus cv Westar. Chlorsulfuron-resistant colonies were selected in vitro and then transferred to shoot and root regeneration medium. Seventeen hybrid lines were regenerated in vitro, and eight were successfully established in the greenhouse, where they flowered. These eight asymmetric hybrids were intermediate in vegetative morphology between Arabidopsis and Brassica. The flowers from these hybrids were male-sterile with abnormal petal and pistil structures. Zymograms for phosphoglucomutase, esterase, and peroxidase showed the presence of all parental isozymes in each of the hybrids tested. Nuclear hybridity was also confirmed for the ribosomal RNA genes using a wheat rDNA probe; however, the chloroplast genome in each of the hybrids was derived solely from the Brassica parent. All selected somatic hybrids were capable of rooting at levels of chlorsulfuron which were inhibitory to unfused Brassica plantlets. The degree of herbicide resistance in the hybrid shoots is presently being evaluated. PMID:24193454

  13. Hybridization between transgenic Brassica napus L. and its wild relatives: Brassica rapa L., Raphanus raphanistrum L., Sinapis arvensis L., and Erucastrum gallicum (Willd.) O.E. Schulz.

    PubMed

    Warwick, S I; Simard, M-J; Légère, A; Beckie, H J; Braun, L; Zhu, B; Mason, P; Séguin-Swartz, G; Stewart, C N

    2003-08-01

    The frequency of gene flow from Brassica napus L. (canola) to four wild relatives, Brassica rapa L., Raphanus raphanistrum L., Sinapis arvensis L. and Erucastrum gallicum (Willd.) O.E. Schulz, was assessed in greenhouse and/or field experiments, and actual rates measured in commercial fields in Canada. Various marker systems were used to detect hybrid individuals: herbicide resistance traits (HR), green fluorescent protein marker (GFP), species-specific amplified fragment length polymorphisms (AFLPs) and ploidy level. Hybridization between B. rapa and B. napus occurred in two field experiments (frequency approximately 7%) and in wild populations in commercial fields (approximately 13.6%). The higher frequency in commercial fields was most likely due to greater distance between B. rapa plants. All F(1) hybrids were morphologically similar to B. rapa, had B. napus- and B. rapa-specific AFLP markers and were triploid (AAC, 2n=29 chromosomes). They had reduced pollen viability (about 55%) and segregated for both self-incompatible and self-compatible individuals (the latter being a B. napus trait). In contrast, gene flow between R. raphanistrum and B. napus was very rare. A single R. raphanistrum x B. napus F1 hybrid was detected in 32,821 seedlings from the HR B. napus field experiment. The hybrid was morphologically similar to R. raphanistrum except for the presence of valves, a B. napus trait, in the distorted seed pods. It had a genomic structure consistent with the fusion of an unreduced gamete of R. raphanistrum and a reduced gamete of B. napus (RrRrAC, 2n=37), both B. napus- and R. raphanistrum-specific AFLP markers, and had <1% pollen viability. No hybrids were detected in the greenhouse experiments (1,534 seedlings), the GFP field experiment (4,059 seedlings) or in commercial fields in Québec and Alberta (22,114 seedlings). No S. arvensis or E. gallicum x B. napus hybrids were detected (42,828 and 21,841 seedlings, respectively) from commercial fields in

  14. Hybridization between transgenic Brassica napus L. and its wild relatives: Brassica rapa L., Raphanus raphanistrum L., Sinapis arvensis L., and Erucastrum gallicum (Willd.) O.E. Schulz.

    PubMed

    Warwick, S I; Simard, M-J; Légère, A; Beckie, H J; Braun, L; Zhu, B; Mason, P; Séguin-Swartz, G; Stewart, C N

    2003-08-01

    The frequency of gene flow from Brassica napus L. (canola) to four wild relatives, Brassica rapa L., Raphanus raphanistrum L., Sinapis arvensis L. and Erucastrum gallicum (Willd.) O.E. Schulz, was assessed in greenhouse and/or field experiments, and actual rates measured in commercial fields in Canada. Various marker systems were used to detect hybrid individuals: herbicide resistance traits (HR), green fluorescent protein marker (GFP), species-specific amplified fragment length polymorphisms (AFLPs) and ploidy level. Hybridization between B. rapa and B. napus occurred in two field experiments (frequency approximately 7%) and in wild populations in commercial fields (approximately 13.6%). The higher frequency in commercial fields was most likely due to greater distance between B. rapa plants. All F(1) hybrids were morphologically similar to B. rapa, had B. napus- and B. rapa-specific AFLP markers and were triploid (AAC, 2n=29 chromosomes). They had reduced pollen viability (about 55%) and segregated for both self-incompatible and self-compatible individuals (the latter being a B. napus trait). In contrast, gene flow between R. raphanistrum and B. napus was very rare. A single R. raphanistrum x B. napus F1 hybrid was detected in 32,821 seedlings from the HR B. napus field experiment. The hybrid was morphologically similar to R. raphanistrum except for the presence of valves, a B. napus trait, in the distorted seed pods. It had a genomic structure consistent with the fusion of an unreduced gamete of R. raphanistrum and a reduced gamete of B. napus (RrRrAC, 2n=37), both B. napus- and R. raphanistrum-specific AFLP markers, and had <1% pollen viability. No hybrids were detected in the greenhouse experiments (1,534 seedlings), the GFP field experiment (4,059 seedlings) or in commercial fields in Québec and Alberta (22,114 seedlings). No S. arvensis or E. gallicum x B. napus hybrids were detected (42,828 and 21,841 seedlings, respectively) from commercial fields in

  15. Transcriptome analysis of canola (Brassica napus) under salt stress at the germination stage.

    PubMed

    Long, Weihua; Zou, Xiling; Zhang, Xuekun

    2015-01-01

    Canola (Brassica napus) is one of the most important oil crops in the world. However, its yield has been constrained by salt stress. In this study, transcriptome profiles were explored using Digital Gene Expression (DGE) at 0, 3, 12 and 24 hours after H2O (control) and NaCl treatments on B. napus roots at the germination stage. Comparisons of gene-expression between the control and the treatment were conducted after tag-mapping to the sequenced Brassica rapa genome. The differentially expressed genes during the time course of salt stress were focused on, and 163 genes were identified to be differentially expressed at all the time points. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that some of the genes were involved in proline metabolism, inositol metabolism, carbohydrate metabolic processes and oxidation-reduction processes and may play vital roles in the salt-stress response at the germination stage. Thus, this study provides new candidate salt stress responding genes, which may function in novel putative nodes in the molecular pathways of salt stress resistance.

  16. Transcriptome Analysis of Canola (Brassica napus) under Salt Stress at the Germination Stage

    PubMed Central

    Long, Weihua; Zou, Xiling; Zhang, Xuekun

    2015-01-01

    Canola (Brassica napus) is one of the most important oil crops in the world. However, its yield has been constrained by salt stress. In this study, transcriptome profiles were explored using Digital Gene Expression (DGE) at 0, 3, 12 and 24 hours after H2O (control) and NaCl treatments on B. napus roots at the germination stage. Comparisons of gene-expression between the control and the treatment were conducted after tag-mapping to the sequenced Brassica rapa genome. The differentially expressed genes during the time course of salt stress were focused on, and 163 genes were identified to be differentially expressed at all the time points. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that some of the genes were involved in proline metabolism, inositol metabolism, carbohydrate metabolic processes and oxidation-reduction processes and may play vital roles in the salt-stress response at the germination stage. Thus, this study provides new candidate salt stress responding genes, which may function in novel putative nodes in the molecular pathways of salt stress resistance. PMID:25679513

  17. Numerous and rapid nonstochastic modifications of gene products in newly synthesized Brassica napus allotetraploids.

    PubMed

    Albertin, Warren; Balliau, Thierry; Brabant, Philippe; Chèvre, Anne-Marie; Eber, Frédérique; Malosse, Christian; Thiellement, Hervé

    2006-06-01

    Polyploidization is a widespread process that results in the merger of two or more genomes in a common nucleus. To investigate modifications of gene expression occurring during allopolyploid formation, the Brassica napus allotetraploid model was chosen. Large-scale analyses of the proteome were conducted on two organs, the stem and root, so that >1600 polypeptides were screened. Comparative proteomics of synthetic B. napus and its homozygous diploid progenitors B. rapa and B. oleracea showed that very few proteins disappeared or appeared in the amphiploids (<1%), but a strikingly high number (25-38%) of polypeptides displayed quantitative nonadditive pattern. Nonstochastic gene expression repatterning was found since 99% of the detected variations were reproducible in four independently created amphiploids. More than 60% of proteins displayed a nonadditive pattern closer to the paternal parent B. rapa. Interspecific hybridization triggered the majority of the deviations (89%), whereas very few variations (approximately 3%) were associated with genome doubling and more significant alterations arose from selfing (approximately 9%). Some nonadditive proteins behaved similarly in both organs, while others exhibited contrasted behavior, showing rapid organ-specific regulation. B. napus formation was therefore correlated with immediate and directed nonadditive changes in gene expression, suggesting that the early steps of allopolyploidization repatterning are controlled by nonstochastic mechanisms.

  18. Reproductive phenology of transgenic Brassica napus cultivars: Effect on intraspecific gene flow.

    PubMed

    Simard, Marie-Josée; Légère, Anne; Willenborg, Christian J

    2009-01-01

    Pollen-mediated gene flow in space is well documented and isolation distances are recommended to ensure genetic purity of Brassica napus seed crops. Isolation in time could also contribute to gene flow management but has been little investigated. We assessed the effects of asynchronous and synchronous flowering on intraspecific B. napus gene flow by seeding adjacent plots of transgenic spring canola cultivars, either resistant to glyphosate or glufosinate, over a 0-4 week interval and measuring outcrossing rates and seed-set. Outcrossing rates, evaluated in the center of the first adjacent row, were reduced to the lowest level in plots flowering first when the seeding interval > 2 weeks. Increasing the time gap increased outcrossing rates in plots flowering second up to a seeding interval of two weeks. Flowers that opened during the last week of the flowering period produced fewer seed (< 10% of total seed production) and a smaller fraction of outcrossed seed (-25%). Observed time gap effects were likely caused by extraneous pollen load during the receptivity of productive seed-setting early flowers. Clearly, manipulation of B. napus flowering development through staggered planting dates can contribute to gene flow management. The approach will need to be validated by additional site-years and increased isolation distances. PMID:20028614

  19. Sequence, expression divergence, and complementation of homologous ALCATRAZ loci in Brassica napus.

    PubMed

    Hua, Shuijin; Shamsi, Imran Haider; Guo, Yuan; Pak, Haksong; Chen, Mingxun; Shi, Congguang; Meng, Huabing; Jiang, Lixi

    2009-08-01

    The genomic era provides new perspectives in understanding polyploidy evolution, mostly on the genome-wide scale. In this paper, we show the sequence and expression divergence between the homologous ALCATRAZ (ALC) loci in Brassica napus, responsible for silique dehiscence. We cloned two homologous ALC loci, namely BnaC.ALC.a and BnaA.ALC.a in B. napus. Driven by the 35S promoter, both the loci complemented to the alc mutation of Arabidopsis thaliana, yet only the expression of BnaC.ALC.a was detectable in the siliques of B. napus. Sequence alignment indicated that BnaC.ALC.a and BolC.ALC.a, or BnaA.ALC.a and BraA.ALC.a, possess a high level of similarity. The understanding of the sequence and expression divergence among homologous loci of a gene is of due importance for an effective gene manipulation and TILLING (or ECOTILLING) analysis for the allelic DNA variation at a given locus. PMID:19504267

  20. Homoeologous Chromosome Sorting and Progression of Meiotic Recombination in Brassica napus: Ploidy Does Matter!

    PubMed

    Grandont, Laurie; Cuñado, Nieves; Coriton, Olivier; Huteau, Virgine; Eber, Frédérique; Chèvre, Anne Marie; Grelon, Mathilde; Chelysheva, Liudmila; Jenczewski, Eric

    2014-04-15

    Meiotic recombination is the fundamental process that produces balanced gametes and generates diversity within species. For successful meiosis, crossovers must form between homologous chromosomes. This condition is more difficult to fulfill in allopolyploid species, which have more than two sets of related chromosomes (homoeologs). Here, we investigated the formation, progression, and completion of several key hallmarks of meiosis in Brassica napus (AACC), a young polyphyletic allotetraploid crop species with closely related homoeologous chromosomes. Altogether, our results demonstrate a precocious and efficient sorting of homologous versus homoeologous chromosomes during early prophase I in two representative B. napus accessions that otherwise show a genotypic difference in the progression of homologous recombination. More strikingly, our detailed comparison of meiosis in near isogenic allohaploid and euploid plants showed that the mechanism(s) promoting efficient chromosome sorting in euploids is adjusted to promote crossover formation between homoeologs in allohaploids. This suggests that, in contrast to other polyploid species, chromosome sorting is context dependent in B. napus. PMID:24737673

  1. Proteome changes in leaves of Brassica napus L. as a result of Sclerotinia sclerotiorum challenge.

    PubMed

    Liang, Yue; Srivastava, Sanjeeva; Rahman, Muhammad H; Strelkov, Stephen E; Kav, Nat N V

    2008-03-26

    Sclerotinia stem rot, caused by the necrotrophic fungal pathogen Sclerotinia sclerotiorum, is a serious disease of canola (Brassica napus L.). To increase the understanding of the B. napus- S. sclerotiorum interaction, proteins potentially involved in mediating this interaction were identified and characterized. Upon infection of canola leaves by S. sclerotiorum, necrosis of host leaves was observed by 12 h and rapidly progressed during the later time points. These morphological observations were supported by microscopic study performed at different time points after pathogen challenge. Leaf proteins were extracted and analyzed by 2-DE, which revealed the modulation of 32 proteins (12 down- and 20 up-regulated). The identities of these proteins were established by ESI-q-TOF MS/MS and included proteins involved in photosynthesis and metabolic pathways, protein folding and modifications, hormone signaling, and antioxidant defense. Gene expression analysis of selected genes was performed by qRT-PCR, whereas the elevated levels of the antioxidant enzymes peroxidase and superoxide dismutase were validated by enzyme assays. To the authors' best knowledge, this is the first proteomics-based investigation of B. napus-S. sclerotiorum interaction, and the roles of many of the proteins identified are discussed within the context of this pathosystem. PMID:18290614

  2. Disruption of Germination and Seedling Development in Brassica napus by Mutations Causing Severe Seed Hormonal Imbalance.

    PubMed

    Nguyen, Tung C T; Obermeier, Christian; Friedt, Wolfgang; Abrams, Suzanne R; Snowdon, Rod J

    2016-01-01

    The Brassica napus (oilseed rape) accession 1012-98 shows a disturbed germination phenotype that was thought to be associated with its lack of testa pigmentation and thin seed coat. Here, we demonstrate that the disturbed germination and seedling development are actually due to independent mutations that disrupt the balance of hormone metabolites and their regulators in the seeds. High-throughput UPLC-MS/MS hormone profiling of seeds and seedlings before and after germination revealed that 1012-98 has a severely disturbed hormone balance with extremely atypical, excessive quantities of auxin and ABA metabolites. The resulting hypersensitivity to abscisic acid (ABA) and a corresponding increase in dormancy often results in death of the embryo after imbibition or high frequencies of disturbed, often lethal developmental phenotypes, resembling Arabidopsis mutants for the auxin regulatory factor gene ARF10 or the auxin-overproducing transgenic line iaaM-OX. Molecular cloning of Brassica ARF10 orthologs revealed four loci in normal B. napus, two derived from the Brassica A genome and two from the C genome. On the other hand, the phenotypic mutant 1012-98 exhibited amplification of C-genome BnaC.ARF10 copy number along with a chimeric allele originating from recombination between homeologous A and C genome loci which lead to minor increase of Bna.ARF10 transcription on the critical timepoint for seed germination, the indirect regulator of ABI3, the germinative inhibitor. Bna.GH3.5 expression was upregulated to conjugate free auxin to IAA-asp between 2 and 6 DAS. Functional amino acid changes were also found in important DNA binding domains of one BnaC.ARF10 locus, suggesting that regulatory changes in Bna.ARF10 are collectively responsible for the observed phenotpyes in 1012-98. To our knowledge, this study is the first to report disruption of germination and seedling development in Brassica napus caused by the crosstalk of auxin-ABA and the corresponding regulators Bna

  3. Disruption of Germination and Seedling Development in Brassica napus by Mutations Causing Severe Seed Hormonal Imbalance.

    PubMed

    Nguyen, Tung C T; Obermeier, Christian; Friedt, Wolfgang; Abrams, Suzanne R; Snowdon, Rod J

    2016-01-01

    The Brassica napus (oilseed rape) accession 1012-98 shows a disturbed germination phenotype that was thought to be associated with its lack of testa pigmentation and thin seed coat. Here, we demonstrate that the disturbed germination and seedling development are actually due to independent mutations that disrupt the balance of hormone metabolites and their regulators in the seeds. High-throughput UPLC-MS/MS hormone profiling of seeds and seedlings before and after germination revealed that 1012-98 has a severely disturbed hormone balance with extremely atypical, excessive quantities of auxin and ABA metabolites. The resulting hypersensitivity to abscisic acid (ABA) and a corresponding increase in dormancy often results in death of the embryo after imbibition or high frequencies of disturbed, often lethal developmental phenotypes, resembling Arabidopsis mutants for the auxin regulatory factor gene ARF10 or the auxin-overproducing transgenic line iaaM-OX. Molecular cloning of Brassica ARF10 orthologs revealed four loci in normal B. napus, two derived from the Brassica A genome and two from the C genome. On the other hand, the phenotypic mutant 1012-98 exhibited amplification of C-genome BnaC.ARF10 copy number along with a chimeric allele originating from recombination between homeologous A and C genome loci which lead to minor increase of Bna.ARF10 transcription on the critical timepoint for seed germination, the indirect regulator of ABI3, the germinative inhibitor. Bna.GH3.5 expression was upregulated to conjugate free auxin to IAA-asp between 2 and 6 DAS. Functional amino acid changes were also found in important DNA binding domains of one BnaC.ARF10 locus, suggesting that regulatory changes in Bna.ARF10 are collectively responsible for the observed phenotpyes in 1012-98. To our knowledge, this study is the first to report disruption of germination and seedling development in Brassica napus caused by the crosstalk of auxin-ABA and the corresponding regulators Bna

  4. Disruption of Germination and Seedling Development in Brassica napus by Mutations Causing Severe Seed Hormonal Imbalance

    PubMed Central

    Nguyen, Tung C. T.; Obermeier, Christian; Friedt, Wolfgang; Abrams, Suzanne R.; Snowdon, Rod J.

    2016-01-01

    The Brassica napus (oilseed rape) accession 1012-98 shows a disturbed germination phenotype that was thought to be associated with its lack of testa pigmentation and thin seed coat. Here, we demonstrate that the disturbed germination and seedling development are actually due to independent mutations that disrupt the balance of hormone metabolites and their regulators in the seeds. High-throughput UPLC-MS/MS hormone profiling of seeds and seedlings before and after germination revealed that 1012-98 has a severely disturbed hormone balance with extremely atypical, excessive quantities of auxin and ABA metabolites. The resulting hypersensitivity to abscisic acid (ABA) and a corresponding increase in dormancy often results in death of the embryo after imbibition or high frequencies of disturbed, often lethal developmental phenotypes, resembling Arabidopsis mutants for the auxin regulatory factor gene ARF10 or the auxin-overproducing transgenic line iaaM-OX. Molecular cloning of Brassica ARF10 orthologs revealed four loci in normal B. napus, two derived from the Brassica A genome and two from the C genome. On the other hand, the phenotypic mutant 1012-98 exhibited amplification of C-genome BnaC.ARF10 copy number along with a chimeric allele originating from recombination between homeologous A and C genome loci which lead to minor increase of Bna.ARF10 transcription on the critical timepoint for seed germination, the indirect regulator of ABI3, the germinative inhibitor. Bna.GH3.5 expression was upregulated to conjugate free auxin to IAA-asp between 2 and 6 DAS. Functional amino acid changes were also found in important DNA binding domains of one BnaC.ARF10 locus, suggesting that regulatory changes in Bna.ARF10 are collectively responsible for the observed phenotpyes in 1012-98. To our knowledge, this study is the first to report disruption of germination and seedling development in Brassica napus caused by the crosstalk of auxin-ABA and the corresponding regulators Bna

  5. Effect of wood ash application on the morphological, physiological and biochemical parameters of Brassica napus L.

    PubMed

    Nabeela, Farhat; Murad, Waheed; Khan, Imran; Mian, Ishaq Ahmad; Rehman, Hazir; Adnan, Muhammad; Azizullah, Azizullah

    2015-10-01

    The present study was conducted to determine the effect of wood ash application on different parameters of Brassica napus L. including seed germination, seedling growth, fresh and dry biomass, water content in seedlings, photosynthetic pigments, soluble sugars, total protein and cell viability. In addition, the effect of wood ash on soil microflora and accumulation of trace elements in seedlings were determined. The seeds of B. napus were grown at different doses of wood ash (0, 1, 10, 25, 50 and 100 g (wood ash)/kg (soil)) and the effect on various parameters was determined. Wood ash significantly inhibited seed germination at doses above 25 g/kg and there was no germination at 100 g/kg of wood ash. At lower concentrations of wood ash, most of the growth parameters of seedlings were stimulated, but at higher concentrations of wood ash most of the studied parameters were adversely affected. Wood ash was found to be very detrimental to B. napus when applied above 25 g/kg. Wood ash application resulted in an increased bioaccumulation of trace elements in seedlings of B. napus. Almost all trace elements were significantly higher in seedlings grown in wood ash above 10 g/kg as compared to the control. An increase in total microbial count was observed with wood ash treatment which was statistically significant at 1 and 10 g/kg of wood ash. It is concluded that at very high concentration, wood ash can be detrimental to plants; however, its application at lower application rate can be recommended.

  6. Hydrogen sulfide alleviates cadmium-induced morpho-physiological and ultrastructural changes in Brassica napus.

    PubMed

    Ali, Basharat; Gill, Rafaqat A; Yang, Su; Gill, Muhammad B; Ali, Shafaqat; Rafiq, Muhammad T; Zhou, Weijun

    2014-12-01

    In the present study, role of hydrogen sulfide (H2S) in alleviating cadmium (Cd) induced stress in oilseed rape (Brassica napus L.) was studied under greenhouse conditions. Plants were grown hydroponically under three levels (0, 100, and 500µM) of Cd and three levels (0, 100 and 200µM) of H2S donor, sodium hydrosulfide (NaHS). Results showed that application of H2S significantly improved the plant growth, root morphology, chlorophyll contents, elements uptake and photosynthetic activity in B. napus plants under Cd stress. Moreover, addition of H2S reduced the Cd concentration in the leaves and roots of B. napus plants under Cd-toxicity. Exogenously applied H2S decreased the production of malondialdehyde and reactive oxygen species in the leaves and roots by improving the enzymatic antioxidant activities under Cd stress conditions. The microscopic examination indicated that application of exogenous H2S improved the cell structures and enabled a clean mesophyll cell having a well developed chloroplast with thylakoid membranes, and a number of mitochondria could be observed in the micrographs. A number of modifications could be found in root tip cell i.e. mature mitochondria, long endoplasmic reticulum and golgibodies under combined application of H2S and Cd. On the basis of these findings, it can be concluded that application of exogenous H2S has a protective role on plant growth, photosynthetic parameters, elements uptake, antioxidants enzyme activities and ultrastructural changes in B. napus under high Cd stress conditions.

  7. Dissecting Quantitative Trait Loci for Boron Efficiency across Multiple Environments in Brassica napus

    PubMed Central

    Zhao, Zunkang; Wu, Likun; Nian, Fuzhao; Ding, Guangda; Shi, Taoxiong; Zhang, Didi; Shi, Lei; Xu, Fangsen; Meng, Jinling

    2012-01-01

    High yield is the most important goal in crop breeding, and boron (B) is an essential micronutrient for plants. However, B deficiency, leading to yield decreases, is an agricultural problem worldwide. Brassica napus is one of the most sensitive crops to B deficiency, and considerable genotypic variation exists among different cultivars in response to B deficiency. To dissect the genetic basis of tolerance to B deficiency in B. napus, we carried out QTL analysis for seed yield and yield-related traits under low and normal B conditions using the double haploid population (TNDH) by two-year and the BQDH population by three-year field trials. In total, 80 putative QTLs and 42 epistatic interactions for seed yield, plant height, branch number, pod number, seed number, seed weight and B efficiency coefficient (BEC) were identified under low and normal B conditions, singly explaining 4.15–23.16% and 0.53–14.38% of the phenotypic variation. An additive effect of putative QTLs was a more important controlling factor than the additive-additive effect of epistatic interactions. Four QTL-by-environment interactions and 7 interactions between epistatic interactions and the environment contributed to 1.27–4.95% and 1.17–3.68% of the phenotypic variation, respectively. The chromosome region on A2 of SYLB-A2 for seed yield under low B condition and BEC-A2 for BEC in the two populations was equivalent to the region of a reported major QTL, BE1. The B. napus homologous genes of Bra020592 and Bra020595 mapped to the A2 region and were speculated to be candidate genes for B efficiency. These findings reveal the complex genetic basis of B efficiency in B. napus. They provide a basis for the fine mapping and cloning of the B efficiency genes and for breeding B-efficient cultivars by marker-assisted selection (MAS). PMID:23028855

  8. EDTA enhanced plant growth, antioxidant defense system, and phytoextraction of copper by Brassica napus L.

    PubMed

    Habiba, Ume; Ali, Shafaqat; Farid, Mujahid; Shakoor, Muhammad Bilal; Rizwan, Muhammad; Ibrahim, Muhammad; Abbasi, Ghulam Hasan; Hayat, Tahir; Ali, Basharat

    2015-01-01

    Copper (Cu) is an essential micronutrient for normal plant growth and development, but in excess, it is also toxic to plants. The present study investigated the influence of ethylenediaminetetraacetic acid (EDTA) in enhancing Cu uptake and tolerance as well as the morphological and physiological responses of Brassica napus L. seedlings under Cu stress. Four-week-old seedlings were transferred to hydroponics containing Hoagland's nutrient solution. After 2 weeks of transplanting, three levels (0, 50, and 100 μM) of Cu were applied with or without application of 2.5 mM EDTA and plants were further grown for 8 weeks in culture media. Results showed that Cu alone significantly decreased plant growth, biomass, photosynthetic pigments, and gas exchange characteristics. Cu stress also reduced the activities of antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) along with protein contents. Cu toxicity increased the concentration of reactive oxygen species (ROS) as indicated by the increased production of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in both leaves and roots. The application of EDTA significantly alleviated Cu-induced toxic effects in B. napus, showing remarkable improvement in all these parameters. EDTA amendment increased the activity of antioxidant enzymes by decreasing the concentrations of MDA and H2O2 both in leaves and roots of B. napus. Although, EDTA amendment with Cu significantly increased Cu uptake in roots, stems, and leaves in decreasing order of concentration but increased the growth, photosynthetic parameters, and antioxidant enzymes. These results showed that the application of EDTA can be a useful strategy for phytoextraction of Cu by B. napus from contaminated soils. PMID:25163559

  9. Effect of wood ash application on the morphological, physiological and biochemical parameters of Brassica napus L.

    PubMed

    Nabeela, Farhat; Murad, Waheed; Khan, Imran; Mian, Ishaq Ahmad; Rehman, Hazir; Adnan, Muhammad; Azizullah, Azizullah

    2015-10-01

    The present study was conducted to determine the effect of wood ash application on different parameters of Brassica napus L. including seed germination, seedling growth, fresh and dry biomass, water content in seedlings, photosynthetic pigments, soluble sugars, total protein and cell viability. In addition, the effect of wood ash on soil microflora and accumulation of trace elements in seedlings were determined. The seeds of B. napus were grown at different doses of wood ash (0, 1, 10, 25, 50 and 100 g (wood ash)/kg (soil)) and the effect on various parameters was determined. Wood ash significantly inhibited seed germination at doses above 25 g/kg and there was no germination at 100 g/kg of wood ash. At lower concentrations of wood ash, most of the growth parameters of seedlings were stimulated, but at higher concentrations of wood ash most of the studied parameters were adversely affected. Wood ash was found to be very detrimental to B. napus when applied above 25 g/kg. Wood ash application resulted in an increased bioaccumulation of trace elements in seedlings of B. napus. Almost all trace elements were significantly higher in seedlings grown in wood ash above 10 g/kg as compared to the control. An increase in total microbial count was observed with wood ash treatment which was statistically significant at 1 and 10 g/kg of wood ash. It is concluded that at very high concentration, wood ash can be detrimental to plants; however, its application at lower application rate can be recommended. PMID:26163419

  10. EDTA enhanced plant growth, antioxidant defense system, and phytoextraction of copper by Brassica napus L.

    PubMed

    Habiba, Ume; Ali, Shafaqat; Farid, Mujahid; Shakoor, Muhammad Bilal; Rizwan, Muhammad; Ibrahim, Muhammad; Abbasi, Ghulam Hasan; Hayat, Tahir; Ali, Basharat

    2015-01-01

    Copper (Cu) is an essential micronutrient for normal plant growth and development, but in excess, it is also toxic to plants. The present study investigated the influence of ethylenediaminetetraacetic acid (EDTA) in enhancing Cu uptake and tolerance as well as the morphological and physiological responses of Brassica napus L. seedlings under Cu stress. Four-week-old seedlings were transferred to hydroponics containing Hoagland's nutrient solution. After 2 weeks of transplanting, three levels (0, 50, and 100 μM) of Cu were applied with or without application of 2.5 mM EDTA and plants were further grown for 8 weeks in culture media. Results showed that Cu alone significantly decreased plant growth, biomass, photosynthetic pigments, and gas exchange characteristics. Cu stress also reduced the activities of antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) along with protein contents. Cu toxicity increased the concentration of reactive oxygen species (ROS) as indicated by the increased production of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in both leaves and roots. The application of EDTA significantly alleviated Cu-induced toxic effects in B. napus, showing remarkable improvement in all these parameters. EDTA amendment increased the activity of antioxidant enzymes by decreasing the concentrations of MDA and H2O2 both in leaves and roots of B. napus. Although, EDTA amendment with Cu significantly increased Cu uptake in roots, stems, and leaves in decreasing order of concentration but increased the growth, photosynthetic parameters, and antioxidant enzymes. These results showed that the application of EDTA can be a useful strategy for phytoextraction of Cu by B. napus from contaminated soils.

  11. Production of high yield short duration Brassica napus by interspecific hybridization between B. oleracea and B. rapa.

    PubMed

    Karim, Md Masud; Siddika, Asfakun; Tonu, Nazmoon Naher; Hossain, Delwar M; Meah, Md Bahadur; Kawanabe, Takahiro; Fujimoto, Ryo; Okazaki, Keiichi

    2014-03-01

    Brassica napus is a leading oilseed crop throughout many parts of the world. It is well adapted to long day photoperiods, however, it does not adapt well to short day subtropical regions. Short duration B. napus plants were resynthesized through ovary culture from interspecific crosses in which B. rapa cultivars were reciprocally crossed with B. oleracea. From five different combinations, 17 hybrid plants were obtained in both directions. By self-pollinating the F1 hybrids or introgressing them with cultivated B. napus, resynthesized (RS) F3 and semi-resynthesized (SRS) F2 generations were produced, respectively. In field trial in Bangladesh, the RS B. napus plants demonstrated variation in days to first flowering ranging from 29 to 73 days; some of which were similar to cultivated short duration B. napus, but not cultivated short duration B. rapa. The RS and SRS B. napus lines produced 2-4.6 and 1.6-3.7 times higher yields, respectively, as compared to cultivated short duration B. napus. Our developed RS lines may be useful for rapeseed breeding not only for subtropical regions, but also for areas such as Canada and Europe where spring rapeseed production can suffer from late spring frosts. Yield and earliness in RS lines are discussed.

  12. Cytogenetic characterization and fae1 gene variation in progenies from asymmetric somatic hybrids between Brassica napus and Crambe abyssinica.

    PubMed

    Wang, Y P; Snowdon, R J; Rudloff, E; Wehling, P; Friedt, W; Sonntag, K

    2004-08-01

    Sexual progenies of asymmetric somatic hybrids between Brassica napus and Crambe abyssinica were analyzed with respect to chromosomal behavior, fae1 gene introgression, fertility, and fatty-acid composition of the seed. Among 24 progeny plants investigated, 11 plants had 38 chromosomes and were characterized by the occurrence of normal meiosis with 19 bivalents. The other 13 plants had more than 38 chromosomes, constituting a complete chromosomal set from B. napus plus different numbers of additional chromosomes from C. abyssinica. The chromosomes of B. napus and C. abyssinica origin could be clearly discriminated by genomic in situ hybridization (GISH) in mitotic and meiotic cells. Furthermore, meiotic GISH enabled identification of intergenomic chromatin bridges and of asynchrony between the B. napus and C. abyssinca meiotic cycles. Lagging, bridging and late disjunction of univalents derived from C. abyssinica were observed. Analysis of cleaved amplified polymorphic sequence (CAPS) markers derived from the fae1 gene showed novel patterns different from the B. napus recipient in some hybrid offspring. Most of the progeny plants had a high pollen fertility and seed set, and some contained significantly greater amounts of seed erucic acid than the B. napus parent. This study demonstrates that a part of the C. abyssinica genome can be transferred into B. napus via asymmetric hybridization and maintained in sexual progenies of the hybrids. Furthermore, it confirms that UV irradiation improves the fertility of the hybrid and of its sexual progeny via chromosomal elimination and facilitates the introgression of exotic genetic material into crop species.

  13. Production of high yield short duration Brassica napus by interspecific hybridization between B. oleracea and B. rapa

    PubMed Central

    Karim, Md. Masud; Siddika, Asfakun; Tonu, Nazmoon Naher; Hossain, Delwar M.; Meah, Md. Bahadur; Kawanabe, Takahiro; Fujimoto, Ryo; Okazaki, Keiichi

    2014-01-01

    Brassica napus is a leading oilseed crop throughout many parts of the world. It is well adapted to long day photoperiods, however, it does not adapt well to short day subtropical regions. Short duration B. napus plants were resynthesized through ovary culture from interspecific crosses in which B. rapa cultivars were reciprocally crossed with B. oleracea. From five different combinations, 17 hybrid plants were obtained in both directions. By self-pollinating the F1 hybrids or introgressing them with cultivated B. napus, resynthesized (RS) F3 and semi-resynthesized (SRS) F2 generations were produced, respectively. In field trial in Bangladesh, the RS B. napus plants demonstrated variation in days to first flowering ranging from 29 to 73 days; some of which were similar to cultivated short duration B. napus, but not cultivated short duration B. rapa. The RS and SRS B. napus lines produced 2–4.6 and 1.6–3.7 times higher yields, respectively, as compared to cultivated short duration B. napus. Our developed RS lines may be useful for rapeseed breeding not only for subtropical regions, but also for areas such as Canada and Europe where spring rapeseed production can suffer from late spring frosts. Yield and earliness in RS lines are discussed. PMID:24757390

  14. Germination stimulants of Phelipanche ramosa in the rhizosphere of Brassica napus are derived from the glucosinolate pathway.

    PubMed

    Auger, Bathilde; Pouvreau, Jean-Bernard; Pouponneau, Karinne; Yoneyama, Kaori; Montiel, Grégory; Le Bizec, Bruno; Yoneyama, Koichi; Delavault, Philippe; Delourme, Régine; Simier, Philippe

    2012-07-01

    Phelipanche ramosa is a major parasitic weed of Brassica napus. The first step in a host-parasitic plant interaction is stimulation of parasite seed germination by compounds released from host roots. However, germination stimulants produced by B. napus have not been identified yet. In this study, we characterized the germination stimulants that accumulate in B. napus roots and are released into the rhizosphere. Eight glucosinolate-breakdown products were identified and quantified in B. napus roots by gas chromatography-mass spectrometry. Two (3-phenylpropanenitrile and 2-phenylethyl isothiocyanate [2-PEITC]) were identified in the B. napus rhizosphere. Among glucosinolate-breakdown products, P. ramosa germination was strongly and specifically triggered by isothiocyanates, indicating that 2-PEITC, in particular, plays a key role in the B. napus-P. ramosa interaction. Known strigolactones were not detected by ultraperformance liquid chromatography-tandem mass spectrometry, and seed of Phelipanche and Orobanche spp. that respond to strigolactones but not to isothiocyanates did not germinate in the rhizosphere of B. napus. Furthermore, both wild-type and strigolactone biosynthesis mutants of Arabidopsis thaliana Atccd7 and Atccd8 induced similar levels of P. ramosa seed germination, suggesting that compounds other than strigolactone function as germination stimulants for P. ramosa in other Brassicaceae spp. Our results open perspectives on the high adaptation potential of root-parasitic plants under host-driven selection pressures. PMID:22414435

  15. Physiological and Transcriptional Analyses Reveal Differential Phytohormone Responses to Boron Deficiency in Brassica napus Genotypes

    PubMed Central

    Zhou, Ting; Hua, Yingpeng; Huang, Yupu; Ding, Guangda; Shi, Lei; Xu, Fangsen

    2016-01-01

    Phytohormones play pivotal roles in the response of plants to various biotic and abiotic stresses. Boron (B) is an essential microelement for plants, and Brassica napus (B. napus) is hypersensitive to B deficiency. However, how auxin responds to B deficiency remained a dilemma for many years and little is known about how other phytohormones respond to B deficiency. The identification of B-efficient/inefficient B. napus indicates that breeding might overcome these constraints in the agriculture production. Here, we seek to identify phytohormone-related processes underlying B-deficiency tolerance in B. napus at the physiological and gene expression levels. Our study indicated low-B reduced indole-3-acetic acid (IAA) concentration in both the shoots and roots of B. napus, and affected the expression of the auxin biosynthesis gene BnNIT1 and the efflux gene BnPIN1 in a time-dependent manner. Low-B increased the jasmonates (JAs) and abscisic acid (ABA) concentrations and induced the expression of the ABA biosynthesis gene BnNCED3 and the ABA sensor gene BnPYL4 in the shoot. In two contrasting genotypes, the auxin concentration decreased more drastically in the B-inefficient genotype ‘W10,’ and together the expression of BnNIT1 and BnPIN1 also decreased more significantly in ‘W10’ under long-term B deficiency. While the JAs concentration was considerably higher in this genotype, and the ABA concentration was induced in ‘W10’ compared with the B-efficient genotype ‘QY10.’ Digital gene expression (DGE) profiling confirmed the differential expression of the phytohormone-related genes, indicating more other phyohormone differences involving in gene regulation between ‘QY10’ and ‘W10’ under low-B stress. Additionally, the activity of DR5:GFP was reduced in the root under low-B in Arabidopsis, and the application of exogenous IAA could partly restore the B-defective phenotype in ‘W10.’ Overall, our data suggested that low-B disturbed phytohormone

  16. Genomic changes in resynthesized Brassica napus and their effect on gene expression and phenotype.

    PubMed

    Gaeta, Robert T; Pires, J Chris; Iniguez-Luy, Federico; Leon, Enrique; Osborn, Thomas C

    2007-11-01

    Many previous studies have provided evidence for genome changes in polyploids, but there are little data on the overall population dynamics of genome change and whether it causes phenotypic variability. We analyzed genetic, epigenetic, gene expression, and phenotypic changes in approximately 50 resynthesized Brassica napus lines independently derived by hybridizing double haploids of Brassica oleracea and Brassica rapa. A previous analysis of the first generation (S0) found that genetic changes were rare, and cytosine methylation changes were frequent. Our analysis of a later generation found that most S0 methylation changes remained fixed in their S5 progeny, although there were some reversions and new methylation changes. Genetic changes were much more frequent in the S5 generation, occurring in every line with lines normally distributed for number of changes. Genetic changes were detected on 36 of the 38 chromosomes of the S5 allopolyploids and were not random across the genome. DNA fragment losses within lines often occurred at linked marker loci, and most fragment losses co-occurred with intensification of signal from homoeologous markers, indicating that the changes were due to homoeologous nonreciprocal transpositions (HNRTs). HNRTs between chromosomes A1 and C1 initiated in early generations, occurred in successive generations, and segregated, consistent with a recombination mechanism. HNRTs and deletions were correlated with qualitative changes in the expression of specific homoeologous genes and anonymous cDNA amplified fragment length polymorphisms and with phenotypic variation among S5 polyploids. Our data indicate that exchanges among homoeologous chromosomes are a major mechanism creating novel allele combinations and phenotypic variation in newly formed B. napus polyploids.

  17. Broadening the Genetic Basis of Verticillium longisporum Resistance in Brassica napus by Interspecific Hybridization.

    PubMed

    Rygulla, W; Snowdon, R J; Eynck, C; Koopmann, B; von Tiedemann, A; Lühs, W; Friedt, W

    2007-11-01

    ABSTRACT Verticillium wilt caused by the vascular fungal pathogen Verticillium longisporum is one of the most important pathogens of oilseed rape (Brassica napus sp. oleifera) in northern Europe. Because production of this major oilseed crop is expanding rapidly and no approved fungicides are available for V. longisporum, long-term control of the disease can only be achieved with cultivars carrying effective quantitative resistance. However, very little resistance to V. longisporum is available within the gene pool of oilseed rape, meaning that interspecific gene transfer from related species is the only possibility for broadening levels of resistance in current varieties. The amphidiploid species B. napus can be resynthesized by crossing the two progenitor species Brassica oleracea and Brassica rapa, hence resistant accessions of these two diploid species can be used as resistance donors. In this study a total of 43 potential B. rapa and B. oleracea resistance donors were tested with regard to their reaction to a mixture of two aggressive V. longisporum isolates, and resistances from diverse lines were combined by embryo rescue-assisted interspecific hybridization in resynthesized rapeseed lines. Progenies from crosses of the two B. rapa gene bank accessions 13444 and 56515 to the B. oleracea gene bank accessions BRA1008, CGN14044, 8207, BRA1398, and 7518 showed a broad spectrum of resistance in pathogenicity tests. Of 45 tested resynthesized lines, 41 lines exhibited a significantly higher level of resistance than the moderately V. longisporum-tolerant oilseed rape cultivar Express. These lines represent a promising basis for the combination of different resistance resources in new varieties.

  18. Consequences of gene flow between oilseed rape (Brassica napus) and its relatives.

    PubMed

    Liu, Yongbo; Wei, Wei; Ma, Keping; Li, Junsheng; Liang, Yuyong; Darmency, Henri

    2013-10-01

    Numerous studies have focused on the probability of occurrence of gene flow between transgenic crops and their wild relatives and the likelihood of transgene escape, which should be assessed before the commercial release of transgenic crops. This review paper focuses on this issue for oilseed rape, Brassica napus L., a species that produces huge numbers of pollen grains and seeds. We analyze separately the distinct steps of gene flow: (1) pollen and seeds as vectors of gene flow; (2) spontaneous hybridization; (3) hybrid behavior, fitness cost due to hybridization and mechanisms of introgression; (4) and fitness benefit due to transgenes (e.g. herbicide resistance and Bt toxin). Some physical, biological and molecular means of transgene containment are also described. Although hybrids and first generation progeny are difficult to identify in fields and non-crop habitats, the literature shows that transgenes could readily introgress into Brassica rapa, Brassica juncea and Brassica oleracea, while introgression is expected to be rare with Brassica nigra, Hirschfeldia incana and Raphanus raphanistrum. The hybrids grow well but produce less seed than their wild parent. The difference declines with increasing generations. However, there is large uncertainty about the evolution of chromosome numbers and recombination, and many parameters of life history traits of hybrids and progeny are not determined with satisfactory confidence to build generic models capable to really cover the wide diversity of situations. We show that more studies are needed to strengthen and organize biological knowledge, which is a necessary prerequisite for model simulations to assess the practical and evolutionary outputs of introgression, and to provide guidelines for gene flow management. PMID:23987810

  19. Consequences of gene flow between oilseed rape (Brassica napus) and its relatives.

    PubMed

    Liu, Yongbo; Wei, Wei; Ma, Keping; Li, Junsheng; Liang, Yuyong; Darmency, Henri

    2013-10-01

    Numerous studies have focused on the probability of occurrence of gene flow between transgenic crops and their wild relatives and the likelihood of transgene escape, which should be assessed before the commercial release of transgenic crops. This review paper focuses on this issue for oilseed rape, Brassica napus L., a species that produces huge numbers of pollen grains and seeds. We analyze separately the distinct steps of gene flow: (1) pollen and seeds as vectors of gene flow; (2) spontaneous hybridization; (3) hybrid behavior, fitness cost due to hybridization and mechanisms of introgression; (4) and fitness benefit due to transgenes (e.g. herbicide resistance and Bt toxin). Some physical, biological and molecular means of transgene containment are also described. Although hybrids and first generation progeny are difficult to identify in fields and non-crop habitats, the literature shows that transgenes could readily introgress into Brassica rapa, Brassica juncea and Brassica oleracea, while introgression is expected to be rare with Brassica nigra, Hirschfeldia incana and Raphanus raphanistrum. The hybrids grow well but produce less seed than their wild parent. The difference declines with increasing generations. However, there is large uncertainty about the evolution of chromosome numbers and recombination, and many parameters of life history traits of hybrids and progeny are not determined with satisfactory confidence to build generic models capable to really cover the wide diversity of situations. We show that more studies are needed to strengthen and organize biological knowledge, which is a necessary prerequisite for model simulations to assess the practical and evolutionary outputs of introgression, and to provide guidelines for gene flow management.

  20. [Production and cytogenetics of hybrids of Ogura CMS Brassica campestris var. purpuraria x Raphanus sativus x Brassica napus].

    PubMed

    Huang, Bang-Quan; Liu, You-Qi; Wu, Wen-Hua; Xue, Xiao-Qiao

    2002-05-01

    Crosses of Ogura CMS Brassica campestris var. purpuraria x Raphanus sativus x Brassica napus were made and four hybrids were produced. One plant (PRN-1) was mosaic with yellow and milk white flowers and some flowers had both yellow and white petals. The others (PRN-2, -3, -4) had white flowers. PRN-4 had degenerated anthers, the other three had three to six anthers and could produce some pollens, but the pollens of PRN-2 were unstainable by I2-KI solution. PRN-2 had four normal honey glands, PRN-1 and PRN-3 had two, and PRN-4 had none. PRN-2 had normal leaf color and the other three showed different degrees of chlorophyll deficiency at low temperature. The chromosome number of PRN-1 was 2n = 38 and had the mean chromosome paring configuration of 14.67 I + 10.07 II + 1.06 III, and its chromosome set constitution might be AACR. This chromosome constitution may be due to the fertilization of female gamete of n = 19 (AR) with male gamete of n = 19 (AC) from B. napus. The occurrence of mosaic flower color in this plant may be attributed to the chromosome abnormalities caused by wide hybridization, such as chromosome deficiency and the formation of chromosome fragments and chromosome bridges. The chromosome number of PRN-2 was 2n = 35 and the mean chromosome paring configuration was 13.89 I + 8.33 II + 1.33 III + 0.11 IV. The chromosome number of PRN-3 was 2n = 33 and the mean chromosome paring configuration was 14.00 I + 7.82 II + 1.00 III + 0.09 IV. The chromosome number of PRN-4 was not determined as there was no pollen mother cell formation. Chromosome bridges and laggards were observed in PRN-1-3. Some seeds were harvested from PRN-1-3 but none was harvested from PRN-4 when backcrossed with B. napus. It seems possible for us to overcome the chlorophyll deficiency and honey gland abnormality and restore the male fertility in Ogura CMS by introduction of the nucleus of R. sativus into this cytoplasmic male sterile line. PMID:12043578

  1. Genome-wide Association Study Identifies New Loci for Resistance to Sclerotinia Stem Rot in Brassica napus

    PubMed Central

    Wu, Jian; Zhao, Qing; Liu, Sheng; Shahid, Muhammad; Lan, Lei; Cai, Guangqin; Zhang, Chunyu; Fan, Chuchuan; Wang, Youping; Zhou, Yongming

    2016-01-01

    Sclerotinia stem rot (SSR) caused by the necrotrophic fungus Sclerotinia sclerotiorum is a major disease in rapeseed (Brassica napus) worldwide. Breeding for SSR resistance in B. napus, as in other crops, relies only on germplasms with quantitative resistance genes. A better understanding of the genetic basis for SSR resistance in B. napus thus holds promise for the genetic improvement of disease resistance. In the present study, a genome-wide association study (GWAS) for SSR resistance in B. napus were performed using an association panel of 448 accessions genotyped with the Brassica 60K Infinium® single-nucleotide polymorphism (SNP) array. A total of 26 SNPs corresponding to three loci, DSRC4, DSRC6, and DSRC8 were associated with SSR resistance. Haplotype analysis showed that the three favorable alleles for SSR resistance exhibited cumulative effects. After aligning SSR resistance quantitative trait loci (QTL) identified in the present and previous studies to the B. napus reference genome, one locus (DSRC6) was found to be located within the confidence interval of a QTL identified in previous QTL mapping studies and another two loci (DSRC4 and DSRC8) were considered novel loci for SSR resistance. A total of 39 candidate genes were predicted for the three loci based on the GWAS combining with the differentially expressed genes identified in previous transcriptomics analyses. PMID:27703464

  2. Exploiting comparative mapping among Brassica species to accelerate the physical delimitation of a genic male-sterile locus (BnRf) in Brassica napus.

    PubMed

    Xie, Yanzhou; Dong, Faming; Hong, Dengfeng; Wan, Lili; Liu, Pingwu; Yang, Guangsheng

    2012-07-01

    The recessive genic male sterility (RGMS) line 9012AB has been used as an important pollination control system for rapeseed hybrid production in China. Here, we report our study on physical mapping of one male-sterile locus (BnRf) in 9012AB by exploiting the comparative genomics among Brassica species. The genetic maps around BnRf from previous reports were integrated and enriched with markers from the Brassica A7 chromosome. Subsequent collinearity analysis of these markers contributed to the identification of a novel ancestral karyotype block F that possibly encompasses BnRf. Fourteen insertion/deletion markers were further developed from this conserved block and genotyped in three large backcross populations, leading to the construction of high-resolution local genetic maps where the BnRf locus was restricted to a less than 0.1-cM region. Moreover, it was observed that the target region in Brassica napus shares a high collinearity relationship with a region from the Brassica rapa A7 chromosome. A BnRf-cosegregated marker (AT3G23870) was then used to screen a B. napus bacterial artificial chromosome (BAC) library. From the resulting 16 positive BAC clones, one (JBnB089D05) was identified to most possibly contain the BnRf (c) allele. With the assistance of the genome sequence from the Brassica rapa homolog, the 13.8-kb DNA fragment covering both closest flanking markers from the BAC clone was isolated. Gene annotation based on the comparison of microcollinear regions among Brassica napus, B. rapa and Arabidopsis showed that five potential open reading frames reside in this fragment. These results provide a foundation for the characterization of the BnRf locus and allow a better understanding of the chromosome evolution around BnRf.

  3. Exploiting comparative mapping among Brassica species to accelerate the physical delimitation of a genic male-sterile locus (BnRf) in Brassica napus.

    PubMed

    Xie, Yanzhou; Dong, Faming; Hong, Dengfeng; Wan, Lili; Liu, Pingwu; Yang, Guangsheng

    2012-07-01

    The recessive genic male sterility (RGMS) line 9012AB has been used as an important pollination control system for rapeseed hybrid production in China. Here, we report our study on physical mapping of one male-sterile locus (BnRf) in 9012AB by exploiting the comparative genomics among Brassica species. The genetic maps around BnRf from previous reports were integrated and enriched with markers from the Brassica A7 chromosome. Subsequent collinearity analysis of these markers contributed to the identification of a novel ancestral karyotype block F that possibly encompasses BnRf. Fourteen insertion/deletion markers were further developed from this conserved block and genotyped in three large backcross populations, leading to the construction of high-resolution local genetic maps where the BnRf locus was restricted to a less than 0.1-cM region. Moreover, it was observed that the target region in Brassica napus shares a high collinearity relationship with a region from the Brassica rapa A7 chromosome. A BnRf-cosegregated marker (AT3G23870) was then used to screen a B. napus bacterial artificial chromosome (BAC) library. From the resulting 16 positive BAC clones, one (JBnB089D05) was identified to most possibly contain the BnRf (c) allele. With the assistance of the genome sequence from the Brassica rapa homolog, the 13.8-kb DNA fragment covering both closest flanking markers from the BAC clone was isolated. Gene annotation based on the comparison of microcollinear regions among Brassica napus, B. rapa and Arabidopsis showed that five potential open reading frames reside in this fragment. These results provide a foundation for the characterization of the BnRf locus and allow a better understanding of the chromosome evolution around BnRf. PMID:22382487

  4. A Complex Recombination Pattern in the Genome of Allotetraploid Brassica napus as Revealed by a High-Density Genetic Map

    PubMed Central

    Yi, Bin; Fan, Chuchuan; Edwards, David; Batley, Jacqueline; Zhou, Yongming

    2014-01-01

    Polyploidy plays a crucial role in plant evolution. Brassica napus (2n = 38, AACC), the most important oil crop in the Brassica genus, is an allotetraploid that originated through natural doubling of chromosomes after the hybridization of its progenitor species, B. rapa (2n = 20, AA) and B. oleracea (2n = 18, CC). A better understanding of the evolutionary relationship between B. napus and B. rapa, B. oleracea, as well as Arabidopsis, which has a common ancestor with these three species, will provide valuable information about the generation and evolution of allopolyploidy. Based on a high-density genetic map with single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers, we performed a comparative genomic analysis of B. napus with Arabidopsis and its progenitor species B. rapa and B. oleracea. Based on the collinear relationship of B. rapa and B. oleracea in the B. napus genetic map, the B. napus genome was found to consist of 70.1% of the skeleton components of the chromosomes of B. rapa and B. oleracea, with 17.7% of sequences derived from reciprocal translocation between homoeologous chromosomes between the A- and C-genome and 3.6% of sequences derived from reciprocal translocation between non-homologous chromosomes at both intra- and inter-genomic levels. The current study thus provides insights into the formation and evolution of the allotetraploid B. napus genome, which will allow for more accurate transfer of genomic information from B. rapa, B. oleracea and Arabidopsis to B. napus. PMID:25356735

  5. A complex recombination pattern in the genome of allotetraploid Brassica napus as revealed by a high-density genetic map.

    PubMed

    Cai, Guangqin; Yang, Qingyong; Yi, Bin; Fan, Chuchuan; Edwards, David; Batley, Jacqueline; Zhou, Yongming

    2014-01-01

    Polyploidy plays a crucial role in plant evolution. Brassica napus (2n = 38, AACC), the most important oil crop in the Brassica genus, is an allotetraploid that originated through natural doubling of chromosomes after the hybridization of its progenitor species, B. rapa (2n = 20, AA) and B. oleracea (2n = 18, CC). A better understanding of the evolutionary relationship between B. napus and B. rapa, B. oleracea, as well as Arabidopsis, which has a common ancestor with these three species, will provide valuable information about the generation and evolution of allopolyploidy. Based on a high-density genetic map with single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers, we performed a comparative genomic analysis of B. napus with Arabidopsis and its progenitor species B. rapa and B. oleracea. Based on the collinear relationship of B. rapa and B. oleracea in the B. napus genetic map, the B. napus genome was found to consist of 70.1% of the skeleton components of the chromosomes of B. rapa and B. oleracea, with 17.7% of sequences derived from reciprocal translocation between homoeologous chromosomes between the A- and C-genome and 3.6% of sequences derived from reciprocal translocation between non-homologous chromosomes at both intra- and inter-genomic levels. The current study thus provides insights into the formation and evolution of the allotetraploid B. napus genome, which will allow for more accurate transfer of genomic information from B. rapa, B. oleracea and Arabidopsis to B. napus.

  6. A complex recombination pattern in the genome of allotetraploid Brassica napus as revealed by a high-density genetic map.

    PubMed

    Cai, Guangqin; Yang, Qingyong; Yi, Bin; Fan, Chuchuan; Edwards, David; Batley, Jacqueline; Zhou, Yongming

    2014-01-01

    Polyploidy plays a crucial role in plant evolution. Brassica napus (2n = 38, AACC), the most important oil crop in the Brassica genus, is an allotetraploid that originated through natural doubling of chromosomes after the hybridization of its progenitor species, B. rapa (2n = 20, AA) and B. oleracea (2n = 18, CC). A better understanding of the evolutionary relationship between B. napus and B. rapa, B. oleracea, as well as Arabidopsis, which has a common ancestor with these three species, will provide valuable information about the generation and evolution of allopolyploidy. Based on a high-density genetic map with single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers, we performed a comparative genomic analysis of B. napus with Arabidopsis and its progenitor species B. rapa and B. oleracea. Based on the collinear relationship of B. rapa and B. oleracea in the B. napus genetic map, the B. napus genome was found to consist of 70.1% of the skeleton components of the chromosomes of B. rapa and B. oleracea, with 17.7% of sequences derived from reciprocal translocation between homoeologous chromosomes between the A- and C-genome and 3.6% of sequences derived from reciprocal translocation between non-homologous chromosomes at both intra- and inter-genomic levels. The current study thus provides insights into the formation and evolution of the allotetraploid B. napus genome, which will allow for more accurate transfer of genomic information from B. rapa, B. oleracea and Arabidopsis to B. napus. PMID:25356735

  7. Nutritional and nutraceutical potential of rape (Brassica napus L. var. napus) and "tronchuda" cabbage (Brassica oleraceae L. var. costata) inflorescences.

    PubMed

    Batista, Cátia; Barros, Lillian; Carvalho, Ana Maria; Ferreira, Isabel C F R

    2011-06-01

    Two traditional cultivated vegetables highly consumed among Northern Portuguese regions were tested for their chemical composition, nutritional profile and in vitro antioxidant properties using four assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging activity, reducing power, inhibition of β-carotene bleaching and inhibition of lipid peroxidation by thiobarbituric acid reactive substances (TBARS) assay. The studied varieties of two Brassica species, locally known as "grelos" (rape) and "espigos" ("tronchuda" cabbage) are nutritionally well-balanced vegetables; particularly "tronchuda" cabbage revealed the highest levels of moisture, proteins, fat, energy, β-carotene and vitamin C; rape gave the highest contents of ash, carbohydrates, sugars (including fructose, glucose, sucrose and raffinose), essential n-3 fatty acid α-linolenic acid, and the best ratios of PUFA/SFA and n-6/n-3 fatty acids, tocopherols, lycopene, chlorophylls, phenolics, flavonoids, and also the highest antioxidant properties. The health benefits associated to the antioxidant properties reinforce their contribution to a healthy and balanced diet, highlight the interest of their consumption, validate the empirical use and add new values to traditional/regional products which have been used for a long time.

  8. Seeds of a possible natural hybrid between herbicide-resistant Brassica napus and Brassica rapa detected on a riverbank in Japan.

    PubMed

    Aono, Mitsuko; Wakiyama, Seiji; Nagatsu, Masato; Kaneko, Yukio; Nishizawa, Toru; Nakajima, Nobuyoshi; Tamaoki, Masanori; Kubo, Akihiro; Saji, Hikaru

    2011-01-01

    Transgenic herbicide-resistant varieties of Brassica napus, or oilseed rape, from which canola oil is obtained, are imported into Japan, where this plant is not commercially cultivated to a large extent. This study aimed to examine the distribution of herbicide-resistant B. napus and transgene flow to escaped populations of its closely related species, B. rapa and B. juncea. Samples were collected from 12 areas near major ports through which oilseed rape imports into Japan passed--Kashima, Chiba, Yokohama, Shimizu, Nagoya, Yokkaichi, Sakai-Senboku, Kobe, Uno, Mizushima, Kita-Kyushu, and Hakata--and the presence of glyphosate- and/or glufosinate-resistant B. napus was confirmed in all areas except Yokohama, Sakai-Senboku, Uno, and Kita-Kyushu. The Yokkaichi area was the focus because several herbicide-resistant B. napus plants were detected not only on the roadside where oilseed rape spilled during transportation but also on the riverbanks, where escaped populations of B. rapa and B. juncea grew. Samples of B. napus that were tolerant to both herbicides were detected in four continuous years (2005-2008) in this area, suggesting the possibility of intraspecific transgene flow within the escaped B. napus populations. Moreover, in 2008, seeds of a possible natural hybrid between herbicide-tolerant B. napus (2n = 38) and B. rapa (2n = 20) were detected; some seedlings derived from the seeds collected at a Yokkaichi site showed glyphosate resistance and had 2n = 29 chromosomes. This observation strongly suggests the occurrence of hybridization between herbicide-resistant B. napus and escaped B. rapa and the probability of introgression of a herbicide-resistance gene into related escaped species.

  9. Production and genetic analysis of partial hybrids from intertribal sexual crosses between Brassica napus and Isatis indigotica and progenies.

    PubMed

    Tu, Y Q; Sun, J; Ge, X H; Li, Z Y

    2010-02-01

    With the dye and medicinal plant Isatis indigotica (2n = 14) as pollen parent, intertribal sexual hybrids with Brassica napus (2n = 38, AACC) were obtained and characterized. Among a lot of F1 plants produced, only five hybrids (H1-H5) were distinguished morphologically from female B. napus parents by showing low fertility and some characters of I. indigotica, and also by having different chromosome numbers. H1-H4 had similar but variable chromosome numbers in their somatic and meiotic cells (2n = 25-30), and H5 had 2n = 19, the same number as the haploid of B. napus. GISH analysis of the cells from H1 and H5 detected one I. indigotica chromosome and one or two chromosome terminal fragments. New B. napus types with phenotypic and genomic alterations were produced by H1 after pollination by B. napus and selfing for several generations, and by H5 after selfing. A progeny plant (2n = 20) was derived from H1 after pollination by I. indigotica twice and had a phenotype similar to a certain type of B. rapa, showing that hybrid H1 likely retained all chromosomes of the A genome and lost some of the C genome in parental B. napus. The reasons for the formation of the partial hybrids with unexpected chromosomal complements and for the chromosome elimination are discussed.

  10. Production of partial new-typed Brassica napus by introgression of genomic components from B. rapa and B. carinata.

    PubMed

    Li, Maoteng; Liu, Jianmin; Wang, Yanting; Yu, Longjiang; Meng, Jinling

    2007-05-01

    A breeding strategy for widening the germplasm of Brassica napus was proposed by introgression of the A(r) subgenome of B. rapa (A(r)A(r)) and C(c) of B. carinata (B(c)B(c)C(c)C(c)) into natural B. napus (A(n)A(n)C(n)C(n)). The progenies with 38 chromosomes that were derived from the self-pollinated seeds of pentaploid hybrids (A(r)A(n)B(c)C(c)C(n)) were used for further research. Some of the partial new-typed B. napus showed normal meiotic behavior, high portion of germinated pollen and normal embryological development. This indicates that the selected new-typed B. napus had a balanced genetic base. Molecular analysis showed that about 50% of the genome in the new-typed B. napus was replaced by A(r) and C(c) subgenome from B. rapa and B. carinata. Considering the genetic diversity among different lines of new-typed B. napus it was deduced that the introgression of the genomic components from B. rapa and B. carinata could widen the genetic diversity of rapeseed.

  11. Production and genetic analysis of partial hybrids from intertribal sexual crosses between Brassica napus and Isatis indigotica and progenies.

    PubMed

    Tu, Y Q; Sun, J; Ge, X H; Li, Z Y

    2010-02-01

    With the dye and medicinal plant Isatis indigotica (2n = 14) as pollen parent, intertribal sexual hybrids with Brassica napus (2n = 38, AACC) were obtained and characterized. Among a lot of F1 plants produced, only five hybrids (H1-H5) were distinguished morphologically from female B. napus parents by showing low fertility and some characters of I. indigotica, and also by having different chromosome numbers. H1-H4 had similar but variable chromosome numbers in their somatic and meiotic cells (2n = 25-30), and H5 had 2n = 19, the same number as the haploid of B. napus. GISH analysis of the cells from H1 and H5 detected one I. indigotica chromosome and one or two chromosome terminal fragments. New B. napus types with phenotypic and genomic alterations were produced by H1 after pollination by B. napus and selfing for several generations, and by H5 after selfing. A progeny plant (2n = 20) was derived from H1 after pollination by I. indigotica twice and had a phenotype similar to a certain type of B. rapa, showing that hybrid H1 likely retained all chromosomes of the A genome and lost some of the C genome in parental B. napus. The reasons for the formation of the partial hybrids with unexpected chromosomal complements and for the chromosome elimination are discussed. PMID:20140033

  12. Homeologous Recombination Plays a Major Role in Chromosome Rearrangements That Occur During Meiosis of Brassica napus Haploids

    PubMed Central

    Nicolas, Stéphane D.; Mignon, Guillaume Le; Eber, Frédérique; Coriton, Olivier; Monod, Hervé; Clouet, Vanessa; Huteau, Virginie; Lostanlen, Antoine; Delourme, Régine; Chalhoub, Boulos; Ryder, Carol D.; Chèvre, Anne Marie; Jenczewski, Eric

    2007-01-01

    Chromosomal rearrangements can be triggered by recombination between distinct but related regions. Brassica napus (AACC; 2n = 38) is a recent allopolyploid species whose progenitor genomes are widely replicated. In this article, we analyze the extent to which chromosomal rearrangements originate from homeologous recombination during meiosis of haploid B. napus (n = 19) by genotyping progenies of haploid × euploid B. napus with molecular markers. Our study focuses on three pairs of homeologous regions selected for their differing levels of divergence (N1/N11, N3/N13, and N9/N18). We show that a high number of chromosomal rearrangements occur during meiosis of B. napus haploid and are transmitted by first division restitution (FDR)-like unreduced gametes to their progeny; half of the progeny of Darmor-bzh haploids display duplications and/or losses in the chromosomal regions being studied. We demonstrate that half of these rearrangements are due to recombination between regions of primary homeology, which represents a 10- to 100-fold increase compared to the frequency of homeologous recombination measured in euploid lines. Some of the other rearrangements certainly result from recombination between paralogous regions because we observed an average of one to two autosyndetic A–A and/or C–C bivalents at metaphase I of the B. napus haploid. These results are discussed in the context of genome evolution of B. napus. PMID:17151256

  13. Hybridization between Brassica napus and B. rapa on a national scale in the United Kingdom.

    PubMed

    Wilkinson, Mike J; Elliott, Luisa J; Allainguillaume, Joël; Shaw, Michael W; Norris, Carol; Welters, Ruth; Alexander, Matthew; Sweet, Jeremy; Mason, David C

    2003-10-17

    Measures blocking hybridization would prevent or reduce biotic or environmental change caused by gene flow from genetically modified (GM) crops to wild relatives. The efficacy of any such measure depends on hybrid numbers within the legislative region over the life-span of the GM cultivar. We present a national assessment of hybridization between rapeseed (Brassica napus) and B. rapa from a combination of sources, including population surveys, remote sensing, pollen dispersal profiles, herbarium data, local Floras, and other floristic databases. Across the United Kingdom, we estimate that 32,000 hybrids form annually in waterside B. rapa populations, whereas the less abundant weedy populations contain 17,000 hybrids. These findings set targets for strategies to eliminate hybridization and represent the first step toward quantitative risk assessment on a national scale.

  14. A seed coat outer integument-specific promoter for Brassica napus.

    PubMed

    Wu, Limin; El-Mezawy, Aliaa; Shah, Saleh

    2011-01-01

    In search for seed coat-specific promoters for canola (Brassica napus), transgenic plants carrying a 2,121 bp fragment of Arabidopsis thaliana At4g12960 promoter (AtGILTpro) fused to the uidA reporter gene (GUS) were generated. Out of 7 independent events in transgenic canola plants raised, 2 exhibited GUS activity exclusively in the outer integument of the seed coat. GUS activity in other tissues was also observed in the remaining five transformants. Therefore, the AtGILT promoter can be used as a canola seed coat outer integument-specific promoter after the generation and selection of desired transformants from several transgenic lines. PMID:21052676

  15. Mg deficiency affects leaf Mg remobilization and the proteome in Brassica napus.

    PubMed

    Billard, Vincent; Maillard, Anne; Coquet, Laurent; Jouenne, Thierry; Cruz, Florence; Garcia-Mina, José-Maria; Yvin, Jean-Claude; Ourry, Alain; Etienne, Philippe

    2016-10-01

    In order to cope with variable mineral nutrient availability, higher plants have developed numerous strategies including the remobilization of nutrients from source to sink tissues. However, such processes remain relatively unknown for magnesium (Mg), which is the third most important cation in plant tissues. Using Mg depletion of Brassica napus, we have demonstrated that Mg is remobilized from old leaves to young shoot tissues. Moreover, this study showed that Mg depletion induces modification of nutrient uptake, especially Zn and Mn. Finally, comparative proteomic analysis of old leaves (source of Mg) revealed amongst other results that some proteins requiring Mg for their functionality (isocitrate dehydrogenase for example) were up-regulated. Moreover, down-regulation of proteases suggested that mobilization of Mg from old leaves was not associated with senescence. PMID:27362297

  16. Iron triggers a rapid induction of ascorbate peroxidase gene expression in Brassica napus.

    PubMed

    Vansuyt, G; Lopez, F; Inzé, D; Briat, J F; Fourcroy, P

    1997-06-30

    In plants, only ferritin gene expression has been reported to be iron-dependent. Here it is demonstrated that an iron overload of Brassica napus seedlings causes a large and rapid accumulation of ascorbate peroxidase transcripts, a plant-specific hydrogen peroxide-scavenging enzyme. This result documents a novel link between iron metabolism and oxidative stress. The ascorbate peroxidase mRNA abundance was not modified by reducing agents like N-acetyl cysteine, glutathione and ascorbate or by pro-oxidants such as hydrogen peroxide or diamide. Furthermore, the iron-induced ascorbate peroxidase mRNA accumulation was not antagonized by N-acetyl cysteine. Abscisic acid had no effect on the ascorbate peroxidase gene expression. Taken together these results suggest that iron-mediated expression of ascorbate peroxidase gene occurs through a signal transduction pathway apparently different from those already described for plant genes responsive to oxidative stress. PMID:9237628

  17. Oil body proteins sequentially accumulate throughout seed development in Brassica napus.

    PubMed

    Jolivet, Pascale; Boulard, Céline; Bellamy, Annick; Valot, Benoît; d'Andréa, Sabine; Zivy, Michel; Nesi, Nathalie; Chardot, Thierry

    2011-11-15

    Despite the importance of seed oil bodies (OBs) as enclosed compartments for oil storage, little is known about lipid and protein accumulation in OBs during seed formation. OBs from rapeseed (Brassica napus) consist of a triacylglycerol (TAG) core surrounded by a phospholipid monolayer embedded with integral proteins which confer high stability to OBs in the mature dry seed. In the present study, we investigated lipid and protein accumulation patterns throughout seed development (from 5 to 65 days after pollination [DAP]) both in the whole seed and in purified OBs. Deposition of the major proteins (oleosins, caleosins and steroleosins) into OBs was assessed through (i) gene expression pattern, (ii) proteomics analysis, and (iii) protein immunodetection. For the first time, a sequential deposition of integral OB proteins was established. Accumulation of oleosins and caleosins was observed starting from early stages of seed development (12-17 DAP), while steroleosins accumulated later (~25 DAP) onwards. PMID:21803444

  18. Comparative proteomics of leaf, stem, and root tissues of synthetic Brassica napus.

    PubMed

    Albertin, Warren; Langella, Olivier; Joets, Johann; Négroni, Luc; Zivy, Michel; Damerval, Catherine; Thiellement, Hervé

    2009-02-01

    Comparative proteomics was applied to three vegetative organs of Brassica napus, the leaf, stem, and root using 2-DE. Among the >1600 analyzed spots, 43% were found to be common to all three organs, suggesting the existence of a "basal" or ubiquitous proteome composed of housekeeping proteins. The green organs, leaf, and stem, were closely related (approximately 80% common spots) while the root displayed more organ-specific polypeptides (approximately 10%). Reference maps were established using MS, allowing the identification of 93, 385, and 266 proteins in leaf, stem, and root proteomes, respectively. Bioinformatic analyses were also performed; in silico functional categorization and cellular localization allow obtaining a precise picture of the cell molecular network within vegetative organs. These proteome maps can be explored using the PROTICdb software at the following address: http://bioinformatique.moulon.inra.fr/proticdb/web_view/.

  19. Patterns of sequence loss and cytosine methylation within a population of newly resynthesized Brassica napus allopolyploids.

    PubMed

    Lukens, Lewis N; Pires, J Chris; Leon, Enrique; Vogelzang, Robert; Oslach, Lynne; Osborn, Thomas

    2006-01-01

    Allopolyploid formation requires the adaptation of two nuclear genomes within a single cytoplasm, which may involve programmed genetic and epigenetic changes during the initial generations following genome fusion. To study the dynamics of genome change, we synthesized 49 isogenic Brassica napus allopolyploids and surveyed them with 76 restriction fragment length polymorphism (RFLP) probes and 30 simple sequence repeat (SSR) primer pairs. Here, we report on the types and distribution of genetic and epigenetic changes within the S(1) genotypes. We found that insertion/deletion (indel) events were rare, but not random. Of the 57,710 (54,383 RFLP and 3,327 SSR) parental fragments expected among the amphidiploids, we observed 56,676 or 99.9%. Three loci derived from Brassica rapa had indels, and one indel occurred repeatedly across 29% (14/49) of the lines. Loss of one parental fragment was due to the 400-bp reduction of a guanine-adenine dinucleotide repeat-rich sequence. In contrast to the 4% (3/76) RFLP probes that detected indels, 48% (35/73) detected changes in the CpG methylation status between parental genomes and the S1 lines. Some loci were far more likely than others to undergo epigenetic change, but the number of methylation changes within each synthetic polyploid was remarkably similar to others. Clear de novo methylation occurred at a much higher frequency than de novo demethylation within allopolyploid sequences derived from B. rapa. Our results suggest that there is little genetic change in the S(0) generation of resynthesized B. napus polyploids. In contrast, DNA methylation was altered extensively in a pattern that indicates tight regulation of epigenetic changes.

  20. Patterns of sequence loss and cytosine methylation within a population of newly resynthesized Brassica napus allopolyploids.

    PubMed

    Lukens, Lewis N; Pires, J Chris; Leon, Enrique; Vogelzang, Robert; Oslach, Lynne; Osborn, Thomas

    2006-01-01

    Allopolyploid formation requires the adaptation of two nuclear genomes within a single cytoplasm, which may involve programmed genetic and epigenetic changes during the initial generations following genome fusion. To study the dynamics of genome change, we synthesized 49 isogenic Brassica napus allopolyploids and surveyed them with 76 restriction fragment length polymorphism (RFLP) probes and 30 simple sequence repeat (SSR) primer pairs. Here, we report on the types and distribution of genetic and epigenetic changes within the S(1) genotypes. We found that insertion/deletion (indel) events were rare, but not random. Of the 57,710 (54,383 RFLP and 3,327 SSR) parental fragments expected among the amphidiploids, we observed 56,676 or 99.9%. Three loci derived from Brassica rapa had indels, and one indel occurred repeatedly across 29% (14/49) of the lines. Loss of one parental fragment was due to the 400-bp reduction of a guanine-adenine dinucleotide repeat-rich sequence. In contrast to the 4% (3/76) RFLP probes that detected indels, 48% (35/73) detected changes in the CpG methylation status between parental genomes and the S1 lines. Some loci were far more likely than others to undergo epigenetic change, but the number of methylation changes within each synthetic polyploid was remarkably similar to others. Clear de novo methylation occurred at a much higher frequency than de novo demethylation within allopolyploid sequences derived from B. rapa. Our results suggest that there is little genetic change in the S(0) generation of resynthesized B. napus polyploids. In contrast, DNA methylation was altered extensively in a pattern that indicates tight regulation of epigenetic changes. PMID:16377753

  1. A Brassica napus Lipase Locates at the Membrane Contact Sites Involved in Chloroplast Development

    PubMed Central

    Tan, Xiaoli; Wang, Qiuye; Tian, Baoxia; Zhang, Henan; Lu, Daoli; Zhou, Jia

    2011-01-01

    Background Fatty acids synthesized in chloroplast are transported to endoplasmic reticulum (ER) for triacylglycerols (TAGs) resembling. The development of chloroplast also requires lipids trafficking from ER to chloroplast. The membrane contact sites (MCSs) between ER and chloroplast has been demonstrated to be involved for the trafficking of lipids and proteins. Lipids trafficking between ER and chloroplast is often accompanied by lipids interconversion. However, it is rarely known how lipids interconversion happens during their trafficking. Methodology/Principal Findings We cloned a lipase gene from Brassica napus L., designated as BnCLIP1. Green fluorescence protein (GFP)-tagged BnCLIP1 was shown to locate at the MCSs between ER and chloroplasts in tobacco leaves. Heterogeneous expression of BnCLIP1 in Saccharomyces cerevisiae (pep4) reduced the total amount of fatty acid. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the truncated BnCLIP1 had a substrate preference for C16:0 lipids in Saccharomyces cerevisiae (pep4). To probe the physiological function of BnCLIP1, two Brassica napus lines with different oil-content were introduced to investigate the transcript patterns of BnCLIP1 during seed development. Intriguingly, the transcript level of BnCLIP1 was found to be immediately up-regulated during the natural seed senescence of both lines; the transcription response of BnCLIP1 in the high oil-content seeds was faster than the lower ones, suggesting a potential role of BnCLIP1 in affecting seed oil synthesis via regulating chloroplast integrity. Further researches showed that chemical disruption of leaf chloroplast also activated the transcription of BnCLIP1. Conclusions/Significance The findings of this study show that BnCLIP1 encodes a lipase, localizes at the MCSs and involves in chloroplast development. PMID:22046373

  2. High efficiency transformation ofBrassica napus usingAgrobacterium vectors.

    PubMed

    Moloney, M M; Walker, J M; Sharma, K K

    1989-04-01

    An efficient procedure for obtaining transgenicBrassica napus plants usingAgrobacterium binary vectors is described. The target tissue for the transformation is the cut end of cotyledonary petioles. These tissues, when cultured with their lamina intact, show a regeneration frequency of more than 80%. The cells of this cut surface, which undergo organogenesis, are very susceptible to topical infection byAgrobacterium. The cocultivation method used does not require feeder layers or use of exogenously applied promoters of virulence. After 72h of infection withAgrobacterium the explants were transferred to selective regeneration medium. Using kanamycin (15μg cm(-3)) for selection, transgenic plantlets emerged within 3 weeks. These plantlets which appeared on over half the explants were excised and rooted for a further 7-10 days. When the plants were large enough, leaves were taken for assay of NPT II activity using dot blots. Most of the plants surviving the selection showed substantial NPT II activity. The frequency of transformation and yield of transgenic plants was higher than in previously reported methods with this species. Southern blotting revealed that integration of the T-DNA frequently occurred in multiple copies and at multiple loci in the genome. The transgenicB. napus plants all grew normally and developed fertile flowers. The transgenic plants were self-pollinated and their progeny studied by two methods. The first was a single-embryo NPT II assay performed on developing seeds of these selfed-plants. The second was a leaf bleaching assay performed by selection of germinating seedlings of the selfed progeny. Both assays yielded segregation ratios consistent with the number of integration events indicated by Southern blots. The method should have broad application in studies of gene expression in theBrassicaceae and will be a cost-effective alternative to those seeking to improveBrassica crops by introduction of foreign genes.

  3. Identification of two novel genes for blackleg resistance in Brassica napus.

    PubMed

    Yu, F; Lydiate, D J; Rimmer, S R

    2005-03-01

    Blackleg, caused by Leptosphaeria maculans, is a major disease of Brassica napus. Two populations of B. napus DH lines, DHP95 and DHP96, with resistance introgressed from B. rapa subsp. sylvestris, were genetically mapped for resistance to blackleg disease with restriction fragment length polymorphism markers. Examination of the DHP95 population indicated that a locus on linkage group N2, named LepR1, was associated with blackleg resistance. In the DHP96 population, a second locus on linkage group N10, designated LepR2, was associated with resistance. We developed BC1 and F2 populations, to study the inheritance of resistance controlled by the genes. Genetic analysis indicated that LepR1 was a dominant nuclear allele, while LepR2 was an incompletely dominant nuclear resistance allele. LepR1 and LepR2 cotyledon resistance was further evaluated by testing 30 isolates from Canada, Australia, Europe, and Mexico. The isolates were from B. napus, B. juncea, and B. oleracea and represented different pathogenicity groups of L. maculans. Results indicated that LepR1 generally conferred a higher level of cotyledon resistance than LepR2. Both genes exhibited race-specific interactions with pathogen isolates; virulence on LepR1 was observed with one isolate, pl87-41, and two isolates, Lifolle 5, and Lifolle 6, were virulent on LepR2. LepR1 prevented hyphal penetration, while LepR2 reduced hyphal growth and inhibited sporulation. Callose deposition was associated with resistance for both loci.

  4. An ultradense genetic recombination map for Brassica napus, consisting of 13551 SRAP markers.

    PubMed

    Sun, Zudong; Wang, Zining; Tu, Jinxing; Zhang, Jiefu; Yu, Fengqun; McVetty, Peter B E; Li, Genyi

    2007-05-01

    Sequence related amplified polymorphism (SRAP) was used to construct an ultradense genetic recombination map for a doubled haploid (DH) population in B. napus. A total of 1,634 primer combinations including 12 fluorescently labeled primers and 442 unlabeled ones produced 13,551 mapped SRAP markers. All these SRAPs were assembled in 1,055 bins that were placed onto 19 linkage groups. Ten of the nineteen linkage groups were assigned to the A genome and the remaining nine to the C genome on the basis of the differential SRAP PCR amplification in two DH lines of B. rapa and B. oleracea. Furthermore, all 19 linkage groups were assigned to their corresponding N1-N19 groups of B. napus by comparison with 55 SSR markers used to construct previous maps in this species. In total, 1,663 crossovers were detected, resulting in a map length span of 1604.8 cM. The marker density is 8.45 SRAPs per cM, and there could be more than one marker in 100 kb physical distance. There are four linkage groups in the A genome with more than 800 SRAP markers each, and three linkage groups in the C genome with more 1,000 SRAP markers each. Our studies suggest that a single SRAP map might be applicable to the three Brassica species, B. napus, B. oleracea and B. rapa. The use of this ultra high-density genetic recombination map in marker development and map-based gene cloning is discussed.

  5. Agronomic and Seed Quality Traits Dissected by Genome-Wide Association Mapping in Brassica napus

    PubMed Central

    Körber, Niklas; Bus, Anja; Li, Jinquan; Parkin, Isobel A. P.; Wittkop, Benjamin; Snowdon, Rod J.; Stich, Benjamin

    2016-01-01

    In Brassica napus breeding, traits related to commercial success are of highest importance for plant breeders. However, such traits can only be assessed in an advanced developmental stage. Molecular markers genetically linked to such traits have the potential to accelerate the breeding process of B. napus by marker-assisted selection. Therefore, the objectives of this study were to identify (i) genome regions associated with the examined agronomic and seed quality traits, (ii) the interrelationship of population structure and the detected associations, and (iii) candidate genes for the revealed associations. The diversity set used in this study consisted of 405 B. napus inbred lines which were genotyped using a 6K single nucleotide polymorphism (SNP) array and phenotyped for agronomic and seed quality traits in field trials. In a genome-wide association study, we detected a total of 112 associations between SNPs and the seed quality traits as well as 46 SNP-trait associations for the agronomic traits with a P < 1.28e-05 (Bonferroni correction of α = 0.05) for the inbreds of the spring and winter trial. For the seed quality traits, a single SNP-sulfur concentration in seeds (SUL) association explained up to 67.3% of the phenotypic variance, whereas for the agronomic traits, a single SNP-blossom color (BLC) association explained up to 30.2% of the phenotypic variance. In a basic local alignment search tool (BLAST) search within a distance of 2.5 Mbp around these SNP-trait associations, 62 hits of potential candidate genes with a BLAST-score of ≥100 and a sequence identity of ≥70% to A. thaliana or B. rapa could be found for the agronomic SNP-trait associations and 187 hits of potential candidate genes for the seed quality SNP-trait associations. PMID:27066036

  6. Isolation and sequence analysis of napin seed specific promoter from Iranian Rapeseed (Brassica napus L.).

    PubMed

    Sohrabi, Maryam; Zebarjadi, Alireza; Najaphy, Abdollah; Kahrizi, Danial

    2015-06-01

    Rapeseed (Brassica napus L.) has become an important crop during the last 30years. In addition to a high lipid level, the seeds also have a significant protein content, which constitutes 20-25% of the dry seed weight. The synthesis of storage proteins is primarily controlled at transcriptional level and seed-specific expression has been shown to be conferred upon the promoter regions of many storage protein genes. Napin is one of the main storage proteins in rapeseed(')s embryo that is produced in seed developing stage. Its promoter region located at 5' upstream of the napin gene has already been isolated (GenBank number, EU416279.1). In current research, seed-specific promoter (napin) of Iranian B. napus L. was isolated from the genomic DNA and cloned into pBI121 plant binary vector to use in future researches. For this purpose, the napin promoter was amplified by PCR method using specific primers, cloned in pSK(+) vector and sequenced. Sequencing analysis showed that the cloned promoter contained all of conserved motifs such as TATA box (TATAAA), RY repeats (CATGCA), dist-B (TCAAACACC) and prox-B elements (GCCACTTGTC), G-box (CACGTG) and CAAT Motifs, which constituted the seed-specific promoter activity and according to this analysis, the seed-specific promoter activity of cloned sequence was predicted. Based on sequence distances of nucleotide sequences, our sequence had the highest similarity (99.8%) whit B. napus sequence (with EU416279.1 accession number). Finally the promoter obtained might be interesting not only as a useful tool for biotechnological application but also for fundamental research.

  7. Agronomic and Seed Quality Traits Dissected by Genome-Wide Association Mapping in Brassica napus.

    PubMed

    Körber, Niklas; Bus, Anja; Li, Jinquan; Parkin, Isobel A P; Wittkop, Benjamin; Snowdon, Rod J; Stich, Benjamin

    2016-01-01

    In Brassica napus breeding, traits related to commercial success are of highest importance for plant breeders. However, such traits can only be assessed in an advanced developmental stage. Molecular markers genetically linked to such traits have the potential to accelerate the breeding process of B. napus by marker-assisted selection. Therefore, the objectives of this study were to identify (i) genome regions associated with the examined agronomic and seed quality traits, (ii) the interrelationship of population structure and the detected associations, and (iii) candidate genes for the revealed associations. The diversity set used in this study consisted of 405 B. napus inbred lines which were genotyped using a 6K single nucleotide polymorphism (SNP) array and phenotyped for agronomic and seed quality traits in field trials. In a genome-wide association study, we detected a total of 112 associations between SNPs and the seed quality traits as well as 46 SNP-trait associations for the agronomic traits with a P < 1.28e-05 (Bonferroni correction of α = 0.05) for the inbreds of the spring and winter trial. For the seed quality traits, a single SNP-sulfur concentration in seeds (SUL) association explained up to 67.3% of the phenotypic variance, whereas for the agronomic traits, a single SNP-blossom color (BLC) association explained up to 30.2% of the phenotypic variance. In a basic local alignment search tool (BLAST) search within a distance of 2.5 Mbp around these SNP-trait associations, 62 hits of potential candidate genes with a BLAST-score of ≥100 and a sequence identity of ≥70% to A. thaliana or B. rapa could be found for the agronomic SNP-trait associations and 187 hits of potential candidate genes for the seed quality SNP-trait associations.

  8. Identification of Polymorphisms Associated with Drought Adaptation QTL in Brassica napus by Resequencing.

    PubMed

    Fletcher, Richard S; Herrmann, David; Mullen, Jack L; Li, Qinfei; Schrider, Daniel R; Price, Nicholas; Lin, Junjiang; Grogan, Kelsi; Kern, Andrew; McKay, John K

    2016-01-01

    Brassica napus is a globally important oilseed for which little is known about the genetics of drought adaptation. We previously mapped twelve quantitative trait loci (QTL) underlying drought-related traits in a biparental mapping population created from a cross between winter and spring B. napus cultivars. Here we resequence the genomes of the mapping population parents to identify genetic diversity across the genome and within QTL regions. We sequenced each parental cultivar on the Illumina HiSeq platform to a minimum depth of 23 × and performed a reference based assembly in order to describe the molecular variation differentiating them at the scale of the genome, QTL and gene. Genome-wide patterns of variation were characterized by an overall higher single nucleotide polymorphism (SNP) density in the A genome and a higher ratio of nonsynonymous to synonymous substitutions in the C genome. Nonsynonymous substitutions were used to categorize gene ontology terms differentiating the parent genomes along with a list of putative functional variants contained within each QTL. Marker assays were developed for several of the discovered polymorphisms within a pleiotropic QTL on chromosome A10. QTL analysis with the new, denser map showed the most associated marker to be that developed from an insertion/deletion polymorphism located in the candidate gene Bna.FLC.A10, and it was the only candidate within the QTL interval with observed polymorphism. Together, these results provide a glimpse of genome-wide variation differentiating annual and biennial B. napus ecotypes as well as a better understanding of the genetic basis of root and drought phenotypes.

  9. Identification of Polymorphisms Associated with Drought Adaptation QTL in Brassica napus by Resequencing

    PubMed Central

    Herrmann, David; Mullen, Jack L.; Li, Qinfei; Schrider, Daniel R.; Price, Nicholas; Lin, Junjiang; Grogan, Kelsi; Kern, Andrew; McKay, John K.

    2016-01-01

    Brassica napus is a globally important oilseed for which little is known about the genetics of drought adaptation. We previously mapped twelve quantitative trait loci (QTL) underlying drought-related traits in a biparental mapping population created from a cross between winter and spring B. napus cultivars. Here we resequence the genomes of the mapping population parents to identify genetic diversity across the genome and within QTL regions. We sequenced each parental cultivar on the Illumina HiSeq platform to a minimum depth of 23 × and performed a reference based assembly in order to describe the molecular variation differentiating them at the scale of the genome, QTL and gene. Genome-wide patterns of variation were characterized by an overall higher single nucleotide polymorphism (SNP) density in the A genome and a higher ratio of nonsynonymous to synonymous substitutions in the C genome. Nonsynonymous substitutions were used to categorize gene ontology terms differentiating the parent genomes along with a list of putative functional variants contained within each QTL. Marker assays were developed for several of the discovered polymorphisms within a pleiotropic QTL on chromosome A10. QTL analysis with the new, denser map showed the most associated marker to be that developed from an insertion/deletion polymorphism located in the candidate gene Bna.FLC.A10, and it was the only candidate within the QTL interval with observed polymorphism. Together, these results provide a glimpse of genome-wide variation differentiating annual and biennial B. napus ecotypes as well as a better understanding of the genetic basis of root and drought phenotypes. PMID:26801646

  10. Transformation of LTP gene into Brassica napus to enhance its resistance to Sclerotinia sclerotiorum.

    PubMed

    Fan, Y; Du, K; Gao, Y; Kong, Y; Chu, C; Sokolov, V; Wang, Y

    2013-04-01

    Rapeseed (Brassica napus L.) is one of the most important economic crops worldwide, and Sclerotinia sclerotiorum is the most dangerous disease that affects its yield greatly. Lipid transfer protein (LTP) has broad-spectrum anti-bacterial and fungal activities. In this study, B. napus was transformed using Agrobacterium tumefaciens harboring the plasmid-containing LTP gene to study its possible capability of increasing plant's resistance. First, we optimized the petiole genetic transformation system by adjusting the days of explants, bacterial concentrations, ratio of hormones, and cultivating condition. Second, we obtained 8 positive plants by PCR analysis of T0 generation. The PCR results of T1 generation were positive, indicating that the LTP gene had been integrated into B. napus. Third, T1 transgenic plants inoculated by detached leaves with mycelia of S. sclerotiorum showed better disease resistance than non-transformants. Oxalic acid belongs to secondary metabolites of S. sclerotiorum, and several studies have demonstrated that the resistance of rapeseed to oxalic acid is significantly consistent with its resistance to S. sclerotiorum. The result from the seed germination assay showed that when T1 seeds were exposed to oxalic acid stress, their germination rate was evidently higher than that of non-transformant seeds. In addition, we measured some physiological changes in T1 plants and control plants under oxalic acid stress. The results showed that T1 transgenic plants had lower malondialdehyde (MDA) content, higher super oxide dismutase (SOD), and peroxidase (POD) activities than non-transformants, whereas disease resistance was related to low MDA content and high SOD and POD activities. PMID:23866620

  11. Agronomic and Seed Quality Traits Dissected by Genome-Wide Association Mapping in Brassica napus.

    PubMed

    Körber, Niklas; Bus, Anja; Li, Jinquan; Parkin, Isobel A P; Wittkop, Benjamin; Snowdon, Rod J; Stich, Benjamin

    2016-01-01

    In Brassica napus breeding, traits related to commercial success are of highest importance for plant breeders. However, such traits can only be assessed in an advanced developmental stage. Molecular markers genetically linked to such traits have the potential to accelerate the breeding process of B. napus by marker-assisted selection. Therefore, the objectives of this study were to identify (i) genome regions associated with the examined agronomic and seed quality traits, (ii) the interrelationship of population structure and the detected associations, and (iii) candidate genes for the revealed associations. The diversity set used in this study consisted of 405 B. napus inbred lines which were genotyped using a 6K single nucleotide polymorphism (SNP) array and phenotyped for agronomic and seed quality traits in field trials. In a genome-wide association study, we detected a total of 112 associations between SNPs and the seed quality traits as well as 46 SNP-trait associations for the agronomic traits with a P < 1.28e-05 (Bonferroni correction of α = 0.05) for the inbreds of the spring and winter trial. For the seed quality traits, a single SNP-sulfur concentration in seeds (SUL) association explained up to 67.3% of the phenotypic variance, whereas for the agronomic traits, a single SNP-blossom color (BLC) association explained up to 30.2% of the phenotypic variance. In a basic local alignment search tool (BLAST) search within a distance of 2.5 Mbp around these SNP-trait associations, 62 hits of potential candidate genes with a BLAST-score of ≥100 and a sequence identity of ≥70% to A. thaliana or B. rapa could be found for the agronomic SNP-trait associations and 187 hits of potential candidate genes for the seed quality SNP-trait associations. PMID:27066036

  12. Deamination role of inducible glutamate dehydrogenase isoenzyme 7 in Brassica napus leaf protoplasts.

    PubMed

    Watanabe, Masami; Yumi, Ohnishi; Itoh, Yasuhiro; Yasuda, Kaori; Kamachi, Kazunari; Ratcliffe, R George

    2011-05-01

    Glutamate dehydrogenase (GDH) is a ubiquitous enzyme that catalyzes the reversible amination of 2-oxoglutarate to glutamate. In Brassica napus, GDH isoenzymes 1 and 7 are hexamers of β and α subunits, respectively and the isoenzyme profile in leaves is known to change on wounding. Here, parallels were sought between the effects of wounding and protoplast isolation because of the possible relevance of changes in GDH activity to the perturbed metabolism in recalcitrant B. napus protoplasts. When leaf protoplasts of B. napus were isolated, GDH7 isoforms predominated. Transcription of GDH2, which encodes the GDH α subunit, was activated and translation of the GDH2 mRNA was also activated to synthesize α subunit polypeptides. When detached leaves absorbed either acidic 5mM jasmonic acid or salicylic acid solutions via petioles, GDH7 isoenzymes were activated and the GDH isoenzyme patterns were similar to those of protoplasts. Salicylic acid β-glycosides were generated soon after treatment with the pectinase-cellulase enzyme solution and peaked at 1h. NMR spectroscopic analysis of protoplasts and unstressed leaves incubated with 5mM (15)NH(4)Cl showed that the change in GDH isoenzyme profile had no effect on ammonium assimilation. Protoplast isolation changed the redox state with NAD(P)H and oxidized glutathione levels increasing, and ascorbate, dehydroascorbate, NAD(P) and glutathione decreasing. ATP content in protoplasts declined to 2.6% of that in leaves, while that in wounded leaves increased by twofold. It is concluded that GDH7 does not support net amination in vivo and it is suggested that the increase in GDH7 activity is a response to oxidative stress during protoplast isolation.

  13. Identification of Polymorphisms Associated with Drought Adaptation QTL in Brassica napus by Resequencing.

    PubMed

    Fletcher, Richard S; Herrmann, David; Mullen, Jack L; Li, Qinfei; Schrider, Daniel R; Price, Nicholas; Lin, Junjiang; Grogan, Kelsi; Kern, Andrew; McKay, John K

    2016-01-01

    Brassica napus is a globally important oilseed for which little is known about the genetics of drought adaptation. We previously mapped twelve quantitative trait loci (QTL) underlying drought-related traits in a biparental mapping population created from a cross between winter and spring B. napus cultivars. Here we resequence the genomes of the mapping population parents to identify genetic diversity across the genome and within QTL regions. We sequenced each parental cultivar on the Illumina HiSeq platform to a minimum depth of 23 × and performed a reference based assembly in order to describe the molecular variation differentiating them at the scale of the genome, QTL and gene. Genome-wide patterns of variation were characterized by an overall higher single nucleotide polymorphism (SNP) density in the A genome and a higher ratio of nonsynonymous to synonymous substitutions in the C genome. Nonsynonymous substitutions were used to categorize gene ontology terms differentiating the parent genomes along with a list of putative functional variants contained within each QTL. Marker assays were developed for several of the discovered polymorphisms within a pleiotropic QTL on chromosome A10. QTL analysis with the new, denser map showed the most associated marker to be that developed from an insertion/deletion polymorphism located in the candidate gene Bna.FLC.A10, and it was the only candidate within the QTL interval with observed polymorphism. Together, these results provide a glimpse of genome-wide variation differentiating annual and biennial B. napus ecotypes as well as a better understanding of the genetic basis of root and drought phenotypes. PMID:26801646

  14. Isolation and sequence analysis of napin seed specific promoter from Iranian Rapeseed (Brassica napus L.).

    PubMed

    Sohrabi, Maryam; Zebarjadi, Alireza; Najaphy, Abdollah; Kahrizi, Danial

    2015-06-01

    Rapeseed (Brassica napus L.) has become an important crop during the last 30years. In addition to a high lipid level, the seeds also have a significant protein content, which constitutes 20-25% of the dry seed weight. The synthesis of storage proteins is primarily controlled at transcriptional level and seed-specific expression has been shown to be conferred upon the promoter regions of many storage protein genes. Napin is one of the main storage proteins in rapeseed(')s embryo that is produced in seed developing stage. Its promoter region located at 5' upstream of the napin gene has already been isolated (GenBank number, EU416279.1). In current research, seed-specific promoter (napin) of Iranian B. napus L. was isolated from the genomic DNA and cloned into pBI121 plant binary vector to use in future researches. For this purpose, the napin promoter was amplified by PCR method using specific primers, cloned in pSK(+) vector and sequenced. Sequencing analysis showed that the cloned promoter contained all of conserved motifs such as TATA box (TATAAA), RY repeats (CATGCA), dist-B (TCAAACACC) and prox-B elements (GCCACTTGTC), G-box (CACGTG) and CAAT Motifs, which constituted the seed-specific promoter activity and according to this analysis, the seed-specific promoter activity of cloned sequence was predicted. Based on sequence distances of nucleotide sequences, our sequence had the highest similarity (99.8%) whit B. napus sequence (with EU416279.1 accession number). Finally the promoter obtained might be interesting not only as a useful tool for biotechnological application but also for fundamental research. PMID:25797503

  15. Apoplastic pH and Ammonium Concentration in Leaves of Brassica napus L.

    PubMed Central

    Husted, S.; Schjoerring, J. K.

    1995-01-01

    A vacuum infiltration technique was developed that enabled the extraction of apoplastic solution with very little cytoplasmic contamination as evident from a malate dehydrogenase activity of less than 1% in the apoplastic solution relative to that in bulk leaf extracts. The volume of apoplastic water, a prerequisite for determination of the concentration of apoplastic solutes, was determined by vacuum infiltration of indigo carmine with subsequent analysis of the dilution of the dye in apoplastic extracts. Indigo carmine was neither transported across the cell membrane nor significantly adsorbed to the cell walls, ensuring reproducible (SE < 2%) and precise determination of apoplastic water. Analysis of leaves from four different positions on senescing Brassica napus plants showed a similar apoplastic pH of 5.8, while apoplastic NH4+ increased from 1.1 mM in lower leaves to 1.3 mM in upper leaves. Inhibition of glutamine synthetase in young B. napus plants resulted in increasing apoplastic pH from 6.0 to 6.8 and increasing apoplastic NH4+ concentration from 1.0 to 25.6 mM, followed by a marked increase in NH3 emission. Calculating NH3 compensation points for B. napus plants on the basis of measured apoplastic H+ and NH4+ concentrations gave values ranging from 4.3 to 5.9 nmol NH3 mol-1 air, consistent with an estimate of 5.3 [plus or minus] 3.6 nmol NH3 mol-1 air obtained by NH3 exchange experiments in growth chambers. A strong linear relationship was found between calculated NH3 compensation points and measured NH3 emission rates in glutamine synthetase-inhibited plants. PMID:12228682

  16. Comparative Proteomic Analysis of Brassica napus in Response to Drought Stress.

    PubMed

    Koh, Jin; Chen, Gang; Yoo, Mi-Jeong; Zhu, Ning; Dufresne, Daniel; Erickson, John E; Shao, Hongbo; Chen, Sixue

    2015-08-01

    Drought is one of the most widespread stresses leading to retardation of plant growth and development. We examined proteome changes of an important oil seed crop, canola (Brassica napus L.), under drought stress over a 14-day period. Using iTRAQ LC-MS/MS, we identified 1976 proteins expressed during drought stress. Among them, 417 proteins showed significant changes in abundance, and 136, 244, 286, and 213 proteins were differentially expressed in the third, seventh, 10th, and 14th day of stress, respectively. Functional analysis indicated that the number of proteins associated with metabolism, protein folding and degradation, and signaling decreased, while those related to energy (photosynthesis), protein synthesis, and stress and defense increased in response to drought stress. The seventh and 10th-day profiles were similar to each other but with more post-translational modifications (PTMs) at day 10. Interestingly, 181 proteins underwent PTMs; 49 of them were differentially changed in drought-stressed plants, and 33 were observed at the 10th day. Comparison of protein expression changes with those of gene transcription showed a positive correlation in B. napus, although different patterns between transcripts and proteins were observed at each time point. Under drought stress, most protein abundance changes may be attributed to gene transcription, and PTMs clearly contribute to protein diversity and functions. PMID:26086353

  17. Stable progeny production of the amphidiploid resynthesized Brassica napus cv. Hanakkori, a newly bred vegetable.

    PubMed

    Fujii, K; Ohmido, N

    2011-12-01

    Resynthesized Brassica napus cv. Hanakkori (AACC, 2n = 38) was produced by cross-hybridization between B. rapa (AA, 2n = 20) and B. oleracea (CC, 2n = 18) as a new vegetative crop. Many studies have provided evidences for the instability and close relationship between A and C genome in the resynthesized B. napus cultivars. In fact, seed produced to obtain progeny in Hanakkori had unstable morphological characters and generated many off-type plants. In this study, we investigated the pollen fertility, chromosome number, structure, and behavior linked to various Hanakkori phenotypes to define factors of unstable phenotypic expression in the progeny. Hanakkori phenotypes were categorized into five types. The results of pollen fertility, chromosome number, and fluorescence in situ hybridization analysis for somatic mitosis cells indicated that the off-type plants had lower pollen fertility, aberrant chromosome number, and structures with small chromosome fragments. Observation of chromosomes at meiosis showed that the meiotic division in off-type plants led to appreciably higher abnormalities than in on-type plants. However, polyvalent chromosomes were observed frequently in both on- and off-type plants in diplotene stage of meiosis. We assume that the unstable morphological characters in resynthesized progeny were the result of abnormal division in meiosis. It results as important that the plants of normal phenotype, chromosome structure and minimized abnormal meiosis are selected to stabilize progeny.

  18. Development and evaluation of single-nucleotide polymorphism markers in allotetraploid rapeseed (Brassica napus L.).

    PubMed

    Westermeier, Peter; Wenzel, Gerhard; Mohler, Volker

    2009-11-01

    Single-nucleotide polymorphisms (SNPs) and insertion-deletions (INDELs) are currently the important classes of genetic markers for major crop species. In this study, methods for developing SNP markers in rapeseed (Brassica napus L.) and their in silico mapping and use for genotyping are demonstrated. For the development of SNP and INDEL markers, 181 fragments from 121 different gene sequences spanning 86 kb were examined. A combination of different selection methods (genome-specific amplification, hetero-duplex analysis and sequence analysis) allowed the detection of 18 singular fragments that showed a total of 87 SNPs and 6 INDELs between 6 different rapeseed varieties. The average frequency of sequence polymorphism was estimated to be one SNP every 247 bp and one INDEL every 3,583 bp. Most SNPs and INDELs were found in non-coding regions. Polymorphism information content values for SNP markers ranged between 0.02 and 0.50 in a set of 86 varieties. Using comparative genetics data for B. napus and Arabidopsis thaliana, an allocation of SNP markers to linkage groups in rapeseed was achieved: a unique location was determined for seven gene sequences; two and three possible locations were found for six and four sequences, respectively. The results demonstrate the usefulness of existing genomic resources for SNP discovery in rapeseed.

  19. Overexpression of Brassica napus MPK4 enhances resistance to Sclerotinia sclerotiorum in oilseed rape.

    PubMed

    Wang, Zheng; Mao, Han; Dong, Caihua; Ji, Ruiqin; Cai, Li; Fu, Hao; Liu, Shengyi

    2009-03-01

    Sclerotinia sclerotiorum causes a highly destructive disease in oilseed rape (Brassica napus) resulting in significant economic losses. Studies on the Arabidopsis thaliana MPK4 loss-of-function mutant have implicated that AtMPK4 is involved in plant defense regulation, and its effect on disease resistance varies in different plant-pathogen interactions. In this study, we isolated a B. napus mitogen-activated protein kinase, BnMPK4, and found that BnMPK4 along with PDF1.2 are inducible in resistant line Zhongshuang9 but both are consistently suppressed in susceptible line 84039 after inoculation with S. sclerotiorum. Transgenic oilseed rape overexpressing BnMPK4 markedly enhances resistance to S. sclerotiorum and Botrytis cinerea. Further experiments showed that transgenic plants inhibited growth of S. sclerotiorum and constitutively activated PDF1.2 but decreased H2O2 production and constitutively suppressed PR-1 expression. Treatment of roots of the transgenic plants with H2O2 solution resulted in enhanced susceptibility to the two pathogens. Our results support the idea that MPK4 positively regulates jasmonic acid-mediated defense response, which might play an important role in resistance to S. sclerotiorum in oilseed rape.

  20. Poly(beta-hydroxybutyrate) production in oilseed leukoplasts of brassica napus

    PubMed

    Houmiel; Slater; Broyles; Casagrande; Colburn; Gonzalez; Mitsky; Reiser; Shah; Taylor; Tran; Valentin; Gruys

    1999-10-01

    Polyhydroxyalkanoates (PHAs) comprise a class of biodegradable polymers which offer an environmentally sustainable alternative to petroleum-based plastics. Production of PHAs in plants is attractive since current fermentation technology is prohibitively expensive. The PHA homopolymer poly(beta-hydroxybutyrate) (PHB) has previously been produced in leaves of Arabidopsis thaliana (Nawrath et al., 1994, Proc Natl Acad Sci USA 91: 12760-12764). However, Brassica napus oilseed may provide a better system for PHB production because acetyl-CoA, the substrate required in the first step of PHB biosynthesis, is prevalent during fatty acid biosynthesis. Three enzymatic activities are needed to synthesize PHB: a beta-ketothiolase, an acetoacetyl-CoA reductase and a PHB synthase. Genes from the bacterium Ralstonia eutropha encoding these enzymes were independently engineered behind the seed-specific Lesquerella fendleri oleate 12-hydroxylase promoter in a modular fashion. The gene cassettes were sequentially transferred into a single, multi-gene vector which was used to transform B. napus. Poly(beta-hydroxybutyrate) accumulated in leukoplasts to levels as high as 7.7% fresh seed weight of mature seeds. Electron-microscopy analyses indicated that leukoplasts from these plants were distorted, yet intact, and appeared to expand in response to polymer accumulation.

  1. Comparative Proteomic Analysis of Brassica napus in Response to Drought Stress.

    PubMed

    Koh, Jin; Chen, Gang; Yoo, Mi-Jeong; Zhu, Ning; Dufresne, Daniel; Erickson, John E; Shao, Hongbo; Chen, Sixue

    2015-08-01

    Drought is one of the most widespread stresses leading to retardation of plant growth and development. We examined proteome changes of an important oil seed crop, canola (Brassica napus L.), under drought stress over a 14-day period. Using iTRAQ LC-MS/MS, we identified 1976 proteins expressed during drought stress. Among them, 417 proteins showed significant changes in abundance, and 136, 244, 286, and 213 proteins were differentially expressed in the third, seventh, 10th, and 14th day of stress, respectively. Functional analysis indicated that the number of proteins associated with metabolism, protein folding and degradation, and signaling decreased, while those related to energy (photosynthesis), protein synthesis, and stress and defense increased in response to drought stress. The seventh and 10th-day profiles were similar to each other but with more post-translational modifications (PTMs) at day 10. Interestingly, 181 proteins underwent PTMs; 49 of them were differentially changed in drought-stressed plants, and 33 were observed at the 10th day. Comparison of protein expression changes with those of gene transcription showed a positive correlation in B. napus, although different patterns between transcripts and proteins were observed at each time point. Under drought stress, most protein abundance changes may be attributed to gene transcription, and PTMs clearly contribute to protein diversity and functions.

  2. Decreased seed oil production in FUSCA3 Brassica napus mutant plants.

    PubMed

    Elahi, Nosheen; Duncan, Robert W; Stasolla, Claudio

    2015-11-01

    Canola (Brassica napus L.) oil is extensively utilized for human consumption and industrial applications. Among the genes regulating seed development and participating in oil accumulation is FUSCA3 (FUS3), a member of the plant-specific B3-domain family of transcription factors. To evaluate the role of this gene during seed storage deposition, three BnFUSCA3 (BnFUS3) TILLING mutants were generated. Mutations occurring downstream of the B3 domain reduced silique number and repressed seed oil level resulting in increased protein content in developing seeds. BnFUS3 mutant seeds also had increased levels of linoleic acid, possibly due to the reduced expression of ω-3 FA DESATURASE (FAD3). These observed phenotypic alterations were accompanied by the decreased expression of genes encoding transcription factors stimulating fatty acid (FA) synthesis: LEAFY COTYLEDON1 and 2 (LEC1 and 2) ABSCISIC ACID-INSENSITIVE 3 (BnABI3) and WRINKLED1 (WRI1). Additionally, expression of genes encoding enzymes involved in sucrose metabolism, glycolysis, and FA modifications were down-regulated in developing seeds of the mutant plants. Collectively, these transcriptional changes support altered sucrose metabolism and reduced glycolytic activity, diminishing the carbon pool available for the synthesis of FA and ultimately seed oil production. Based on these observations, it is suggested that targeted manipulations of BnFUS3 can be used as a tool to influence oil accumulation in the economically important species B. napus.

  3. Mating system of Brassica napus and its relationship with morphological and ecological parameters in northwestern Spain.

    PubMed

    Soengas, Pilar; Velasco, Pablo; Vilar, Marta; Cartea, Maria Elena

    2013-01-01

    Mating systems play a central role in determining population genetic structure and the methods to be used to develop new cultivars and preserve the variability of a crop. A Brassica napus crop called nabicol is grown in northwestern Spain. Knowledge on its mating system is needed in order to manage the germplasm correctly and design breeding strategies. The aims of this work were to study the mating system of nabicol under field conditions and the relationship of different traits with the mating system. We analyzed 2 populations with microsatellites using a multilocus approach, finding that both had a mixed mating system with an outcrossing rate of 30%. This system would allow application of breeding methods for both autogamous and allogamous species in order to improve nabicol populations. Nabicol populations should be multiplied in isolation conditions in the same way as allogamous species in order to avoid contamination and preserve genetic integrity. The relationship of outcrossing rate, phenological, ecological, and morphological traits was studied, but the model explained only a small percentage of the variability. None of the traits studied could be used as indirect selection criteria for a type of mating system under the conditions of northwestern Spain. This is the first work that studies in depth the possible causes of the mixed mating system of B. napus, finding that, surprisingly, it is not related to the most obvious factors. PMID:23530142

  4. Associative Transcriptomics Study Dissects the Genetic Architecture of Seed Glucosinolate Content in Brassica napus

    PubMed Central

    Lu, Guangyuan; Harper, Andrea L.; Trick, Martin; Morgan, Colin; Fraser, Fiona; O'Neill, Carmel; Bancroft, Ian

    2014-01-01

    Breeding new varieties with low seed glucosinolate (GS) concentrations has long been a prime target in Brassica napus. In this study, a novel association mapping methodology termed ‘associative transcriptomics’ (AT) was applied to a panel of 101 B. napus lines to define genetic regions and also candidate genes controlling total seed GS contents. Over 100,000 informative single-nucleotide polymorphisms (SNPs) and gene expression markers (GEMs) were developed for AT analysis, which led to the identification of 10 SNP and 7 GEM association peaks. Within these peaks, 26 genes were inferred to be involved in GS biosynthesis. A weighted gene co-expression network analysis provided additional 40 candidate genes. The transcript abundance in leaves of two candidate genes, BnaA.GTR2a located on chromosome A2 and BnaC.HAG3b on C9, was correlated with seed GS content, explaining 18.8 and 16.8% of phenotypic variation, respectively. Resequencing of genomic regions revealed six new SNPs in BnaA.GTR2a and four insertions or deletions in BnaC.HAG3b. These deletion polymorphisms were then successfully converted into polymerase chain reaction–based diagnostic markers that can, due to high linkage disequilibrium observed in these regions of the genome, be used for marker-assisted breeding for low seed GS lines. PMID:25030463

  5. Overexpression of Brassica napus MPK4 enhances resistance to Sclerotinia sclerotiorum in oilseed rape.

    PubMed

    Wang, Zheng; Mao, Han; Dong, Caihua; Ji, Ruiqin; Cai, Li; Fu, Hao; Liu, Shengyi

    2009-03-01

    Sclerotinia sclerotiorum causes a highly destructive disease in oilseed rape (Brassica napus) resulting in significant economic losses. Studies on the Arabidopsis thaliana MPK4 loss-of-function mutant have implicated that AtMPK4 is involved in plant defense regulation, and its effect on disease resistance varies in different plant-pathogen interactions. In this study, we isolated a B. napus mitogen-activated protein kinase, BnMPK4, and found that BnMPK4 along with PDF1.2 are inducible in resistant line Zhongshuang9 but both are consistently suppressed in susceptible line 84039 after inoculation with S. sclerotiorum. Transgenic oilseed rape overexpressing BnMPK4 markedly enhances resistance to S. sclerotiorum and Botrytis cinerea. Further experiments showed that transgenic plants inhibited growth of S. sclerotiorum and constitutively activated PDF1.2 but decreased H2O2 production and constitutively suppressed PR-1 expression. Treatment of roots of the transgenic plants with H2O2 solution resulted in enhanced susceptibility to the two pathogens. Our results support the idea that MPK4 positively regulates jasmonic acid-mediated defense response, which might play an important role in resistance to S. sclerotiorum in oilseed rape. PMID:19245318

  6. Associative transcriptomics study dissects the genetic architecture of seed glucosinolate content in Brassica napus.

    PubMed

    Lu, Guangyuan; Harper, Andrea L; Trick, Martin; Morgan, Colin; Fraser, Fiona; O'Neill, Carmel; Bancroft, Ian

    2014-12-01

    Breeding new varieties with low seed glucosinolate (GS) concentrations has long been a prime target in Brassica napus. In this study, a novel association mapping methodology termed 'associative transcriptomics' (AT) was applied to a panel of 101 B. napus lines to define genetic regions and also candidate genes controlling total seed GS contents. Over 100,000 informative single-nucleotide polymorphisms (SNPs) and gene expression markers (GEMs) were developed for AT analysis, which led to the identification of 10 SNP and 7 GEM association peaks. Within these peaks, 26 genes were inferred to be involved in GS biosynthesis. A weighted gene co-expression network analysis provided additional 40 candidate genes. The transcript abundance in leaves of two candidate genes, BnaA.GTR2a located on chromosome A2 and BnaC.HAG3b on C9, was correlated with seed GS content, explaining 18.8 and 16.8% of phenotypic variation, respectively. Resequencing of genomic regions revealed six new SNPs in BnaA.GTR2a and four insertions or deletions in BnaC.HAG3b. These deletion polymorphisms were then successfully converted into polymerase chain reaction-based diagnostic markers that can, due to high linkage disequilibrium observed in these regions of the genome, be used for marker-assisted breeding for low seed GS lines.

  7. Species-wide genome sequence and nucleotide polymorphisms from the model allopolyploid plant Brassica napus

    PubMed Central

    Schmutzer, Thomas; Samans, Birgit; Dyrszka, Emmanuelle; Ulpinnis, Chris; Weise, Stephan; Stengel, Doreen; Colmsee, Christian; Lespinasse, Denis; Micic, Zeljko; Abel, Stefan; Duchscherer, Peter; Breuer, Frank; Abbadi, Amine; Leckband, Gunhild; Snowdon, Rod; Scholz, Uwe

    2015-01-01

    Brassica napus (oilseed rape, canola) is one of the world’s most important sources of vegetable oil for human nutrition and biofuel, and also a model species for studies investigating the evolutionary consequences of polyploidisation. Strong bottlenecks during its recent origin from interspecific hybridisation, and subsequently through intensive artificial selection, have severely depleted the genetic diversity available for breeding. On the other hand, high-throughput genome profiling technologies today provide unprecedented scope to identify, characterise and utilise genetic diversity in primary and secondary crop gene pools. Such methods also enable implementation of genomic selection strategies to accelerate breeding progress. The key prerequisite is availability of high-quality sequence data and identification of high-quality, genome-wide sequence polymorphisms representing relevant gene pools. We present comprehensive genome resequencing data from a panel of 52 highly diverse natural and synthetic B. napus accessions, along with a stringently selected panel of 4.3 million high-confidence, genome-wide SNPs. The data is of great interest for genomics-assisted breeding and for evolutionary studies on the origins and consequences in allopolyploidisation in plants. PMID:26647166

  8. The control of seed oil polyunsaturate content in the polyploid crop species Brassica napus.

    PubMed

    Wells, Rachel; Trick, Martin; Soumpourou, Eleni; Clissold, Leah; Morgan, Colin; Werner, Peter; Gibbard, Carl; Clarke, Matthew; Jennaway, Richard; Bancroft, Ian

    2014-01-01

    Many important plant species have polyploidy in their recent ancestry, complicating inferences about the genetic basis of trait variation. Although the principal locus controlling the proportion of polyunsaturated fatty acids (PUFAs) in seeds of Arabidopsis thaliana is known (fatty acid desaturase 2; FAD2), commercial cultivars of a related crop, oilseed rape (Brassica napus), with very low PUFA content have yet to be developed. We showed that a cultivar of oilseed rape with lower than usual PUFA content has non-functional alleles at three of the four orthologous FAD2 loci. To explore the genetic basis further, we developed an ethyl methanesulphonate mutagenised population, JBnaCAB_E, and used it to identify lines that also carried mutations in the remaining functional copy. This confirmed the hypothesised basis of variation, resulting in an allelic series of mutant lines showing a spectrum of PUFA contents of seed oil. Several lines had PUFA content of ~6 % and oleic acid content of ~84 %, achieving a long-standing industry objective: very high oleic, very low PUFA rapeseed without the use of genetic modification technology. The population contains a high rate of mutations and represents an important resource for research in B. napus. PMID:24489479

  9. New NIRS calibrations for fiber fractions reveal broad genetic variation in Brassica napus seed quality.

    PubMed

    Wittkop, Benjamin; Snowdon, Rod J; Friedt, Wolfgang

    2012-03-01

    Near-infrared reflectance spectroscopy (NIRS) calibrations were developed for the estimation of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) in intact seeds of oilseed rape ( Brassica napus ). A set of 338 diverse winter oilseed rape genotypes showing broad variation for seed color was used as a basis for the new calibrations. Different calibrations were generated for 10 or 1 mL seed volumes, respectively. In both seed volumes good coefficients of determination for external validation (R(2)) of the calibrations were obtained for ADL, the major antinutritional fiber fraction in oilseed rape meal, and adequate calibrations for NDF and ADF. Evaluation of diverse B. napus germplasm with the new calibrations revealed a surprisingly broad variation in contents of ADL in dark-seeded oilseed rape. The ability to use NIRS for efficient selection of low-fiber genotypes, irrespective of seed color, represents an important breakthrough in breeding for improved nutritional quality of seed extraction meals from oilseed rape. PMID:22296210

  10. Alteration of Gene Expression during the Induction of Freezing Tolerance in Brassica napus Suspension Cultures.

    PubMed

    Johnson-Flanagan, A M; Singh, J

    1987-11-01

    Brassica napus suspension-cultured cells can be hardened to a lethal temperature for 50% of the sample of -20 degrees C in eight days at room temperature with abscisic acid. During the induction of freezing tolerance, changes were observed in the electrophoretic pattern of [(35)S]methionine labeled polypeptides. In hardening cells, a 20 kilodalton polypeptide was induced on day 2 and its level increased during hardening. The induction of freezing tolerance with nonmaximal hardening regimens also resulted in increases in the 20 kilodalton polypeptide. The 20 kilodalton polypeptide was associated with a membrane fraction enriched in endoplasmic reticulum and was resolved as a single spot by two-dimensional electrophoresis. In vitro translation of mRNA indicate alteration of gene expression during abscisic acid induction of freezing tolerance. The new mRNA encodes a 20 kilodalton polypeptide associated with increased freezing tolerance induced by either abscisic acid or high sucrose. A 20 kilodalton polypeptide was also translated by mRNA isolated from cold-hardened B. napus plants. PMID:16665763

  11. Alteration of gene expression during the induction of freezing tolerance in Brassica napus suspension cultures

    SciTech Connect

    Johnson-Flanagan, A.M.; Singh, J.

    1987-11-01

    Brassica napus suspension-cultured cells can be hardened to a lethal temperature for 50% of the sample of -20/sup 0/C in eight days at room temperature with abscisic acid. During the induction of freezing tolerance, changes were observed in the electrophoretic pattern of (/sup 35/S)methionine labeled polypeptides. In hardening cells, a 20 kilodalton polypeptide was induced on day 2 and its level increased during hardening. The induction of freezing tolerance with nonmaximal hardening regimens also resulted in increases in the 20 kilodalton polypeptide. The 20 kilodalton polypeptide was associated with a membrane fraction enriched in endoplasmic reticulum and was resolved as a single spot by two-dimensional electrophoresis. In vitro translation of mRNA indicate alteration of gene expression during abscisic acid induction of freezing tolerance. The new mRNA encodes a 20 kilodalton polypeptide associated with increased freezing tolerance induced by either abscisic acid or high sucrose. A 20 kilodalton polypeptide was also translated by mRNA isolated from cold-hardened B. napus plants.

  12. Species-wide genome sequence and nucleotide polymorphisms from the model allopolyploid plant Brassica napus.

    PubMed

    Schmutzer, Thomas; Samans, Birgit; Dyrszka, Emmanuelle; Ulpinnis, Chris; Weise, Stephan; Stengel, Doreen; Colmsee, Christian; Lespinasse, Denis; Micic, Zeljko; Abel, Stefan; Duchscherer, Peter; Breuer, Frank; Abbadi, Amine; Leckband, Gunhild; Snowdon, Rod; Scholz, Uwe

    2015-01-01

    Brassica napus (oilseed rape, canola) is one of the world's most important sources of vegetable oil for human nutrition and biofuel, and also a model species for studies investigating the evolutionary consequences of polyploidisation. Strong bottlenecks during its recent origin from interspecific hybridisation, and subsequently through intensive artificial selection, have severely depleted the genetic diversity available for breeding. On the other hand, high-throughput genome profiling technologies today provide unprecedented scope to identify, characterise and utilise genetic diversity in primary and secondary crop gene pools. Such methods also enable implementation of genomic selection strategies to accelerate breeding progress. The key prerequisite is availability of high-quality sequence data and identification of high-quality, genome-wide sequence polymorphisms representing relevant gene pools. We present comprehensive genome resequencing data from a panel of 52 highly diverse natural and synthetic B. napus accessions, along with a stringently selected panel of 4.3 million high-confidence, genome-wide SNPs. The data is of great interest for genomics-assisted breeding and for evolutionary studies on the origins and consequences in allopolyploidisation in plants. PMID:26647166

  13. Fine mapping of a dominant gene conferring chlorophyll-deficiency in Brassica napus

    PubMed Central

    Wang, Yankun; He, Yongjun; Yang, Mao; He, Jianbo; Xu, Pan; Shao, Mingquan; Chu, Pu; Guan, Rongzhan

    2016-01-01

    Leaf colour regulation is important in photosynthesis and dry material production. Most of the reported chlorophyll-deficient loci are recessive. The dominant locus is rarely reported, although it may be more important than the recessive locus in the regulation of photosynthesis efficiency. During the present study, we mapped a chlorophyll-deficient dominant locus (CDE1) from the ethyl methanesulfonate-mutagenized Brassica napus line NJ7982. Using an F2 population derived from the chlorophyll-deficient mutant (cde1) and the canola variety ‘zhongshuang11’, a high-density linkage map was constructed, consisting of 19 linkage groups with 2,878 bins containing 13,347 SNP markers, with a total linkage map length of 1,968.6 cM. Next, the CDE1 locus was mapped in a 0.9-cM interval of chromosome C08 of B. napus, co-segregating with nine SNP markers. In the following fine-mapping of the gene using the inherited F2:3 populations of 620 individuals, the locus was identified in an interval with a length of 311 kb. A bioinformatics analysis revealed that the mapping interval contained 22 genes. These results produced a good foundation for continued research on the dominant locus involved in chlorophyll content regulation. PMID:27506952

  14. Profiling of phenylpropanoids in transgenic low-sinapine oilseed rape (Brassica napus).

    PubMed

    Wolfram, Karina; Schmidt, Jürgen; Wray, Victor; Milkowski, Carsten; Schliemann, Willibald; Strack, Dieter

    2010-07-01

    A dsRNAi approach silencing a key enzyme of sinapate ester biosynthesis (UDP-glucose:sinapate glucosyltransferase, encoded by the UGT84A9 gene) in oilseed rape (Brassica napus) seeds was performed to reduce the anti-nutritive properties of the seeds by lowering the content of the major seed component sinapine (sinapoylcholine) and various minor sinapate esters. The transgenic seeds have been produced so far to the T6 generation and revealed a steady suppression of sinapate ester accumulation. HPLC analysis of the wild-type and transgenic seeds revealed, as in the previous generations, marked alterations of the sinapate ester pattern of the transformed seeds. Besides strong reduction of the amount of the known sinapate esters, HPLC analysis revealed unexpectedly the appearance of several minor hitherto unknown rapeseed constituents. These compounds were isolated and identified by mass spectrometric and NMR spectroscopic analyses. Structures of 11 components were elucidated to be 4-O-glucosides of syringate, caffeyl alcohol and its 7,8-dihydro derivative as well as of sinapate and sinapine, along with sinapoylated kaempferol glycosides, a hexoside of a cyclic spermidine alkaloid and a sinapine derivative with an ether-bridge to a C(6)-C(3)-unit. These results indicate a strong impact of the transgenic approach on the metabolic network of phenylpropanoids in B. napus seeds. Silencing of UGT84A9 gene expression disrupt the metabolic flow through sinapoylglucose and alters the amounts and nature of the phenylpropanoid endproducts. PMID:20451226

  15. Fine mapping of a dominant gene conferring chlorophyll-deficiency in Brassica napus.

    PubMed

    Wang, Yankun; He, Yongjun; Yang, Mao; He, Jianbo; Xu, Pan; Shao, Mingquan; Chu, Pu; Guan, Rongzhan

    2016-01-01

    Leaf colour regulation is important in photosynthesis and dry material production. Most of the reported chlorophyll-deficient loci are recessive. The dominant locus is rarely reported, although it may be more important than the recessive locus in the regulation of photosynthesis efficiency. During the present study, we mapped a chlorophyll-deficient dominant locus (CDE1) from the ethyl methanesulfonate-mutagenized Brassica napus line NJ7982. Using an F2 population derived from the chlorophyll-deficient mutant (cde1) and the canola variety 'zhongshuang11', a high-density linkage map was constructed, consisting of 19 linkage groups with 2,878 bins containing 13,347 SNP markers, with a total linkage map length of 1,968.6 cM. Next, the CDE1 locus was mapped in a 0.9-cM interval of chromosome C08 of B. napus, co-segregating with nine SNP markers. In the following fine-mapping of the gene using the inherited F2:3 populations of 620 individuals, the locus was identified in an interval with a length of 311 kb. A bioinformatics analysis revealed that the mapping interval contained 22 genes. These results produced a good foundation for continued research on the dominant locus involved in chlorophyll content regulation. PMID:27506952

  16. Decreased seed oil production in FUSCA3 Brassica napus mutant plants.

    PubMed

    Elahi, Nosheen; Duncan, Robert W; Stasolla, Claudio

    2015-11-01

    Canola (Brassica napus L.) oil is extensively utilized for human consumption and industrial applications. Among the genes regulating seed development and participating in oil accumulation is FUSCA3 (FUS3), a member of the plant-specific B3-domain family of transcription factors. To evaluate the role of this gene during seed storage deposition, three BnFUSCA3 (BnFUS3) TILLING mutants were generated. Mutations occurring downstream of the B3 domain reduced silique number and repressed seed oil level resulting in increased protein content in developing seeds. BnFUS3 mutant seeds also had increased levels of linoleic acid, possibly due to the reduced expression of ω-3 FA DESATURASE (FAD3). These observed phenotypic alterations were accompanied by the decreased expression of genes encoding transcription factors stimulating fatty acid (FA) synthesis: LEAFY COTYLEDON1 and 2 (LEC1 and 2) ABSCISIC ACID-INSENSITIVE 3 (BnABI3) and WRINKLED1 (WRI1). Additionally, expression of genes encoding enzymes involved in sucrose metabolism, glycolysis, and FA modifications were down-regulated in developing seeds of the mutant plants. Collectively, these transcriptional changes support altered sucrose metabolism and reduced glycolytic activity, diminishing the carbon pool available for the synthesis of FA and ultimately seed oil production. Based on these observations, it is suggested that targeted manipulations of BnFUS3 can be used as a tool to influence oil accumulation in the economically important species B. napus. PMID:26302483

  17. Genetic load and transgenic mitigating genes in transgenic Brassica rapa (field mustard) × Brassica napus (oilseed rape) hybrid populations

    PubMed Central

    2009-01-01

    Background One theoretical explanation for the relatively poor performance of Brassica rapa (weed) × Brassica napus (crop) transgenic hybrids suggests that hybridization imparts a negative genetic load. Consequently, in hybrids genetic load could overshadow any benefits of fitness enhancing transgenes and become the limiting factor in transgenic hybrid persistence. Two types of genetic load were analyzed in this study: random/linkage-derived genetic load, and directly incorporated genetic load using a transgenic mitigation (TM) strategy. In order to measure the effects of random genetic load, hybrid productivity (seed yield and biomass) was correlated with crop- and weed-specific AFLP genomic markers. This portion of the study was designed to answer whether or not weed × transgenic crop hybrids possessing more crop genes were less competitive than hybrids containing fewer crop genes. The effects of directly incorporated genetic load (TM) were analyzed through transgene persistence data. TM strategies are proposed to decrease transgene persistence if gene flow and subsequent transgene introgression to a wild host were to occur. Results In the absence of interspecific competition, transgenic weed × crop hybrids benefited from having more crop-specific alleles. There was a positive correlation between performance and number of B. napus crop-specific AFLP markers [seed yield vs. marker number (r = 0.54, P = 0.0003) and vegetative dry biomass vs. marker number (r = 0.44, P = 0.005)]. However under interspecific competition with wheat or more weed-like conditions (i.e. representing a situation where hybrid plants emerge as volunteer weeds in subsequent cropping systems), there was a positive correlation between the number of B. rapa weed-specific AFLP markers and seed yield (r = 0.70, P = 0.0001), although no such correlation was detected for vegetative biomass. When genetic load was directly incorporated into the hybrid genome, by inserting a fitness

  18. Mitigation of establishment of Brassica napus transgenes in volunteers using a tandem construct containing a selectively unfit gene.

    PubMed

    Al-Ahmad, Hani; Dwyer, Jennice; Moloney, Maurice; Gressel, Jonathan

    2006-01-01

    Transgenic oilseed rape (Brassica napus) plants may remain as 'volunteer' weeds in following crops, complicating cultivation and contaminating crop yield. Volunteers can become feral as well as act as a genetic bridge for the transfer of transgenes to weedy relatives. Transgenic mitigation using genes that are positive or neutral to the crop, but deleterious to weeds, should prevent volunteer establishment, as previously intimated using a tobacco (Nicotiana tabacum) model. A transgenically mitigated (TM), dwarf, herbicide-resistant construct using a gibberellic acid-insensitive (Deltagai) gene in the B. napus crop was effective in offsetting the risks of transgene establishment in volunteer populations of B. napus. This may be useful in the absence of herbicide, e.g. when wheat is rotated with oilseed rape. The TM dwarf B. napus plants grown alone had a much higher yield than the non-transgenics, but were exceedingly unfit in competition with non-transgenic tall cohorts. The reproductive fitness of TM B. napus was 0% at 2.5-cm and 4% at 5-cm spacing between glasshouse-grown plants relative to non-transgenic B. napus. Under screen-house conditions, the reproductive fitness of TM B. napus relative to non-transgenic B. napus was less than 12%, and the harvest index of the TM plants was less than 40% of that of the non-transgenic competitors. The data clearly indicate that the Deltagai gene greatly enhances the yield in a weed-free transgenic crop, but the dwarf plants can be eliminated when competing with non-transgenic cohorts (and presumably other species) when the selective herbicide is not used.

  19. Mitigation of establishment of Brassica napus transgenes in volunteers using a tandem construct containing a selectively unfit gene.

    PubMed

    Al-Ahmad, Hani; Dwyer, Jennice; Moloney, Maurice; Gressel, Jonathan

    2006-01-01

    Transgenic oilseed rape (Brassica napus) plants may remain as 'volunteer' weeds in following crops, complicating cultivation and contaminating crop yield. Volunteers can become feral as well as act as a genetic bridge for the transfer of transgenes to weedy relatives. Transgenic mitigation using genes that are positive or neutral to the crop, but deleterious to weeds, should prevent volunteer establishment, as previously intimated using a tobacco (Nicotiana tabacum) model. A transgenically mitigated (TM), dwarf, herbicide-resistant construct using a gibberellic acid-insensitive (Deltagai) gene in the B. napus crop was effective in offsetting the risks of transgene establishment in volunteer populations of B. napus. This may be useful in the absence of herbicide, e.g. when wheat is rotated with oilseed rape. The TM dwarf B. napus plants grown alone had a much higher yield than the non-transgenics, but were exceedingly unfit in competition with non-transgenic tall cohorts. The reproductive fitness of TM B. napus was 0% at 2.5-cm and 4% at 5-cm spacing between glasshouse-grown plants relative to non-transgenic B. napus. Under screen-house conditions, the reproductive fitness of TM B. napus relative to non-transgenic B. napus was less than 12%, and the harvest index of the TM plants was less than 40% of that of the non-transgenic competitors. The data clearly indicate that the Deltagai gene greatly enhances the yield in a weed-free transgenic crop, but the dwarf plants can be eliminated when competing with non-transgenic cohorts (and presumably other species) when the selective herbicide is not used. PMID:17177781

  20. Two Clades of Type-1 Brassica napus Diacylglycerol Acyltransferase Exhibit Differences in Acyl-CoA Preference.

    PubMed

    Greer, Michael S; Pan, Xue; Weselake, Randall J

    2016-06-01

    Diacylglycerol acyltransferase (DGAT) catalyzes the acyl-CoA-dependent acylation of sn-1, 2-diacylglycerol to produce triacylglycerol, which is the main component of the seed oil of Brassica oilseed species. Phylogenetic analysis of the amino acid sequences encoded by four transcriptionally active DGAT1 genes from Brassica napus suggests that the gene forms diverged over time into two clades (I and II), with representative members in each genome (A and C). The majority of the amino acid sequence differences in these forms of DGAT1, however, reside outside of motifs suggested to be involved in catalysis. Despite this, the clade II enzymes displayed a significantly enhanced preference for linoleoyl-CoA when assessed using in-vitro enzyme assays with yeast microsomes containing recombinant enzyme forms. These findings contribute to our understanding of triacylglycerol biosynthesis in B. napus, and may advance our ability to engineer DGAT1s with desired substrate selectivity properties. PMID:27138895

  1. Genome-wide association study reveals the genetic architecture of flowering time in rapeseed (Brassica napus L.).

    PubMed

    Xu, Liping; Hu, Kaining; Zhang, Zhenqian; Guan, Chunyun; Chen, Song; Hua, Wei; Li, Jiana; Wen, Jing; Yi, Bin; Shen, Jinxiong; Ma, Chaozhi; Tu, Jinxing; Fu, Tingdong

    2016-02-01

    Flowering time adaptation is a major breeding goal in the allopolyploid species Brassica napus. To investigate the genetic architecture of flowering time, a genome-wide association study (GWAS) of flowering time was conducted with a diversity panel comprising 523 B. napus cultivars and inbred lines grown in eight different environments. Genotyping was performed with a Brassica 60K Illumina Infinium SNP array. A total of 41 single-nucleotide polymorphisms (SNPs) distributed on 14 chromosomes were found to be associated with flowering time, and 12 SNPs located in the confidence intervals of quantitative trait loci (QTL) identified in previous researches based on linkage analyses. Twenty-five candidate genes were orthologous to Arabidopsis thaliana flowering genes. To further our understanding of the genetic factors influencing flowering time in different environments, GWAS was performed on two derived traits, environment sensitivity and temperature sensitivity. The most significant SNPs were found near Bn-scaff_16362_1-p380982, just 13 kb away from BnaC09g41990D, which is orthologous to A. thaliana CONSTANS (CO), an important gene in the photoperiod flowering pathway. These results provide new insights into the genetic control of flowering time in B. napus and indicate that GWAS is an effective method by which to reveal natural variations of complex traits in B. napus.

  2. Genome-wide association study reveals the genetic architecture of flowering time in rapeseed (Brassica napus L.)

    PubMed Central

    Xu, Liping; Hu, Kaining; Zhang, Zhenqian; Guan, Chunyun; Chen, Song; Hua, Wei; Li, Jiana; Wen, Jing; Yi, Bin; Shen, Jinxiong; Ma, Chaozhi; Tu, Jinxing; Fu, Tingdong

    2016-01-01

    Flowering time adaptation is a major breeding goal in the allopolyploid species Brassica napus. To investigate the genetic architecture of flowering time, a genome-wide association study (GWAS) of flowering time was conducted with a diversity panel comprising 523 B. napus cultivars and inbred lines grown in eight different environments. Genotyping was performed with a Brassica 60K Illumina Infinium SNP array. A total of 41 single-nucleotide polymorphisms (SNPs) distributed on 14 chromosomes were found to be associated with flowering time, and 12 SNPs located in the confidence intervals of quantitative trait loci (QTL) identified in previous researches based on linkage analyses. Twenty-five candidate genes were orthologous to Arabidopsis thaliana flowering genes. To further our understanding of the genetic factors influencing flowering time in different environments, GWAS was performed on two derived traits, environment sensitivity and temperature sensitivity. The most significant SNPs were found near Bn-scaff_16362_1-p380982, just 13 kb away from BnaC09g41990D, which is orthologous to A. thaliana CONSTANS (CO), an important gene in the photoperiod flowering pathway. These results provide new insights into the genetic control of flowering time in B. napus and indicate that GWAS is an effective method by which to reveal natural variations of complex traits in B. napus. PMID:26659471

  3. Stable Bacillus thuringiensis transgene introgression from Brassica napus to wild mustard B. juncea.

    PubMed

    Cao, Di; Stewart, C Neal; Zheng, Min; Guan, Zhengjun; Tang, Zhi-Xi; Wei, Wei; Ma, Ke-Ping

    2014-10-01

    Transgenic canola (Brassica napus) with a Bacillus thuringiensis cry1Ac gene and a green fluorescent protein (GFP) marker gene was used in hybridization experiments with wild Brassica juncea. Hybrid F1 and successive five backcross generations were obtained. The pod-set frequency on backcrossed B. juncea plants was over 66%, which suggested relatively high crossing compatibility between the hybrids and wild species. The seed setting in BC1 was the least of all generations tested, and then increased at the BC2 generation for which the thousand-seed weight was the highest of all generations. Seed size in backcrossed generations eventually approached that of the wild parent. The plants in all backcrossed generations were consistent with the expected 1:1 segregation ratio of the transgenes. The Bt Cry1Ac protein concentrations at bolting and flowering stages was higher compared to the 4-5-leaf and pod-formation stages. Nonetheless, the Bt toxin in the fifth backcrossing generation (BC5) was sufficient to kill both polyphagous (Helicoverpa armigera) and oligophagous (Plutella xylostella) Lepidoptera. As a consequence, the subsequent generations harboring the transgene from F1 to BC5 could have selection advantage against insect pests. The result is useful in understanding gene flow from transgenic crops and the followed transgene introgression into wild. PMID:25219305

  4. Degradation of glyoxalase I in Brassica napus stigma leads to self-incompatibility response.

    PubMed

    Sankaranarayanan, Subramanian; Jamshed, Muhammad; Samuel, Marcus A

    2015-01-01

    Self-incompatibility (rejection of 'self'-pollen) is a reproductive barrier that allows hermaphroditic flowering plants to prevent inbreeding, to promote outcrossing and hybrid vigour. The self-incompatibility response in Brassica involves allele-specific interaction between the pollen small cysteine-rich, secreted protein ligand (SCR/SP11) and the stigmatic S-receptor kinase (SRK), which leads to the activation of the E3 ubiquitin ligase ARC1 (Armadillo repeat-containing 1), resulting in proteasomal degradation of compatibility factors needed for successful pollination. Despite this, targets of ARC1 and the intracellular signalling network that is regulated by these targets, have remained elusive. Here we show that glyoxalase I (GLO1), an enzyme that is required for the detoxification of methylglyoxal (MG, a cytotoxic by-product of glycolysis), is a stigmatic compatibility factor required for pollination to occur and is targeted by the self-incompatibility system. Suppression of GLO1 was sufficient to reduce compatibility, and overexpression of GLO1 in self-incompatible Brassica napus stigmas resulted in partial breakdown of the self-incompatibility response. ARC1-mediated destruction of GLO1 after self-pollination results in increased MG levels and a concomitant increase in MG-modified proteins (including GLO1), which are efficiently targeted for destruction in the papillary cells, leading to pollen rejection. Our findings demonstrate the elegant nature of plants to use a metabolic by-product to regulate the self-incompatibility response. PMID:27251720

  5. Cloning and functions analysis of a pyruvate dehydrogenase kinase in Brassica napus.

    PubMed

    Li, Rong-Jun; Hu, Zhi-Yong; Zhang, Hua-Shan; Zhan, Gao-Miao; Wang, Han-Zhong; Hua, Wei

    2011-08-01

    Pyruvate dehydrogenase kinase (PDK) is a negative regulator of the mitochondrial pyruvate dehydrogenase complex (mtPDC), which plays a key role in intermediary metabolism. In this study, a 1,490-bp PDK in Brassica napus (BnPDK1) was isolated and cloned from Brassica cDNA library. BnPDK1 has an 1,104 open reading frame encoding 367 amino acids. Genomic DNA gel blot analysis result indicated that BnPDK1 is a multi-copy gene. RNA gel blot analysis and RNA in situ hybridization were used to determine the expression of BnPDK1 in different organs. BnPDK1 gene was ubiquitously expressed in almost all the tissues tested, having the highest expression in the stamen and the young silique. Over-expression of BnPDK1 in transgenic Arabidopsis lines would repress the PDC activity, and resulted in the decrease of seed oil content and leaf photosynthesis. These results implied that BnPDK1 was involved in the regulation of fatty acid biosynthesis in developing seeds.

  6. Stable Bacillus thuringiensis transgene introgression from Brassica napus to wild mustard B. juncea.

    PubMed

    Cao, Di; Stewart, C Neal; Zheng, Min; Guan, Zhengjun; Tang, Zhi-Xi; Wei, Wei; Ma, Ke-Ping

    2014-10-01

    Transgenic canola (Brassica napus) with a Bacillus thuringiensis cry1Ac gene and a green fluorescent protein (GFP) marker gene was used in hybridization experiments with wild Brassica juncea. Hybrid F1 and successive five backcross generations were obtained. The pod-set frequency on backcrossed B. juncea plants was over 66%, which suggested relatively high crossing compatibility between the hybrids and wild species. The seed setting in BC1 was the least of all generations tested, and then increased at the BC2 generation for which the thousand-seed weight was the highest of all generations. Seed size in backcrossed generations eventually approached that of the wild parent. The plants in all backcrossed generations were consistent with the expected 1:1 segregation ratio of the transgenes. The Bt Cry1Ac protein concentrations at bolting and flowering stages was higher compared to the 4-5-leaf and pod-formation stages. Nonetheless, the Bt toxin in the fifth backcrossing generation (BC5) was sufficient to kill both polyphagous (Helicoverpa armigera) and oligophagous (Plutella xylostella) Lepidoptera. As a consequence, the subsequent generations harboring the transgene from F1 to BC5 could have selection advantage against insect pests. The result is useful in understanding gene flow from transgenic crops and the followed transgene introgression into wild.

  7. DNA Methylation Alterations at 5'-CCGG Sites in the Interspecific and Intraspecific Hybridizations Derived from Brassica rapa and B. napus.

    PubMed

    Xiong, Wanshan; Li, Xiaorong; Fu, Donghui; Mei, Jiaqin; Li, Qinfei; Lu, Guanyuan; Qian, Lunwen; Fu, Yin; Disi, Joseph Onwusemu; Li, Jiana; Qian, Wei

    2013-01-01

    DNA methylation is an important regulatory mechanism for gene expression that involved in the biological processes of development and differentiation in plants. To investigate the association of DNA methylation with heterosis in Brassica, a set of intraspecific hybrids in Brassica rapa and B. napus and interspecific hybrids between B. rapa and B. napus, together with parental lines, were used to monitor alterations in cytosine methylation at 5'-CCGG sites in seedlings and buds by methylation-sensitive amplification polymorphism analysis. The methylation status of approximately a quarter of the methylation sites changed between seedlings and buds. These alterations were related closely to the genomic structure and heterozygous status among accessions. The methylation status in the majority of DNA methylation sites detected in hybrids was the same as that in at least one of the parental lines in both seedlings and buds. However, the association between patterns of cytosine methylation and heterosis varied among different traits and between tissues in hybrids of Brassica, although a few methylation loci were associated with heterosis. Our data suggest that changes in DNA methylation at 5'-CCGG sites are not associated simply with heterosis in the interspecific and intraspecific hybridizations derived from B. rapa and B. napus.

  8. Reducing progoitrin and enriching glucoraphanin in Brassica napus seeds through silencing of the GSL-ALK gene family.

    PubMed

    Liu, Zheng; Hirani, Arvind H; McVetty, Peter B E; Daayf, Fouad; Quiros, Carlos F; Li, Genyi

    2012-05-01

    The hydrolytic products of glucosinolates in brassica crops are bioactive compounds. Some glucosinolate derivatives such as oxazolidine-2-thione from progoitrin in brassica oilseed meal are toxic and detrimental to animals, but some isothiocyanates such as sulforaphane are potent anti-carcinogens that have preventive effects on several human cancers. In most B. rapa, B. napus and B. juncea vegetables and oilseeds, there is no or only trace amount of glucoraphanin that is the precursor to sulforaphane. In this paper, RNA interference (RNAi) of the GSL-ALK gene family was used to down-regulate the expression of GSL-ALK genes in B. napus. The detrimental glucosinolate progoitrin was reduced by 65 %, and the beneficial glucosinolate glucoraphanin was increased to a relatively high concentration (42.6 μmol g(-1) seed) in seeds of B. napus transgenic plants through silencing of the GSL-ALK gene family. Therefore, there is potential application of the new germplasm with reduced detrimental glucosinolates and increased beneficial glucosinolates for producing improved brassica vegetables.

  9. MicroRNAs and their putative targets in Brassica napus seed maturation

    PubMed Central

    2013-01-01

    Background MicroRNAs (miRNAs) are 20–21 nucleotide RNA molecules that suppress the transcription of target genes and may also inhibit translation. Despite the thousands of miRNAs identified and validated in numerous plant species, only small numbers have been identified from the oilseed crop plant Brassica napus (canola) – especially in seeds. Results Using next-generation sequencing technologies, we performed a comprehensive analysis of miRNAs during seed maturation at 9 time points from 10 days after flowering (DAF) to 50 DAF using whole seeds and included separate analyses of radicle, hypocotyl, cotyledon, embryo, endosperm and seed coat tissues at 4 selected time points. We identified more than 500 conserved miRNA or variant unique sequences with >300 sequence reads and also found 10 novel miRNAs. Only 27 of the conserved miRNA sequences had been previously identified in B. napus (miRBase Release 18). More than 180 MIRNA loci were identified/annotated using the B. rapa genome as a surrogate for the B.napus A genome. Numerous miRNAs were expressed in a stage- or tissue-specific manner suggesting that they have specific functions related to the fine tuning of transcript abundance during seed development. miRNA targets in B. napus were predicted and their expression patterns profiled using microarray analyses. Global correlation analysis of the expression patterns of miRNAs and their targets revealed complex miRNA-target gene regulatory networks during seed development. The miR156 family was the most abundant and the majority of the family members were primarily expressed in the embryo. Conclusions Large numbers of miRNAs with diverse expression patterns, multiple-targeting and co-targeting of many miRNAs, and complex relationships between expression of miRNAs and targets were identified in this study. Several key miRNA-target expression patterns were identified and new roles of miRNAs in regulating seed development are suggested. miR156, miR159, miR172, mi

  10. Transformation of Brassica napus and Brassica oleracea Using Agrobacterium tumefaciens and the Expression of the bar and neo Genes in the Transgenic Plants

    PubMed Central

    De Block, Marc; De Brouwer, Dirk; Tenning, Paul

    1989-01-01

    An efficient and largely genotype-independent transformation method for Brassica napus and Brassica oleracea was established based on neo or bar as selectable marker genes. Hypocotyl explants of Brassica napus and Brassica oleracea cultivars were infected with Agrobacterium strains containing chimeric neo and bar genes. The use of AgNO3 was a prerequisite for efficient shoot regeneration under selective conditions. Vitrification was avoided by decreasing the water potential of the medium, by decreasing the relative humidity in the tissue culture vessel, and by lowering the cytokinin concentration. In this way, rooted transformed shoots were obtained with a 30% efficiency in 9 to 12 weeks. Southern blottings and genetic analysis of S1-progeny showed that the transformants contained on average between one and three copies of the chimeric genes. A wide range of expression levels of the chimeric genes was observed among independent transformants. Up to 25% of the transformants showed no detectable phosphinotricin acetyltransferase or neomycin phosphotransferase II enzyme activities although Southern blottings demonstrated that these plants were indeed transformed. Images Figure 1 Figure 2 PMID:16667089

  11. Repeated Polyploidy Drove Different Levels of Crossover Suppression between Homoeologous Chromosomes in Brassica napus Allohaploids[C][W

    PubMed Central

    Cifuentes, Marta; Eber, Frédérique; Lucas, Marie-Odile; Lode, Maryse; Chèvre, Anne-Marie; Jenczewski, Eric

    2010-01-01

    Allopolyploid species contain more than two sets of related chromosomes (homoeologs) that must be sorted during meiosis to ensure fertility. As polyploid species usually have multiple origins, one intriguing, yet largely underexplored, question is whether different mechanisms suppressing crossovers between homoeologs may coexist within the same polyphyletic species. We addressed this question using Brassica napus, a young polyphyletic allopolyploid species. We first analyzed the meiotic behavior of 363 allohaploids produced from 29 accessions, which represent a large part of B. napus genetic diversity. Two main clear-cut meiotic phenotypes were observed, encompassing a twofold difference in the number of univalents at metaphase I. We then sequenced two chloroplast intergenic regions to gain insight into the maternal origins of the same 29 accessions; only two plastid haplotypes were found, and these correlated with the dichotomy of meiotic phenotypes. Finally, we analyzed genetic diversity at the PrBn locus, which was shown to determine meiotic behavior in a segregating population of B. napus allohaploids. We observed that segregation of two alleles at PrBn could adequately explain a large part of the variation in meiotic behavior found among B. napus allohaploids. Overall, our results suggest that repeated polyploidy resulted in different levels of crossover suppression between homoeologs in B. napus allohaploids. PMID:20639447

  12. Long-term monitoring of feral genetically modified herbicide-tolerant Brassica napus populations around unloading Japanese ports

    PubMed Central

    Katsuta, Kensuke; Matsuo, Kazuhito; Yoshimura, Yasuyuki; Ohsawa, Ryo

    2015-01-01

    Genetically modified, herbicide-tolerant (GMHT) Brassica napus plants originating from seed spill have recently been found along roadsides leading from Japanese ports that unload oilseed rape. Such introductions have potential biodiversity effects (as defined by the Cartagena Protocol): these include replacement of native elements in the biota through competitive suppression or hybridization. We conducted surveys in the period 2006–2011 to assess such threats. We examined shifts in the population distribution and occurrence of GMHT plants in 1,029 volunteer introduced assemblages of B. napus, 1,169 of B. juncea, and 184 of B. rapa around 12 ports. GMHT B. napus was found around 10 of 12 ports, but its proportion in the populations varied greatly by year and location. Over the survey period, the distributions of a pure non-GMHT population around Tobata and a pure GMHT population around Hakata increased significantly. However, there was no common trend of population expansion or contraction around the 12 ports. Furthermore, we found no herbicide tolerant B. juncea and B. rapa plants derived from crosses with GMHT B. napus. Therefore, GMHT B. napus is not invading native vegetation surrounding its populations and not likely to cross with congeners in Japanese environment. PMID:26175624

  13. Long-term monitoring of feral genetically modified herbicide-tolerant Brassica napus populations around unloading Japanese ports.

    PubMed

    Katsuta, Kensuke; Matsuo, Kazuhito; Yoshimura, Yasuyuki; Ohsawa, Ryo

    2015-06-01

    Genetically modified, herbicide-tolerant (GMHT) Brassica napus plants originating from seed spill have recently been found along roadsides leading from Japanese ports that unload oilseed rape. Such introductions have potential biodiversity effects (as defined by the Cartagena Protocol): these include replacement of native elements in the biota through competitive suppression or hybridization. We conducted surveys in the period 2006-2011 to assess such threats. We examined shifts in the population distribution and occurrence of GMHT plants in 1,029 volunteer introduced assemblages of B. napus, 1,169 of B. juncea, and 184 of B. rapa around 12 ports. GMHT B. napus was found around 10 of 12 ports, but its proportion in the populations varied greatly by year and location. Over the survey period, the distributions of a pure non-GMHT population around Tobata and a pure GMHT population around Hakata increased significantly. However, there was no common trend of population expansion or contraction around the 12 ports. Furthermore, we found no herbicide tolerant B. juncea and B. rapa plants derived from crosses with GMHT B. napus. Therefore, GMHT B. napus is not invading native vegetation surrounding its populations and not likely to cross with congeners in Japanese environment. PMID:26175624

  14. Genetic and Epigenetic Changes in Oilseed Rape (Brassica napus L.) Extracted from Intergeneric Allopolyploid and Additions with Orychophragmus

    PubMed Central

    Gautam, Mayank; Dang, Yanwei; Ge, Xianhong; Shao, Yujiao; Li, Zaiyun

    2016-01-01

    Allopolyploidization with the merger of the genomes from different species has been shown to be associated with genetic and epigenetic changes. But the maintenance of such alterations related to one parental species after the genome is extracted from the allopolyploid remains to be detected. In this study, the genome of Brassica napus L. (2n = 38, genomes AACC) was extracted from its intergeneric allohexaploid (2n = 62, genomes AACCOO) with another crucifer Orychophragmus violaceus (2n = 24, genome OO), by backcrossing and development of alien addition lines. B. napus-type plants identified in the self-pollinated progenies of nine monosomic additions were analyzed by the methods of amplified fragment length polymorphism, sequence-specific amplified polymorphism, and methylation-sensitive amplified polymorphism. They showed modifications to certain extents in genomic components (loss and gain of DNA segments and transposons, introgression of alien DNA segments) and DNA methylation, compared with B. napus donor. The significant differences in the changes between the B. napus types extracted from these additions likely resulted from the different effects of individual alien chromosomes. Particularly, the additions which harbored the O. violaceus chromosome carrying dominant rRNA genes over those of B. napus tended to result in the development of plants which showed fewer changes, suggesting a role of the expression levels of alien rRNA genes in genomic stability. These results provided new cues for the genetic alterations in one parental genome that are maintained even after the genome becomes independent. PMID:27148282

  15. Different timing and spatial separation of parental chromosomes in intergeneric somatic hybrids between Brassica napus and Orychophragmus violaceus.

    PubMed

    Ding, L; Zhao, Z G; Ge, X H; Li, Z Y

    2014-01-01

    Experimental and newly formed hybrids and polyploids generated by wide crosses usually show varying degrees of cytological instability. The spatial separation of parental genomes and uniparental chromosome elimination in hybrid cells has been reported in many hybrids from plants and animals. Herein, the behavior of parental genomes in intergeneric somatic hybrids between Brassica napus and Orychophragmus violaceus was analyzed using genomic in situ hybridization (GISH). In mitotic and meiotic cells, the chromosomes from O. violaceus were distinguished from B. napus by their larger size and staining patterns. In interphase nuclei of the hybrid, O. violaceus-labeled chromatin appeared as large heterochromatic blocks that were nonrandomly distributed at prophase, typically distributed toward one side of the nucleus. In pollen mother cells at prophase I of meiosis, O. violaceus chromosomes appeared as one or two deeply stained chromatin blocks that resolved into bivalents at a late stage, after bivalents from B. napus were visible. Thereafter, bivalents of O. violaceus congressed to the equatorial plate and segregated at anaphase I after those from B. napus. The different behavior of O. violaceus chromosomes in the hybrids indicates that they have differential condensation states at interphase and progress later through the cell cycle and meiosis than B. napus chromosomes. This difference in behavior may restrict or prevent the formation of bivalents of mixed genome origin. Differential gene expression of parental alleles including rDNA loci may contribute to their distinct cytological behavior and to the phenotype of hybrids. PMID:24782049

  16. Population genomic analysis reveals differential evolutionary histories and patterns of diversity across subgenomes and subpopulations of Brassica napus L.

    DOE PAGES

    Gazave, Elodie; Tassone, Erica E.; Ilut, Daniel C.; Wingerson, Megan; Datema, Erwin; Witsenboer, Hanneke M. A.; Davis, James B.; Grant, David; Dyer, John M.; Jenks, Matthew A.; et al

    2016-04-21

    Here, the allotetraploid species Brassica napus L. is a global crop of major economic importance, providing canola oil (seed) and vegetables for human consumption and fodder and meal for livestock feed. Characterizing the genetic diversity present in the extant germplasm pool of B. napus is fundamental to better conserve, manage and utilize the genetic resources of this species. We used sequence-based genotyping to identify and genotype 30,881 SNPs in a diversity panel of 782 B. napus accessions, representing samples of winter and spring growth habits originating from 33 countries across Europe, Asia, and America. We detected strong population structure broadlymore » concordant with growth habit and geography, and identified three major genetic groups: spring (SP), winter Europe (WE), and winter Asia (WA). Subpopulation-specific polymorphism patterns suggest enriched genetic diversity within the WA group and a smaller effective breeding population for the SP group compared to WE. Interestingly, the two subgenomes of B. napus appear to have different geographic origins, with phylogenetic analysis placing WE and WA as basal clades for the other subpopulations in the C and A subgenomes, respectively. Finally, we identified 16 genomic regions where the patterns of diversity differed markedly from the genome-wide average, several of which are suggestive of genomic inversions. The results obtained in this study constitute a valuable resource for worldwide breeding efforts and the genetic dissection and prediction of complex B. napus traits.« less

  17. Differential accumulation of phenolic compounds and expression of related genes in black- and yellow-seeded Brassica napus

    PubMed Central

    Qu, Cunmin; Fu, Fuyou; Lu, Kun; Zhang, Kai; Wang, Rui; Xu, Xinfu; Wang, Min; Lu, Junxing; Wan, Huafang; Zhanglin, Tang; Li, Jiana

    2013-01-01

    Developing yellow-seeded Brassica napus (rapeseed) with improved qualities is a major breeding goal. The intermediate and final metabolites of the phenylpropanoid and flavonoid pathways affect not only oil quality but also seed coat colour of B. napus. Here, the accumulation of phenolic compounds was analysed in the seed coats of black-seeded (ZY821) and yellow-seeded (GH06) B. napus. Using toluidine blue O staining and liquid chromatography–mass spectrometry, histochemical and biochemical differences were identified in the accumulation of phenolic compounds between ZY821 and GH06. Two and 13 unique flavonol derivatives were detected in ZY821 and GH06, respectively. Quantitative real-time PCR analysis revealed significant differences between ZY821 and GH06 in the expression of common phenylpropanoid biosynthetic genes (BnPAL and BnC4H), common flavonoid biosynthetic genes (BnTT4 and BnTT6), anthocyanin- and proanthocyandin-specific genes (BnTT3 and BnTT18), proanthocyandin-specific genes (BnTT12, BnTT10, and BnUGT2) and three transcription factor genes (BnTTG1, BnTTG2, and BnTT8) that function in the flavonoid biosynthetic pathway. These data provide insight into pigment accumulation in B. napus, and serve as a useful resource for researchers analysing the formation of seed coat colour and the underlying regulatory mechanisms in B. napus. PMID:23698630

  18. Genetic and Epigenetic Changes in Oilseed Rape (Brassica napus L.) Extracted from Intergeneric Allopolyploid and Additions with Orychophragmus.

    PubMed

    Gautam, Mayank; Dang, Yanwei; Ge, Xianhong; Shao, Yujiao; Li, Zaiyun

    2016-01-01

    Allopolyploidization with the merger of the genomes from different species has been shown to be associated with genetic and epigenetic changes. But the maintenance of such alterations related to one parental species after the genome is extracted from the allopolyploid remains to be detected. In this study, the genome of Brassica napus L. (2n = 38, genomes AACC) was extracted from its intergeneric allohexaploid (2n = 62, genomes AACCOO) with another crucifer Orychophragmus violaceus (2n = 24, genome OO), by backcrossing and development of alien addition lines. B. napus-type plants identified in the self-pollinated progenies of nine monosomic additions were analyzed by the methods of amplified fragment length polymorphism, sequence-specific amplified polymorphism, and methylation-sensitive amplified polymorphism. They showed modifications to certain extents in genomic components (loss and gain of DNA segments and transposons, introgression of alien DNA segments) and DNA methylation, compared with B. napus donor. The significant differences in the changes between the B. napus types extracted from these additions likely resulted from the different effects of individual alien chromosomes. Particularly, the additions which harbored the O. violaceus chromosome carrying dominant rRNA genes over those of B. napus tended to result in the development of plants which showed fewer changes, suggesting a role of the expression levels of alien rRNA genes in genomic stability. These results provided new cues for the genetic alterations in one parental genome that are maintained even after the genome becomes independent. PMID:27148282

  19. Population Genomic Analysis Reveals Differential Evolutionary Histories and Patterns of Diversity across Subgenomes and Subpopulations of Brassica napus L.

    PubMed

    Gazave, Elodie; Tassone, Erica E; Ilut, Daniel C; Wingerson, Megan; Datema, Erwin; Witsenboer, Hanneke M A; Davis, James B; Grant, David; Dyer, John M; Jenks, Matthew A; Brown, Jack; Gore, Michael A

    2016-01-01

    The allotetraploid species Brassica napus L. is a global crop of major economic importance, providing canola oil (seed) and vegetables for human consumption and fodder and meal for livestock feed. Characterizing the genetic diversity present in the extant germplasm pool of B. napus is fundamental to better conserve, manage and utilize the genetic resources of this species. We used sequence-based genotyping to identify and genotype 30,881 SNPs in a diversity panel of 782 B. napus accessions, representing samples of winter and spring growth habits originating from 33 countries across Europe, Asia, and America. We detected strong population structure broadly concordant with growth habit and geography, and identified three major genetic groups: spring (SP), winter Europe (WE), and winter Asia (WA). Subpopulation-specific polymorphism patterns suggest enriched genetic diversity within the WA group and a smaller effective breeding population for the SP group compared to WE. Interestingly, the two subgenomes of B. napus appear to have different geographic origins, with phylogenetic analysis placing WE and WA as basal clades for the other subpopulations in the C and A subgenomes, respectively. Finally, we identified 16 genomic regions where the patterns of diversity differed markedly from the genome-wide average, several of which are suggestive of genomic inversions. The results obtained in this study constitute a valuable resource for worldwide breeding efforts and the genetic dissection and prediction of complex B. napus traits.

  20. Population Genomic Analysis Reveals Differential Evolutionary Histories and Patterns of Diversity across Subgenomes and Subpopulations of Brassica napus L.

    PubMed Central

    Gazave, Elodie; Tassone, Erica E.; Ilut, Daniel C.; Wingerson, Megan; Datema, Erwin; Witsenboer, Hanneke M. A.; Davis, James B.; Grant, David; Dyer, John M.; Jenks, Matthew A.; Brown, Jack; Gore, Michael A.

    2016-01-01

    The allotetraploid species Brassica napus L. is a global crop of major economic importance, providing canola oil (seed) and vegetables for human consumption and fodder and meal for livestock feed. Characterizing the genetic diversity present in the extant germplasm pool of B. napus is fundamental to better conserve, manage and utilize the genetic resources of this species. We used sequence-based genotyping to identify and genotype 30,881 SNPs in a diversity panel of 782 B. napus accessions, representing samples of winter and spring growth habits originating from 33 countries across Europe, Asia, and America. We detected strong population structure broadly concordant with growth habit and geography, and identified three major genetic groups: spring (SP), winter Europe (WE), and winter Asia (WA). Subpopulation-specific polymorphism patterns suggest enriched genetic diversity within the WA group and a smaller effective breeding population for the SP group compared to WE. Interestingly, the two subgenomes of B. napus appear to have different geographic origins, with phylogenetic analysis placing WE and WA as basal clades for the other subpopulations in the C and A subgenomes, respectively. Finally, we identified 16 genomic regions where the patterns of diversity differed markedly from the genome-wide average, several of which are suggestive of genomic inversions. The results obtained in this study constitute a valuable resource for worldwide breeding efforts and the genetic dissection and prediction of complex B. napus traits. PMID:27148342

  1. Long-term monitoring of feral genetically modified herbicide-tolerant Brassica napus populations around unloading Japanese ports.

    PubMed

    Katsuta, Kensuke; Matsuo, Kazuhito; Yoshimura, Yasuyuki; Ohsawa, Ryo

    2015-06-01

    Genetically modified, herbicide-tolerant (GMHT) Brassica napus plants originating from seed spill have recently been found along roadsides leading from Japanese ports that unload oilseed rape. Such introductions have potential biodiversity effects (as defined by the Cartagena Protocol): these include replacement of native elements in the biota through competitive suppression or hybridization. We conducted surveys in the period 2006-2011 to assess such threats. We examined shifts in the population distribution and occurrence of GMHT plants in 1,029 volunteer introduced assemblages of B. napus, 1,169 of B. juncea, and 184 of B. rapa around 12 ports. GMHT B. napus was found around 10 of 12 ports, but its proportion in the populations varied greatly by year and location. Over the survey period, the distributions of a pure non-GMHT population around Tobata and a pure GMHT population around Hakata increased significantly. However, there was no common trend of population expansion or contraction around the 12 ports. Furthermore, we found no herbicide tolerant B. juncea and B. rapa plants derived from crosses with GMHT B. napus. Therefore, GMHT B. napus is not invading native vegetation surrounding its populations and not likely to cross with congeners in Japanese environment.

  2. Identifying the chromosomes of the A- and C-genome diploid Brassica species B. rapa (syn. campestris) and B. oleracea in their amphidiploid B. napus.

    PubMed

    Snowdon, R. J.; Friedrich, T.; Friedt, W.; Köhler, W.

    2002-03-01

    Oilseed rape ( Brassica napus L.) is an amphidiploid species that originated from a spontaneous hybridisation of Brassica rapa L. (syn. campestris) and Brassica oleracea L., and contains the complete diploid chromosome sets of both parental genomes. The metaphase chromosomes of the highly homoeologous A genome of B. rapa and the C genome of B. oleracea cannot be reliably distinguished in B. napus because of their morphological similarity. Fluorescence in situ hybridisation (FISH) with 5S and 25S ribosomal DNA probes to prometaphase chromosomes, in combination with DAPI staining, allows more dependable identification of Brassica chromosomes. By comparing rDNA hybridisation and DAPI staining patterns from B. rapa and B. oleracea prometaphase chromosomes with those from B. napus, we were able to identify the putative homologues of B. napus chromosomes in the diploid chromosome sets of B. rapa and B. oleracea, respectively. In some cases, differences were observed between the rDNA hybridisation patterns of chromosomes in the diploid species and their putative homologue in B. napus, indicating locus losses or alterations in rDNA copy number. The ability to reliably identify A and C genome chromosomes in B. napus is discussed with respect to evolutionary and breeding aspects.

  3. Development of a population for substantial new type Brassica napus diversified at both A/C genomes.

    PubMed

    Xiao, Yong; Chen, Lunlin; Zou, Jun; Tian, Entang; Xia, Wei; Meng, Jinling

    2010-10-01

    Intersubgenomic heterosis in rapeseed has been revealed in previous studies by using traditional Brassica napus (A(n)A(n)C(n)C(n)) to cross partial new type B. napus with A(r)/C(c) introgression from the genomes of B. rapa and B. carinata, respectively. To further enlarge the genetic basis of B. napus and to facilitate a sustained heterosis breeding in rapeseed, it is crucial to create a population for substantial new type B. napus diversified at both A/C genomes. In this experiment, hundreds of artificial hexaploid plants (A(r)A(r)B(c)B(c)C(c)C(c)) involving hundreds of B. carinata/B. rapa combinations were first crossed with elite lines of partial new type B. napus. The pentaploid plants (AABCC) were open-pollinated in isolated conditions, and their offspring were successively self-pollinated and intensively selected for two generations. Thereafter, a population of substantial new type B. napus mainly with a genomic composition of A(r)A(r)C(c)C(c) harbouring genetic diversity from 25 original cultivars of B. rapa and 72 accessions of B. carinata was constructed. The population was cytologically verified to have the correct chromosome constitution of AACC and differed genetically from traditional B. napus, in terms of the genome components of A(r)/C(c) and B(c) as well as the novel genetic variations induced by the interspecific hybridisation process. Synchronously, rich phenotypic variation with plenty of novel valuable traits was observed in the population. The origin of the novel variations and the value of the population are discussed.

  4. Genome Wide Analysis of Flowering Time Trait in Multiple Environments via High-Throughput Genotyping Technique in Brassica napus L.

    PubMed Central

    Dalton-Morgan, Jessica; Batley, Jacqueline; Yu, Longjiang; Meng, Jinling; Li, Maoteng

    2015-01-01

    The prediction of the flowering time (FT) trait in Brassica napus based on genome-wide markers and the detection of underlying genetic factors is important not only for oilseed producers around the world but also for the other crop industry in the rotation system in China. In previous studies the low density and mixture of biomarkers used obstructed genomic selection in B. napus and comprehensive mapping of FT related loci. In this study, a high-density genome-wide SNP set was genotyped from a double-haploid population of B. napus. We first performed genomic prediction of FT traits in B. napus using SNPs across the genome under ten environments of three geographic regions via eight existing genomic predictive models. The results showed that all the models achieved comparably high accuracies, verifying the feasibility of genomic prediction in B. napus. Next, we performed a large-scale mapping of FT related loci among three regions, and found 437 associated SNPs, some of which represented known FT genes, such as AP1 and PHYE. The genes tagged by the associated SNPs were enriched in biological processes involved in the formation of flowers. Epistasis analysis showed that significant interactions were found between detected loci, even among some known FT related genes. All the results showed that our large scale and high-density genotype data are of great practical and scientific values for B. napus. To our best knowledge, this is the first evaluation of genomic selection models in B. napus based on a high-density SNP dataset and large-scale mapping of FT loci. PMID:25790019

  5. Genome wide analysis of flowering time trait in multiple environments via high-throughput genotyping technique in Brassica napus L.

    PubMed

    Li, Lun; Long, Yan; Zhang, Libin; Dalton-Morgan, Jessica; Batley, Jacqueline; Yu, Longjiang; Meng, Jinling; Li, Maoteng

    2015-01-01

    The prediction of the flowering time (FT) trait in Brassica napus based on genome-wide markers and the detection of underlying genetic factors is important not only for oilseed producers around the world but also for the other crop industry in the rotation system in China. In previous studies the low density and mixture of biomarkers used obstructed genomic selection in B. napus and comprehensive mapping of FT related loci. In this study, a high-density genome-wide SNP set was genotyped from a double-haploid population of B. napus. We first performed genomic prediction of FT traits in B. napus using SNPs across the genome under ten environments of three geographic regions via eight existing genomic predictive models. The results showed that all the models achieved comparably high accuracies, verifying the feasibility of genomic prediction in B. napus. Next, we performed a large-scale mapping of FT related loci among three regions, and found 437 associated SNPs, some of which represented known FT genes, such as AP1 and PHYE. The genes tagged by the associated SNPs were enriched in biological processes involved in the formation of flowers. Epistasis analysis showed that significant interactions were found between detected loci, even among some known FT related genes. All the results showed that our large scale and high-density genotype data are of great practical and scientific values for B. napus. To our best knowledge, this is the first evaluation of genomic selection models in B. napus based on a high-density SNP dataset and large-scale mapping of FT loci.

  6. Identification and characterization of microRNAs in oilseed rape (Brassica napus) responsive to infection with the pathogenic fungus Verticillium longisporum using Brassica AA (Brassica rapa) and CC (Brassica oleracea) as reference genomes.

    PubMed

    Shen, Dan; Suhrkamp, Ina; Wang, Yu; Liu, Shenyi; Menkhaus, Jan; Verreet, Joseph-Alexander; Fan, Longjiang; Cai, Daguang

    2014-11-01

    Verticillium longisporum, a soil-borne pathogenic fungus, causes vascular disease in oilseed rape (Brassica napus). We proposed that plant microRNAs (miRNAs) are involved in the plant-V. longisporum interaction. To identify oilseed rape miRNAs, we deep-sequenced two small RNA libraries made from V. longisporum infected/noninfected roots and employed Brassica rapa and Brassica oleracea genomes as references for miRNA prediction and characterization. We identified 893 B. napus miRNAs representing 360 conserved and 533 novel miRNAs, and mapped 429 and 464 miRNAs to the AA and CC genomes, respectively. Microsynteny analysis with the conserved miRNAs and their flanking protein coding sequences revealed 137 AA-CC genome syntenic miRNA pairs and 61 AA and 42 CC genome-unique miRNAs. Sixty-two miRNAs were responsive to the V. longisporum infection. We present data for specific interactions and simultaneously reciprocal changes in the expression levels of the miRNAs and their targets in the infected roots. We demonstrate that miRNAs are involved in the plant-fungus interaction and that miRNA168-Argonaute 1 (AGO1) expression modulation might act as a key regulatory module in a compatible plant-V. longisporum interaction. Our results suggest that V. longisporum may have evolved a virulence mechanism by interference with plant miRNAs to reprogram plant gene expression and achieve infection.

  7. Identification and characterization of microRNAs in oilseed rape (Brassica napus) responsive to infection with the pathogenic fungus Verticillium longisporum using Brassica AA (Brassica rapa) and CC (Brassica oleracea) as reference genomes.

    PubMed

    Shen, Dan; Suhrkamp, Ina; Wang, Yu; Liu, Shenyi; Menkhaus, Jan; Verreet, Joseph-Alexander; Fan, Longjiang; Cai, Daguang

    2014-11-01

    Verticillium longisporum, a soil-borne pathogenic fungus, causes vascular disease in oilseed rape (Brassica napus). We proposed that plant microRNAs (miRNAs) are involved in the plant-V. longisporum interaction. To identify oilseed rape miRNAs, we deep-sequenced two small RNA libraries made from V. longisporum infected/noninfected roots and employed Brassica rapa and Brassica oleracea genomes as references for miRNA prediction and characterization. We identified 893 B. napus miRNAs representing 360 conserved and 533 novel miRNAs, and mapped 429 and 464 miRNAs to the AA and CC genomes, respectively. Microsynteny analysis with the conserved miRNAs and their flanking protein coding sequences revealed 137 AA-CC genome syntenic miRNA pairs and 61 AA and 42 CC genome-unique miRNAs. Sixty-two miRNAs were responsive to the V. longisporum infection. We present data for specific interactions and simultaneously reciprocal changes in the expression levels of the miRNAs and their targets in the infected roots. We demonstrate that miRNAs are involved in the plant-fungus interaction and that miRNA168-Argonaute 1 (AGO1) expression modulation might act as a key regulatory module in a compatible plant-V. longisporum interaction. Our results suggest that V. longisporum may have evolved a virulence mechanism by interference with plant miRNAs to reprogram plant gene expression and achieve infection. PMID:25132374

  8. Fitness of hybrids between rapeseed (Brassica napus) and wild Brassica rapa in natural habitats.

    PubMed

    Allainguillaume, J; Alexander, M; Bullock, J M; Saunders, M; Allender, C J; King, G; Ford, C S; Wilkinson, M J

    2006-04-01

    Fitness of hybrids between genetically modified (GM) crops and wild relatives influences the likelihood of ecological harm. We measured fitness components in spontaneous (non-GM) rapeseed x Brassica rapa hybrids in natural populations. The F1 hybrids yielded 46.9% seed output of B. rapa, were 16.9% as effective as males on B. rapa and exhibited increased self-pollination. Assuming 100% GM rapeseed cultivation, we conservatively predict < 7000 second-generation transgenic hybrids annually in the United Kingdom (i.e. approximately 20% of F1 hybrids). Conversely, whilst reduced hybrid fitness improves feasibility of bio-containment, stage projection matrices suggests broad scope for some transgenes to offset this effect by enhancing fitness.

  9. Physiological and morphological responses of the root system of Indian mustard (Brassica juncea L. Czern.) and rapeseed (Brassica napus L.) to copper stress.

    PubMed

    Feigl, Gábor; Kumar, Devanand; Lehotai, Nóra; Tugyi, Nóra; Molnár, Arpád; Ordög, Attila; Szepesi, Agnes; Gémes, Katalin; Laskay, Gábor; Erdei, László; Kolbert, Zsuzsanna

    2013-08-01

    Copper (Cu) is an essential microelement for growth and development, but in excess it can cause toxicity in plants. In this comparative study, the uptake and accumulation of Cu as well as the morphological and physiological responses of Indian mustard (Brassica juncea L. Czern.) and rapeseed (Brassica napus L.) roots to Cu treatment were investigated. The possible involvement of redox active molecules (reactive oxygen species and nitric oxide) and modification in cell wall structure associated with Cu-induced morphological responses were also studied. In short- and long-term treatments, B. juncea suffered more pronounced growth inhibition as compared with B. napus. In addition to the shortening of primary and lateral roots, the number and the density of the laterals were also decreased by Cu. Exposure to copper induced nitric oxide generation in the root tips and this event proved to be dependent on the duration of the exposure and on the plant species. In short- and long-term treatments, Indian mustard showed more significant activation of superoxide dismutase (SOD), inhibition of ascorbate peroxidase (APX) and oxidation of ascorbate (AsA) than B. napus. Moreover, H2O2-dependent lignification was also observed in the Cu-exposed plants. In longer term, significant AsA accumulation and callose deposition were observed, reflecting serious oxidative stress in B. juncea. Based on the morphological and physiological results, we conclude that rapeseed tolerates Cu excess better than Indian mustard. PMID:23755862

  10. Mitigation using a tandem construct containing a selectively unfit gene precludes establishment of Brassica napus transgenes in hybrids and backcrosses with weedy Brassica rapa.

    PubMed

    Al-Ahmad, Hani; Gressel, Jonathan

    2006-01-01

    Transgenic oilseed rape (Brassica napus) plants can interbreed with nearby weedy Brassica rapa, potentially enhancing the weediness and/or invasiveness of subsequent hybrid offspring. We have previously demonstrated that transgenic mitigation effectively reduces the fitness of the transgenic dwarf and herbicide-resistant B. napus volunteers. We now report the efficacy of such a tandem construct, including a primary herbicide-resistant gene and a dwarfing mitigator gene, to preclude the risks of gene establishment in the related weed B. rapa and its backcross progeny. The transgenically mitigated and non-transgenic B. rapa x B. napus interspecific hybrids and the backcrosses (BC(1)) with B. rapa were grown alone and in competition with B. rapa weed. The reproductive fitness of hybrid offspring progressively decreased with increased B. rapa genes in the offspring, illustrating the efficacy of the concept. The fitness of F(2) interspecific non-transgenic hybrids was between 50% and 80% of the competing weedy B. rapa, whereas the fitness of the comparable T(2) interspecific transgenic hybrids was never more than 2%. The reproductive fitness of the transgenic T(2) BC(1) mixed with B. rapa was further severely suppressed to 0.9% of that of the competing weed due to dwarfism. Clearly, the mitigation technology works efficiently in a rapeseed crop-weed system under biocontainment-controlled environments, but field studies should further validate its utility for minimizing the risks of gene flow.

  11. Mitigation using a tandem construct containing a selectively unfit gene precludes establishment of Brassica napus transgenes in hybrids and backcrosses with weedy Brassica rapa.

    PubMed

    Al-Ahmad, Hani; Gressel, Jonathan

    2006-01-01

    Transgenic oilseed rape (Brassica napus) plants can interbreed with nearby weedy Brassica rapa, potentially enhancing the weediness and/or invasiveness of subsequent hybrid offspring. We have previously demonstrated that transgenic mitigation effectively reduces the fitness of the transgenic dwarf and herbicide-resistant B. napus volunteers. We now report the efficacy of such a tandem construct, including a primary herbicide-resistant gene and a dwarfing mitigator gene, to preclude the risks of gene establishment in the related weed B. rapa and its backcross progeny. The transgenically mitigated and non-transgenic B. rapa x B. napus interspecific hybrids and the backcrosses (BC(1)) with B. rapa were grown alone and in competition with B. rapa weed. The reproductive fitness of hybrid offspring progressively decreased with increased B. rapa genes in the offspring, illustrating the efficacy of the concept. The fitness of F(2) interspecific non-transgenic hybrids was between 50% and 80% of the competing weedy B. rapa, whereas the fitness of the comparable T(2) interspecific transgenic hybrids was never more than 2%. The reproductive fitness of the transgenic T(2) BC(1) mixed with B. rapa was further severely suppressed to 0.9% of that of the competing weed due to dwarfism. Clearly, the mitigation technology works efficiently in a rapeseed crop-weed system under biocontainment-controlled environments, but field studies should further validate its utility for minimizing the risks of gene flow. PMID:17177782

  12. A High-Density Genetic Map Identifies a Novel Major QTL for Boron Efficiency in Oilseed Rape (Brassica napus L.)

    PubMed Central

    Wang, Xiaohua; Zhao, Hua; Shi, Lei; Xu, Fangsen

    2014-01-01

    Low boron (B) seriously limits the growth of oilseed rape (Brassica napus L.), a high B demand species that is sensitive to low B conditions. Significant genotypic variations in response to B deficiency have been observed among B. napus cultivars. To reveal the genetic basis for B efficiency in B. napus, quantitative trait loci (QTLs) for the plant growth traits, B uptake traits and the B efficiency coefficient (BEC) were analyzed using a doubled haploid (DH) population derived from a cross between a B-efficient parent, Qingyou 10, and a B-inefficient parent, Westar 10. A high-density genetic map was constructed based on single nucleotide polymorphisms (SNPs) assayed using Brassica 60 K Infinium BeadChip Array, simple sequence repeats (SSRs) and amplified fragment length polymorphisms (AFLPs). The linkage map covered a total length of 2139.5 cM, with 19 linkage groups (LGs) and an average distance of 1.6 cM between adjacent markers. Based on hydroponic evaluation of six B efficiency traits measured in three separate repeated trials, a total of 52 QTLs were identified, accounting for 6.14–46.27% of the phenotypic variation. A major QTL for BEC, qBEC-A3a, was co-located on A3 with other QTLs for plant growth and B uptake traits under low B stress. Using a subset of substitution lines, qBEC-A3a was validated and narrowed down to the interval between CNU384 and BnGMS436. The results of this study provide a novel major locus located on A3 for B efficiency in B. napus that will be suitable for fine mapping and marker-assisted selection breeding for B efficiency in B. napus. PMID:25375356

  13. Nitrogen Use Efficiency Is Mediated by Vacuolar Nitrate Sequestration Capacity in Roots of Brassica napus.

    PubMed

    Han, Yong-Liang; Song, Hai-Xing; Liao, Qiong; Yu, Yin; Jian, Shao-Fen; Lepo, Joe Eugene; Liu, Qiang; Rong, Xiang-Min; Tian, Chang; Zeng, Jing; Guan, Chun-Yun; Ismail, Abdelbagi M; Zhang, Zhen-Hua

    2016-03-01

    Enhancing nitrogen use efficiency (NUE) in crop plants is an important breeding target to reduce excessive use of chemical fertilizers, with substantial benefits to farmers and the environment. In Arabidopsis (Arabidopsis thaliana), allocation of more NO3 (-) to shoots was associated with higher NUE; however, the commonality of this process across plant species have not been sufficiently studied. Two Brassica napus genotypes were identified with high and low NUE. We found that activities of V-ATPase and V-PPase, the two tonoplast proton-pumps, were significantly lower in roots of the high-NUE genotype (Xiangyou15) than in the low-NUE genotype (814); and consequently, less vacuolar NO3 (-) was retained in roots of Xiangyou15. Moreover, NO3 (-) concentration in xylem sap, [(15)N] shoot:root (S:R) and [NO3 (-)] S:R ratios were significantly higher in Xiangyou15. BnNRT1.5 expression was higher in roots of Xiangyou15 compared with 814, while BnNRT1.8 expression was lower. In both B. napus treated with proton pump inhibitors or Arabidopsis mutants impaired in proton pump activity, vacuolar sequestration capacity (VSC) of NO3 (-) in roots substantially decreased. Expression of NRT1.5 was up-regulated, but NRT1.8 was down-regulated, driving greater NO3 (-) long-distance transport from roots to shoots. NUE in Arabidopsis mutants impaired in proton pumps was also significantly higher than in the wild type col-0. Taken together, these data suggest that decrease in VSC of NO3 (-) in roots will enhance transport to shoot and essentially contribute to higher NUE by promoting NO3 (-) allocation to aerial parts, likely through coordinated regulation of NRT1.5 and NRT1.8. PMID:26757990

  14. Heterologous Expression of Hepatitis C Virus Core Protein in Oil Seeds of Brassica napus L.

    PubMed Central

    Mohammadzadeh, Sara; Roohvand, Farzin; Ajdary, Soheila; Ehsani, Parastoo; Hatef Salmanian, Ali

    2015-01-01

    Background: Hepatitis c virus (HCV), prevalent among 3% of the world population, is a major worldwide public health concern and an effective vaccination could help to overcome this problem. Plant seeds as low-cost vaccine expression platforms are highly desirable to produce antigens. Objectives: The present study was aimed at investigating the possible expression of recombinant HCV core protein, as a leading HCV vaccine candidate, in canola (Brassica napus) plant seeds in order to be used as an effective immunogen for vaccine researches. Materials and Methods: A codon-optimized gene harboring the Kozak sequence, 6 × His-tag, HCVcp (1 - 122 residues) and KDEL (Lys-Asp-Glu-Leu) peptide in tandem was designed and expressed under the control of the seed specific promoter, fatty acid elongase 1 (FAE1), to accumulate the recombinant protein in canola (B. napus L.) seeds. Transgenic lines were screened and the presence of the transgene was confirmed in the T0 plants by polymerase chain reaction (PCR). The quantity and quality of the HCV core protein (HCVcp) in transgenic seeds were evaluated by enzyme-linked immunosorbent assay (ELISA) and western blot, respectively. Results: Western blot analysis using anti-His antibody confirmed the presence of a 15 kDa protein in the seeds of T1 transgenic lines. The amount of antigenic protein accumulated in the seeds of these transgenic lines was up to 0.05% of the total soluble protein (TSP). Conclusions: The canola oilseeds could provide a useful expression system to produce HCV core protein as a vaccine candidate. PMID:26855744

  15. Inheritance and expression patterns of BN28, a low temperature induced gene in Brassica napus, throughout the Brassicaceae.

    PubMed

    Hawkins, G P; Nykiforuk, C L; Johnson-Flanagan, A M; Boothe, J G

    1996-08-01

    Molecular genetics is becoming an important tool in the breeding and selection of agronomically important traits. BN28 is a low temperature induced gene in Brassicaceae species. PCR and Southern blot analysis indicate that BN28 is polymorphic in the three diploid genomes: Brassica rapa (AA), Brassica nigra (BB), and Brassica oleracea (CC). Of the allotetraploids, Brassica napus (AACC) is the only species to have inherited homologous genes from both parental genomes. Brassica juncea (AABB) and Brassica carinata (BBCC) have inherited homologues from the AA and CC genomes, respectively, while Sinapsis arvensis (SS) contains a single homologue from the BB genome and Sinapsis alba (dd) appears to be different from all the diploid parents. All species show message induction when exposed to low temperature. However, differences in expression were noticed at the protein level, with silencing occurring in the BB genome at the level of translation. Results suggest that silencing is occurring in diploid species where duplication may not have occurred. Molecular characterization and inheritance of BN28 homologues in the Brassicaceae may play an important role in determining their quantitative function during exposure to low temperature. Key words : Brassicaceae, BN28, inheritance, polymorphism.

  16. Towards positional cloning in Brassica napus: generation and analysis of doubled haploid B. rapa possessing the B. napus pol CMS and Rfp nuclear restorer gene.

    PubMed

    Formanová, Natasa; Li, Xiu-Qing; Ferrie, Alison M R; Depauw, Mary; Keller, Wilf A; Landry, Benoit; Brown, Gregory G

    2006-05-01

    The Polima (pol) system of cytoplasmic male sterility (CMS) and its fertility restorer gene Rfp are used in hybrid rapeseed production in Brassica napus. To facilitate map-based cloning of the Rfp gene, we have successfully transferred the pol cytoplasm and Rfp from the amphidiploid B. napus to the diploid species B. rapa and generated a doubled haploid pol cytoplasm B. rapa population that segregates for the Rfp gene. This was achieved through interspecific crosses, in vitro rescue of hybrid embryos, backcrosses, and microspore culture. Male fertility conditioned by Rfp was shown to co-segregate in this population with Rfp-specific mitochondrial transcript modifications and with DNA markers previously shown to be linked to Rfp in B. napus. The selfed-progeny of one doubled haploid plant were confirmed to be characteristic B. rapa diploids by cytogenetic analysis. Clones recovered from a genomic library derived from this plant line using the RFLP probe cRF1 fell into several distinct physical contigs, one of which contained Rfp-linked polymorphic restriction fragments detected by this probe. This indicates that chromosomal DNA segments anchored in the Rfp region can be recovered from this library and that the library may therefore prove to be a useful resource for the eventual isolation of the Rfp gene.

  17. Pollen-mediated intraspecific gene flow from herbicide resistant oilseed rape (Brassica napus L.).

    PubMed

    Hüsken, Alexandra; Dietz-Pfeilstetter, Antje

    2007-10-01

    The cultivation of genetically modified (GM) herbicide resistant oilseed rape (Brassica napus) has increased over the past few years. The transfer of herbicide resistance genes via pollen (gene flow) from GM crops to non-GM crops is of relevance for the realisation of co-existence of different agricultural cultivation forms as well as for weed management. Therefore the likelihood of pollen-mediated gene flow has been investigated in numerous studies. Despite the difficulty to compare different experiments with varying levels of outcrossing, we performed a literature search for world-wide studies on cross-fertilisation in fully fertile oilseed rape. The occurrence and frequency of pollen-mediated intraspecific gene flow (outcrossing rate) can vary according to cultivar, experimental design, local topography and environmental conditions. The outcrossing rate from one field to another depends also on the size and arrangement of donor and recipient populations and on the ratio between donor and recipient plot size. The outcrossing levels specified in the presented studies are derived mostly from experiments where the recipient field is either surrounding the donor field (continuous design) or is located as a patch at different distances from the donor field (discontinuous design). Reports of gene flow in Brassica napus generally show that the amount of cross-fertilisation decreases as the distance from the pollen source increases. The evidence given in various studies reveals that the bulk of GM cross-fertilisation occurs within the first 10 m of the recipient field. The removal of the first 10 m of a non-transgenic field facing a GM crop might therefore be more efficient for reducing the total level of cross-fertilisation in a recipient sink population than to recommend separation distances. Future experiments should investigate cross-fertilisation with multiple adjacent donor fields at the landscape level under different spatial distributions of rapeseed cultivars

  18. TRANSPARENT TESTA 12 genes from Brassica napus and parental species: cloning, evolution, and differential involvement in yellow seed trait.

    PubMed

    Chai, You-Rong; Lei, Bo; Huang, Hua-Lei; Li, Jia-Na; Yin, Jia-Ming; Tang, Zhang-Lin; Wang, Rui; Chen, Li

    2009-01-01

    Molecular dissection of the Brassica yellow seed trait has been the subject of intense investigation. Arabidopsis thaliana TRANSPARENT TESTA 12 (AtTT12) encodes a multidrug and toxic compound extrusion (MATE) transporter involved in seed coat pigmentation. Two, one, and one full-length TT12 genes were isolated from B. napus, B. oleracea, and B. rapa, respectively, and Southern hybridization confirmed these gene numbers, implying loss of some of the triplicated TT12 genes in Brassica. BnTT12-1, BnTT12-2, BoTT12, and BrTT12 are 2,714, 3,062, 4,760, and 2,716 bp, with the longest mRNAs of 1,749, 1,711, 1,739, and 1,752 bp, respectively. All genes contained alternative transcriptional start and polyadenylation sites. BrTT12 and BoTT12 are the progenitors of BnTT12-1 and BnTT12-2, respectively, validating B. napus as an amphidiploid. All Brassica TT12 proteins displayed high levels of identity (>99%) to each other and to AtTT12 (>92%). Brassica TT12 genes resembled AtTT12 in such basic features as MatE/NorM CDs, subcellular localization, transmembrane helices, and phosphorylation sites. Plant TT12 orthologs differ from other MATE proteins by two specific motifs. Like AtTT12, all Brassica TT12 genes are most highly expressed in developing seeds. However, a range of organ specificity was observed with BnTT12 genes being less organ-specific. TT12 expression is absent in B. rapa yellow-seeded line 06K124, but not downregulated in B. oleracea yellow-seeded line 06K165. In B. napus yellow-seeded line L2, BnTT12-2 expression is absent, whereas BnTT12-1 is expressed normally. Among Brassica species, TT12 genes are differentially related to the yellow seed trait. The molecular basis for the yellow seed trait, in Brassica, and the theoretical and practical implications of the highly variable intron 1 of these TT12 genes are discussed.

  19. Genetic and physical mapping of flowering time loci in canola (Brassica napus L.).

    PubMed

    Raman, Harsh; Raman, Rosy; Eckermann, Paul; Coombes, Neil; Manoli, Sahana; Zou, Xiaoxiao; Edwards, David; Meng, Jinling; Prangnell, Roslyn; Stiller, Jiri; Batley, Jacqueline; Luckett, David; Wratten, Neil; Dennis, Elizabeth

    2013-01-01

    We identified quantitative trait loci (QTL) underlying variation for flowering time in a doubled haploid (DH) population of vernalisation-responsive canola (Brassica napus L.) cultivars Skipton and Ag-Spectrum and aligned them with physical map positions of predicted flowering genes from the Brassica rapa genome. Significant genetic variation in flowering time and response to vernalisation were observed among the DH lines from Skipton/Ag-Spectrum. A molecular linkage map was generated comprising 674 simple sequence repeat, sequence-related amplified polymorphism, sequence characterised amplified region, Diversity Array Technology, and candidate gene based markers loci. QTL analysis indicated that flowering time is a complex trait and is controlled by at least 20 loci, localised on ten different chromosomes. These loci each accounted for between 2.4 and 28.6% of the total genotypic variation for first flowering and response to vernalisation. However, identification of consistent QTL was found to be dependant upon growing environments. We compared the locations of QTL with the physical positions of predicted flowering time genes located on the sequenced genome of B. rapa. Some QTL associated with flowering time on A02, A03, A07, and C06 may represent homologues of known flowering time genes in Arabidopsis; VERNALISATION INSENSITIVE 3, APETALA1, CAULIFLOWER, FLOWERING LOCUS C, FLOWERING LOCUS T, CURLY LEAF, SHORT VEGETATIVE PHASE, GA3 OXIDASE, and LEAFY. Identification of the chromosomal location and effect of the genes influencing flowering time may hasten the development of canola varieties having an optimal time for flowering in target environments such as for low rainfall areas, via marker-assisted selection.

  20. Inheritance of GFP-Bt transgenes from Brassica napus in backcrosses with three wild B. rapa accessions.

    PubMed

    Zhu, Bin; Lawrence, John R; Warwick, Suzanne I; Mason, Peter; Braun, Lorraine; Halfhill, Matthew D; Stewart, C Neal

    2004-01-01

    Transgenes from transgenic oilseed rape, Brassica napus (AACC genome), can introgress into populations of wild B. rapa (AA genome), but little is known about the long-term persistence of transgenes from different transformation events. For example, transgenes that are located on the crop's C chromosomes may be lost during the process of introgression. We investigated the genetic behavior of transgenes in backcross generations of wild B. rapa after nine GFP (green fluorescent protein)-Bt (Bacillus thuringiensis) B. napus lines, named GT lines, were hybridized with three wild B. rapa accessions, respectively. Each backcross generation involved crosses between hemizygous GT plants and non-GT B. rapa pollen recipients. In some cases, sample sizes were too small to allow the detection of major deviations from Mendelian segregation ratios, but the segregation of GT:non-GT was consistent with an expected ratio of 1:1 in all crosses in the BC1 generation. Starting with the BC2 generation, significantly different genetic behavior of the transgenes was observed among the nine GT B. napus lines. In some lines, the segregation of GT:non-GT showed a ratio of 1:1 in the BC2, BC3, and BC4 generations. However, in other GT B. napus lines the segregation ratio of GT:non-GT significantly deviated from 1:1 in the BC2 and BC3 generations, which had fewer transgenic progeny than expected, but not in the BC4 generation. Most importantly, in two GT B. napus lines the segregation of GT:non-GT did not fit into a ratio of 1:1 in the BC2, BC3 or BC4 generations due to a deficiency of transgenic progeny. For these lines, a strong reduction of transgene introgression was observed in all three B. rapa accessions. These findings imply that the genomic location of transgenes in B. napus may affect the long-term persistence of transgenes in B. rapa after hybridization has occurred.

  1. Involvement of genes encoding ABI1 protein phosphatases in the response of Brassica napus L. to drought stress.

    PubMed

    Babula-Skowrońska, Danuta; Ludwików, Agnieszka; Cieśla, Agata; Olejnik, Anna; Cegielska-Taras, Teresa; Bartkowiak-Broda, Iwona; Sadowski, Jan

    2015-07-01

    In this report we characterized the Arabidopsis ABI1 gene orthologue and Brassica napus gene paralogues encoding protein phosphatase 2C (PP2C, group A), which is known to be a negative regulator of the ABA signaling pathway. Six homologous B. napus sequences were identified and characterized as putative PP2C group A members. To gain insight into the conservation of ABI1 function in Brassicaceae, and understand better its regulatory effects in the drought stress response, we generated transgenic B. napus plants overexpressing A. thaliana ABI1. Transgenic plants subjected to drought showed a decrease in relative water content, photosynthetic pigments content and expression level of RAB18- and RD19A-drought-responsive marker genes relative to WT plants. We present the characterization of the drought response of B. napus with the participation of ABI1-like paralogues. The expression pattern of two evolutionarily distant paralogues, BnaA01.ABI1.a and BnaC07.ABI1.b in B. napus and their promoter activity in A. thaliana showed differences in the induction of the paralogues under dehydration stress. Comparative sequence analysis of both BnaABI1 promoters showed variation in positions of cis-acting elements that are especially important for ABA- and stress-inducible expression. Together, these data reveal that subfunctionalization following gene duplication may be important in the maintenance and functional divergence of the BnaABI1 paralogues. Our results provide a framework for a better understanding of (1) the role of ABI1 as a hub protein regulator of the drought response, and (2) the differential involvement of the duplicated BnaABI1 genes in the response of B. napus to dehydration-related stresses.

  2. Involvement of genes encoding ABI1 protein phosphatases in the response of Brassica napus L. to drought stress.

    PubMed

    Babula-Skowrońska, Danuta; Ludwików, Agnieszka; Cieśla, Agata; Olejnik, Anna; Cegielska-Taras, Teresa; Bartkowiak-Broda, Iwona; Sadowski, Jan

    2015-07-01

    In this report we characterized the Arabidopsis ABI1 gene orthologue and Brassica napus gene paralogues encoding protein phosphatase 2C (PP2C, group A), which is known to be a negative regulator of the ABA signaling pathway. Six homologous B. napus sequences were identified and characterized as putative PP2C group A members. To gain insight into the conservation of ABI1 function in Brassicaceae, and understand better its regulatory effects in the drought stress response, we generated transgenic B. napus plants overexpressing A. thaliana ABI1. Transgenic plants subjected to drought showed a decrease in relative water content, photosynthetic pigments content and expression level of RAB18- and RD19A-drought-responsive marker genes relative to WT plants. We present the characterization of the drought response of B. napus with the participation of ABI1-like paralogues. The expression pattern of two evolutionarily distant paralogues, BnaA01.ABI1.a and BnaC07.ABI1.b in B. napus and their promoter activity in A. thaliana showed differences in the induction of the paralogues under dehydration stress. Comparative sequence analysis of both BnaABI1 promoters showed variation in positions of cis-acting elements that are especially important for ABA- and stress-inducible expression. Together, these data reveal that subfunctionalization following gene duplication may be important in the maintenance and functional divergence of the BnaABI1 paralogues. Our results provide a framework for a better understanding of (1) the role of ABI1 as a hub protein regulator of the drought response, and (2) the differential involvement of the duplicated BnaABI1 genes in the response of B. napus to dehydration-related stresses. PMID:26059040

  3. Citric acid improves lead (pb) phytoextraction in brassica napus L. by mitigating pb-induced morphological and biochemical damages.

    PubMed

    Shakoor, Muhammad Bilal; Ali, Shafaqat; Hameed, Amjad; Farid, Mujahid; Hussain, Sabir; Yasmeen, Tahira; Najeeb, Ullah; Bharwana, Saima Aslam; Abbasi, Ghulam Hasan

    2014-11-01

    Phytoextraction is an environmentally friendly and a cost-effective strategy for remediation of heavy metal contaminated soils. However, lower bioavailability of some of the metals in polluted environments e.g. lead (Pb) is a major constraint of phytoextraction process that could be overcome by applying organic chelators. We conducted a glasshouse experiment to evaluate the role of citric acid (CA) in enhancing Pb phytoextraction. Brassica napus L. seedlings were grown in hydroponic media and exposed to various treatments of Pb (50 and 100 μM) as alone or in combination with CA (2.5mM) for six weeks. Pb-induced damage in B. napus toxicity was evident from elevated levels of malondialdehyde (MDA) and H2O2 that significantly inhibited plant growth, biomass accumulation, leaf chlorophyll contents and gas exchange parameters. Alternatively, CA application to Pb-stressed B. napus plants arrested lipid membrane damage by limiting MDA and H2O2 production and by improving antioxidant enzyme activities. In addition, CA significantly increased the Pb accumulation in B. napus plants. The study concludes that CA has a potential to improve Pb phytoextraction without damaging plant growth. PMID:25164201

  4. Male fitness of oilseed rape (Brassica napus), weedy B. rapa and their F(1) hybrids when pollinating B. rapa seeds.

    PubMed

    Pertl, M; Hauser, T P; Damgaard, C; Jørgensen, R B

    2002-09-01

    The likelihood that two species hybridise and backcross may depend strongly on environmental conditions, and possibly on competitive interactions between parents and hybrids. We studied the paternity of seeds produced by weedy Brassica rapa growing in mixtures with oilseed rape (B. napus) and their F(1) hybrids at different frequencies and densities. Paternity was determined by the presence of a transgene, morphology, and AFLP markers. In addition, observations of flower and pollen production, and published data on pollen fertilisation success, zygote survival, and seed germination, allowed us to estimate an expected paternity. The frequency and density of B. napus, B. rapa, and F(1) plants had a strong influence on flower, pollen, and seed production, and on the paternity of B. rapa seeds. Hybridisation and backcrossing mostly occurred at low densities and at high frequencies of B. napus and F(1), respectively. F(1) and backcross offspring were produced mainly by a few B. rapa mother plants. The observed hybridisation and backcrossing frequencies were much lower than expected from our compilation of fitness components. Our results show that the male fitness of B. rapa, B. napus, and F(1) hybrids is strongly influenced by their local frequencies, and that male fitness of F(1)hybrids, when pollinating B. rapa seeds, is low even when their female fitness (seed set) is high.

  5. Divergent patterns of allelic diversity from similar origins: the case of oilseed rape (Brassica napus L.) in China and Australia.

    PubMed

    Chen, S; Nelson, M N; Ghamkhar, K; Fu, T; Cowling, W A

    2008-01-01

    Oilseed rape (Brassica napus) in Australia and China have similar origins, with introductions from Europe, Canada, and Japan in the mid 20th century, and there has been some interchange of germplasm between China and Australia since that time. Allelic diversity of 72 B. napus genotypes representing contemporary germplasm in Australia and China, including samples from India, Europe, and Canada, was characterized by 55 polymorphic simple sequence repeat (SSR) markers spanning the entire B. napus genome. Hierarchical clustering and two-dimensional multidimensional scaling identified a Chinese group (China-1) that was separated from "mixed group" of Australian, Chinese (China-2), European, and Canadian lines. A small group from India was distinctly separated from all other B. napus genotypes. Chinese genotypes, especially in the China-1 group, have inherited unique alleles from interspecific crossing, primarily with B. rapa, and the China-2 group has many alleles in common with Australian genotypes. The concept of "private alleles" is introduced to describe both the greater genetic diversity and the genetic distinctiveness of Chinese germplasm, compared with Australian germplasm, after 50 years of breeding from similar origins.

  6. Glycerol-3-phosphate acyltransferase 4 is essential for the normal development of reproductive organs and the embryo in Brassica napus.

    PubMed

    Chen, Xue; Chen, Guanqun; Truksa, Martin; Snyder, Crystal L; Shah, Saleh; Weselake, Randall J

    2014-08-01

    The enzyme sn-glycerol-3-phosphate acyltransferase 4 (GPAT4) is involved in the biosynthesis of plant lipid poly-esters. The present study further characterizes the enzymatic activities of three endoplasmic reticulum-bound GPAT4 isoforms of Brassica napus and examines their roles in the development of reproductive organs and the embryo. All three BnGPAT4 isoforms exhibited sn-2 acyltransferase and phosphatase activities with dicarboxylic acid-CoA as acyl donor. When non-substituted acyl-CoA was used as acyl donor, the rate of acylation was considerably lower and phosphatase activity was not manifested. RNA interference (RNAi)-mediated down-regulation of all GPAT4 homologues in B. napus under the control of the napin promoter caused abnormal development of several reproductive organs and reduced seed set. Microscopic examination and reciprocal crosses revealed that both pollen grains and developing embryo sacs of the B. napus gpat4 lines were affected. The gpat4 mature embryos showed decreased cutin content and altered monomer composition. The defective embryo development further affected the oil body morphology, oil content, and fatty acid composition in gpat4 seeds. These results suggest that GPAT4 has a critical role in the development of reproductive organs and the seed of B. napus.

  7. Separation and identification of candidate protein elicitors from the cultivation medium of Leptosphaeria maculans inducing resistance in Brassica napus.

    PubMed

    Nováková, Miroslava; Kim, Phuong Dinh; Šašek, Vladimír; Burketová, Lenka; Jindřichová, Barbora; Šantrůček, Jiří; Valentová, Olga

    2016-07-01

    The Dothideomycete Leptosphaeria maculans, a worldwide fungal pathogen of oilseed rape (Brassica napus), secretes a broad spectrum of molecules into the cultivation medium during growth in vitro. Here, candidate elicitor molecules, which induce resistance in B. napus to L. maculans, were identified in the cultivation medium. The elicitation activity was indicated by increased transcription of pathogenesis-related gene 1 (PR1) and enhanced resistance of B. napus plants to the invasion of L. maculans. The elicitation activity was significantly lowered when the cultivation medium was heated to 80°C. Active components were further characterized by specific cleavage with the proteolytic enzymes trypsin and proteinase K and with glycosidases α-amylase and β-glucanase. The elicitor activity was eliminated by proteolytic digestion while glycosidases had no effect. The filtered medium was fractionated by either ion-exchange chromatography or isoelectric focusing. Mass spectrometry analysis of the most active fractions obtained by both separation procedures revealed predominantly enzymes that can be involved in the degradation of plant cell wall polysaccharides. This is the first study searching for L. maculans-specific secreted elicitors with a potential to be used as defense-activating agents in the protection of B. napus against L. maculans in agriculture. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:918-928, 2016. PMID:27009514

  8. Glycerol-3-phosphate acyltransferase 4 is essential for the normal development of reproductive organs and the embryo in Brassica napus

    PubMed Central

    Chen, Xue; Chen, Guanqun; Truksa, Martin; Snyder, Crystal L.; Shah, Saleh; Weselake, Randall J.

    2014-01-01

    The enzyme sn-glycerol-3-phosphate acyltransferase 4 (GPAT4) is involved in the biosynthesis of plant lipid poly-esters. The present study further characterizes the enzymatic activities of three endoplasmic reticulum-bound GPAT4 isoforms of Brassica napus and examines their roles in the development of reproductive organs and the embryo. All three BnGPAT4 isoforms exhibited sn-2 acyltransferase and phosphatase activities with dicarboxylic acid-CoA as acyl donor. When non-substituted acyl-CoA was used as acyl donor, the rate of acylation was considerably lower and phosphatase activity was not manifested. RNA interference (RNAi)-mediated down-regulation of all GPAT4 homologues in B. napus under the control of the napin promoter caused abnormal development of several reproductive organs and reduced seed set. Microscopic examination and reciprocal crosses revealed that both pollen grains and developing embryo sacs of the B. napus gpat4 lines were affected. The gpat4 mature embryos showed decreased cutin content and altered monomer composition. The defective embryo development further affected the oil body morphology, oil content, and fatty acid composition in gpat4 seeds. These results suggest that GPAT4 has a critical role in the development of reproductive organs and the seed of B. napus. PMID:24821955

  9. Citric acid improves lead (pb) phytoextraction in brassica napus L. by mitigating pb-induced morphological and biochemical damages.

    PubMed

    Shakoor, Muhammad Bilal; Ali, Shafaqat; Hameed, Amjad; Farid, Mujahid; Hussain, Sabir; Yasmeen, Tahira; Najeeb, Ullah; Bharwana, Saima Aslam; Abbasi, Ghulam Hasan

    2014-11-01

    Phytoextraction is an environmentally friendly and a cost-effective strategy for remediation of heavy metal contaminated soils. However, lower bioavailability of some of the metals in polluted environments e.g. lead (Pb) is a major constraint of phytoextraction process that could be overcome by applying organic chelators. We conducted a glasshouse experiment to evaluate the role of citric acid (CA) in enhancing Pb phytoextraction. Brassica napus L. seedlings were grown in hydroponic media and exposed to various treatments of Pb (50 and 100 μM) as alone or in combination with CA (2.5mM) for six weeks. Pb-induced damage in B. napus toxicity was evident from elevated levels of malondialdehyde (MDA) and H2O2 that significantly inhibited plant growth, biomass accumulation, leaf chlorophyll contents and gas exchange parameters. Alternatively, CA application to Pb-stressed B. napus plants arrested lipid membrane damage by limiting MDA and H2O2 production and by improving antioxidant enzyme activities. In addition, CA significantly increased the Pb accumulation in B. napus plants. The study concludes that CA has a potential to improve Pb phytoextraction without damaging plant growth.

  10. Glycerol-3-phosphate acyltransferase 4 is essential for the normal development of reproductive organs and the embryo in Brassica napus.

    PubMed

    Chen, Xue; Chen, Guanqun; Truksa, Martin; Snyder, Crystal L; Shah, Saleh; Weselake, Randall J

    2014-08-01

    The enzyme sn-glycerol-3-phosphate acyltransferase 4 (GPAT4) is involved in the biosynthesis of plant lipid poly-esters. The present study further characterizes the enzymatic activities of three endoplasmic reticulum-bound GPAT4 isoforms of Brassica napus and examines their roles in the development of reproductive organs and the embryo. All three BnGPAT4 isoforms exhibited sn-2 acyltransferase and phosphatase activities with dicarboxylic acid-CoA as acyl donor. When non-substituted acyl-CoA was used as acyl donor, the rate of acylation was considerably lower and phosphatase activity was not manifested. RNA interference (RNAi)-mediated down-regulation of all GPAT4 homologues in B. napus under the control of the napin promoter caused abnormal development of several reproductive organs and reduced seed set. Microscopic examination and reciprocal crosses revealed that both pollen grains and developing embryo sacs of the B. napus gpat4 lines were affected. The gpat4 mature embryos showed decreased cutin content and altered monomer composition. The defective embryo development further affected the oil body morphology, oil content, and fatty acid composition in gpat4 seeds. These results suggest that GPAT4 has a critical role in the development of reproductive organs and the seed of B. napus. PMID:24821955

  11. Effect of pyrolysis temperature on chemical and surface properties of biochar of rapeseed (Brassica napus L.).

    PubMed

    Angin, Dilek; Sensöz, Sevgi

    2014-01-01

    The biochar is an important carbon-rich product that is generated from biomass sources through pyrolysis. Biochar (charcoal) can be both used directly as a potential source of solid biofuels and as soil amendments for barren lands. The aim of this study was investigate influence of pyrolysis temperature on the physicochemical properties and structure of biochar. The biochars were produced by pyrolysis of rapeseed (Brassica napus L.) using a fixed-bed reactor at different pyrolysis temperatures (400-700 degrees C). The produced biochars were characterized by proximate and elemental analysis, Brunauer-Emmett-Teller (BET) surface area, particle size distributions, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy. The results showed that both chemical and surface properties of the biochars were significantly affected by the pyrolysis temperature. Aromatic hydrocarbons, hydroxyl and carbonyl compounds were the majority components of the biochar. The biochar obtained at 700 degrees C had a high fixed carbon content (66.16%) as well as a high heating value, and therefore it could be used as solid fuel, precursor in the activated carbons manufacture (specific surface area until 25.38 m(2) g(-1)), or to obtain category-A briquettes. PMID:24933878

  12. Effects of Fe deficiency on the protein profile of Brassica napus phloem sap.

    PubMed

    Gutierrez-Carbonell, Elain; Lattanzio, Giuseppe; Albacete, Alfonso; Rios, Juan José; Kehr, Julia; Abadía, Anunciación; Grusak, Michael A; Abadía, Javier; López-Millán, Ana Flor

    2015-11-01

    The aim of this work was to study the effect of Fe deficiency on the protein profile of phloem sap exudates from Brassica napus using 2DE (IEF-SDS-PAGE). The experiment was repeated thrice and two technical replicates per treatment were done. Phloem sap purity was assessed by measuring sugar concentrations. Two hundred sixty-three spots were consistently detected and 15.6% (41) of them showed significant changes in relative abundance (22 decreasing and 19 increasing) as a result of Fe deficiency. Among them, 85% (35 spots), were unambiguously identified. Functional categories containing the largest number of protein species showing changes as a consequence of Fe deficiency were signaling and regulation (32%), and stress and redox homeostasis (17%). The Phloem sap showed a higher oxidative stress and significant changes in the hormonal profile as a result of Fe deficiency. Results indicate that Fe deficiency elicits major changes in signaling pathways involving Ca and hormones, which are generally associated with flowering and developmental processes, causes an alteration in ROS homeostasis processes, and induces decreases in the abundances of proteins involved in sieve element repair, suggesting that Fe-deficient plants may have an impaired capacity to heal sieve elements upon injury.

  13. Extending the rapeseed gene pool with resynthesized Brassica napus II: Heterosis.

    PubMed

    Girke, Andreas; Schierholt, Antje; Becker, Heiko C

    2012-04-01

    Hybrid breeding relies on the combination of parents from two differing heterotic groups. However, the genetic diversity in adapted oilseed rape breeding material is rather limited. Therefore, the use of resynthesized Brassica napus as a distant gene pool was investigated. Hybrids were derived from crosses between 44 resynthesized lines with a diverse genetic background and two male sterile winter oilseed rape tester lines. The hybrids were evaluated together with their parents and check cultivars in 2 years and five locations in Germany. Yield, plant height, seed oil, and protein content were monitored, and genetic distances were estimated with molecular markers (127 polymorphic RFLP fragments). Resynthesized lines varied in yield between 40.9 dt/ha and 21.5 dt/ha, or between 85.1 and 44.6% of check cultivar yields. Relative to check cultivars, hybrids varied from 91.6 to 116.6% in yield and from 94.5 to 103.3% in seed oil content. Mid-parent heterosis varied from -3.5 to 47.2% for yield. The genetic distance of parental lines was not significantly correlated with heterosis or hybrid yield. Although resynthesized lines do not meet the elite rapeseed standards, they are a valuable source for hybrid breeding due to their large distance from present breeding material and their high heterosis when combined with European winter oilseed rape.

  14. Synthesis of high erucic acid rapeseed (Brassica napus L.) somatic hybrids with improved agronomic characters.

    PubMed

    Heath, D W; Earle, E D

    1995-11-01

    Novel Brassica napus somatic hybrids have been created through protoplast fusion of B. oleracea var. botrytis and B. rapa var. oleifera genotypes selected for high erucic acid (22:1) content in the seed oil. Fifty amphidiploids (aacc) and one putative hexaploid (aacccc) hybrid were recovered in one fusion experiment. Conversely, only one amphidiploid and numerous regenerates with higher DNA contents were produced in a similar fusion using a different B. rapa partner. Hybridity was confirmed by morphology, isozyme expression, flow cytometry, and DNA hybridization. Analysis of organellar DNA revealed a distinct bias toward the inheritance of chloroplasts from the B. rapa (aa) genome. All amphidiploids set self-pollinated seed. A erucic acid content as high as 57.4% was found in the seed oil of one regenerated plant. Fatty acid composition was stable in the R1 generation and was coupled with increased female fertility. Other novel agronomic characters in the hybrids recovered include large seed size, lodging resistance, and non-shattering seed pods.

  15. Effect of dissolved organic matters on napropamide availability and ecotoxicity in rapeseed ( Brassica napus ).

    PubMed

    Zhang, Rui; Cui, Jing; Zhu, Hong Mei; Yang, Hong

    2010-03-10

    Napropamide is a herbicide widely used for controlling annual weeds. Substantial use of napropamide in recent years has led to its bioaccumulation in ecosystems and thus contamination to crops. Meanwhile, application of dissolved organic matters (DOMs) to soils in the form of compost, sludge, or plant residues has become a popular practice in agriculture management owning to its low cost and recycling of nutrients. However, whether DOMs affect environmental behaviors of herbicides in soil-plant systems is poorly understood. This study investigated napropamide accumulation and biological responses as affected by DOMs in Brassica napus . Plants exposed to 0-16 mg/kg napropamide show inhibited growth and oxidative damage. Treatment with 50 mg of DOC/kg DOMs derived from either sludge or straw improved plant growth and reduced napropamide accumulation in plants. Both DOMs reduced the production of reactive oxygen species (ROS) and the activities of antioxidative enzymes in napropamide-exposed plants. Analysis of FT-IR spectra confirmed the difference between structures of the two DOMs. Additional evidence was provided by three-dimensional excitation-emission matrix (EEM) fluorescence spectra to demonstrate the DOM-napropamide complex formed during the process of the interaction.

  16. Profile and distribution of soluble and insoluble phenolics in Chinese rapeseed (Brassica napus).

    PubMed

    Liu, Qin; Wu, Li; Pu, Huiming; Li, Chunyang; Hu, Qiuhui

    2012-11-15

    The profile and distribution of soluble and insoluble phenolics in 10 rapeseed (Brassica napus) varieties were studied in this work. Photometric results show that the soluble total phenolic content (TPC) and the total tannin content (TTC) of rapeseed dehulled flours are much higher than those of rapeseed hulls. Soluble and insoluble phenolics were further analysed by HPLC/MS and MS/MS. For soluble phenolics, seven species were identified and quantified. Sinapine was found to be the major component in both defatted rapeseed hulls and dehulled flours, with its content ranging from 0.93 to 1.76 mg/g and 15.65 to 21.88 mg/g, respectively. For insoluble phenolics, eight phenolic acids were detected in rapeseed hulls, while only two of them were found in their dehulled flours. Sinapic acid and protocatechuic acid, which also were found in dehulled flours, were identified as two major insoluble phenolics in rapeseed hulls. Insoluble TPCs in defatted rapeseed hulls and dehulled flours were shown to be in the similar range.

  17. SNP discovery by amplicon sequencing and multiplex SNP genotyping in the allopolyploid species Brassica napus.

    PubMed

    Durstewitz, G; Polley, A; Plieske, J; Luerssen, H; Graner, E M; Wieseke, R; Ganal, M W

    2010-11-01

    Oilseed rape (Brassica napus) is an allotetraploid species consisting of two genomes, derived from B. rapa (A genome) and B. oleracea (C genome). The presence of these two genomes makes single nucleotide polymorphism (SNP) marker identification and SNP analysis more challenging than in diploid species, as for a given locus usually two versions of a DNA sequence (based on the two ancestral genomes) have to be analyzed simultaneously during SNP identification and analysis. One hundred amplicons derived from expressed sequence tag (ESTs) were analyzed to identify SNPs in a panel of oilseed rape varieties and within two sister species representing the ancestral genomes. A total of 604 SNPs were identified, averaging one SNP in every 42 bp. It was possible to clearly discriminate SNPs that are polymorphic between different plant varieties from SNPs differentiating the two ancestral genomes. To validate the identified SNPs for their use in genetic analysis, we have developed Illumina GoldenGate assays for some of the identified SNPs. Through the analysis of a number of oilseed rape varieties and mapping populations with GoldenGate assays, we were able to identify a number of different segregation patterns in allotetraploid oilseed rape. The majority of the identified SNP markers can be readily used for genetic mapping, showing that amplicon sequencing and Illumina GoldenGate assays can be used to reliably identify SNP markers in tetraploid oilseed rape and to convert them into successful SNP assays that can be used for genetic analysis.

  18. Polyploid formation pathways have an impact on genetic rearrangements in resynthesized Brassica napus.

    PubMed

    Szadkowski, E; Eber, F; Huteau, V; Lodé, M; Coriton, O; Jenczewski, E; Chèvre, A M

    2011-08-01

    • Polyploids can be produced by the union of unreduced gametes or through somatic doubling of F(1) interspecific hybrids. The first route is suspected to produce allopolyploid species under natural conditions, whereas experimental data have only been thoroughly gathered for the latter. • We analyzed the meiotic behavior of an F(1) interspecific hybrid (by crossing Brassica oleracea and B.rapa, progenitors of B.napus) and the extent to which recombined homoeologous chromosomes were transmitted to its progeny. These results were then compared with results obtained for a plant generated by somatic doubling of this F₁ hybrid (CD.S₀) and an amphidiploid (UG.S₀) formed via a pathway involving unreduced gametes; we studied the impact of this method of polyploid formation on subsequent generations. • This study revealed that meiosis of the F₁ interspecific hybrid generated more gametes with recombined chromosomes than did meiosis of the plant produced by somatic doubling, although the size of these translocations was smaller. In the progeny of the UG.S₀ plant, there was an unexpected increase in the frequency at which the C1 chromosome was replaced by the A1 chromosome. • We conclude that polyploid formation pathways differ in their genetic outcome. Our study opens up perspectives for the understanding of polyploid origins.

  19. Preparation and antioxidative properties of a rapeseed ( Brassica napus ) protein hydrolysate and three peptide fractions.

    PubMed

    Xue, Zhaohui; Yu, Wancong; Liu, Zhiwei; Wu, Moucheng; Kou, Xiaohong; Wang, Jiehua

    2009-06-24

    This study investigated the possibility of converting the insoluble rapeseed meal protein into functionally active ingredients for food applications. The rapeseed ( Brassica napus ) meal protein isolates were first digested by Alcalase and Flavourzyme, and the resultant rapeseed crude hydrolysate (RSCH) exhibited a dose-dependent reducing antioxidant power and hydroxyl radical scavenging ability. RSCH could also inhibit the malonyldialdehyde (MDA) generation by 50% in blood serum at 150 mg/mL. RSCH was further separated into three fractions (RSP1, RSP2, and RSP3) by Sephadex gel filtration according to their different molecular weights. The amino acid compositions and antioxidant potentials were assessed for RSP1-3 fractions. All three fractions showed inhibiting effects on superoxide anion generation to various extents. They could also inhibit the autohemolysis of rat red blood cells and MDA formation in rat liver tissue homogenate. The results suggested that rapeseed peptide hydrolysate may be useful as a human food addition as a source of bioactive peptides with antioxidant properties.

  20. Influence of peptides-phenolics interaction on the antioxidant profile of protein hydrolysates from Brassica napus.

    PubMed

    Hernández-Jabalera, Anaid; Cortés-Giraldo, Isabel; Dávila-Ortíz, Gloria; Vioque, Javier; Alaiz, Manuel; Girón-Calle, Julio; Megías, Cristina; Jiménez-Martínez, Cristian

    2015-07-01

    The role of the peptides-phenolic compounds (PC) interaction on the antioxidant capacity profile (ACP) of protein hydrolysates from rapeseed (Brassica napus) was studied in 36 hydrolysates obtained from a PC-rich and PC-reduced protein substrate. The latent profile analysis (LPA), with data of seven in vitro methods and one assay for cellular antioxidant activity (CAA), allowed identifying five distinctive groups of hydrolysates, each one with distinctive ACP. The interaction of peptides with naturally present PC diminished in vitro antioxidant activity in comparison with their PC-reduced counterparts. However, CAA increased when peptides-PC interaction occurred. The profile with the highest average CAA (62.41 ± 1.48%), shown by hydrolysates obtained by using alcalase, shared typical values of Cu(2+)-catalysed β-carotene oxidation (62.41 ± 0.43%), β-carotene bleaching inhibition (91.75 ± 0.22%) and Cu(2+)-chelating activity (74.53 ± 0.58%). The possibilities for a sample to exhibit ACP with higher CAA increased with each unit of positively charged amino acids, according to multinomial logistic regression analysis.

  1. Global Dynamic Transcriptome Programming of Rapeseed (Brassica napus L.) Anther at Different Development Stages.

    PubMed

    Li, Zhanjie; Zhang, Peipei; Lv, Jinyang; Cheng, Yufeng; Cui, Jianmin; Zhao, Huixian; Hu, Shengwu

    2016-01-01

    Rapeseed (Brassica napus L.) is an important oil crop worldwide and exhibits significant heterosis. Effective pollination control systems, which are closely linked to anther development, are a prerequisite for utilizing heterosis. The anther, which is the male organ in flowering plants, undergoes many metabolic processes during development. Although the gene expression patterns underlying pollen development are well studied in model plant Arabidopsis, the regulatory networks of genome-wide gene expression during rapeseed anther development is poorly understood, especially regarding metabolic regulations. In this study, we systematically analyzed metabolic processes occurring during anther development in rapeseed using ultrastructural observation and global transcriptome analysis. Anther ultrastructure exhibited that numerous cellular organelles abundant with metabolic materials, such as elaioplast, tapetosomes, plastids (containing starch deposits) etc. appeared, accompanied with anther structural alterations during anther development, suggesting many metabolic processes occurring. Global transcriptome analysis revealed dynamic changes in gene expression during anther development that corresponded to dynamic functional alterations between early and late anther developmental stages. The early stage anthers preferentially expressed genes involved in lipid metabolism that are related to pollen extine formation as well as elaioplast and tapetosome biosynthesis, whereas the late stage anthers expressed genes associated with carbohydrate metabolism to form pollen intine and to accumulate starch in mature pollen grains. Finally, a predictive gene regulatory module responsible for early pollen extine formation was generated. Taken together, this analysis provides a comprehensive understanding of dynamic gene expression programming of metabolic processes in the rapeseed anther, especially with respect to lipid and carbohydrate metabolism during pollen development.

  2. Changes in Protein Synthesis in Rapeseed (Brassica napus) Seedlings during a Low Temperature Treatment 1

    PubMed Central

    Meza-Basso, Luis; Alberdi, Miren; Raynal, Monique; Ferrero-Cadinanos, Maria-Luz; Delseny, Michel

    1986-01-01

    Changes induced by cold treatment in young rapeseed (Brassica napus) seedlings were investigated at the molecular level. Following germination at 18°C for 48 hours, one half of the seedlings was transferred to 0°C for another 48 hour period, the other half being kept at 18°C as a control. Newly synthesized proteins were labeled for the last 6 hours of incubation with [35S]methionine. The different polypeptides were separated by two-dimensional electrophoresis in polyacrylamide gels. Newly synthesized proteins were revealed by fluorography. Protein synthesis clearly continues at 0°C and some polypeptides preferentially accumulate at this temperature. On the other hand, synthesis of several others is repressed while many are insensitive to cold treatment. Similar changes are also observed when mRNA is prepared from cold treated seedlings, translated in vitro in a reticulocyte cell free system and compared with the products of mRNA extracted from control samples. Among the genes which are repressed we identified the small subunit of ribulose 1,6-bisphosphate carboxylase. These changes are also detectable after shorter treatments. Images Fig. 1 Fig. 2 Fig. 3 PMID:16665102

  3. Frying stability of rapeseed Kizakinonatane (Brassica napus) oil in comparison with canola oil.

    PubMed

    Ma, Jin-Kui; Zhang, Han; Tsuchiya, Tomohiro; Akiyama, Yoshinobu; Chen, Jie-Yu

    2015-04-01

    This study was carried out to investigate the frying performance of Kizakinonatane (Brassica napus) oil during deep-fat frying of frozen French fries with/without replenishment. Commercial regular canola oil was used for comparison. The frying oils were used during intermittent frying of frozen French fries at 180, 200, and 220 ℃ for 7 h daily over four consecutive days. The Kizakinonatane oil exhibited lower levels of total polar compounds, carbonyl value, and viscosity as well as comparable color (optical density) values to that of the canola oil. The monounsaturated fatty acid/polyunsaturated fatty acid ratios were lower than that of canola oil, whereas the polyunsaturated fatty acid/saturated fatty acid ratios are higher than that of canola oil after heating. Results showed that fresh Kizakinonatane oil contains higher levels of acid value, viscosity, optical density values, tocopherols, and total phenolics contents than that of canola oil. Replenishment with fresh oil had significant effects on all chemical and physical parameters, except the acid value of the Kizakinonatane oil during frying processes. Based on the results, the Kizakinonatane oil is inherently suitable for preparing deep-fried foods at high temperatures.

  4. Sequential light programs shape kale (Brassica napus) sprout appearance and alter metabolic and nutrient content

    PubMed Central

    Carvalho, Sofia D; Folta, Kevin M

    2014-01-01

    Different light wavelengths have specific effects on plant growth and development. Narrow-bandwidth light-emitting diode (LED) lighting may be used to directionally manipulate size, color and metabolites in high-value fruits and vegetables. In this report, Red Russian kale (Brassica napus) seedlings were grown under specific light conditions and analyzed for photomorphogenic responses, pigment accumulation and nutraceutical content. The results showed that this genotype responds predictably to darkness, blue and red light, with suppression of hypocotyl elongation, development of pigments and changes in specific metabolites. However, these seedlings were relatively hypersensitive to far-red light, leading to uncharacteristically short hypocotyls and high pigment accumulation, even after growth under very low fluence rates (<1 μmol m−2 s−1). General antioxidant levels and aliphatic glucosinolates are elevated by far-red light treatments. Sequential treatments of darkness, blue light, red light and far-red light were applied throughout sprout development to alter final product quality. These results indicate that sequential treatment with narrow-bandwidth light may be used to affect key economically important traits in high-value crops. PMID:26504531

  5. Assessment of DNA methylation changes in tissue culture of Brassica napus.

    PubMed

    Gao, Y; Ran, L; Kong, Y; Jiang, J; Sokolov, V; Wang, Y

    2014-11-01

    Plant tissue culture, as a fundamental technique for genetic engineering, has great potential of epigenetic variation, of which DNA methylation is well known of importance to genome activity. We assessed DNA methylation level of explants during tissue culture of Brassica napus (cv. Yangyou 9), using high-performance liquid chromatography (HPLC) assisted quantification. By detecting methylation levels in hypocotyls cultured in mediums with different concentrations of hormones, we found dissected tissue:cultured with 0.1 mg/L 2,4-D and 1.0 mg/L 6-BA, presented the lowest methylation level and highest induction rate of callus (91.0%). Different time point of cultured explants also showed obvious methylation variations, explants cultured after 6 and 21 days exhibited methylation ratios of 4.33 and 8.07%, respectively. Whereas, the methylation ratio raised to 38.7% after 30 days cultivation, indicating that methylation level of hypocotyls ranged during tissue culture. Moreover, we observed that the methylation level in callus is the highest during regeneration of rape-seed, following the regenerated plantlets and hypocotyls. This paper indicated the function of hormones and differentiation of callus is relevant to the methylation levels during tissue culture. PMID:25739287

  6. Cadmium stress alters the redox reaction and hormone balance in oilseed rape (Brassica napus L.) leaves.

    PubMed

    Yan, Hui; Filardo, Fiona; Hu, Xiaotao; Zhao, Xiaomin; Fu, DongHui

    2016-02-01

    In order to understand the physiological response of oilseed rape (Brassica napus L.) leaves to cadmium (Cd) stress and exploit the physiological mechanisms involved in Cd tolerance, macro-mineral and chlorophyll concentrations, reactive oxygen species (ROS) accumulation, activities of enzymatic antioxidants, nonenzymatic compounds metabolism, endogenous hormonal changes, and balance in leaves of oilseed rape exposed to 0, 100, or 200 μM CdSO4 were investigated. The results showed that under Cd exposure, Cd concentrations in the leaves continually increased while macro-minerals and chlorophyll concentrations decreased significantly. Meanwhile, with increased Cd stress, superoxide anion (O2(• -)) production rate and hydrogen peroxide (H2O2) concentrations in the leaves increased significantly, which caused malondialdehyde (MDA) accumulation and oxidative stress. For scavenging excess accumulated ROS and alleviating oxidative injury in the leaves, the activity of enzymatic antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), was increased significantly at certain stress levels. However, with increased Cd stress, the antioxidant enzyme activities all showed a trend towards reduction. The nonenzymatic antioxidative compounds, such as proline and total soluble sugars, accumulated continuously with increased Cd stress to play a long-term role in scavenging ROS. In addition, ABA levels also increased continuously with Cd stress while ZR decreased and the ABA/ZR ratio increased, which might also be providing a protective role against Cd toxicity. PMID:26498815

  7. Phytoremediation of 2,4-dichlorophenol by Brassica napus hairy root cultures.

    PubMed

    Agostini, Elizabeth; Coniglio, María S; Milrad, Silvia R; Tigier, Horacio A; Giulietti, Ana M

    2003-04-01

    We have obtained hairy root cultures of Brassica napus with high biomass and genetic stability which produce peroxidases, enzymes involved in biodegradation processes. In this work, these hairy root cultures were used to study the removal of 2,4-dichlorophenol (2,4-DCP), a common contaminant in industrial effluents that is highly toxic for human and aquatic life. The optimum conditions to obtain high efficiency in the removal process were established. Roots were able to remove 2,4-DCP from aqueous solutions containing 100-1000 mg/l, in the presence of H(2)O(2) concentrations ranging from 5 to 10 mM. After a short period of incubation (15 min), high removal efficiencies were achieved (91-94%) and maximal removal, of approx. 97-98%, was obtained with 1 h of reaction. High removal efficiencies (93-95%) were observed in a broad pH range (pH 3-9), reaching 98-99% in the range pH 4-8. Moreover, roots could be re-used, almost for six consecutive cycles, to remove 2,4-DCP. The oxidation catalysed by peroxidases would be the main mechanism involved in this process. The results suggest that these cultures could be useful tools for phytoremediation. PMID:12630901

  8. [Effects of magnetized soil on physiological and biochemical indexes of Brassica napus seedlings].

    PubMed

    Gu, Jiguang; Zhou, Qixing

    2003-05-01

    Nitrate reductase, peroxidase, water-soluble sugars, root vitality and total biomass of Brassica napus seedlings were investigated with soil after magnetization treatment. The results showed that nitrate reductase activity was increased by 10.76% after 200 mT treatment. The contents of water-soluble sugars were increased by 11.05% and root vitality by 26.40% for 300 and 100 mT treatments, respectively. Total biomass also showed a trend of increase as the magnetization increased. The highest biomass of the above-ground parts was achieved at 300 mT, which was 13.28% higher than that of control. In addition, total biomass of below-ground parts was the highest at 200 mT, which was 13.17% higher than that of control, and the ratio of below-ground to above-ground parts decreased by 10.00%, suggesting that the overall environmental quality of the soil was improved significantly. PMID:12924143

  9. Salicylic acid reduces napropamide toxicity by preventing its accumulation in rapeseed (Brassica napus L.).

    PubMed

    Cui, Jing; Zhang, Rui; Wu, Guo Lin; Zhu, Hong Mei; Yang, Hong

    2010-07-01

    Napropamide is a widely used herbicide for controlling weeds in crop production. However, extensive use of the herbicide has led to its accumulation in ecosystems, thus causing toxicity to crops and reducing crop production and quality. Salicylic acid (SA) plays multiple roles in regulating plant adaptive responses to biotic and environmental stresses. However, whether SA regulates plant response to herbicides (or pesticides) was unknown. In this study, we investigated the effect of SA on herbicide napropamide accumulation and biological processes in rapeseed (Brassica napus). Plants exposed to 8 mg kg(-1) napropamide showed growth stunt and oxidative damage. Treatment with 0.1 mM SA improved growth and reduced napropamide levels in plants. Treatment with SA also decreased the abundance of O (2) (-.) and H(2)O(2) as well as activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), and increased activities of guaiacol peroxidase (POD) and glutathione-S-transferase (GST) in napropamide-exposed plants. Analysis of SOD, CAT, and POD activities using nondenaturing polyacrylamide gel electrophoresis (PAGE) confirmed the results. These results may help to understand how SA regulates plant response to organic contaminants and provide a basis to control herbicide/pesticide contamination in crop production. PMID:19967348

  10. Effect of dissolved organic matters on napropamide availability and ecotoxicity in rapeseed ( Brassica napus ).

    PubMed

    Zhang, Rui; Cui, Jing; Zhu, Hong Mei; Yang, Hong

    2010-03-10

    Napropamide is a herbicide widely used for controlling annual weeds. Substantial use of napropamide in recent years has led to its bioaccumulation in ecosystems and thus contamination to crops. Meanwhile, application of dissolved organic matters (DOMs) to soils in the form of compost, sludge, or plant residues has become a popular practice in agriculture management owning to its low cost and recycling of nutrients. However, whether DOMs affect environmental behaviors of herbicides in soil-plant systems is poorly understood. This study investigated napropamide accumulation and biological responses as affected by DOMs in Brassica napus . Plants exposed to 0-16 mg/kg napropamide show inhibited growth and oxidative damage. Treatment with 50 mg of DOC/kg DOMs derived from either sludge or straw improved plant growth and reduced napropamide accumulation in plants. Both DOMs reduced the production of reactive oxygen species (ROS) and the activities of antioxidative enzymes in napropamide-exposed plants. Analysis of FT-IR spectra confirmed the difference between structures of the two DOMs. Additional evidence was provided by three-dimensional excitation-emission matrix (EEM) fluorescence spectra to demonstrate the DOM-napropamide complex formed during the process of the interaction. PMID:20143852

  11. Methyl Jasmonate Regulates Antioxidant Defense and Suppresses Arsenic Uptake in Brassica napus L.

    PubMed

    Farooq, Muhammad A; Gill, Rafaqat A; Islam, Faisal; Ali, Basharat; Liu, Hongbo; Xu, Jianxiang; He, Shuiping; Zhou, Weijun

    2016-01-01

    Methyl jasmonate (MJ) is an important plant growth regulator, involved in plant defense against abiotic stresses, however, its possible function in response to metal stress is poorly understood. In the present study, the effect of MJ on physiological and biochemical changes of the plants exposed to arsenic (As) stress were investigated in two Brassica napus L. cultivars (ZS 758 - a black seed type, and Zheda 622 - a yellow seed type). The As treatment at 200 μM was more phytotoxic, however, its combined application with MJ resulted in significant increase in leaf chlorophyll fluorescence, biomass production and reduced malondialdehyde content compared with As stressed plants. The application of MJ minimized the oxidative stress, as revealed via a lower level of reactive oxygen species (ROS) synthesis (H2O2 and OH(-)) in leaves and the maintenance of high redox states of glutathione and ascorbate. Enhanced enzymatic activities and gene expression of important antioxidants (SOD, APX, CAT, POD), secondary metabolites (PAL, PPO, CAD) and induction of lypoxygenase gene suggest that MJ plays an effective role in the regulation of multiple transcriptional pathways which were involved in oxidative stress responses. The content of As was higher in yellow seeded plants (cv. Zheda 622) as compared to black seeded plants (ZS 758). The application of MJ significantly reduced the As content in leaves and roots of both cultivars. Findings of the present study reveal that MJ improves ROS scavenging through enhanced antioxidant defense system, secondary metabolite and reduced As contents in both the cultivars. PMID:27148299

  12. Graphene oxide modulates root growth of Brassica napus L. and regulates ABA and IAA concentration.

    PubMed

    Cheng, Fan; Liu, Yu-Feng; Lu, Guang-Yuan; Zhang, Xue-Kun; Xie, Ling-Li; Yuan, Cheng-Fei; Xu, Ben-Bo

    2016-04-01

    Researchers have proven that nanomaterials have a significant effect on plant growth and development. To better understand the effects of nanomaterials on plants, Zhongshuang 11 was treated with different concentrations of graphene oxide. The results indicated that 25-100mg/l graphene oxide treatment resulted in shorter seminal root length compared with the control samples. The fresh root weight decreased when treated with 50-100mg/l graphene oxide. The graphene oxide treatment had no significant effect on the Malondialdehyde (MDA) content. Treatment with 50mg/l graphene oxide increased the transcript abundance of genes involved in ABA biosynthesis (NCED, AAO, and ZEP) and some genes involved in IAA biosynthesis (ARF2, ARF8, IAA2, and IAA3), but inhibited the transcript levels of IAA4 and IAA7. The graphene oxide treatment also resulted in a higher ABA content, but a lower IAA content compared with the control samples. The results indicated that graphene oxide modulated the root growth of Brassica napus L. and affected ABA and IAA biosynthesis and concentration. PMID:26945480

  13. Effects of thermal stress of protein synthesis and gene expression in Brassica napus

    SciTech Connect

    Halle, J.R.; Ghosh, S.; Dumbroff, E.B.; Heikkila, J.J. )

    1989-04-01

    Leaf segments of Brassica napus were exposed to 22{degrees}, 35{degrees}, 38{degrees} or 40{degrees}C for up to 4 h. Analysis of radiolabelled proteins by 2-D SDS-PAGE and fluorography revealed two major groups of heat shock proteins (HSPs). One group comprised HSPs, 70, 76 and 87, with pIs ranging from 5.7 to 6.1, whereas the second group had molecular weights ranging from 23 to 16 kD and pIs from 5.6 to 6.9. Immunoblot analysis using antibodies directed against the large (RLSU) and small (RSSU) subunits of ribulose-1,5-bisphosphate carboxylase (RUBISCO) showed that increasing temperatures from 35{degrees} to 38{degrees} or 40{degrees}C or the duration of thermal stress from 1 to 5 h did not affect levels of the RSSU (15 kd) whereas levels of the RLSU (52 kD) fell sharply. Nevertheless, RUBISCO activity was not adversely affected at 38{degree}C for periods of up to 5 h. The increase observed in HSP 70 during heat shock was transcriptionally regulated, but the decrease in the RLSU was not accompanied by any detectable change in levels of its mRNA.

  14. Frying stability of rapeseed Kizakinonatane (Brassica napus) oil in comparison with canola oil.

    PubMed

    Ma, Jin-Kui; Zhang, Han; Tsuchiya, Tomohiro; Akiyama, Yoshinobu; Chen, Jie-Yu

    2015-04-01

    This study was carried out to investigate the frying performance of Kizakinonatane (Brassica napus) oil during deep-fat frying of frozen French fries with/without replenishment. Commercial regular canola oil was used for comparison. The frying oils were used during intermittent frying of frozen French fries at 180, 200, and 220 ℃ for 7 h daily over four consecutive days. The Kizakinonatane oil exhibited lower levels of total polar compounds, carbonyl value, and viscosity as well as comparable color (optical density) values to that of the canola oil. The monounsaturated fatty acid/polyunsaturated fatty acid ratios were lower than that of canola oil, whereas the polyunsaturated fatty acid/saturated fatty acid ratios are higher than that of canola oil after heating. Results showed that fresh Kizakinonatane oil contains higher levels of acid value, viscosity, optical density values, tocopherols, and total phenolics contents than that of canola oil. Replenishment with fresh oil had significant effects on all chemical and physical parameters, except the acid value of the Kizakinonatane oil during frying processes. Based on the results, the Kizakinonatane oil is inherently suitable for preparing deep-fried foods at high temperatures. PMID:24474189

  15. Sequential light programs shape kale (Brassica napus) sprout appearance and alter metabolic and nutrient content.

    PubMed

    Carvalho, Sofia D; Folta, Kevin M

    2014-01-01

    Different light wavelengths have specific effects on plant growth and development. Narrow-bandwidth light-emitting diode (LED) lighting may be used to directionally manipulate size, color and metabolites in high-value fruits and vegetables. In this report, Red Russian kale (Brassica napus) seedlings were grown under specific light conditions and analyzed for photomorphogenic responses, pigment accumulation and nutraceutical content. The results showed that this genotype responds predictably to darkness, blue and red light, with suppression of hypocotyl elongation, development of pigments and changes in specific metabolites. However, these seedlings were relatively hypersensitive to far-red light, leading to uncharacteristically short hypocotyls and high pigment accumulation, even after growth under very low fluence rates (<1 μmol m(-2) s(-1)). General antioxidant levels and aliphatic glucosinolates are elevated by far-red light treatments. Sequential treatments of darkness, blue light, red light and far-red light were applied throughout sprout development to alter final product quality. These results indicate that sequential treatment with narrow-bandwidth light may be used to affect key economically important traits in high-value crops.

  16. Methyl Jasmonate Regulates Antioxidant Defense and Suppresses Arsenic Uptake in Brassica napus L.

    PubMed Central

    Farooq, Muhammad A.; Gill, Rafaqat A.; Islam, Faisal; Ali, Basharat; Liu, Hongbo; Xu, Jianxiang; He, Shuiping; Zhou, Weijun

    2016-01-01

    Methyl jasmonate (MJ) is an important plant growth regulator, involved in plant defense against abiotic stresses, however, its possible function in response to metal stress is poorly understood. In the present study, the effect of MJ on physiological and biochemical changes of the plants exposed to arsenic (As) stress were investigated in two Brassica napus L. cultivars (ZS 758 – a black seed type, and Zheda 622 – a yellow seed type). The As treatment at 200 μM was more phytotoxic, however, its combined application with MJ resulted in significant increase in leaf chlorophyll fluorescence, biomass production and reduced malondialdehyde content compared with As stressed plants. The application of MJ minimized the oxidative stress, as revealed via a lower level of reactive oxygen species (ROS) synthesis (H2O2 and OH-) in leaves and the maintenance of high redox states of glutathione and ascorbate. Enhanced enzymatic activities and gene expression of important antioxidants (SOD, APX, CAT, POD), secondary metabolites (PAL, PPO, CAD) and induction of lypoxygenase gene suggest that MJ plays an effective role in the regulation of multiple transcriptional pathways which were involved in oxidative stress responses. The content of As was higher in yellow seeded plants (cv. Zheda 622) as compared to black seeded plants (ZS 758). The application of MJ significantly reduced the As content in leaves and roots of both cultivars. Findings of the present study reveal that MJ improves ROS scavenging through enhanced antioxidant defense system, secondary metabolite and reduced As contents in both the cultivars. PMID:27148299

  17. Arabidopsis cpSRP54 regulates carotenoid accumulation in Arabidopsis and Brassica napus

    PubMed Central

    Gruber, Margaret Y.; Hannoufa, Abdelali

    2012-01-01

    An Arabidopsis thaliana mutant, cbd (carotenoid biosynthesis deficient), was recovered from a mutant population based on its yellow cotyledons, yellow-first true leaves, and stunted growth. Seven-day-old seedlings and mature seeds of this mutant had lower chlorophyll and total carotenoids than the wild type (WT). Genetic and molecular characterization revealed that cbd was a recessive mutant caused by a T-DNA insertion in the gene cpSRP54 encoding the 54kDa subunit of the chloroplast signal recognition particle. Transcript levels of most of the main carotenoid biosynthetic genes in cbd were unchanged relative to WT, but expression increased in carotenoid and abscisic acid catabolic genes. The chloroplasts of cbd also had developmental defects that contributed to decreased carotenoid and chlorophyll contents. Transcription of AtGLK1 (Golden 2-like 1), AtGLK2, and GUN4 appeared to be disrupted in the cbd mutant suggesting that the plastid-to-nucleus retrograde signal may be affected, regulating the changes in chloroplast functional and developmental states and carotenoid content flux. Transformation of A. thaliana and Brassica napus with a gDNA encoding the Arabidopsis cpSRP54 showed the utility of this gene in enhancing levels of seed carotenoids without affecting growth or seed yield. PMID:22791829

  18. Cadmium stress alters the redox reaction and hormone balance in oilseed rape (Brassica napus L.) leaves.

    PubMed

    Yan, Hui; Filardo, Fiona; Hu, Xiaotao; Zhao, Xiaomin; Fu, DongHui

    2016-02-01

    In order to understand the physiological response of oilseed rape (Brassica napus L.) leaves to cadmium (Cd) stress and exploit the physiological mechanisms involved in Cd tolerance, macro-mineral and chlorophyll concentrations, reactive oxygen species (ROS) accumulation, activities of enzymatic antioxidants, nonenzymatic compounds metabolism, endogenous hormonal changes, and balance in leaves of oilseed rape exposed to 0, 100, or 200 μM CdSO4 were investigated. The results showed that under Cd exposure, Cd concentrations in the leaves continually increased while macro-minerals and chlorophyll concentrations decreased significantly. Meanwhile, with increased Cd stress, superoxide anion (O2(• -)) production rate and hydrogen peroxide (H2O2) concentrations in the leaves increased significantly, which caused malondialdehyde (MDA) accumulation and oxidative stress. For scavenging excess accumulated ROS and alleviating oxidative injury in the leaves, the activity of enzymatic antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), was increased significantly at certain stress levels. However, with increased Cd stress, the antioxidant enzyme activities all showed a trend towards reduction. The nonenzymatic antioxidative compounds, such as proline and total soluble sugars, accumulated continuously with increased Cd stress to play a long-term role in scavenging ROS. In addition, ABA levels also increased continuously with Cd stress while ZR decreased and the ABA/ZR ratio increased, which might also be providing a protective role against Cd toxicity.

  19. Sulfate resupply accentuates protein synthesis in coordination with nitrogen metabolism in sulfur deprived Brassica napus.

    PubMed

    Zhang, Qian; Lee, Bok-Rye; Park, Sang-Hyun; Zaman, Rashed; Avice, Jean-Christophe; Ourry, Alain; Kim, Tae-Hwan

    2015-02-01

    To investigate the regulatory interactions between S assimilation and N metabolism in Brassica napus, de novo synthesis of amino acids and proteins was quantified by (15)N and (34)S tracing, and the responses of transporter genes, assimilatory enzymes and metabolites pool involving in nitrate and sulfate metabolism were assessed under continuous sulfur supply, sulfur deprivation and sulfate resupply after 3 days of sulfur (S) deprivation. S-deprived plants were characterized by a strong induction of sulfate transporter genes, ATP sulfurylase (ATPS) and adenosine 5'-phosphosulfate reductase (APR), and by a repressed activity of nitrate reductase (NR) and glutamine synthetase (GS). Sulfate resupply to the S-deprived plants strongly increased cysteine, amino acids and proteins concentration. The increase in sulfate and cysteine concentration caused by sulfate resupply was not matched with the expression of sulfate transporters and the activity of ATPS and APR which were rapidly decreased by sulfate resupply. A strong induction of O-acetylserine(thiol)lyase (OASTL), NR and GS upon sulfate resupply was accompanied with the increase in cysteine, amino acids and proteins pool. Sulfate resupply resulted in a strong increase in de novo synthesis of amino acids and proteins, as evidenced by the increases in N and S incorporation into amino acids (1.8- and 2.4-fold increase) and proteins (2.2-and 6.3-fold increase) when compared to S-deprived plants. The results thus indicate that sulfate resupply followed by S-deprivation accelerates nitrate assimilation for protein synthesis.

  20. Correction of chlorophyll-defective male-sterile winter oilseed rape (Brassica napus) through organelle exchange: molecular analysis of the cytoplasm of parental lines and corrected progeny.

    PubMed

    Jarl, C I; van Grinsven, M Q; van den Mark, F

    1989-01-01

    Cytoplasmic differences between male-fertile and male-sterile Brassica napus as well as Raphanus sativus were investigated. Plastids of the male-fertile B. napus were found to differ from those of male-sterile B. napus and R. sativus with respect to DNA restriction enzyme patterns. Differences between male-fertile and male-sterile B. napus mitochondria were detected not only in the restriction fragment patterns of their DNA, but also at the level of expression by in organello translation of mitochondrial polypeptides.The chlorophyll deficiency obtained upon transferral of the male-sterility-conferring radish cytoplasm to a winter variety of B. napus had been corrected earlier through protoplast fusion. The cytoplasmic composition of the corrected lines was analysed using DNA restriction analysis and in organello translation. The stability of the recombined cytoplasm in the corrected lines was confirmed by analysis of the subsequent seed-derived generation. PMID:24232486

  1. Overexpression of the Brassica napus BnLAS gene in Arabidopsis affects plant development and increases drought tolerance.

    PubMed

    Yang, Minggui; Yang, Qingyong; Fu, Tingdong; Zhou, Yongming

    2011-03-01

    The GRAS proteins are a family of transcription regulators found in plants and play diverse roles in plant growth and development. To study the biological roles of GRAS family genes in Brassica napus, an Arabidopsis LAS homologous gene, BnLAS and its two homologs were cloned from B. napus and its two progenitor species, Brassica rapa and Brassica oleracea. Relatively high levels of BnLAS were observed in roots, shoot tips, lateral meristems and flower organs based on the analysis of the transcripts by quantitative RT-PCR and promoter-reporter assays. Constitutive overexpression of BnLAS in Arabidopsis resulted in inhibition of growth, and delays in leaf senescence and flowering time. A large portion of transgenic lines had darker leaf color and higher chlorophyll content than in wild type plants. Interestingly, water lose rates in transgenic leaves were reduced, and transgenic plants exhibited enhanced drought tolerance and increased recovery after exposed to dehydration treatment. The stomatal density on leaves of the transgenic plants increased significantly due to the smaller cell size. However, the stomatal aperture on the leaves of the transgenic plants reduced significantly compared with wild type plants. More epidermal wax deposition on transgenic leaves was observed. Furthermore, several genes involved in wax synthesis and regulation, including CER1, CER2, KCS1 and KCS2, were upregulated in the transgenic plants. Our results indicate a potential to utilize BnLAS in the improvement of drought tolerance in plants.

  2. Fine mapping and candidate gene analysis of the nuclear restorer gene Rfp for pol CMS in rapeseed (Brassica napus L.).

    PubMed

    Liu, Zhi; Liu, Pingwu; Long, Furong; Hong, Dengfeng; He, Qingbiao; Yang, Guangsheng

    2012-08-01

    The Polima (pol) system of cytoplasmic male sterility (CMS) in rapeseed is widely used in China for commercial hybrid seed production. Genetic studies have shown that its fertility restorer gene (Rfp) is monogenic dominant. For fine mapping of the Rfp gene, a near isogenic line comprising 3,662 individuals of BC(14)F(1) generation segregating for the Rfp gene was created. Based on the sequences of two SCAR markers, SCAP0612ST and SCAP0612EM2, developed by Zhao et al. (Genes Genom 30(3):191-196, 2008) and the synteny region of Brassica napus and other Brassica species, 13 markers strongly linked with the Rfp gene were identified. By integrating three of these markers to the published linkage map, the Rfp gene was mapped on linkage group N9 of B. napus. Using these markers, the Rfp locus was narrowed down to a 29.2-kb genomic region of Brassica rapa. Seven open reading frames (ORFs) were predicted in the target region, of these, ORF2, encoding a PPR protein, was the most likely candidate gene of Rfp. These results lay a solid foundation for map-based cloning of the Rfp gene and will be helpful for marker-assisted selection of elite CMS restorer lines.

  3. Gene silencing of BnTT10 family genes causes retarded pigmentation and lignin reduction in the seed coat of Brassica napus.

    PubMed

    Zhang, Kai; Lu, Kun; Qu, Cunmin; Liang, Ying; Wang, Rui; Chai, Yourong; Li, Jiana

    2013-01-01

    Yellow-seed (i.e., yellow seed coat) is one of the most important agronomic traits of Brassica plants, which is correlated with seed oil and meal qualities. Previous studies on the Brassicaceae, including Arabidopsis and Brassica species, proposed that the seed-color trait is correlative to flavonoid and lignin biosynthesis, at the molecular level. In Arabidopsis thaliana, the oxidative polymerization of flavonoid and biosynthesis of lignin has been demonstrated to be catalyzed by laccase 15, a functional enzyme encoded by the AtTT10 gene. In this study, eight Brassica TT10 genes (three from B. napus, three from B. rapa and two from B. oleracea) were isolated and their roles in flavonoid oxidation/polymerization and lignin biosynthesis were investigated. Based on our phylogenetic analysis, these genes could be divided into two groups with obvious structural and functional differentiation. Expression studies showed that Brassica TT10 genes are active in developing seeds, but with differential expression patterns in yellow- and black-seeded near-isogenic lines. For functional analyses, three black-seeded B. napus cultivars were chosen for transgenic studies. Transgenic B. napus plants expressing antisense TT10 constructs exhibited retarded pigmentation in the seed coat. Chemical composition analysis revealed increased levels of soluble proanthocyanidins, and decreased extractable lignin in the seed coats of these transgenic plants compared with that of the controls. These findings indicate a role for the Brassica TT10 genes in proanthocyanidin polymerization and lignin biosynthesis, as well as seed coat pigmentation in B. napus.

  4. A Genome-Wide Association Study Reveals New Loci for Resistance to Clubroot Disease in Brassica napus

    PubMed Central

    Li, Lixia; Luo, Yujie; Chen, Biyun; Xu, Kun; Zhang, Fugui; Li, Hao; Huang, Qian; Xiao, Xin; Zhang, Tianyao; Hu, Jihong; Li, Feng; Wu, Xiaoming

    2016-01-01

    Rapeseed (Brassica napus L.) is one of the most important oil crops in the world. However, the yield and quality of rapeseed were largely decreased by clubroot (Plasmodiophora brassicae Woronin). Therefore, it is of great importance for screening more resistant germplasms or genes and improving the resistance to P. brassicae in rapeseed breeding. In this study, a massive resistant identification for a natural global population was conducted in two environments with race/pathotype 4 of P. brassicae which was the most predominant in China, and a wide range of phenotypic variation was found in the population. In addition, a genome-wide association study of 472 accessions for clubroot resistance (CR) was performed with 60K Brassica Infinium SNP arrays for the first time. In total, nine QTLs were detected, seven of which were novel through integrative analysis. Furthermore, additive effects in genetic control of CR in rapeseed among the above loci were found. By bioinformatic analyses, the candidate genes of these loci were predicted, which indicated that TIR-NBS gene family might play an important role in CR. It is believable that the results presented in our study could provide valuable information for understanding the genetic mechanism and molecular regulation of CR. PMID:27746804

  5. Zn deficiency in Brassica napus induces Mo and Mn accumulation associated with chloroplast proteins variation without Zn remobilization.

    PubMed

    Billard, Vincent; Maillard, Anne; Garnica, Maria; Cruz, Florence; Garcia-Mina, José-Maria; Yvin, Jean-Claude; Ourry, Alain; Etienne, Philippe

    2015-01-01

    The importance of zinc (Zn) has been of little concern in human nutrition despite a strong decrease of this element in crops since the rise of high yielding varieties. For better food quality, Zn biofortification can be used, but will be optimal only if mechanisms governing Zn management are better known. Using Zn deficiency, we are able to demonstrate that Zn is not remobilized in Brassica napus (B. napus). Thus, remobilization processes should not be targeted by biofortification strategies. This study also complemented previous work by investigating leaf responses to Zn deficiency, especially from proteomic and ionomic points of view, showing for example, an increase in Manganese (Mn) content and of the Mn-dependent protein, Oxygen Evolving Enhancer. PMID:25438138

  6. Transgenic Brassica napus and tobacco plants harboring human metallothionein gene are resistant to toxic levels of heavy metals

    SciTech Connect

    Misra, S. )

    1989-04-01

    A chimeric gene containing a cloned human metallothionein-II (MT-II) processed gene was introduced into Brassica napus and tobacco cells on a disarmed Ti plasmid of Agrobacterium tumefaciens. Transformants expressed MT protein as a nuclear trait, and in a constitutive manner. Seeds from self-fertilized transgenic plants were germinated on media containing toxic levels of cadmium and scored for tolerance/susceptibility to this heavy metal. The growth of root and shoot of transformed seedlings was unaffected by up to 100{mu}M CdCl{sub 2}, whereas, control seedlings showed severe inhibition of root and shoot growth and chlorosis of leaves. The results of these experiments indicate that agriculturally important plants such a B. napus can be genetically engineered for heavy metals tolerance/sequestration and eventually for partitioning of heavy metals in non-consumed plant tissues.

  7. GISH analysis of disomic Brassica napus-Crambe abyssinica chromosome addition lines produced by microspore culture from monosomic addition lines.

    PubMed

    Wang, Youping; Sonntag, Karin; Rudloff, Eicke; Wehling, Peter; Snowdon, Rod J

    2006-02-01

    Two Brassica napus-Crambe abyssinica monosomic addition lines (2n=39, AACC plus a single chromosome from C. abyssinca) were obtained from the F(2) progeny of the asymmetric somatic hybrid. The alien chromosome from C. abyssinca in the addition line was clearly distinguished by genomic in situ hybridization (GISH). Twenty-seven microspore-derived plants from the addition lines were obtained. Fourteen seedlings were determined to be diploid plants (2n=38) arising from spontaneous chromosome doubling, while 13 seedlings were confirmed as haploid plants. Doubled haploid plants produced after treatment with colchicine and two disomic chromosome addition lines (2n=40, AACC plus a single pair of homologous chromosomes from C. abyssinca) could again be identified by GISH analysis. The lines are potentially useful for molecular genetic analysis of novel C. abyssinica genes or alleles contributing to traits relevant for oilseed rape (B. napus) breeding.

  8. Effect of enzyme-aided cell wall disintegration on protein extractability from intact and dehulled rapeseed (Brassica rapa L. and Brassica napus L.) press cakes.

    PubMed

    Rommi, Katariina; Hakala, Terhi K; Holopainen, Ulla; Nordlund, Emilia; Poutanen, Kaisa; Lantto, Raija

    2014-08-13

    Cell-wall- and pectin-degrading enzyme preparations were used to enhance extractability of proteins from rapeseed press cake. Rapeseed press cakes from cold pressing of intact Brassica rapa and partially dehulled Brassica napus seeds, containing 36-40% protein and 35% carbohydrates, were treated with pectinolytic (Pectinex Ultra SP-L), xylanolytic (Depol 740L), and cellulolytic (Celluclast 1.5L) enzyme preparations. Pectinex caused effective disintegration of embryonic cell walls through hydrolysis of pectic polysaccharides and glucans and increased protein extraction by up to 1.7-fold in comparison to treatment without enzyme addition. Accordingly, 56% and 74% of the total protein in the intact and dehulled press cakes was extracted. Light microscopy of the press cakes suggested the presence of pectins colocalized with proteins inside the embryo cells. Hydrolysis of these intracellular pectins and deconstruction of embryonic cell walls during Pectinex treatment were concluded to relate with enhanced protein release.

  9. Molecular cloning of a cDNA from Brassica napus L. for a homologue of acyl-CoA-binding protein.

    PubMed

    Hills, M J; Dann, R; Lydiate, D; Sharpe, A

    1994-08-01

    A cDNA encoding an acyl-CoA-binding protein (ACBP) homologue has been cloned from a lambda gt11 library made from mRNA isolated from developing seeds of oilseed rape (Brassica napus L.). The derived amino acid sequence reveals a protein 92 amino acids in length which is highly conserved when compared with ACBP sequences from yeast, cow, man and fruit fly. Southern blot analysis of Brassica napus genomic DNA revealed the presence of 6 genes, 3 derived from the Brassica rapa parent and 3 from Brassica oleracea. Northern blot analysis showed that ACBP genes are expressed strongly in developing embryo, flowers and cotyledons of seedlings and to a lesser extent in leaves and roots.

  10. Genome-wide association mapping unravels the genetic control of seed germination and vigor in Brassica napus.

    PubMed

    Hatzig, Sarah V; Frisch, Matthias; Breuer, Frank; Nesi, Nathalie; Ducournau, Sylvie; Wagner, Marie-Helene; Leckband, Gunhild; Abbadi, Amine; Snowdon, Rod J

    2015-01-01

    Rapid and uniform seed germination is a crucial prerequisite for crop establishment and high yield levels in crop production. A disclosure of genetic factors contributing to adequate seed vigor would help to further increase yield potential and stability. Here we carried out a genome-wide association study in order to define genomic regions influencing seed germination and early seedling growth in oilseed rape (Brassica napus L.). A population of 248 genetically diverse winter-type B. napus accessions was genotyped with the Brassica 60k SNP Illumina genotyping array. Automated high-throughput in vitro phenotyping provided extensive data for multiple traits related to germination and early vigor, such as germination speed, absolute germination rate and radicle elongation. The data obtained indicate that seed germination and radicle growth are strongly environmentally dependent, but could nevertheless be substantially improved by genomic-based breeding. Conditions during seed production and storage were shown to have a profound effect on seed vigor, and a variable manifestation of seed dormancy appears to contribute to differences in germination performance in B. napus. Several promising positional and functional candidate genes could be identified within the genomic regions associated with germination speed, absolute germination rate, radicle growth and thousand seed weight. These include B. napus orthologs of the Arabidopsis thaliana genes SNOWY COTYLEDON 1 (SCO1), ARABIDOPSIS TWO-COMPONENT RESPONSE REGULATOR (ARR4), and ARGINYL-t-RNA PROTEIN TRANSFERASE 1 (ATE1), which have been shown previously to play a role in seed germination and seedling growth in A. thaliana. PMID:25914704

  11. Genome-wide association mapping unravels the genetic control of seed germination and vigor in Brassica napus

    PubMed Central

    Hatzig, Sarah V.; Frisch, Matthias; Breuer, Frank; Nesi, Nathalie; Ducournau, Sylvie; Wagner, Marie-Helene; Leckband, Gunhild; Abbadi, Amine; Snowdon, Rod J.

    2015-01-01

    Rapid and uniform seed germination is a crucial prerequisite for crop establishment and high yield levels in crop production. A disclosure of genetic factors contributing to adequate seed vigor would help to further increase yield potential and stability. Here we carried out a genome-wide association study in order to define genomic regions influencing seed germination and early seedling growth in oilseed rape (Brassica napus L.). A population of 248 genetically diverse winter-type B. napus accessions was genotyped with the Brassica 60k SNP Illumina genotyping array. Automated high-throughput in vitro phenotyping provided extensive data for multiple traits related to germination and early vigor, such as germination speed, absolute germination rate and radicle elongation. The data obtained indicate that seed germination and radicle growth are strongly environmentally dependent, but could nevertheless be substantially improved by genomic-based breeding. Conditions during seed production and storage were shown to have a profound effect on seed vigor, and a variable manifestation of seed dormancy appears to contribute to differences in germination performance in B. napus. Several promising positional and functional candidate genes could be identified within the genomic regions associated with germination speed, absolute germination rate, radicle growth and thousand seed weight. These include B. napus orthologs of the Arabidopsis thaliana genes SNOWY COTYLEDON 1 (SCO1), ARABIDOPSIS TWO-COMPONENT RESPONSE REGULATOR (ARR4), and ARGINYL-t-RNA PROTEIN TRANSFERASE 1 (ATE1), which have been shown previously to play a role in seed germination and seedling growth in A. thaliana. PMID:25914704

  12. Genome-Wide Identification and Expression Analysis of WRKY Transcription Factors under Multiple Stresses in Brassica napus.

    PubMed

    He, Yajun; Mao, Shaoshuai; Gao, Yulong; Zhu, Liying; Wu, Daoming; Cui, Yixin; Li, Jiana; Qian, Wei

    2016-01-01

    WRKY transcription factors play important roles in responses to environmental stress stimuli. Using a genome-wide domain analysis, we identified 287 WRKY genes with 343 WRKY domains in the sequenced genome of Brassica napus, 139 in the A sub-genome and 148 in the C sub-genome. These genes were classified into eight groups based on phylogenetic analysis. In the 343 WRKY domains, a total of 26 members showed divergence in the WRKY domain, and 21 belonged to group I. This finding suggested that WRKY genes in group I are more active and variable compared with genes in other groups. Using genome-wide identification and analysis of the WRKY gene family in Brassica napus, we observed genome duplication, chromosomal/segmental duplications and tandem duplication. All of these duplications contributed to the expansion of the WRKY gene family. The duplicate segments that were detected indicated that genome duplication events occurred in the two diploid progenitors B. rapa and B. olearecea before they combined to form B. napus. Analysis of the public microarray database and EST database for B. napus indicated that 74 WRKY genes were induced or preferentially expressed under stress conditions. According to the public QTL data, we identified 77 WRKY genes in 31 QTL regions related to various stress tolerance. We further evaluated the expression of 26 BnaWRKY genes under multiple stresses by qRT-PCR. Most of the genes were induced by low temperature, salinity and drought stress, indicating that the WRKYs play important roles in B. napus stress responses. Further, three BnaWRKY genes were strongly responsive to the three multiple stresses simultaneously, which suggests that these 3 WRKY may have multi-functional roles in stress tolerance and can potentially be used in breeding new rapeseed cultivars. We also found six tandem repeat pairs exhibiting similar expression profiles under the various stress conditions, and three pairs were mapped in the stress related QTL regions

  13. Genome-Wide Identification and Expression Analysis of WRKY Transcription Factors under Multiple Stresses in Brassica napus.

    PubMed

    He, Yajun; Mao, Shaoshuai; Gao, Yulong; Zhu, Liying; Wu, Daoming; Cui, Yixin; Li, Jiana; Qian, Wei

    2016-01-01

    WRKY transcription factors play important roles in responses to environmental stress stimuli. Using a genome-wide domain analysis, we identified 287 WRKY genes with 343 WRKY domains in the sequenced genome of Brassica napus, 139 in the A sub-genome and 148 in the C sub-genome. These genes were classified into eight groups based on phylogenetic analysis. In the 343 WRKY domains, a total of 26 members showed divergence in the WRKY domain, and 21 belonged to group I. This finding suggested that WRKY genes in group I are more active and variable compared with genes in other groups. Using genome-wide identification and analysis of the WRKY gene family in Brassica napus, we observed genome duplication, chromosomal/segmental duplications and tandem duplication. All of these duplications contributed to the expansion of the WRKY gene family. The duplicate segments that were detected indicated that genome duplication events occurred in the two diploid progenitors B. rapa and B. olearecea before they combined to form B. napus. Analysis of the public microarray database and EST database for B. napus indicated that 74 WRKY genes were induced or preferentially expressed under stress conditions. According to the public QTL data, we identified 77 WRKY genes in 31 QTL regions related to various stress tolerance. We further evaluated the expression of 26 BnaWRKY genes under multiple stresses by qRT-PCR. Most of the genes were induced by low temperature, salinity and drought stress, indicating that the WRKYs play important roles in B. napus stress responses. Further, three BnaWRKY genes were strongly responsive to the three multiple stresses simultaneously, which suggests that these 3 WRKY may have multi-functional roles in stress tolerance and can potentially be used in breeding new rapeseed cultivars. We also found six tandem repeat pairs exhibiting similar expression profiles under the various stress conditions, and three pairs were mapped in the stress related QTL regions

  14. Genome-Wide Identification and Expression Analysis of WRKY Transcription Factors under Multiple Stresses in Brassica napus

    PubMed Central

    He, Yajun; Mao, Shaoshuai; Gao, Yulong; Zhu, Liying; Wu, Daoming; Cui, Yixin; Li, Jiana; Qian, Wei

    2016-01-01

    WRKY transcription factors play important roles in responses to environmental stress stimuli. Using a genome-wide domain analysis, we identified 287 WRKY genes with 343 WRKY domains in the sequenced genome of Brassica napus, 139 in the A sub-genome and 148 in the C sub-genome. These genes were classified into eight groups based on phylogenetic analysis. In the 343 WRKY domains, a total of 26 members showed divergence in the WRKY domain, and 21 belonged to group I. This finding suggested that WRKY genes in group I are more active and variable compared with genes in other groups. Using genome-wide identification and analysis of the WRKY gene family in Brassica napus, we observed genome duplication, chromosomal/segmental duplications and tandem duplication. All of these duplications contributed to the expansion of the WRKY gene family. The duplicate segments that were detected indicated that genome duplication events occurred in the two diploid progenitors B. rapa and B. olearecea before they combined to form B. napus. Analysis of the public microarray database and EST database for B. napus indicated that 74 WRKY genes were induced or preferentially expressed under stress conditions. According to the public QTL data, we identified 77 WRKY genes in 31 QTL regions related to various stress tolerance. We further evaluated the expression of 26 BnaWRKY genes under multiple stresses by qRT-PCR. Most of the genes were induced by low temperature, salinity and drought stress, indicating that the WRKYs play important roles in B. napus stress responses. Further, three BnaWRKY genes were strongly responsive to the three multiple stresses simultaneously, which suggests that these 3 WRKY may have multi-functional roles in stress tolerance and can potentially be used in breeding new rapeseed cultivars. We also found six tandem repeat pairs exhibiting similar expression profiles under the various stress conditions, and three pairs were mapped in the stress related QTL regions

  15. Characterization of the quantitative trait locus OilA1 for oil content in Brassica napus.

    PubMed

    Chen, Yubo; Qi, Lu; Zhang, Xiaoyu; Huang, Jixiang; Wang, Jibian; Chen, Hongcheng; Ni, Xiyuan; Xu, Fei; Dong, Yanjun; Xu, Haiming; Zhao, Jianyi

    2013-10-01

    Increasing seed oil content has become one of the most important breeding criteria in rapeseed (Brassica napus). However, oil content is a complex quantitative trait. QTL mapping in a double haploid population (SG population) emerging from a cross between a German (Sollux) and Chinese (Gaoyou) cultivars revealed one QTL for oil content on linkage group A1 (OilA1), which was mapped to a 17 cM genetic interval. To further validate and characterize the OilA1, we constructed a high-resolution map using B. rapa sequence resources and developed a set of near-isogenic lines (NILs) by employing a DH line SG-DH267 as donor and Chinese parent Gaoyou as recurrent background. The results showed highly conserved synteny order between B. rapa and B. napus within the linkage group A1 and revealed a possible centromere region between two markers ZAASA1-38 and NTP3 (2.5 cM). OilA1 was firstly validated by 250 BC5F2 plants and was confirmed in a 10.6 cM interval between the markers ZAASA1-47 and ZAASA1-77. Further substitution mapping was conducted by using two generations of QTL-NILs, 283 lines from eight BC5F3:4 families and 428 plants from six BC5F4 sub-NILs and thus narrowed the OilA1 interval to 6.9 cM and 4.3 cM (1.4 Mb), respectively. Field investigations with two replications using homozygous BC5F3:4 sister sub-NILs indicated that NILs, which carry a Sollux chromosome segment across the target region showed significant higher oil content (1.26 %, p < 0.001) than their sister NILs containing Gaoyou chromosome. The OilA1 locus is of particular interest for breeding purpose in China because 80 % of Chinese cultivars do not carry this desirable allele.

  16. Identification of a Novel Proline-Rich Antimicrobial Peptide from Brassica napus.

    PubMed

    Cao, Huihui; Ke, Tao; Liu, Renhu; Yu, Jingyin; Dong, Caihua; Cheng, Mingxing; Huang, Junyan; Liu, Shengyi

    2015-01-01

    Proline-rich antimicrobial peptides (PR-AMPs) are a group of cationic host defense peptides that are characterized by a high content of proline residues. Up to now, they have been reported in some insects, vertebrate and invertebrate animals, but are not found in plants. In this study, we performed an in silico screening of antimicrobial peptides, which led to discovery of a Brassica napus gene encoding a novel PR-AMP. This gene encodes a 35-amino acid peptide with 13 proline residues, designated BnPRP1. BnPRP1 has 40.5% identity with a known proline-rich antimicrobial peptide SP-B from the pig. BnPRP1 was artificially synthetized and cloned into the prokaryotic expression vector pET30a/His-EDDIE-GFP. Recombinant BnPRP1 was produced in Escherichia coli and has a predicted molecular mass of 3.8 kDa. Analysis of its activity demonstrated that BnPRP1 exhibited strong antimicrobial activity against Gram-positive bacterium, Gram-negative bacterium, yeast and also had strong antifungal activity against several pathogenic fungi, such as Sclerotinia sclerotiorum, Mucor sp., Magnaporthe oryzae and Botrytis cinerea. Circular dichroism (CD) revealed the main secondary structure of BnPRP1 was the random coil. BnPRP1 gene expression detected by qRT-PCR is responsive to pathogen inoculation. At 48 hours after S. sclerotiorum inoculation, the expression of BnPRP1 increased significantly in the susceptible lines while slight decrease occurred in resistant lines. These suggested that BnPRP1 might play a role in the plant defense response against S. sclerotiorum. BnPRP1 isolated from B. napus was the first PR-AMP member that was characterized in plants, and its homology sequences were found in some other Brassicaceae plants by the genome sequences analysis. Compared with the known PR-AMPs, BnPRP1 has the different primary sequences and antimicrobial activity. Above all, this study gives a chance to cast a new light on further understanding about the AMPs' mechanism and application.

  17. Identification of a Novel Proline-Rich Antimicrobial Peptide from Brassica napus.

    PubMed

    Cao, Huihui; Ke, Tao; Liu, Renhu; Yu, Jingyin; Dong, Caihua; Cheng, Mingxing; Huang, Junyan; Liu, Shengyi

    2015-01-01

    Proline-rich antimicrobial peptides (PR-AMPs) are a group of cationic host defense peptides that are characterized by a high content of proline residues. Up to now, they have been reported in some insects, vertebrate and invertebrate animals, but are not found in plants. In this study, we performed an in silico screening of antimicrobial peptides, which led to discovery of a Brassica napus gene encoding a novel PR-AMP. This gene encodes a 35-amino acid peptide with 13 proline residues, designated BnPRP1. BnPRP1 has 40.5% identity with a known proline-rich antimicrobial peptide SP-B from the pig. BnPRP1 was artificially synthetized and cloned into the prokaryotic expression vector pET30a/His-EDDIE-GFP. Recombinant BnPRP1 was produced in Escherichia coli and has a predicted molecular mass of 3.8 kDa. Analysis of its activity demonstrated that BnPRP1 exhibited strong antimicrobial activity against Gram-positive bacterium, Gram-negative bacterium, yeast and also had strong antifungal activity against several pathogenic fungi, such as Sclerotinia sclerotiorum, Mucor sp., Magnaporthe oryzae and Botrytis cinerea. Circular dichroism (CD) revealed the main secondary structure of BnPRP1 was the random coil. BnPRP1 gene expression detected by qRT-PCR is responsive to pathogen inoculation. At 48 hours after S. sclerotiorum inoculation, the expression of BnPRP1 increased significantly in the susceptible lines while slight decrease occurred in resistant lines. These suggested that BnPRP1 might play a role in the plant defense response against S. sclerotiorum. BnPRP1 isolated from B. napus was the first PR-AMP member that was characterized in plants, and its homology sequences were found in some other Brassicaceae plants by the genome sequences analysis. Compared with the known PR-AMPs, BnPRP1 has the different primary sequences and antimicrobial activity. Above all, this study gives a chance to cast a new light on further understanding about the AMPs' mechanism and application

  18. Genome-Wide Gene Expressions Respond Differently to A-subgenome Origins in Brassica napus Synthetic Hybrids and Natural Allotetraploid

    PubMed Central

    Zhang, Dawei; Pan, Qi; Tan, Chen; Zhu, Bin; Ge, Xianhong; Shao, Yujiao; Li, Zaiyun

    2016-01-01

    The young allotetraploid Brassica napus (2n = 38, AACC) is one of models to study genomic responses to allopolyploidization. The extraction of AA component from natural B. napus and then restitution of progenitor B. rapa should provide a unique opportunity to reveal the genome interplay for gene expressions during the evolution. Herein, B. napus hybrids (2n = 19, AC) between the extracted and extant B. rapa (2n = 20, AA) and the same B. oleracea genotype (2n = 18, CC) were studied by RNA-seq and compared with natural B. napus donor, to reveal the gene expression changes from hybridization and domestication and the effects of A genome with different origins. Upon the initial merger of two diploid genomes, additive gene expression was prevalent in these two hybrids, for non-additively expressed genes only represented a small portion of total expressed genes. A high proportion of genes exhibited expression level dominance, with no preference to either of the parental genomes. Comparison of homoeolog expressions also showed no bias toward any genomes and the parental expression patterns were often maintained in the hybrids and natural allotetraploids. Although, the overall patterns of gene expression were highly conserved between two hybrids, the extracted B. rapa responded less and appeared more compatible for hybridization than the extant B. rapa. Our results suggested that expression level dominance and homoeolog expressions bias were balanced at the initial stage of genome merger, and such balance were largely maintained during the domestication of B. napus, despite the increased extent over time. PMID:27790227

  19. Development of rapeseed with high erucic acid content by asymmetric somatic hybridization between Brassica napus and Crambe abyssinica.

    PubMed

    Wang, Y P; Sonntag, K; Rudloff, E

    2003-05-01

    PEG-induced asymmetric somatic hybridization between Brassica napus and Crambe abyssinica was carried out. C. abyssinica is an annual cruciferous oil crop with a high content of erucic acid in the seed oil valuable for technical purposes. UV-irradiated mesophyll protoplasts of C. abyssinica cv 'Carmen' and cv 'Galactica' were fused with hypocotyl protoplasts of different genotypes of B. napus cv 'Maplus' and breeding line '11502'. Shoot regeneration frequency varied between 6.1% and 20.8% among the different doses of UV-irradiation, ranging from 0.05 J/cm(2) to 0.30 J/cm(2). In total, 124 shoots were regenerated, of which 20 asymmetric somatic hybrids were obtained and verified by nuclear DNA content and AFLP analysis. AFLP data showed that some of the characteristic bands from C. abyssinica were present in the hybrids. Cytological analysis of these hybrids showed that 9 out of 20 asymmetric hybrids had 38 chromosomes, the others contained 40-78 chromosomes, having additional chromosomes between 2 and 40 beyond the 38 expected for B. napus. The investigation into the fertility of asymmetric somatic hybrids indicated that the fertility increased with increasing UV-doses ranging from 0.05 J/cm(2) to 0.15 J/cm(2). All of the hybrids were cultured to full maturity, and could be fertilized and set seeds after self-pollination or backcrosses with B. napus. An analysis of fatty acid composition in the seeds was conducted and found to contain significantly greater amounts of erucic acid than B. napus. This study indicates that UV-irradiation could be used as a tool to produce asymmetric somatic hybrids and to promote the fertility of the hybrids.

  20. Identification and characterization of orthologs of AtNHX5 and AtNHX6 in Brassica napus.

    PubMed

    Ford, Brett A; Ernest, Joanne R; Gendall, Anthony R

    2012-01-01

    Improving crop species by breeding for salt tolerance or introducing salt tolerant traits is one method of increasing crop yields in saline affected areas. Extensive studies of the model plant species Arabidopsis thaliana has led to the availability of substantial information regarding the function and importance of many genes involved in salt tolerance. However, the identification and characterization of A. thaliana orthologs in species such as Brassica napus (oilseed rape) can prove difficult due to the significant genomic changes that have occurred since their divergence approximately 20 million years ago (MYA). The recently released Brassica rapa genome provides an excellent resource for comparative studies of A. thaliana and the cultivated Brassica species, and facilitates the identification of Brassica species orthologs which may be of agronomic importance. Sodium hydrogen antiporter (NHX) proteins transport a sodium or potassium ion in exchange for a hydrogen ion in the other direction across a membrane. In A. thaliana there are eight members of the NHX family, designated AtNHX1-8, that can be sub-divided into three clades, based on their subcellular localization: plasma membrane (PM), intracellular class I (IC-I) and intracellular class II (IC-II). In plants, many NHX proteins are primary determinants of salt tolerance and act by transporting Na(+) out of the cytosol where it would otherwise accumulate to toxic levels. Significant work has been done to determine the role of both PM and IC-I clade members in salt tolerance in a variety of plant species, but relatively little analysis has been described for the IC-II clade. Here we describe the identification of B. napus orthologs of AtNHX5 and AtNHX6, using the B. rapa genome sequence, macro- and micro-synteny analysis, comparative expression and promoter motif analysis, and highlight the value of these multiple approaches for identifying true orthologs in closely related species with multiple paralogs.

  1. Multiple NUCLEAR FACTOR Y transcription factors respond to abiotic stress in Brassica napus L.

    PubMed

    Xu, Li; Lin, Zhongyuan; Tao, Qing; Liang, Mingxiang; Zhao, Gengmao; Yin, Xiangzhen; Fu, Ruixin

    2014-01-01

    Members of the plant NUCLEAR FACTOR Y (NF-Y) family are composed of the NF-YA, NF-YB, and NF-YC subunits. In Brassica napus (canola), each of these subunits forms a multimember subfamily. Plant NF-Ys were reported to be involved in several abiotic stresses. In this study, we demonstrated that multiple members of thirty three BnNF-Ys responded rapidly to salinity, drought, or ABA treatments. Transcripts of five BnNF-YAs, seven BnNF-YBs, and two BnNF-YCs were up-regulated by salinity stress, whereas the expression of thirteen BnNF-YAs, ten BnNF-YBs, and four BnNF-YCs were induced by drought stress. Under NaCl treatments, the expression of one BnNF-YA10 and four NF-YBs (BnNF-YB3, BnNF-YB7, BnNF-YB10, and BnNF-YB14) were greatly increased. Under PEG treatments, the expression levels of four NF-YAs (BnNF-YA9, BnNF-YA10, BnNF-YA11, and BnNF-YA12) and five NF-YBs (BnNF-YB1, BnNF-YB8, BnNF-YB10, BnNF-YB13, and BnNF-YB14) were greatly induced. The expression profiles of 20 of the 27 salinity- or drought-induced BnNF-Ys were also affected by ABA treatment. The expression levels of six NF-YAs (BnNF-YA1, BnNF-YA7, BnNF-YA8, BnNF-YA9, BnNF-YA10, and BnNF-YA12) and seven BnNF-YB members (BnNF-YB2, BnNF-YB3, BnNF-YB7, BnNF-YB10, BnNF-YB11, BnNF-YB13, and BnNF-YB14) and two NF-YC members (BnNF-YC2 and BnNF-YC3) were greatly up-regulated by ABA treatments. Only a few BnNF-Ys were inhibited by the above three treatments. Several NF-Y subfamily members exhibited collinear expression patterns. The promoters of all stress-responsive BnNF-Ys harbored at least two types of stress-related cis-elements, such as ABRE, DRE, MYB, or MYC. The cis-element organization of BnNF-Ys was similar to that of Arabidopsis thaliana, and the promoter regions exhibited higher levels of nucleotide sequence identity with Brassica rapa than with Brassica oleracea. This work represents an entry point for investigating the roles of canola NF-Y proteins during abiotic stress responses and provides insight into

  2. Multiple NUCLEAR FACTOR Y transcription factors respond to abiotic stress in Brassica napus L.

    PubMed

    Xu, Li; Lin, Zhongyuan; Tao, Qing; Liang, Mingxiang; Zhao, Gengmao; Yin, Xiangzhen; Fu, Ruixin

    2014-01-01

    Members of the plant NUCLEAR FACTOR Y (NF-Y) family are composed of the NF-YA, NF-YB, and NF-YC subunits. In Brassica napus (canola), each of these subunits forms a multimember subfamily. Plant NF-Ys were reported to be involved in several abiotic stresses. In this study, we demonstrated that multiple members of thirty three BnNF-Ys responded rapidly to salinity, drought, or ABA treatments. Transcripts of five BnNF-YAs, seven BnNF-YBs, and two BnNF-YCs were up-regulated by salinity stress, whereas the expression of thirteen BnNF-YAs, ten BnNF-YBs, and four BnNF-YCs were induced by drought stress. Under NaCl treatments, the expression of one BnNF-YA10 and four NF-YBs (BnNF-YB3, BnNF-YB7, BnNF-YB10, and BnNF-YB14) were greatly increased. Under PEG treatments, the expression levels of four NF-YAs (BnNF-YA9, BnNF-YA10, BnNF-YA11, and BnNF-YA12) and five NF-YBs (BnNF-YB1, BnNF-YB8, BnNF-YB10, BnNF-YB13, and BnNF-YB14) were greatly induced. The expression profiles of 20 of the 27 salinity- or drought-induced BnNF-Ys were also affected by ABA treatment. The expression levels of six NF-YAs (BnNF-YA1, BnNF-YA7, BnNF-YA8, BnNF-YA9, BnNF-YA10, and BnNF-YA12) and seven BnNF-YB members (BnNF-YB2, BnNF-YB3, BnNF-YB7, BnNF-YB10, BnNF-YB11, BnNF-YB13, and BnNF-YB14) and two NF-YC members (BnNF-YC2 and BnNF-YC3) were greatly up-regulated by ABA treatments. Only a few BnNF-Ys were inhibited by the above three treatments. Several NF-Y subfamily members exhibited collinear expression patterns. The promoters of all stress-responsive BnNF-Ys harbored at least two types of stress-related cis-elements, such as ABRE, DRE, MYB, or MYC. The cis-element organization of BnNF-Ys was similar to that of Arabidopsis thaliana, and the promoter regions exhibited higher levels of nucleotide sequence identity with Brassica rapa than with Brassica oleracea. This work represents an entry point for investigating the roles of canola NF-Y proteins during abiotic stress responses and provides insight into

  3. Real-time polymerase chain reaction (PCR) quantitative detection of Brassica napus using a locked nucleic acid TaqMan probe.

    PubMed

    Schmidt, Anna-Mary; Rott, Michael E

    2006-02-22

    Several countries have introduced mandatory labeling requirements on foods derived from genetically modified organisms. Real-time quantitative Polymerase Chain Reaction (PCR) has quickly become the method of choice in support of these regulations and requires the development of separate PCR assays targeting the transgenic sequence as well as a specific endogenous gene sequence. To develop a Brassica napus-specific PCR assay, partial sequences of the acetyl-CoA carboxylase BnACCg8 gene from B. napus and the closely related Brassica rapa were determined and compared, and a region of unique nucleotide sequence was identified. Universal amplification primers were designed to either side of this region, and a locked nucleic acid TaqMan probe was designed to the B. napus-specific sequence. Evaluation of this primer/probe combination indicated a high level of specificity to B. napus: no amplification signal was observed with any other species tested, including five closely related Brassica species. The method was assayed with 14 different B. napus cultivars, and comparable amplification curves were consistently obtained for all. The assay was highly sensitive, with a limit of detection between 1 and 10 haploid copies. Practically, the method was demonstrated to be effective for the detection of processed food samples and for the quantification of Roundup Ready canola content in mixed samples.

  4. Seeding date affects fall growth of winter canola (Brassica napus L. ‘Baldur’) and its performance as a winter cover crop in central Iowa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, interest has increased in finding non-grass cover crop species that could be planted after soybean (Glycine max (L) Merr.) and before corn (Zea mays L.) in Iowa crop rotations. In this study, we investigate the use of winter canola (Brassica napus L.) as an alternative cover crop fo...

  5. Yield reduction in Brassica napus, B. rapa, B. juncea, and Sinapis alba caused by flea beetle (Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae)) infestation in northern Idaho.

    PubMed

    Brown, Jack; McCaffrey, Joseph P; Brown, Donna A; Harmon, Bradley L; Davis, James B

    2004-10-01

    Phyllotreta cruciferae is an important insect pest of spring-planted Brassica crops, especially during the seedling stage. To determine the effect of early season P. cruciferae infestation on seed yield, 10 genotypes from each of two canola species (Brassica napus L. and Brassica rapa L.) and two mustard species (Brassica juncea L. and Sinapis alba L.) were grown in 2 yr under three different P. cruciferae treatments: (1) no insecticide control; (2) foliar applications of endosulfan; and (3) carbofuran with seed at planting plus foliar application of carbaryl. Averaged over 10 genotypes, B. rapa showed most visible P. cruciferae injury and showed greatest yield reduction without insecticide application. Mustard species (S. alba and B. juncea) showed least visible injury and higher yield without insecticide compared with canola species (B. napus and B. rapa). Indeed, average seed yield of S. alba without insecticide was higher than either B. napus or B. rapa with most effective P. cruciferae control. Significant variation occurred within each species. A number of lines from B. napus, B. juncea, anid S. alba showed less feeding injury and yield reduction as a result of P. cruciferae infestation compared with other lines from the same species examined, thus having potential genetic background for developing resistant cultivars.

  6. Draft Genome Sequence of the Beneficial Rhizobacterium Pseudomonas fluorescens DSM 8569, a Natural Isolate of Oilseed Rape (Brassica napus)

    PubMed Central

    Nesemann, Kai; Braus-Stromeyer, Susanna A.; Thuermer, Andrea; Daniel, Rolf

    2015-01-01

    Pseudomonas fluorescens DSM 8569 represents a natural isolate of the rhizosphere of oilseed rape (Brassica napus) in Germany and possesses antagonistic potential toward the fungal pathogen Verticillium. We report here the draft genome sequence of strain DSM 8569, which comprises 5,914 protein-coding sequences. PMID:25814596

  7. Meligethes aeneus pollen-feeding suppresses, and oviposition induces, Brassica napus volatiles: beetle attraction/repellence to lilac aldehydes and veratrole

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect pollination and pollen-feeding can reduce plant volatile emissions and future insect floral attraction, with oviposition having different effects. Meligethes aeneus F. (Coleoptera: Nitidulidae), is a pollen-feeding pest beetle of oilseed rape, Brassica napus L. (Brassicaceae). We measured pla...

  8. Draft Genome Sequence of the Beneficial Rhizobacterium Pseudomonas fluorescens DSM 8569, a Natural Isolate of Oilseed Rape (Brassica napus).

    PubMed

    Nesemann, Kai; Braus-Stromeyer, Susanna A; Thuermer, Andrea; Daniel, Rolf; Braus, Gerhard H

    2015-03-26

    Pseudomonas fluorescens DSM 8569 represents a natural isolate of the rhizosphere of oilseed rape (Brassica napus) in Germany and possesses antagonistic potential toward the fungal pathogen Verticillium. We report here the draft genome sequence of strain DSM 8569, which comprises 5,914 protein-coding sequences.

  9. Development of amplified consensus genetic markers (ACGM) in Brassica napus from Arabidopsis thaliana sequences of known biological function.

    PubMed

    Brunel, D; Froger, N; Pelletier, G

    1999-06-01

    A method for the development of consensus genetic markers between species of the same taxonomic family is described in this paper. It is based on the conservation of the peptide sequences and on the potential polymorphism within non-coding sequences. Six loci sequenced from Arabidopsis thaliana, AG, LFY3, AP3, FAD7, FAD3, and ADH, were analysed for one ecotype of A. thaliana, four lines of Brassica napus, and one line for each parental species, Brassica oleracea and Brassica rapa. Positive amplifications with the degenerate primers showed one band for A. thaliana, two to four bands in rapeseed, and one to two bands in the parental species. Direct sequencing of the PCR products confirms their peptide similarity with the "mother" sequence. By comparison of intron sequences, the correspondence between each rapeseed gene and its homologue in one of the parental species can be determined without ambiguity. Another important result is the presence of a polymorphism inside these fragments between the rapeseed lines. This variability could generally be detected by differences of electrophoretic migration on long non-denaturing polyacrylamide gels. This method enables a quick and easy shuttle between A. thaliana and Brassica species without cloning.

  10. RNAi knockdown of fatty acid elongase1 alters fatty acid composition in Brassica napus.

    PubMed

    Shi, Jianghua; Lang, Chunxiu; Wu, Xuelong; Liu, Renhu; Zheng, Tao; Zhang, Dongqing; Chen, Jinqing; Wu, Guanting

    2015-10-23

    The quality and end-use of oil from oilseed crops is determined by its fatty acid composition. In particular, the relative proportions of erucic and oleic acids are key selection traits for breeders. The goal of our research is to genetically improve the nutritional quality of Brassica napus cultivar CY2, the oil of which is high in erucic acid (about 40%) and low in oleic acid (about 20%). Here, we report the use of a seed-specific napin A promoter to drive the knockdown of BnFAE1 in transgenic CY2. Southern blotting results confirmed the presence of the transgene. RT-PCR analysis showed that the levels of BnFAE1 were greatly decreased in BnFAE1-Ri lines compared with the CY2 cultivar. Knockdown of BnFAE1 sharply decreased the levels of erucic acid (less than 3%), largely increased the contents of oleic acid (more than 60%) and slightly increased the polyunsaturated chain fatty acids. Compared with high erucic acid parents, expression of BnFAE1 was dramatically decreased in developing F1 seeds derived from reciprocally crossed BnFAE1-Ri lines and high erucic acid cultivars. In addition, F1 seeds derived from reciprocal crosses between BnFAE1-Ri lines and high erucic acid cultivars showed significantly increased oleic acid (more than 52%) and sharply decreased erucic acid (less than 4%), demonstrating that the RNAi construct of BnFAE1 can effectively interfere with the target gene in F1 seeds. Taken together, our results demonstrate that BnFAE1 is a reliable target for genetic improvement of rapeseed in seed oil quality promotion.

  11. Chromium-induced physio-chemical and ultrastructural changes in four cultivars of Brassica napus L.

    PubMed

    Gill, Rafaqat A; Zang, Lili; Ali, Basharat; Farooq, Muhammad A; Cui, Peng; Yang, Su; Ali, Shafaqat; Zhou, Weijun

    2015-02-01

    In nature, plants are continuously exposed to several biotic and abiotic stresses. Among these stresses, chromium (Cr) stress is one of the most adverse factors that affects the plant growth, and productivity, and imposes a severe threat for sustainable crop production. In the present study, toxic effects of Cr were studied in hydroponically grown seedlings of four different cultivars of Brassica napus L. viz. ZS 758, Zheda 619, ZY 50 and Zheda 622. The study revealed that elevated Cr concentrations reduced the plant growth rate and biomass as compared to respective controls in all the cultivars and this decline was more obvious in Zheda 622. It was observed that reduction of photosynthetic attributes was more pronounced in Zheda 622 as compared to other cultivars; while, cultivar ZS 758 performed better under Cr-toxicity. Results showed that Cr contents in different parts of seedlings were higher in Zheda 622 as compared to other cultivars and Cr contents were higher in roots than shoots in all the cultivars. Accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) were induced under different Cr concentrations. Results showed that some of anti-oxidant enzyme activities in leaves and roots were increased under the Cr-toxicity. The electron microscopic study showed that ultrastructural damages in leaf mesophyll and root tip cells were more prominent in Zheda 622 as compared to other cultivars under 400 μM Cr stress. Under 400 μM Cr concentration, changes like broken cell wall, immature nucleus, a number of mitochondria, ruptured thylakoid membranes and large size of vacuole and starch grains were observed in leaf ultrastructures. The damages in root cells were observed in the form of disruption of golgibodies and diffused cell wall under the higher concentration of Cr (400 μM). On the basis of these observations, it was concluded that Zheda 622 was found to be more sensitive as followed by ZY 50, Zheda 619 and ZS 758 under Cr-toxicity.

  12. An insight in the genetic control and interrelationship of some quality traits in Brassica napus.

    PubMed

    Ahmad, S; Sadaqat, H A; Tahir, M H N; Awan, F S

    2015-12-22

    A study on three leading lines (KN-256, KN-257, and KN-258) of Brassica napus and an approved variety, Punjab-Sarson, was conducted to gain insight into the genetic control of some quality traits using generation mean analysis. Our results showed that additive gene action predominated in the inheritance of oil content and erucic acid in cross KN-256 x KN-257 and in that of glucosinolates in KN-258 x Punjab-Sarson, indicating that these traits may be improved through selection in early segregating generations. Negative dominance can be exploited through heterosis breeding for the development of lines with low glucosinolates in cross KN-256 x KN-257. Protein content and oleic acid in cross KN-256 x KN-257, and oil content, protein content, and erucic acid in cross KN-258 x Punjab-Sarson depicted non-additive gene action and require further improvement in the later segregating generations. Most of the traits displayed high heritability estimates; glucosinolate content in both the crosses and erucic acid in cross KN- 258 x Punjab-Sarson also displayed high genetic advance, reflecting improvement of the trait in the early segregating generations. All the quality traits were positively correlated with oil content and with one another at both (genotypic and phenotypic) levels in KN-256 x KN-257. Negative correlation was observed between glucosinolate and erucic acid, oleic acid and erucic acid, and linolenic acid and oil content in cross KN-258 x Punjab-Sarson. Thus, gene action changed with the material, and cross KN-258 x Punjab-Sarson carried favorable combinations compared to KN-256 x KN-257.

  13. Study on salt tolerance with YHem1 transgenic canola (Brassica napus).

    PubMed

    Sun, Xin-E; Feng, Xin-Xin; Li, Cui; Zhang, Zhi-Ping; Wang, Liang-Ju

    2015-06-01

    5-Aminolevulinic acid (5-ALA) has been suggested for improving plant salt tolerance via exogenous application. In this study, we used a transgenic canola (Brassica napus), which contained a constituted gene YHem1 and biosynthesized more 5-ALA, to study salt stress responses. In a long-term pot experiment, the transgenic plants produced higher yield under 200 mmol L(-1) NaCl treatment than the wild type (WT). In a short-term experiment, the YHem1 transformation accelerated endogenous 5-ALA metabolism, leading to more chlorophyll accumulation, higher diurnal photosynthetic rates and upregulated expression of the gene encoding Rubisco small subunit. Furthermore, the activities of antioxidant enzymes, including superoxide dismutase, guaiacol peroxidase, catalase and ascorbate peroxidase, were significantly higher in the transgenic plants than the WT, while the levels of O2 ·(-) and malondialdehyde were lower than the latter. Additionally, the Na(+) content was higher in the transgenic leaves than that in the WT under salinity, but K(+) and Cl(-) were significantly lower. The levels of N, P, Cu, and S in the transgenic plants were also significantly lower than those in the WT, but the Fe content was significantly improved. As the leaf Fe content was decreased by salinity, it was suggested that the stronger salt tolerance of the transgenic plants was related to the higher Fe acquisition. Lastly, YHem1 transformation improved the leaf proline content, but salinity decreased rather than increased it. The content of free amino acids and soluble sugars was similarly decreased as salinity increased, but it was higher in the transgenic plants than that in the WT.

  14. Inhibition and covalent modification of rape seed (Brassica napus) enoyl ACP reductase by phenylglyoxal.

    PubMed

    Cottingham, I R; Austin, A J; Slabas, A R

    1989-05-01

    The NADH-dependent enoyl-ACP reductase from oil seed rape (Brassica napus) was inactivated by treatment with phenylglyoxal, a reagent which specifically modifies arginine residues. The inhibition at various phenylglyoxal concentrations shows pseudo-first-order kinetics, with an apparent second-order rate constant of 14.2 M-1.min-1 for inactivation. The protective ability of several substrates and substrate analogues was investigated in order to ascertain if the inhibition was directed towards the active site of the enzyme. NADH and NAD+ did not protect but acyl carrier protein (ACP) and reduced coenzyme A, along with various derivatives, did protect. 9 microM ACP gave 35% protection from inactivation and 10 mM reduced coenzyme A gave 98% protection. The effectiveness of various subfragments of coenzyme A in protecting against inhibition indicates that the phosphate group is essential for preventing the binding of phenylglyoxal. The idea that phenylglyoxal is inhibiting by binding at the active site is further supported by the observation that the incorporation of 14C-labelled phenylglyoxal is directly related to the loss of activity. Extrapolation of the amount of label incorporated to give total inhibition shows that 4 mol of phenylglyoxal would be incorporated per mol of enzyme. This corresponds to the modification of two arginine side-chains with equal reactiveness towards the reagent. These results are consistent with there being two arginine residues either at the active site of the enzyme or in an environment which is protected from phenylglyoxal by a conformational change induced by coenzyme A binding.

  15. Regulation of Photosynthesis in Triazine-Resistant and -Susceptible Brassica napus 1

    PubMed Central

    Dekker, Jack H.; Sharkey, Thomas D.

    1992-01-01

    The response of photosynthetic carbon assimilation and chlorophyll fluorescence quenching to changes in intercellular CO2 partial pressure (Ci), O2 partial pressure, and leaf temperature (15-35°C) in triazine-resistant and -susceptible biotypes of Brassica napus were examined to determine the effects of the changes in the resistant biotype on the overall process of photosynthesis in intact leaves. Three categories of photosynthetic regulation were observed. The first category of photosynthetic response, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)-limited photosynthesis, was observed at 15, 25, and 35°C leaf temperatures with low Ci. When the carbon assimilation rate was Rubisco-limited, there was little difference between the resistant and susceptible biotypes, and Rubisco activity parameters were similar between the two biotypes. A second category, called feedback-limited photosynthesis, was evident at 15 and 25°C above 300 microbars Ci. The third category, photosynthetic electron transport-limited photosynthesis, was evident at 25 and 35°C at moderate to high CO2. At low temperature, when the response curves of carbon assimilation to Ci indicated little or no electron transport limitation, the carbon assimilation rate was similar in the resistant and susceptible biotypes. With increasing temperature, more electron transport-limited carbon assimilation was observed, and a greater difference between resistant and susceptible biotypes was observed. These observations reveal the increasing importance of photosynthetic electron transport in controlling the overall rate of photosynthesis in the resistant biotype as temperature increases. Photochemical quenching of chlorophyll fluorescence (qP) in the resistant biotype never exceeded 60%, and triazine resistance effects were more evident when the susceptible biotype had greater than 60% qP, but not when it had less than 60% qP. PMID:16668728

  16. Application of Brassica napus hairy root cultures for phenol removal from aqueous solutions.

    PubMed

    Coniglio, María S; Busto, Victor D; González, Paola S; Medina, María I; Milrad, Silvia; Agostini, Elizabeth

    2008-07-01

    Phenolic compounds present in the drainage from several industries are harmful pollutants and represent a potential danger to human health. In this work we have studied the removal of phenol from water using Brassica napus hairy roots as a source of enzymes, such as peroxidases, which were able to oxidise phenol. These hairy roots were investigated for their tolerance to highly toxic concentrations of phenol and for the involvement of their peroxidase isoenzymes in the removal of phenol. Roots grew normally in medium containing phenol in concentrations not exceeding 100 mg l(-1), without the addition of H(2)O(2). However, roots were able to remove phenol concentrations up to 500 mg l(-1), in the presence of H(2)O(2), reaching high removal efficiency, within 1h of treatment and over a wide range of pH (4-9). Hairy roots could be re-used, at least, for three to four consecutive cycles. Peroxidase activity gradually decreased to approximately 20% of the control, at the fifth cycle. Basic and near neutral isoenzymes (BNP) decreased along time of recycling while acidic isoenzymes (AP) remained without changes. Although both group of isoenzymes would be involved in phenol removal, AP showed higher affinity and catalytic efficiency for phenol as substrate than BNP. In addition, AP retained more activity than BNP after phenol treatment. Thus, AP appears to be a promising isoenzyme for phenol removal and for application in continuous treatments. Furthermore, enzyme isolation might not be necessary and the entire hairy roots, might constitute less expensive enzymatic systems for decontamination processes. PMID:18499219

  17. Study on salt tolerance with YHem1 transgenic canola (Brassica napus).

    PubMed

    Sun, Xin-E; Feng, Xin-Xin; Li, Cui; Zhang, Zhi-Ping; Wang, Liang-Ju

    2015-06-01

    5-Aminolevulinic acid (5-ALA) has been suggested for improving plant salt tolerance via exogenous application. In this study, we used a transgenic canola (Brassica napus), which contained a constituted gene YHem1 and biosynthesized more 5-ALA, to study salt stress responses. In a long-term pot experiment, the transgenic plants produced higher yield under 200 mmol L(-1) NaCl treatment than the wild type (WT). In a short-term experiment, the YHem1 transformation accelerated endogenous 5-ALA metabolism, leading to more chlorophyll accumulation, higher diurnal photosynthetic rates and upregulated expression of the gene encoding Rubisco small subunit. Furthermore, the activities of antioxidant enzymes, including superoxide dismutase, guaiacol peroxidase, catalase and ascorbate peroxidase, were significantly higher in the transgenic plants than the WT, while the levels of O2 ·(-) and malondialdehyde were lower than the latter. Additionally, the Na(+) content was higher in the transgenic leaves than that in the WT under salinity, but K(+) and Cl(-) were significantly lower. The levels of N, P, Cu, and S in the transgenic plants were also significantly lower than those in the WT, but the Fe content was significantly improved. As the leaf Fe content was decreased by salinity, it was suggested that the stronger salt tolerance of the transgenic plants was related to the higher Fe acquisition. Lastly, YHem1 transformation improved the leaf proline content, but salinity decreased rather than increased it. The content of free amino acids and soluble sugars was similarly decreased as salinity increased, but it was higher in the transgenic plants than that in the WT. PMID:25220348

  18. Global Dynamic Transcriptome Programming of Rapeseed (Brassica napus L.) Anther at Different Development Stages.

    PubMed

    Li, Zhanjie; Zhang, Peipei; Lv, Jinyang; Cheng, Yufeng; Cui, Jianmin; Zhao, Huixian; Hu, Shengwu

    2016-01-01

    Rapeseed (Brassica napus L.) is an important oil crop worldwide and exhibits significant heterosis. Effective pollination control systems, which are closely linked to anther development, are a prerequisite for utilizing heterosis. The anther, which is the male organ in flowering plants, undergoes many metabolic processes during development. Although the gene expression patterns underlying pollen development are well studied in model plant Arabidopsis, the regulatory networks of genome-wide gene expression during rapeseed anther development is poorly understood, especially regarding metabolic regulations. In this study, we systematically analyzed metabolic processes occurring during anther development in rapeseed using ultrastructural observation and global transcriptome analysis. Anther ultrastructure exhibited that numerous cellular organelles abundant with metabolic materials, such as elaioplast, tapetosomes, plastids (containing starch deposits) etc. appeared, accompanied with anther structural alterations during anther development, suggesting many metabolic processes occurring. Global transcriptome analysis revealed dynamic changes in gene expression during anther development that corresponded to dynamic functional alterations between early and late anther developmental stages. The early stage anthers preferentially expressed genes involved in lipid metabolism that are related to pollen extine formation as well as elaioplast and tapetosome biosynthesis, whereas the late stage anthers expressed genes associated with carbohydrate metabolism to form pollen intine and to accumulate starch in mature pollen grains. Finally, a predictive gene regulatory module responsible for early pollen extine formation was generated. Taken together, this analysis provides a comprehensive understanding of dynamic gene expression programming of metabolic processes in the rapeseed anther, especially with respect to lipid and carbohydrate metabolism during pollen development. PMID

  19. Global Dynamic Transcriptome Programming of Rapeseed (Brassica napus L.) Anther at Different Development Stages

    PubMed Central

    Li, Zhanjie; Zhang, Peipei; Lv, Jinyang; Cheng, Yufeng; Cui, Jianmin; Zhao, Huixian; Hu, Shengwu

    2016-01-01

    Rapeseed (Brassica napus L.) is an important oil crop worldwide and exhibits significant heterosis. Effective pollination control systems, which are closely linked to anther development, are a prerequisite for utilizing heterosis. The anther, which is the male organ in flowering plants, undergoes many metabolic processes during development. Although the gene expression patterns underlying pollen development are well studied in model plant Arabidopsis, the regulatory networks of genome-wide gene expression during rapeseed anther development is poorly understood, especially regarding metabolic regulations. In this study, we systematically analyzed metabolic processes occurring during anther development in rapeseed using ultrastructural observation and global transcriptome analysis. Anther ultrastructure exhibited that numerous cellular organelles abundant with metabolic materials, such as elaioplast, tapetosomes, plastids (containing starch deposits) etc. appeared, accompanied with anther structural alterations during anther development, suggesting many metabolic processes occurring. Global transcriptome analysis revealed dynamic changes in gene expression during anther development that corresponded to dynamic functional alterations between early and late anther developmental stages. The early stage anthers preferentially expressed genes involved in lipid metabolism that are related to pollen extine formation as well as elaioplast and tapetosome biosynthesis, whereas the late stage anthers expressed genes associated with carbohydrate metabolism to form pollen intine and to accumulate starch in mature pollen grains. Finally, a predictive gene regulatory module responsible for early pollen extine formation was generated. Taken together, this analysis provides a comprehensive understanding of dynamic gene expression programming of metabolic processes in the rapeseed anther, especially with respect to lipid and carbohydrate metabolism during pollen development. PMID

  20. Identification and characterization of NF-Y transcription factor families in Canola (Brassica napus L.).

    PubMed

    Liang, Mingxiang; Yin, Xiangzhen; Lin, Zhongyuan; Zheng, Qingsong; Liu, Guohong; Zhao, Gengmao

    2014-01-01

    NF-Y (NUCLEAR FACTOR-Y), a heterotrimeric transcription factor, is composed of NF-YA, NF-YB, and NF-YC proteins in yeast, animal, and plant systems. In plants, each of the NF-YA/B/C subunit forms a multi-member family. NF-Ys are key regulators with important roles in many physiological processes, such as drought tolerance, flowering time, and seed development. In this study, we identified, annotated, and further characterized 14 NF-YA, 14 NF-YB, and 5 NF-YC proteins in Brassica napus (canola). Phylogenetic analysis revealed that the NF-YA/B/C subunits were more closely clustered with the Arabidopsis thaliana (Arabidopsis) homologs than with rice OsHAP2/3/5 subunits. Analyses of the conserved domain indicated that the BnNF-YA/B/C subfamilies, respectively, shared the same conserved domains with those in other organisms, including Homo sapiens, Saccharomyces cerevisiae, Arabidopsis, and Oryza sativa (rice). An examination of exon/intron structures revealed that most gene structures of BnNF-Y were similar to their homologs in Arabidopsis, a model dicot plant, but different from those in the model monocot plant rice, suggesting that plant NF-Ys diverged before monocot and dicot plants differentiated. Spatial-tempo expression patterns, as determined by qRT-PCR, showed that most BnNF-Ys were widely expressed in different tissues throughout the canola life cycle and that several closely related BnNF-Y subunits had similar expression profiles. Based on these findings, we predict that BnNF-Y proteins have functions that are conserved in the homologous proteins in other plants. This study provides the first extensive evaluation of the BnNF-Y family, and provides a useful foundation for dissecting the functions of BnNF-Y. PMID:24097262

  1. Agravitropic behaviour of roots of rapeseed (Brassica napus L.) transformed by Agrobacterium rhizogenes.

    PubMed

    Odegaard, E; Nielsen, K M; Beisvag, T; Evjen, K; Johnsson, A; Rasmussen, O; Iversen, T H

    1997-10-01

    Transgenic hairy roots of Brassica napus (cv. Omega) have been developed, using Agrobacterium rhizogenes strain AR 25, for use as a model system in the investigation of physiological and morphological differences between transgenic and normal roots. The basic parameters of growth and normal or altered gravitropical behaviour of hairy roots are for the first time presented in this paper together with an ultrastructural and morphological analysis of the root statocytes. The results obtained also represented the basis for the TRANSF0RM-experiment on the IML-2 mission performed onboard the Space Shuttle Columbia. Typical hairy root traits such as hormone-autonomous growth high growth rate, lateral branching, and changed/absence of gravitropism were detected. The transformed nature of the roots was confirmed by Southern blot analyses. The gravitropical behaviour of apices from hairy root cultures of this clone has been compared with root tips from normal seedlings. While the wild type roots curved progressively with increasing stimulation angles, the transformed roots showed no curvature when stimulated at 45 degrees, 90 degrees or 135 degrees on the ground. The morphology and ultrastructure of the root tip regions were examined by light microscopy and transmission electron microscopy. At the ultrastructural level no major differences could be detected between the roots studied. There was, however, a slight reduction in the starch content of most of the amyloplasts of the transgenic root tips, and the root cap was more V-shaped in the transgenic roots than in the wild type. Preliminary results from the Shuttle experiment TRANSFORM show a random distribution of amyloplasts in the root cells of both transformed and wild type root caps after 14 h on a 1xg centrifuge followed by 37 h in microgravity.

  2. Resynthesized lines from domesticated and wild Brassica taxa and their hybrids with B. napus L.: genetic diversity and hybrid yield.

    PubMed

    Jesske, Tobias; Olberg, Birgit; Schierholt, Antje; Becker, Heiko C

    2013-04-01

    Resynthesized (Resyn) Brassica napus L. can be used to broaden the genetic diversity and to develop a heterotic genepool for rapeseed hybrid breeding. Domesticated vegetable types are usually employed as B. oleracea parents. We sought to evaluate the potential of wild species as parents for Resyn lines. Fifteen Resyn lines were derived by crossing wild B. oleracea ssp. oleracea and oilseed B. rapa, and 29 Resyn lines were generated from 10 wild Brassica species (B. bourgaei, B. cretica, B. incana, B. insularis, B. hilarionis, B. macrocarpa, B. montana, B. rupestris, B. taurica, B. villosa). Genetic distances were analyzed with AFLP markers for 71 Resyn lines from wild and domesticated B. oleracea, and compared with 55 winter, spring, vegetable, and Asian B. napus genotypes. The genetic distances clearly showed that Resyn lines with wild species provide a genetic diversity absent from the breeding material or Resyn lines from domesticated species. Forty-two Resyn lines were crossed with one or two winter oilseed rape testers, resulting in 64 hybrids that were grown in one year and four locations in Germany and France. The correlation between hybrid yield and genetic distance was slightly negative (r = -0.29). Most of the hybrids with Resyn lines from wild B. oleracea were lower in yield than hybrids with Resyn lines from domesticated B. oleracea. It is promising that Resyn lines descending from unselected wild B. oleracea accessions produced high-yielding hybrids when crossed with adapted genotypes: these Resyn lines would be suited to develop heterotic pools in hybrid breeding.

  3. QTL analysis of root morphology, flowering time, and yield reveals trade-offs in response to drought in Brassica napus.

    PubMed

    Fletcher, Richard S; Mullen, Jack L; Heiliger, Annie; McKay, John K

    2015-01-01

    Drought escape and dehydration avoidance represent alternative strategies for drought adaptation in annual crops. The mechanisms underlying these two strategies are reported to have a negative correlation, suggesting a trade-off. We conducted a quantitative trait locus (QTL) analysis of flowering time and root mass, traits representing each strategy, in Brassica napus to understand if a trade-off exists and what the genetic basis might be. Our field experiment used a genotyped population of doubled haploid lines and included both irrigated and rainfed treatments, allowing analysis of plasticity in each trait. We found strong genetic correlations among all traits, suggesting a trade-off among traits may exist. Summing across traits and treatments we found 20 QTLs, but many of these co-localized to two major QTLs, providing evidence that the trade-off is genetically constrained. To understand the mechanistic relationship between root mass, flowering time, and QTLs, we analysed the data by conditioning upon correlated traits. Our results suggest a causal model where such QTLs affect root mass directly as well as through their impacts on flowering time. Additionally, we used draft Brassica genomes to identify orthologues of well characterized Arabidopsis thaliana flowering time genes as candidate genes. This research provides valuable clues to breeding for drought adaptation as it is the first to analyse the inheritance of the root system in B. napus in relation to drought.

  4. Transcriptome Analysis of Interspecific Hybrid between Brassica napus and B. rapa Reveals Heterosis for Oil Rape Improvement.

    PubMed

    Zhang, Jinfang; Li, Guangrong; Li, Haojie; Pu, Xiaobin; Jiang, Jun; Chai, Liang; Zheng, Benchuan; Cui, Cheng; Yang, Zujun; Zhu, Yongqing; Jiang, Liangcai

    2015-01-01

    The hybrid between Brassica napus and B. rapa displays obvious heterosis in both growth performance and stress tolerances. A comparative transcriptome analysis for B. napus (A(n)A(n)CC genome), B. rapa (A(r)A(r) genome), and its hybrid F1 (A(n)A(r)C genome) was carried out to reveal the possible molecular mechanisms of heterosis at the gene expression level. A total of 40,320 nonredundant unigenes were identified using B. rapa (AA genome) and B. oleracea (CC genome) as reference genomes. A total of 6,816 differentially expressed genes (DEGs) were mapped in the A and C genomes with 4,946 DEGs displayed nonadditively by comparing the gene expression patterns among the three samples. The coexistence of nonadditive DEGs including high-parent dominance, low-parent dominance, overdominance, and underdominance was observed in the gene action modes of F1 hybrid, which were potentially related to the heterosis. The coexistence of multiple gene actions in the hybrid was observed and provided a list of candidate genes and pathways for heterosis. The expression bias of transposable element-associated genes was also observed in the hybrid compared to their parents. The present study could be helpful for the better understanding of the determination and regulation of mechanisms of heterosis to aid Brassica improvement.

  5. Incorporation of hygromycin resistance in Brassica nigra and its transfer to B. napus through asymmetric protoplast fusion.

    PubMed

    Sacristán, M D; Gerdemann-Knörck, M; Schieder, O

    1989-08-01

    With the idea to develop a selection system for asymmetric somatic hybrids between oilseed rape (Brassica napus) and black mustard (B. nigra), the marker gene hygromycin resistance was introduced in this last species by protoplast transformation with the disarmed Agrobacterium tumefaciens strain C58 pGV 3850 HPT. The B. nigra lines used for transformation had been previously selected for resistance to two important rape pathogens (Phoma lingam, Plasmodiophora brassicae). Asymmetric somatic hybrids were obtained through fusion of X-ray irradiated (mitotically inactivated) B. nigra protoplasts from transformed lines as donor with intact protoplasts of B. napus, using the hygromycin resistance as selection marker for fusion products. The somatic hybrids hitherto obtained expressed both hygromycin phosphotransferase and nopaline synthase genes. Previous experience with other plant species had demonstrated that besides the T-DNA, other genes of the donor genome can be co-transferred. In this way, the produced hybrids constitute a valuable material for studying the possibility to transfer agronomically relevant characters - in our case, diseases resistances - through asymmetric protoplast fusion.

  6. Transcriptome Analysis of Interspecific Hybrid between Brassica napus and B. rapa Reveals Heterosis for Oil Rape Improvement

    PubMed Central

    Zhang, Jinfang; Li, Guangrong; Li, Haojie; Pu, Xiaobin; Jiang, Jun; Chai, Liang; Zheng, Benchuan; Cui, Cheng; Yang, Zujun; Zhu, Yongqing; Jiang, Liangcai

    2015-01-01

    The hybrid between Brassica napus and B. rapa displays obvious heterosis in both growth performance and stress tolerances. A comparative transcriptome analysis for B. napus (AnAnCC genome), B. rapa (ArAr genome), and its hybrid F1 (AnArC genome) was carried out to reveal the possible molecular mechanisms of heterosis at the gene expression level. A total of 40,320 nonredundant unigenes were identified using B. rapa (AA genome) and B. oleracea (CC genome) as reference genomes. A total of 6,816 differentially expressed genes (DEGs) were mapped in the A and C genomes with 4,946 DEGs displayed nonadditively by comparing the gene expression patterns among the three samples. The coexistence of nonadditive DEGs including high-parent dominance, low-parent dominance, overdominance, and underdominance was observed in the gene action modes of F1 hybrid, which were potentially related to the heterosis. The coexistence of multiple gene actions in the hybrid was observed and provided a list of candidate genes and pathways for heterosis. The expression bias of transposable element-associated genes was also observed in the hybrid compared to their parents. The present study could be helpful for the better understanding of the determination and regulation of mechanisms of heterosis to aid Brassica improvement. PMID:26448924

  7. Transcriptome Analysis of Interspecific Hybrid between Brassica napus and B. rapa Reveals Heterosis for Oil Rape Improvement.

    PubMed

    Zhang, Jinfang; Li, Guangrong; Li, Haojie; Pu, Xiaobin; Jiang, Jun; Chai, Liang; Zheng, Benchuan; Cui, Cheng; Yang, Zujun; Zhu, Yongqing; Jiang, Liangcai

    2015-01-01

    The hybrid between Brassica napus and B. rapa displays obvious heterosis in both growth performance and stress tolerances. A comparative transcriptome analysis for B. napus (A(n)A(n)CC genome), B. rapa (A(r)A(r) genome), and its hybrid F1 (A(n)A(r)C genome) was carried out to reveal the possible molecular mechanisms of heterosis at the gene expression level. A total of 40,320 nonredundant unigenes were identified using B. rapa (AA genome) and B. oleracea (CC genome) as reference genomes. A total of 6,816 differentially expressed genes (DEGs) were mapped in the A and C genomes with 4,946 DEGs displayed nonadditively by comparing the gene expression patterns among the three samples. The coexistence of nonadditive DEGs including high-parent dominance, low-parent dominance, overdominance, and underdominance was observed in the gene action modes of F1 hybrid, which were potentially related to the heterosis. The coexistence of multiple gene actions in the hybrid was observed and provided a list of candidate genes and pathways for heterosis. The expression bias of transposable element-associated genes was also observed in the hybrid compared to their parents. The present study could be helpful for the better understanding of the determination and regulation of mechanisms of heterosis to aid Brassica improvement. PMID:26448924

  8. Overproduction of stromal ferredoxin:NADPH oxidoreductase in H2O 2-accumulating Brassica napus leaf protoplasts.

    PubMed

    Tewari, Rajesh Kumar; Satoh, Mamoru; Kado, Sayaka; Mishina, Kohei; Anma, Misato; Enami, Kazuhiko; Hanaoka, Mitsumasa; Watanabe, Masami

    2014-12-01

    The isolation of Brassica napus leaf protoplasts induces reactive oxygen species generation and accumulation in the chloroplasts. An activated isoform of NADPH oxidase-like protein was detected in the protoplasts and the protoplast chloroplasts. The purpose of this study is to define the NADH oxidase-like activities in the H2O2-accumulating protoplast chloroplasts. Proteomic analysis of this protein revealed an isoform of ferredoxin:NADPH oxidoreductase (FNR1). While leaves highly expressed the LFNR1 transcript, protoplasts decreased the expression significantly. The protoplast chloroplasts predominantly expressed soluble FNR1 proteins. While the albino leaves of white kale (Brassica oleracea var. acephala f. tricolor cv. white pigeon) expressed FNR1 protein at the same level as B. napus leaves, the protoplasts of albino leaves displayed reduced FNR1 expression. The albino leaf protoplasts of white kale generated and accumulated H2O2 in the cytoplasm and on the plasma membrane. Intracellular pH showed that the chloroplasts were acidic, which suggest that excess H(+) was generated in chloroplast stroma. NADPH content of the protoplast chloroplasts increased by over sixfold during the isolation of protoplasts. This study reports a possibility of mediating electrons to oxygen by an overproduced soluble FNR, and suggests that the FNR has a function in utilizing any excess reducing power of NADPH.

  9. QTL analysis of root morphology, flowering time, and yield reveals trade-offs in response to drought in Brassica napus.

    PubMed

    Fletcher, Richard S; Mullen, Jack L; Heiliger, Annie; McKay, John K

    2015-01-01

    Drought escape and dehydration avoidance represent alternative strategies for drought adaptation in annual crops. The mechanisms underlying these two strategies are reported to have a negative correlation, suggesting a trade-off. We conducted a quantitative trait locus (QTL) analysis of flowering time and root mass, traits representing each strategy, in Brassica napus to understand if a trade-off exists and what the genetic basis might be. Our field experiment used a genotyped population of doubled haploid lines and included both irrigated and rainfed treatments, allowing analysis of plasticity in each trait. We found strong genetic correlations among all traits, suggesting a trade-off among traits may exist. Summing across traits and treatments we found 20 QTLs, but many of these co-localized to two major QTLs, providing evidence that the trade-off is genetically constrained. To understand the mechanistic relationship between root mass, flowering time, and QTLs, we analysed the data by conditioning upon correlated traits. Our results suggest a causal model where such QTLs affect root mass directly as well as through their impacts on flowering time. Additionally, we used draft Brassica genomes to identify orthologues of well characterized Arabidopsis thaliana flowering time genes as candidate genes. This research provides valuable clues to breeding for drought adaptation as it is the first to analyse the inheritance of the root system in B. napus in relation to drought. PMID:25371500

  10. QTL for Yield Traits and Their Association with Functional Genes in Response to Phosphorus Deficiency in Brassica napus

    PubMed Central

    Shi, Taoxiong; Li, Ruiyuan; Zhao, Zunkang; Ding, Guangda; Long, Yan; Meng, Jinling; Xu, Fangsen; Shi, Lei

    2013-01-01

    Background Oilseed rape (Brassica napus L.) is one of the most important oil crops. A primary limitation to the cultivation of this crop is the lack of available phosphorus (P) in soils. To elucidate the genetic control of P deficiency tolerance in Brassica napus, quantitative trait locus (QTL) for seed yield and yield related-traits in response to P deficiency were identified using a double haploid mapping population (TN DH) derived from a cross between a P-efficient cultivar, Ningyou 7 and a P-inefficient cultivar, Tapidor. Results Three field trials were conducted to determine seed yield (SY), plant height (PH), number of primary branches (BN), height to the first primary branch (FBH), relative first primary branch height (RBH), pod number per plant (PN), seed number per pod (SN) and seed weight of 1,000 seeds (SW) in 188 lines of TN DH population exposed to low P (LP) and optimal P (OP) conditions. P deficiency decreased PH, BN, SN, PN and SY, and increased FBH and RBH with no effect on SW. Three reproducible LP-specific QTL regions were identified on chromosomes A2, A3 and A5 that controlled SN, PN and SW respectively. In addition, six reproducible constitutive regions were also mapped with two each for SY-LP on A2, and FBH-LP on C6 and one each for PH-LP and SW-LP on A3. About 30 markers derived from 19 orthologous genes involved in Arabidopsis P homeostasis were mapped on 24 QTL regions by comparative mapping between Arabidopsis and Brassica napus. Among these genes, GPT1, MGD2 and SIZ1 were associated with two major loci regulating SY-LP and other yield-related traits on A2 between 77.1 and 95.0 cM. Conclusion The stable QTLs detected under LP conditions and their candidate genes may provide useful information for marker-assisted selection in breeding high-yield B. napus varieties with improved P efficiency. PMID:23382913

  11. Metabolic network reconstruction and flux variability analysis of storage synthesis in developing oilseed rape (Brassica napus L.) embryos

    SciTech Connect

    Hay, J.; Schwender, J.

    2011-08-01

    Computational simulation of large-scale biochemical networks can be used to analyze and predict the metabolic behavior of an organism, such as a developing seed. Based on the biochemical literature, pathways databases and decision rules defining reaction directionality we reconstructed bna572, a stoichiometric metabolic network model representing Brassica napus seed storage metabolism. In the highly compartmentalized network about 25% of the 572 reactions are transport reactions interconnecting nine subcellular compartments and the environment. According to known physiological capabilities of developing B. napus embryos, four nutritional conditions were defined to simulate heterotrophy or photoheterotrophy, each in combination with the availability of inorganic nitrogen (ammonia, nitrate) or amino acids as nitrogen sources. Based on mathematical linear optimization the optimal solution space was comprehensively explored by flux variability analysis, thereby identifying for each reaction the range of flux values allowable under optimality. The range and variability of flux values was then categorized into flux variability types. Across the four nutritional conditions, approximately 13% of the reactions have variable flux values and 10-11% are substitutable (can be inactive), both indicating metabolic redundancy given, for example, by isoenzymes, subcellular compartmentalization or the presence of alternative pathways. About one-third of the reactions are never used and are associated with pathways that are suboptimal for storage synthesis. Fifty-seven reactions change flux variability type among the different nutritional conditions, indicating their function in metabolic adjustments. This predictive modeling framework allows analysis and quantitative exploration of storage metabolism of a developing B. napus oilseed.

  12. Hydrogen sulfide alleviates the aluminum-induced changes in Brassica napus as revealed by physiochemical and ultrastructural study of plant.

    PubMed

    Ali, Basharat; Qian, Ping; Sun, Rui; Farooq, Muhammad A; Gill, Rafaqat A; Wang, Jian; Azam, Muhammad; Zhou, Weijun

    2015-02-01

    In the present study, ameliorating role of hydrogen sulfide (H2S) in oilseed rape (Brassica napus L.) was studied with or without application of H2S donor sodium hydrosulfide (NaHS) (0.3 mM) in hydroponic conditions under three levels (0, 0.1 and 0.3 mM) of aluminum (Al). Results showed that addition of H2S significantly improved the plant growth, photosynthetic gas exchange, and nutrients concentration in the leaves and roots of B. napus plants under Al stress. Exogenously applied H2S significantly lowered the Al concentration in different plant parts, and reduced the production of malondialdehyde and reactive oxygen species by improving antioxidant enzyme activities in the leaves and roots under Al stress. Moreover, the present study indicated that exogenously applied H2S improved the cell structure and displayed clean mesophyll and root tip cells. The chloroplast with well-developed thylakoid membranes could be observed in the micrographs. Under the combined application of H2S and Al, a number of modifications could be observed in root tip cell, such as mitochondria, endoplasmic reticulum, and golgi bodies. Thus, it can be concluded that exogenous application of H2S under Al stress improved the plant growth, photosynthetic parameters, elements concentration, and biochemical and ultrastructural changes in leaves and roots of B. napus.

  13. Apis mellifera (Hymenoptera: Apidae) as a potential Brassica napus pollinator (cv. Hyola 432) (Brassicaceae), in Southern Brazil.

    PubMed

    Rosa, A S; Blochtein, B; Ferreira, N R; Witter, S

    2010-11-01

    Brassica napus Linnaeus is considered a self-compatible crop; however, studies show that bee foraging elevates their seed production. Considering bee food shortages during the winter season and that the canola is a winter crop, this study aimed to evaluate the foraging behaviour of Apis mellifera Linnaeus, 1758 regarding those flowers, and to verify if it presents adequate behaviour for successfully pollinating this crop in Rio Grande do Sul State. The study was carried out in a canola field, in Southern Brazil. The anthesis stages were morphologically characterised and then related to stigma receptivity and pollen grain viability. Similarly, the behaviour of A. mellifera individuals on flowers was followed, considering the number of flowers visited per plant, the amount of time spent on the flowers, touched structures, and collected resources. Floral fidelity was inferred by analysing the pollen load of bees collected on flowers. The bees visited from 1-7 flowers/plant (x = 2.02; sd = 1.16), the time spent on the flowers varied between 1-43 seconds (x = 3.29; sd = 2.36) and, when seeking nectar and pollen, they invariably touched anthers and stigmas. The pollen load presented 100% of B. napus pollen. The bees' attendance to a small number of flowers/plants, their short permanence on flowers, their contact with anthers and stigma and the integral floral constancy allows their consideration as potential B. napus pollinators. PMID:21180917

  14. Effect of arabinogalactan proteins from the root caps of pea and Brassica napus on Aphanomyces euteiches zoospore chemotaxis and germination.

    PubMed

    Cannesan, Marc Antoine; Durand, Caroline; Burel, Carole; Gangneux, Christophe; Lerouge, Patrice; Ishii, Tadashi; Laval, Karine; Follet-Gueye, Marie-Laure; Driouich, Azeddine; Vicré-Gibouin, Maïté

    2012-08-01

    Root tips of many plant species release a number of border, or border-like, cells that are thought to play a major role in the protection of root meristem. However, little is currently known on the structure and function of the cell wall components of such root cells. Here, we investigate the sugar composition of the cell wall of the root cap in two species: pea (Pisum sativum), which makes border cells, and Brassica napus, which makes border-like cells. We find that the cell walls are highly enriched in arabinose and galactose, two major residues of arabinogalactan proteins. We confirm the presence of arabinogalactan protein epitopes on root cap cell walls using immunofluorescence microscopy. We then focused on these proteoglycans by analyzing their carbohydrate moieties, linkages, and electrophoretic characteristics. The data reveal (1) significant structural differences between B. napus and pea root cap arabinogalactan proteins and (2) a cross-link between these proteoglycans and pectic polysaccharides. Finally, we assessed the impact of root cap arabinogalactan proteins on the behavior of zoospores of Aphanomyces euteiches, an oomycetous pathogen of pea roots. We find that although the arabinogalactan proteins of both species induce encystment and prevent germination, the effects of both species are similar. However, the arabinogalactan protein fraction from pea attracts zoospores far more effectively than that from B. napus. This suggests that root arabinogalactan proteins are involved in the control of early infection of roots and highlights a novel role for these proteoglycans in root-microbe interactions.

  15. Development of new restorer lines for CMS ogura system with the use of resynthesized oilseed rape (Brassica napus L.)

    PubMed Central

    Szała, Laurencja; Sosnowska, Katarzyna; Popławska, Wiesława; Liersch, Alina; Olejnik, Anna; Kozłowska, Katarzyna; Bocianowski, Jan; Cegielska-Taras, Teresa

    2016-01-01

    Resynthesized (RS) oilseed rape (Brassica napus L.) is potentially of great interest for hybrid breeding. However, a major problem with the direct use of RS B. napus is the quality of seed oil (high level of erucic acid) and seed meal (high glucosinolate content), which does not comply with double-low quality oilseed rape. Thus, additional developments are needed before RS B. napus can be introduced into breeding practice. In this study, RS oilseed rape was obtained through crosses between B. rapa ssp. chinensis var. chinensis and B. oleracea ssp. acephala var. sabellica. RS plant was then crossed with double-low (00) winter oilseed rape lines containing the Rfo gene for Ogura cytoplasmic male sterility (CMS ogu) system. Populations of doubled haploids (DH) were developed from these F1 hybrids using the microspore in vitro culture method. The seeds of semi-RS DH lines were analyzed for erucic acid and glucosinolate content. Among the populations of semi-RS DHs four 00-quality lines with the Rfo gene were selected. Using 344 AFLP markers to estimate genetic relatedness, we showed that the RS lines and semi-RS lines formed clusters that were clearly distinct from 96 winter oilseed rape parental lines of F1 hybrids. PMID:27795676

  16. Genome-wide identification of Brassica napus microRNAs and their targets in response to cadmium.

    PubMed

    Zhou, Zhao Sheng; Song, Jian Bo; Yang, Zhi Min

    2012-07-01

    MicroRNAs (miRNAs) are a distinct class of small RNAs in plants that not only regulate biological processes but also regulate response to environmental stresses. The toxic heavy metal cadmium (Cd) induces expression of several miRNAs in rapeseed (Brassica napus), but it is not known on a genome-wide scale how the expression of miRNAs and their target genes, is regulated by Cd. In this study, four small RNA libraries and four degradome libraries were constructed from Cd-treated and non-Cd-treated roots and shoots of B. napus seedlings. Using high-throughput sequencing, the study identified 84 conserved and non-conserved miRNAs (belonging to 37 miRNA families) from Cd-treated and non-treated B. napus, including 19 miRNA members that were not identified before. Some of the miRNAs were validated by RNA gel blotting. Most of the identified miRNAs were found to be differentially expressed in roots/shoots or regulated by Cd exposure. The study simultaneously identified 802 targets for the 37 (24 conserved and 13 non-conserved) miRNA families, from which there are 200, 537, and 65 targets, belonging to categories I, II, and III, respectively. In category I alone, many novel targets for miRNAs were identified and shown to be involved in plant response to Cd.

  17. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.).

    PubMed

    Wang, Jia; Jian, Hongju; Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS.

  18. Determination of essential fatty acid composition among mutant lines of Canola (Brassica napus), through high pressure liquid chromatography.

    PubMed

    Raza, Ghulam; Siddique, Aquil; Khan, Imtiaz Ahmad; Ashraf, Muhammed Yasin; Khatri, Abdullah

    2009-12-01

    The present study aimed to quantify the methyl esters of lenoleic acid (LA), gamma-lenolenic acid (LNA) and oleic acid (OL) in the oil of Brassica napus mutants. Five stable mutants (ROO-75/1, ROO-100/6, ROO-125/12, ROO-125/14, and ROO-125/17) of B. napus cv. 'Rainbow' (P) and three mutants (W97-95/16, W97-0.75/11 and W97-.075/13) of B. napus cv. 'Westar' (P) at M6 stage, exhibiting better yield and yield components, were analyzed for essential fatty acids. The highest seed yield was observed in the mutant (ROO-100/6) followed by ROO-125/14 of Rainbow, that is, 34% and 32% higher than their parent plants, respectively. Westar mutant W97-75/11 also showed 30% higher seed yield than its parent plant. High performance liquid chromatography analysis of the composition of fatty acids indicated that OL was the most dominant fatty acid, ranging from 39.1 to 66.3%; LA was second (15.3-41.6%) and LNA was third (18.1-28.9%). Mutant ROO-125/14 showed higher OL contents than parent (Rainbow). These results are expected to support the approval of ROO-125/14 in the National Uniform Varietal Yield Trials (NUVYT) as a new variety based on high oil quality.

  19. Similar Photosynthetic Performance in Low Light-Grown Isonuclear Triazine-Resistant and -Susceptible Brassica napus L

    PubMed Central

    Hart, Jonathan J.; Stemler, Alan

    1990-01-01

    Triazine-resistant plants grown under moderate to high photon flux density (PFD) conditions exhibit decreased photon yield, decreased light-saturated O2 evolution and slower growth than triazine-susceptible plants. In this study we tested the hypothesis that the comparable growth previously observed in resistant and susceptible Brassica napus L. lines grown under low PFD was accompanied by comparable photon yield and light-saturated O2 evolution. We measured photon yield, O2 flash yield, fluorescence decay kinetics, fluorescence transient kinetics, and quenching components, Fv/Fm and light saturated O2 evolution in leaf disks of low PFD-grown triazine-resistant and susceptible B. napus isogenic lines. Results indicated that slow electron transfer from the primary to secondary quinone electron acceptors of photosystem II was still present in the resistant line but photon yield and light-saturated O2 evolution were similar in the two B. napus lines. We conclude that the alteration in the D1 protein that confers resistance does not necessarily cause decreased photosynthetic performance. Decreased photon yield in resistant plants grown at high PFD is not a direct consequence of the alteration in D1, but represents secondary damage. PMID:16667832

  20. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.).

    PubMed

    Wang, Jia; Jian, Hongju; Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS. PMID:26673885

  1. Improved Agrobacterium-mediated transformation and high efficiency of root formation from hypocotyl meristem of spring Brassica napus 'Precocity' cultivar.

    PubMed

    Liu, X X; Lang, S R; Su, L Q; Liu, X; Wang, X F

    2015-01-01

    Rape seed (Brassica napus L.) is one of the most important oil seed crops in the world. Genetic manipulation of rapeseed requires a suitable tissue culture system and an efficient method for plant regeneration, as well as an efficient transformation procedure. However, development of transgenic B. napus has been problematic, and current studies are limited to cultivated varieties. In this study, we report a protocol for regeneration of transgenic rape after Agrobacterium-mediated transformation of hypocotyls from the spring B. napus 'Precocity' cultivar. We analyzed the effects of plant growth regulators in the medium on regeneration. Additionally, factors affecting the transformation efficiency, including seedling age, Agrobacterium concentration, infection time, and co-cultivation time, were assessed by monitoring GUS expression. Results from these experiments revealed that transformation was optimized when the meristematic parts of the hypocotyls were taken from 8 day-old seedlings, cultured on Murashinge and Skoog basal media containing 0.1 mg/L 1-naphthaleneacetic acid and 2.5 mg/L 6-benzylaminopurine, and incubated in Agrobacterium suspension (OD600 = 0.5) for 3 to 5 min, followed by 2 days of co-cultivation. Integration of T-DNA into the plant genome was confirmed by polymerase chain reaction (PCR), b-glucuronidase histochemical staining, and quantitative real-time PCR. The protocols developed for regeneration, transformation, and rooting described in this study could help to accelerate the development of transgenic spring rape varieties with novel features. PMID:26681030

  2. A Mutant Brassica napus (Canola) Population for the Identification of New Genetic Diversity via TILLING and Next Generation Sequencing

    PubMed Central

    Gilchrist, Erin J.; Sidebottom, Christine H. D.; Koh, Chu Shin; MacInnes, Tanya; Sharpe, Andrew G.; Haughn, George W.

    2013-01-01

    We have generated a Brassica napus (canola) population of 3,158 EMS-mutagenised lines and used TILLING to demonstrate that the population has a high enough mutation density that it will be useful for identification of mutations in genes of interest in this important crop species. TILLING is a reverse genetics technique that has been successfully used in many plant and animal species. Classical TILLING involves the generation of a mutagenised population, followed by screening of DNA samples using a mismatch-specific endonuclease that cleaves only those PCR products that carry a mutation. Polyacrylamide gel detection is then used to visualise the mutations in any gene of interest. We have used this TILLING technique to identify 432 unique mutations in 26 different genes in B. napus (canola cv. DH12075). This reflects a mutation density ranging from 1/56 kb to 1/308 kb (depending on the locus) with an average of 1/109 kb. We have also successfully verified the utility of next generation sequencing technology as a powerful approach for the identification of rare mutations in a population of plants, even in polyploid species such as B. napus. Most of the mutants we have identified are publically available. PMID:24376800

  3. The functional role of the photosynthetic apparatus in the recovery of Brassica napus plants from pre-emergent metazachlor exposure.

    PubMed

    Vercampt, H; Koleva, L; Vassilev, A; Horemans, N; Biermans, G; Vangronsveld, J; Cuypers, A

    2016-06-01

    Metazachlor is a chloroacetamide herbicide, frequently used in Brassica napus cultivations around the world. Its primary target is the inhibition of very long chain fatty acid biosynthesis. This study included a morphological and physiological screening of hydroponically grown B. napus, exposed to a concentration range of 0, 0.25, 0.50, 0.75 and 1.0kg metazachlor per hectare. The results indicate that within a month after application, growth and development of B. napus are severely affected by low metazachlor doses. At intermediate metazachlor concentrations, loss of phosphorous and potassium from the plant tissues suggests destabilisation of cellular membranes, which may be a direct consequence of metazachlor application. This membrane instability could be indirectly linked with alterations of electron transport and a reduction of carbon assimilation. At increased metazachlor doses of 0.75kga.i.ha(-1), pigment concentrations are strongly reduced. However, chlorophyll fluorescence parameters seem to remain unaffected at metazachlor doses up to 0.75kga.i.ha(-1). At a metazachlor concentration of 1.0kga.i.ha(-1), negative effects are observed on all tested parameters, resulting in limited survival. The results indicate photosynthesis is assured at intermediate metazachlor concentrations for the cost of growth and development. It is clear that photosynthesis plays a key role in the survival strategy of young plants to overcome initially induced chemical stress. PMID:27135933

  4. Improved Agrobacterium-mediated transformation and high efficiency of root formation from hypocotyl meristem of spring Brassica napus 'Precocity' cultivar.

    PubMed

    Liu, X X; Lang, S R; Su, L Q; Liu, X; Wang, X F

    2015-12-14

    Rape seed (Brassica napus L.) is one of the most important oil seed crops in the world. Genetic manipulation of rapeseed requires a suitable tissue culture system and an efficient method for plant regeneration, as well as an efficient transformation procedure. However, development of transgenic B. napus has been problematic, and current studies are limited to cultivated varieties. In this study, we report a protocol for regeneration of transgenic rape after Agrobacterium-mediated transformation of hypocotyls from the spring B. napus 'Precocity' cultivar. We analyzed the effects of plant growth regulators in the medium on regeneration. Additionally, factors affecting the transformation efficiency, including seedling age, Agrobacterium concentration, infection time, and co-cultivation time, were assessed by monitoring GUS expression. Results from these experiments revealed that transformation was optimized when the meristematic parts of the hypocotyls were taken from 8 day-old seedlings, cultured on Murashinge and Skoog basal media containing 0.1 mg/L 1-naphthaleneacetic acid and 2.5 mg/L 6-benzylaminopurine, and incubated in Agrobacterium suspension (OD600 = 0.5) for 3 to 5 min, followed by 2 days of co-cultivation. Integration of T-DNA into the plant genome was confirmed by polymerase chain reaction (PCR), b-glucuronidase histochemical staining, and quantitative real-time PCR. The protocols developed for regeneration, transformation, and rooting described in this study could help to accelerate the development of transgenic spring rape varieties with novel features.

  5. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.)

    PubMed Central

    Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS. PMID:26673885

  6. High-Density SNP Map Construction and QTL Identification for the Apetalous Character in Brassica napus L.

    PubMed Central

    Wang, Xiaodong; Yu, Kunjiang; Li, Hongge; Peng, Qi; Chen, Feng; Zhang, Wei; Chen, Song; Hu, Maolong; Zhang, Jiefu

    2015-01-01

    The apetalous genotype is a morphological ideotype for increasing seed yield and should be of considerable agricultural use; however, only a few studies have focused on the genetic control of this trait in Brassica napus. In the present study, a recombinant inbred line, the AH population, containing 189 individuals was derived from a cross between an apetalous line ‘APL01’ and a normally petalled variety ‘Holly’. The Brassica 60 K Infinium BeadChip Array harboring 52,157 single nucleotide polymorphism (SNP) markers was used to genotype the AH individuals. A high-density genetic linkage map was constructed based on 2,755 bins involving 11,458 SNPs and 57 simple sequence repeats, and was used to identify loci associated with petalous degree (PDgr). The linkage map covered 2,027.53 cM, with an average marker interval of 0.72 cM. The AH map had good collinearity with the B. napus reference genome, indicating its high quality and accuracy. After phenotypic analyses across five different experiments, a total of 19 identified quantitative trait loci (QTLs) distributed across chromosomes A3, A5, A6, A9 and C8 were obtained, and these QTLs were further integrated into nine consensus QTLs by a meta-analysis. Interestingly, the major QTL qPD.C8-2 was consistently detected in all five experiments, and qPD.A9-2 and qPD.C8-3 were stably expressed in four experiments. Comparative mapping between the AH map and the B. napus reference genome suggested that there were 328 genes underlying the confidence intervals of the three steady QTLs. Based on the Gene Ontology assignments of 52 genes to the regulation of floral development in published studies, 146 genes were considered as potential candidate genes for PDgr. The current study carried out a QTL analysis for PDgr using a high-density SNP map in B. napus, providing novel targets for improving seed yield. These results advanced our understanding of the genetic control of PDgr regulation in B. napus. PMID:26779193

  7. High-Density SNP Map Construction and QTL Identification for the Apetalous Character in Brassica napus L.

    PubMed

    Wang, Xiaodong; Yu, Kunjiang; Li, Hongge; Peng, Qi; Chen, Feng; Zhang, Wei; Chen, Song; Hu, Maolong; Zhang, Jiefu

    2015-01-01

    The apetalous genotype is a morphological ideotype for increasing seed yield and should be of considerable agricultural use; however, only a few studies have focused on the genetic control of this trait in Brassica napus. In the present study, a recombinant inbred line, the AH population, containing 189 individuals was derived from a cross between an apetalous line 'APL01' and a normally petalled variety 'Holly'. The Brassica 60 K Infinium BeadChip Array harboring 52,157 single nucleotide polymorphism (SNP) markers was used to genotype the AH individuals. A high-density genetic linkage map was constructed based on 2,755 bins involving 11,458 SNPs and 57 simple sequence repeats, and was used to identify loci associated with petalous degree (PDgr). The linkage map covered 2,027.53 cM, with an average marker interval of 0.72 cM. The AH map had good collinearity with the B. napus reference genome, indicating its high quality and accuracy. After phenotypic analyses across five different experiments, a total of 19 identified quantitative trait loci (QTLs) distributed across chromosomes A3, A5, A6, A9 and C8 were obtained, and these QTLs were further integrated into nine consensus QTLs by a meta-analysis. Interestingly, the major QTL qPD.C8-2 was consistently detected in all five experiments, and qPD.A9-2 and qPD.C8-3 were stably expressed in four experiments. Comparative mapping between the AH map and the B. napus reference genome suggested that there were 328 genes underlying the confidence intervals of the three steady QTLs. Based on the Gene Ontology assignments of 52 genes to the regulation of floral development in published studies, 146 genes were considered as potential candidate genes for PDgr. The current study carried out a QTL analysis for PDgr using a high-density SNP map in B. napus, providing novel targets for improving seed yield. These results advanced our understanding of the genetic control of PDgr regulation in B. napus.

  8. High-Density SNP Map Construction and QTL Identification for the Apetalous Character in Brassica napus L.

    PubMed

    Wang, Xiaodong; Yu, Kunjiang; Li, Hongge; Peng, Qi; Chen, Feng; Zhang, Wei; Chen, Song; Hu, Maolong; Zhang, Jiefu

    2015-01-01

    The apetalous genotype is a morphological ideotype for increasing seed yield and should be of considerable agricultural use; however, only a few studies have focused on the genetic control of this trait in Brassica napus. In the present study, a recombinant inbred line, the AH population, containing 189 individuals was derived from a cross between an apetalous line 'APL01' and a normally petalled variety 'Holly'. The Brassica 60 K Infinium BeadChip Array harboring 52,157 single nucleotide polymorphism (SNP) markers was used to genotype the AH individuals. A high-density genetic linkage map was constructed based on 2,755 bins involving 11,458 SNPs and 57 simple sequence repeats, and was used to identify loci associated with petalous degree (PDgr). The linkage map covered 2,027.53 cM, with an average marker interval of 0.72 cM. The AH map had good collinearity with the B. napus reference genome, indicating its high quality and accuracy. After phenotypic analyses across five different experiments, a total of 19 identified quantitative trait loci (QTLs) distributed across chromosomes A3, A5, A6, A9 and C8 were obtained, and these QTLs were further integrated into nine consensus QTLs by a meta-analysis. Interestingly, the major QTL qPD.C8-2 was consistently detected in all five experiments, and qPD.A9-2 and qPD.C8-3 were stably expressed in four experiments. Comparative mapping between the AH map and the B. napus reference genome suggested that there were 328 genes underlying the confidence intervals of the three steady QTLs. Based on the Gene Ontology assignments of 52 genes to the regulation of floral development in published studies, 146 genes were considered as potential candidate genes for PDgr. The current study carried out a QTL analysis for PDgr using a high-density SNP map in B. napus, providing novel targets for improving seed yield. These results advanced our understanding of the genetic control of PDgr regulation in B. napus. PMID:26779193

  9. Characterization of interploid hybrids from crosses between Brassica juncea and B. oleracea and the production of yellow-seeded B. napus.

    PubMed

    Wen, Jing; Zhu, Lixia; Qi, Liping; Ke, Hongmei; Yi, Bin; Shen, Jinxiong; Tu, Jinxing; Ma, Chaozhi; Fu, Tingdong

    2012-06-01

    Yellow-seeded Brassica napus was for the first time developed from interspecific crosses using yellow-seeded B. juncea (AABB), yellow-seeded B. oleracea (CC), and black-seeded artificial B. napus (AACC). Three different mating approaches were undertaken to eliminate B-genome chromosomes after trigenomic hexaploids (AABBCC) were generated. Hybrids (AABCC, ABCC) from crosses AABBCC × AACC, AABBCC × CC and ABCC × AACC were advanced by continuous selfing in approach 1, 2 and 3, respectively. To provide more insight into Brassica genome evolution and the cytological basis for B. napus resynthesis in each approach, B-genome chromosome pairing and segregation were intensively analyzed in AABCC and ABCC plants using genomic in situ hybridization methods. The frequencies at which B-genome chromosomes underwent autosyndesis and allosyndesis were generally higher in ABCC than in AABCC plants. The difference was statistically significant for allosyndesis but not autosyndesis. Abnormal distributions of B-genome chromosomes were encountered at anaphase I, including chromosome lagging and precocious sister centromere separation of univalents. These abnormalities were observed at a significantly higher frequency in AABCC than in ABCC plants, which resulted in more rapid B-genome chromosome elimination in the AABCC derivatives. Yellow or yellow-brown seeds were obtained in all approaches, although true-breeding yellow-seeded B. napus was developed only in approaches 2 and 3. The efficiency of the B. napus construction approaches was in the order 1 > 3 > 2 whereas this order was 3 > 2 > 1 with respect to the construction of yellow-seeded B. napus. The results are discussed in relation to Brassica genome evolution and the development and utilization of the yellow-seeded B. napus obtained here. PMID:22350176

  10. Overexpression of Three Glucosinolate Biosynthesis Genes in Brassica napus Identifies Enhanced Resistance to Sclerotinia sclerotiorum and Botrytis cinerea.

    PubMed

    Zhang, Yuanyuan; Huai, Dongxin; Yang, Qingyong; Cheng, Yan; Ma, Ming; Kliebenstein, Daniel J; Zhou, Yongming

    2015-01-01

    Sclerotinia sclerotiorum and Botrytis cinerea are notorious plant pathogenic fungi with an extensive host range including Brassica crops. Glucosinolates (GSLs) are an important group of secondary metabolites characteristic of the Brassicales order, whose degradation products are proving to be increasingly important in plant protection. Enhancing the defense effect of GSL and their associated degradation products is an attractive strategy to strengthen the resistance of plants by transgenic approaches. We generated the lines of Brassica napus with three biosynthesis genes involved in GSL metabolic pathway (BnMAM1, BnCYP83A1 and BnUGT74B1), respectively. We then measured the foliar GSLs of each transgenic lines and inoculated them with S. sclerotiorum and B. cinerea. Compared with the wild type control, over-expressing BnUGT74B1 in B. napus increased the aliphatic and indolic GSL levels by 1.7 and 1.5 folds in leaves respectively; while over-expressing BnMAM1 or BnCYP83A1 resulted in an approximate 1.5-fold higher only in the aliphatic GSL level in leaves. The results of plant inoculation demonstrated that BnUGT74B1-overexpressing lines showed less severe disease symptoms and tissue damage compared with the wild type control, but BnMAM1 or BnCYP83A1-overexpressing lines showed no significant difference in comparison to the controls. These results suggest that the resistance to S. sclerotiorum and B. cinerea in B. napus could be enhanced through tailoring the GSL profiles by transgenic approaches or molecular breeding, which provides useful information to assist plant breeders to design improved breeding strategies.

  11. Overexpression of Three Glucosinolate Biosynthesis Genes in Brassica napus Identifies Enhanced Resistance to Sclerotinia sclerotiorum and Botrytis cinerea

    PubMed Central

    Yang, Qingyong; Cheng, Yan; Ma, Ming; Kliebenstein, Daniel J.; Zhou, Yongming

    2015-01-01

    Sclerotinia sclerotiorum and Botrytis cinerea are notorious plant pathogenic fungi with an extensive host range including Brassica crops. Glucosinolates (GSLs) are an important group of secondary metabolites characteristic of the Brassicales order, whose degradation products are proving to be increasingly important in plant protection. Enhancing the defense effect of GSL and their associated degradation products is an attractive strategy to strengthen the resistance of plants by transgenic approaches. We generated the lines of Brassica napus with three biosynthesis genes involved in GSL metabolic pathway (BnMAM1, BnCYP83A1 and BnUGT74B1), respectively. We then measured the foliar GSLs of each transgenic lines and inoculated them with S. sclerotiorum and B. cinerea. Compared with the wild type control, over-expressing BnUGT74B1 in B. napus increased the aliphatic and indolic GSL levels by 1.7 and 1.5 folds in leaves respectively; while over-expressing BnMAM1 or BnCYP83A1 resulted in an approximate 1.5-fold higher only in the aliphatic GSL level in leaves. The results of plant inoculation demonstrated that BnUGT74B1-overexpressing lines showed less severe disease symptoms and tissue damage compared with the wild type control, but BnMAM1 or BnCYP83A1-overexpressing lines showed no significant difference in comparison to the controls. These results suggest that the resistance to S. sclerotiorum and B. cinerea in B. napus could be enhanced through tailoring the GSL profiles by transgenic approaches or molecular breeding, which provides useful information to assist plant breeders to design improved breeding strategies. PMID:26465156

  12. Overexpression of Three Glucosinolate Biosynthesis Genes in Brassica napus Identifies Enhanced Resistance to Sclerotinia sclerotiorum and Botrytis cinerea.

    PubMed

    Zhang, Yuanyuan; Huai, Dongxin; Yang, Qingyong; Cheng, Yan; Ma, Ming; Kliebenstein, Daniel J; Zhou, Yongming

    2015-01-01

    Sclerotinia sclerotiorum and Botrytis cinerea are notorious plant pathogenic fungi with an extensive host range including Brassica crops. Glucosinolates (GSLs) are an important group of secondary metabolites characteristic of the Brassicales order, whose degradation products are proving to be increasingly important in plant protection. Enhancing the defense effect of GSL and their associated degradation products is an attractive strategy to strengthen the resistance of plants by transgenic approaches. We generated the lines of Brassica napus with three biosynthesis genes involved in GSL metabolic pathway (BnMAM1, BnCYP83A1 and BnUGT74B1), respectively. We then measured the foliar GSLs of each transgenic lines and inoculated them with S. sclerotiorum and B. cinerea. Compared with the wild type control, over-expressing BnUGT74B1 in B. napus increased the aliphatic and indolic GSL levels by 1.7 and 1.5 folds in leaves respectively; while over-expressing BnMAM1 or BnCYP83A1 resulted in an approximate 1.5-fold higher only in the aliphatic GSL level in leaves. The results of plant inoculation demonstrated that BnUGT74B1-overexpressing lines showed less severe disease symptoms and tissue damage compared with the wild type control, but BnMAM1 or BnCYP83A1-overexpressing lines showed no significant difference in comparison to the controls. These results suggest that the resistance to S. sclerotiorum and B. cinerea in B. napus could be enhanced through tailoring the GSL profiles by transgenic approaches or molecular breeding, which provides useful information to assist plant breeders to design improved breeding strategies. PMID:26465156

  13. Genomic DNA enrichment using sequence capture microarrays: a novel approach to discover sequence nucleotide polymorphisms (SNP) in Brassica napus L.

    PubMed

    Clarke, Wayne E; Parkin, Isobel A; Gajardo, Humberto A; Gerhardt, Daniel J; Higgins, Erin; Sidebottom, Christine; Sharpe, Andrew G; Snowdon, Rod J; Federico, Maria L; Iniguez-Luy, Federico L

    2013-01-01

    Targeted genomic selection methodologies, or sequence capture, allow for DNA enrichment and large-scale resequencing and characterization of natural genetic variation in species with complex genomes, such as rapeseed canola (Brassica napus L., AACC, 2n=38). The main goal of this project was to combine sequence capture with next generation sequencing (NGS) to discover single nucleotide polymorphisms (SNPs) in specific areas of the B. napus genome historically associated (via quantitative trait loci -QTL- analysis) to traits of agronomical and nutritional importance. A 2.1 million feature sequence capture platform was designed to interrogate DNA sequence variation across 47 specific genomic regions, representing 51.2 Mb of the Brassica A and C genomes, in ten diverse rapeseed genotypes. All ten genotypes were sequenced using the 454 Life Sciences chemistry and to assess the effect of increased sequence depth, two genotypes were also sequenced using Illumina HiSeq chemistry. As a result, 589,367 potentially useful SNPs were identified. Analysis of sequence coverage indicated a four-fold increased representation of target regions, with 57% of the filtered SNPs falling within these regions. Sixty percent of discovered SNPs corresponded to transitions while 40% were transversions. Interestingly, fifty eight percent of the SNPs were found in genic regions while 42% were found in intergenic regions. Further, a high percentage of genic SNPs was found in exons (65% and 64% for the A and C genomes, respectively). Two different genotyping assays were used to validate the discovered SNPs. Validation rates ranged from 61.5% to 84% of tested SNPs, underpinning the effectiveness of this SNP discovery approach. Most importantly, the discovered SNPs were associated with agronomically important regions of the B. napus genome generating a novel data resource for research and breeding this crop species.

  14. Selection of reference genes for quantitative reverse-transcription polymerase chain reaction normalization in Brassica napus under various stress conditions.

    PubMed

    Wang, Zheng; Chen, Yu; Fang, Hedi; Shi, Haifeng; Chen, Keping; Zhang, Zhiyan; Tan, Xiaoli

    2014-10-01

    Data normalization is essential for reliable output of quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) assays, as the unsuitable choice of reference gene(s), whose expression might be influenced by exogenous treatments in plant tissues, could cause misinterpretation of results. To date, no systematic studies on reference genes have been performed in stressed Brassica napus. In this study, we investigated the expression variations of nine candidate reference genes in 40 samples of B. napus leaves subjected to various exogenous treatments. Parallel analyses by geNorm and NormFinder revealed that optimal reference genes differed across the different sets of samples. The best-ranked reference genes were PP2A and TIP41 for salt stress, TIP41 and ACT7 for heavy metal (Cr(6+)) stress, PP2A and UBC21 for drought stress, F-box and SAND for cold stress, F-box and ZNF for salicylic acid stress, TIP41, ACT7, and PP2A for methyl jasmonate stress, TIP41 and ACT7 for abscisic acid stress, and TIP41, UBC21, and PP2A for Sclerotinia sclerotiorum stress. Two newly employed reference genes, TIP41 and PP2A, showed better performances, suggesting their suitability in multiple conditions. To further validate the suitability of the reference genes, the expression patterns of BnWRKY40 and BnMKS1 were studied in parallel. This study is the first systematic analysis of reference gene selection for qRT-PCR normalization in B. napus, an agriculturally important crop, under different stress conditions. The results will contribute toward more accurate and widespread use of qRT-PCR in gene analysis of the genus Brassica. PMID:24770781

  15. BnaC.Tic40, a plastid inner membrane translocon originating from Brassica oleracea, is essential for tapetal function and microspore development in Brassica napus.

    PubMed

    Dun, Xiaoling; Zhou, Zhengfu; Xia, Shengqian; Wen, Jing; Yi, Bin; Shen, Jinxiong; Ma, Chaozhi; Tu, Jinxing; Fu, Tingdong

    2011-11-01

    Here, we describe the characteristics of a Brassica napus male sterile mutant 7365A with loss of the BnMs3 gene, which exhibits abnormal enlargement of the tapetal cells during meiosis. Later in development, the absence of the BnMs3 gene in the mutant results in a loss of the secretory function of the tapetum, as suggested by abortive callose dissolution and retarded tapetal degradation. The BnaC.Tic40 gene (equivalent to BnMs3) was isolated by a map-based cloning approach and was confirmed by genetic complementation. Sequence analyses suggested that BnaC.Tic40 originated from BolC.Tic40 on the Brassica oleracea linkage group C9, whereas its allele Bnms3 was derived from BraA.Tic40 on the Brassica rapa linkage group A10. The BnaC.Tic40 gene is highly expressed in the tapetum and encodes a putative plastid inner envelope membrane translocon, Tic40, which is localized into the chloroplast. Transmission electron microscopy (TEM) and lipid staining analyses suggested that BnaC.Tic40 is a key factor in controlling lipid accumulation in the tapetal plastids. These data indicate that BnaC.Tic40 participates in specific protein translocation across the inner envelope membrane in the tapetal plastid, which is required for tapetal development and function.

  16. Retention of triplicated phytoene synthase (PSY) genes in Brassica napus L. and its diploid progenitors during the evolution of the Brassiceae.

    PubMed

    Cárdenas, Pablo D; Gajardo, Humberto A; Huebert, Terry; Parkin, Isobel A; Iniguez-Luy, Federico L; Federico, María L

    2012-05-01

    The extent of genome redundancy exhibited by Brassica species provides a model to study the evolutionary fate of multi-copy genes and the effects of polyploidy in economically important crops. Phytoene synthase (PSY) catalyzes the first committed reaction of the carotenoid biosynthetic pathway, which has been shown to be rate-limiting in Brassica napus seeds. In Arabidopsis thaliana, a single PSY gene (AtPSY) regulates phytoene synthesis in all tissues. Considering that diploid Brassica genomes contain three Arabidopsis-like subgenomes, the objectives of the present work were to determine whether PSY gene families exist in B. napus (AACC) and its diploid progenitor species, Brassica rapa (AA) and Brassica oleracea (CC); to establish the level of retention of Brassica PSY genes; to map PSY gene family members in the A and C genomes and to compare Brassica PSY gene expression patterns. A total of 12 PSY homologues were identified, 6 in B. napus (BnaX.PSY.a-f) and 3 in B. rapa (BraA.PSY.a-c) and B. oleracea (BolC.PSY.a-c). Indeed, with six members, B. napus has the largest PSY gene family described to date. Sequence comparison between AtPSY and Brassica PSY genes revealed a highly conserved gene structure and identity percentages above 85% at the coding sequence (CDS) level. Altogether, our data indicate that PSY gene family expansion preceded the speciation of B. rapa and B. oleracea, dating back to the paralogous subgenome triplication event. In these three Brassica species, all PSY homologues are expressed, exhibiting overlapping redundancy and signs of subfunctionalization among photosynthetic and non-photosynthetic tissues. This evidence supports the hypothesis that functional divergence of PSY gene expression facilitates the accumulation of high levels of carotenoids in chromoplast-rich tissues. Thus, functional retention of triplicated Brassica PSY genes could be at least partially explained by the selective advantage provided by increased levels of gene

  17. Identification and mapping of a third blackleg resistance locus in Brassica napus derived from B. rapa subsp. sylvestris.

    PubMed

    Yu, Fengqun; Lydiate, Derek J; Rimmer, S Roger

    2008-01-01

    The spectrum of resistance to isolates of Leptosphaeria maculans and the map location of a new blackleg resistance gene found in the canola cultivar Brassica napus 'Surpass 400' are described. Two blackleg resistance genes, LepR1 and LepR2, from B. rapa subsp. sylvestris and introgressed in B. napus were identified previously. 'Surpass 400' also has blackleg resistance introgressed from B. rapa subsp. sylvestris. Using 31 diverse isolates of L. maculans, the disease reaction of 'Surpass 400' was compared with those of the resistant breeding lines AD9 (which contains LepR1), AD49 (which contains LepR2), and MC1-8 (which contains both LepR1 and LepR2). The disease reaction on 'Surpass 400' was different from those observed on AD9 and MC1-8, indicating that 'Surpass 400' carries neither LepR1 nor both LepR1 and LepR2 in combination. Disease reactions of 'Surpass 400' to most of the isolates tested were indistinguishable from those of AD49, which suggested 'Surpass 400' might contain LepR2 or a similar resistance gene. Classical genetic analysis of F1 and BC1 plants showed that a dominant allele conferred resistance to isolates of L. maculans in 'Surpass 400'. The resistance gene, which mapped to B. napus linkage group N10 in an interval of 2.9 cM flanked by microsatellite markers sR12281a and sN2428Rb and 11.7 cM below LepR2, was designated LepR3. A 9 cM region of the B. napus genome containing LepR3 was found to be syntenic with a segment of Arabidopsis chromosome 5.

  18. Regulation of Cadmium-Induced Proteomic and Metabolic Changes by 5-Aminolevulinic Acid in Leaves of Brassica napus L.

    PubMed

    Ali, Basharat; Gill, Rafaqat A; Yang, Su; Gill, Muhammad B; Farooq, Muhammad A; Liu, Dan; Daud, Muhammad K; Ali, Shafaqat; Zhou, Weijun

    2015-01-01

    It is evident from previous reports that 5-aminolevulinic acid (ALA), like other known plant growth regulators, is effective in countering the injurious effects of heavy metal-stress in oilseed rape (Brassica napus L.). The present study was carried out to explore the capability of ALA to improve cadmium (Cd2+) tolerance in B. napus through physiological, molecular, and proteomic analytical approaches. Results showed that application of ALA helped the plants to adjust Cd2+-induced metabolic and photosynthetic fluorescence changes in the leaves of B. napus under Cd2+ stress. The data revealed that ALA treatment enhanced the gene expressions of antioxidant enzyme activities substantially and could increase the expression to a certain degree under Cd2+ stress conditions. In the present study, 34 protein spots were identified that differentially regulated due to Cd2+ and/or ALA treatments. Among them, 18 proteins were significantly regulated by ALA, including the proteins associated with stress related, carbohydrate metabolism, catalysis, dehydration of damaged protein, CO2 assimilation/photosynthesis and protein synthesis/regulation. From these 18 ALA-regulated proteins, 12 proteins were significantly down-regulated and 6 proteins were up-regulated. Interestingly, it was observed that ALA-induced the up-regulation of dihydrolipoyl dehydrogenase, light harvesting complex photo-system II subunit 6 and 30S ribosomal proteins in the presence of Cd2+ stress. In addition, it was also observed that ALA-induced the down-regulation in thioredoxin-like protein, 2, 3-bisphosphoglycerate, proteasome and thiamine thiazole synthase proteins under Cd2+ stress. Taken together, the present study sheds light on molecular mechanisms involved in ALA-induced Cd2+ tolerance in B. napus leaves and suggests a more active involvement of ALA in plant physiological processes than previously proposed.

  19. Transcriptomic analysis of nitrogen starvation- and cultivar-specific leaf senescence in winter oilseed rape (Brassica napus L.).

    PubMed

    Koeslin-Findeklee, Fabian; Rizi, Vajiheh Safavi; Becker, Martin A; Parra-Londono, Sebastian; Arif, Muhammad; Balazadeh, Salma; Mueller-Roeber, Bernd; Kunze, Reinhard; Horst, Walter J

    2015-04-01

    High nitrogen (N) efficiency, characterized by high grain yield under N limitation, is an important agricultural trait in Brassica napus L. cultivars related to delayed senescence of older leaves during reproductive growth (a syndrome called stay-green). The aim of this study was thus to identify genes whose expression is specifically altered during N starvation-induced leaf senescence and that can be used as markers to distinguish cultivars at early stages of senescence prior to chlorophyll loss. To this end, the transcriptomes of leaves of two B. napus cultivars differing in stay-green characteristics and N efficiency were analyzed 4 days after the induction of senescence by either N starvation, leaf shading or detaching. In addition to N metabolism genes, N starvation mostly (and specifically) repressed genes related to photosynthesis, photorespiration and cell-wall structure, while genes related to mitochondrial electron transport and flavonoid biosynthesis were predominately up-regulated. A kinetic study over a period of 12 days with four B. napus cultivars differing in their stay-green characteristics confirmed the cultivar-specific regulation of six genes in agreement with their senescence behavior: the senescence regulator ANAC029, the anthocyanin synthesis-related genes ANS and DFR-like1, the ammonium transporter AMT1;4, the ureide transporter UPS5, and SPS1 involved in sucrose biosynthesis. The identified genes represent markers for the detection of cultivar-specific differences in N starvation-induced leaf senescence and can thus be employed as valuable tools in B. napus breeding.

  20. Regulation of Cadmium-Induced Proteomic and Metabolic Changes by 5-Aminolevulinic Acid in Leaves of Brassica napus L.

    PubMed Central

    Ali, Basharat; Gill, Rafaqat A.; Yang, Su; Gill, Muhammad B.; Farooq, Muhammad A.; Liu, Dan; Daud, Muhammad K.; Ali, Shafaqat; Zhou, Weijun

    2015-01-01

    It is evident from previous reports that 5-aminolevulinic acid (ALA), like other known plant growth regulators, is effective in countering the injurious effects of heavy metal-stress in oilseed rape (Brassica napus L.). The present study was carried out to explore the capability of ALA to improve cadmium (Cd2+) tolerance in B. napus through physiological, molecular, and proteomic analytical approaches. Results showed that application of ALA helped the plants to adjust Cd2+-induced metabolic and photosynthetic fluorescence changes in the leaves of B. napus under Cd2+ stress. The data revealed that ALA treatment enhanced the gene expressions of antioxidant enzyme activities substantially and could increase the expression to a certain degree under Cd2+ stress conditions. In the present study, 34 protein spots were identified that differentially regulated due to Cd2+ and/or ALA treatments. Among them, 18 proteins were significantly regulated by ALA, including the proteins associated with stress related, carbohydrate metabolism, catalysis, dehydration of damaged protein, CO2 assimilation/photosynthesis and protein synthesis/regulation. From these 18 ALA-regulated proteins, 12 proteins were significantly down-regulated and 6 proteins were up-regulated. Interestingly, it was observed that ALA-induced the up-regulation of dihydrolipoyl dehydrogenase, light harvesting complex photo-system II subunit 6 and 30S ribosomal proteins in the presence of Cd2+ stress. In addition, it was also observed that ALA-induced the down-regulation in thioredoxin-like protein, 2, 3-bisphosphoglycerate, proteasome and thiamine thiazole synthase proteins under Cd2+ stress. Taken together, the present study sheds light on molecular mechanisms involved in ALA-induced Cd2+ tolerance in B. napus leaves and suggests a more active involvement of ALA in plant physiological processes than previously proposed. PMID:25909456

  1. Molecular cloning and expression analysis of a RGA-like gene responsive to plant hormones in Brassica napus.

    PubMed

    Gao, Yong; Chen, Jianmin; Zhao, Yun; Li, Tingting; Wang, Maolin

    2012-02-01

    DELLA proteins are negative regulators of GA-induced growth. DELLA protein family is characterized by a DELLA domain essential for GA-dependent proteasomal degradation of DELLA repressors. A full-length cDNA encoding a putative DELLA protein with high sequence homology to Arabidopsis thaliana RGA (AtRGA), designated as BnRGA, was isolated from Brassica napus. The full-length cDNA of BnRGA contained a 1,740 bp open reading frame (ORF) encoding a precursor protein of 579 amino acid residues. Comparative and bioinformatics analyses revealed that BnRGA showed a high degree of homology with DELLA proteins and contained the DELLA domain, TVHYNP domain, VHIID domain and RVER domain. Using real-time PCR, the expression patterns of BnRGA and two our previously isolated genes, BnGID1a and BnSLY1 in B. napus, were analyzed by adding exogenous gibberellins acid-3 (GA(3)), GA biosynthetic inhibitor paclobutrazol (PAC) and abscisic acid (ABA). The results showed that the expression of BnGID1a and BnSLY1 was down-regulated after treated by GA(3) and induced by PAC and ABA. These results suggest that the expression of BnGID1a and BnSLY1 may be negatively regulated by the level of endogenous GA in B. napus. Moreover, BnRGA was not significantly regulated by GA(3), PAC and ABA in the low concentrations. These suggest that GA-GID1-SCF-DELLA complex may have a mechanism of self-regulation, thereby preserving the stability of the expression level of BnRGA in B. napus.

  2. Transcriptomic analysis of nitrogen starvation- and cultivar-specific leaf senescence in winter oilseed rape (Brassica napus L.).

    PubMed

    Koeslin-Findeklee, Fabian; Rizi, Vajiheh Safavi; Becker, Martin A; Parra-Londono, Sebastian; Arif, Muhammad; Balazadeh, Salma; Mueller-Roeber, Bernd; Kunze, Reinhard; Horst, Walter J

    2015-04-01

    High nitrogen (N) efficiency, characterized by high grain yield under N limitation, is an important agricultural trait in Brassica napus L. cultivars related to delayed senescence of older leaves during reproductive growth (a syndrome called stay-green). The aim of this study was thus to identify genes whose expression is specifically altered during N starvation-induced leaf senescence and that can be used as markers to distinguish cultivars at early stages of senescence prior to chlorophyll loss. To this end, the transcriptomes of leaves of two B. napus cultivars differing in stay-green characteristics and N efficiency were analyzed 4 days after the induction of senescence by either N starvation, leaf shading or detaching. In addition to N metabolism genes, N starvation mostly (and specifically) repressed genes related to photosynthesis, photorespiration and cell-wall structure, while genes related to mitochondrial electron transport and flavonoid biosynthesis were predominately up-regulated. A kinetic study over a period of 12 days with four B. napus cultivars differing in their stay-green characteristics confirmed the cultivar-specific regulation of six genes in agreement with their senescence behavior: the senescence regulator ANAC029, the anthocyanin synthesis-related genes ANS and DFR-like1, the ammonium transporter AMT1;4, the ureide transporter UPS5, and SPS1 involved in sucrose biosynthesis. The identified genes represent markers for the detection of cultivar-specific differences in N starvation-induced leaf senescence and can thus be employed as valuable tools in B. napus breeding. PMID:25711825

  3. Identification of Heat Responsive Genes in Brassica napus Siliques at the Seed-Filling Stage through Transcriptional Profiling

    PubMed Central

    Yang, Qingyong; Li, Xiaodong; Wan, Bingxi; Dong, Yanni; Wang, Xuemin; Zhou, Yongming

    2014-01-01

    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, global transcription profiles of 20 d-old siliques of B. napus were analyzed after heat stress using a Brassica 95k EST microarray. The up-regulated genes included many HSF/HSP transcripts and other heat-related marker genes, such as ROF2, DREB2a, MBF1c and Hsa32, reflecting the conservation of key heat resistance factors among plants. Other up-regulated genes were preferentially expressed in heat-stressed silique walls or seeds, including some transcription factors and potential developmental regulators. In contrast, down-regulated genes differed between the silique wall and seeds and were largely tied to the biological functions of each tissue, such as glucosinolate metabolism in the silique wall and flavonoid synthesis in seeds. Additionally, a large proportion (one-third) of these differentially expressed genes had unknown functions. Based on these gene expression profiles, Arabidopsis mutants for eight heat-induced Brassica homologous genes were treated with different heat stress methods, and thermotolerance varied with each mutation, heat stress regimen and plant development stage. At least two of the eight mutants exhibited sensitivity to the heat treatments, suggesting the importance of the respective genes in responding to heat stress. In summary, this study elucidated the molecular bases of the heat responses in siliques during later reproductive stages and provides valuable information and gene resources for the genetic improvement of heat tolerance in oilseed rape breeding. PMID:25013950

  4. Genetic changes following hybridization and genome doubling in synthetic Brassica napus.

    PubMed

    Xu, Yanhao; Xu, Hong; Wu, Xiaoming; Fang, Xiaoping; Wang, Jianbo

    2012-08-01

    Genetic changes were investigated in two sets of independently synthesized Brasscia napus allopolyploids by the AFLP approach in the present study. We found that 1.17 % of the loci showed genetic changes following both hybridization and genome doubling in the synthesized B. napus F04J2 relative to its diploid progenitors, B. rapa (AA genome) and B. oleracea (CC genome). No significant difference between the proportion of A-genome-specific genetic changes and that of C-genome-specific genetic changes was detected in B. napus F04J2. Approximately 0.6 % of the loci displayed genetic changes following somatic genome doubling in the amphidiploid B. napus DCE11 relative to the amphihaploid in the dimorphic plants. This study showed that rapid genetic changes occurred after hybridization and/or genome doubling in synthesized B. napus allopolyploids and indicated that both hybridization and genome doubling could affect the genomic architecture in newly formed allopolyploids.

  5. Three homologous genes encoding sn-glycerol-3-phosphate acyltransferase 4 exhibit different expression patterns and functional divergence in Brassica napus.

    PubMed

    Chen, Xue; Truksa, Martin; Snyder, Crystal L; El-Mezawy, Aliaa; Shah, Saleh; Weselake, Randall J

    2011-02-01

    Brassica napus is an allotetraploid (AACC) formed from the fusion of two diploid progenitors, Brassica rapa (AA) and Brassica oleracea (CC). Polyploidy and genome-wide rearrangement during the evolution process have resulted in genes that are present as multiple homologs in the B. napus genome. In this study, three B. napus homologous genes encoding endoplasmic reticulum-bound sn-glycerol-3-phosphate acyltransferase 4 (GPAT4) were identified and characterized. Although the three GPAT4 homologs share a high sequence similarity, they exhibit different expression patterns and altered epigenetic features. Heterologous expression in yeast further revealed that the three BnGPAT4 homologs encoded functional GPAT enzymes but with different levels of polypeptide accumulation. Complementation of the Arabidopsis (Arabidopsis thaliana) gpat4 gpat8 double mutant line with individual BnGPAT4 homologs suggested their physiological roles in cuticle formation. Analysis of gpat4 RNA interference lines of B. napus revealed that the BnGPAT4 deficiency resulted in reduced cutin content and altered stomatal structures in leaves. Our results revealed that the BnGPAT4 homologs have evolved into functionally divergent forms and play important roles in cutin synthesis and stomatal development.

  6. Allopolyploidy has a moderate impact on restructuring at three contrasting transposable element insertion sites in resynthesized Brassica napus allotetraploids.

    PubMed

    Sarilar, Véronique; Palacios, Paulina Martinez; Rousselet, Agnès; Ridel, Céline; Falque, Matthieu; Eber, Frédérique; Chèvre, Anne-Marie; Joets, Johann; Brabant, Philippe; Alix, Karine

    2013-04-01

    The role played by whole-genome duplication (WGD) in evolution and adaptation is particularly well illustrated in allopolyploids, where WGD is concomitant with interspecific hybridization. This 'Genome Shock', usually accompanied by structural and functional modifications, has been associated with the activation of transposable elements (TEs). However, the impact of allopolyploidy on TEs has been studied in only a few polyploid species, and not in Brassica, which has been marked by recurrent polyploidy events. Here, we developed sequence-specific amplification polymorphism (SSAP) markers for three contrasting TEs, and compared profiles between resynthesized Brassica napus allotetraploids and their diploid Brassica progenitors. To evaluate restructuring at TE insertion sites, we scored changes in SSAP profiles and analysed a large set of differentially amplified SSAP bands. No massive structural changes associated with the three TEs surveyed were detected. However, several transposition events, specific to the youngest TE originating from the B. oleracea genome, were identified. Our study supports the hypothesis that TE responses to allopolyploidy are highly specific. The changes observed in SSAP profiles lead us to hypothesize that they may partly result from changes in DNA methylation, questioning the role of epigenetics during the formation of a new allopolyploid genome.

  7. The genes BnSCT1 and BnSCT2 from Brassica napus encoding the final enzyme of sinapine biosynthesis: molecular characterization and suppression.

    PubMed

    Weier, Diana; Mittasch, Juliane; Strack, Dieter; Milkowski, Carsten

    2008-01-01

    This study describes the molecular characterization of the genes BnSCT1 and BnSCT2 from oilseed rape (Brassica napus) encoding the enzyme 1-O-sinapoyl-beta-glucose:choline sinapoyltransferase (SCT; EC 2.3.1.91). SCT catalyzes the 1-O-beta-acetal ester-dependent biosynthesis of sinapoylcholine (sinapine), the most abundant phenolic compound in seeds of B. napus. GUS fusion experiments indicated that seed specificity of BnSCT1 expression is caused by an inducible promoter confining transcription to embryo tissues and the aleurone layer. A dsRNAi construct designed to silence seed-specifically the BnSCT1 gene was effective in reducing the sinapine content of Arabidopsis seeds thus defining SCT genes as targets for molecular breeding of low sinapine cultivars of B. napus. Sequence analyses revealed that in the allotetraploid genome of B. napus the gene BnSCT1 represents the C genome homologue from the B. oleracea progenitor whereas BnSCT2 was derived from the Brassica A genome of B. rapa. The BnSCT1 and BnSCT2 loci showed colinearity with the homologous Arabidopsis SNG2 gene locus although the genomic microstructure revealed the deletion of a cluster of three genes and several coding regions in the B. napus genome.

  8. The genes BnSCT1 and BnSCT2 from Brassica napus encoding the final enzyme of sinapine biosynthesis: molecular characterization and suppression.

    PubMed

    Weier, Diana; Mittasch, Juliane; Strack, Dieter; Milkowski, Carsten

    2008-01-01

    This study describes the molecular characterization of the genes BnSCT1 and BnSCT2 from oilseed rape (Brassica napus) encoding the enzyme 1-O-sinapoyl-beta-glucose:choline sinapoyltransferase (SCT; EC 2.3.1.91). SCT catalyzes the 1-O-beta-acetal ester-dependent biosynthesis of sinapoylcholine (sinapine), the most abundant phenolic compound in seeds of B. napus. GUS fusion experiments indicated that seed specificity of BnSCT1 expression is caused by an inducible promoter confining transcription to embryo tissues and the aleurone layer. A dsRNAi construct designed to silence seed-specifically the BnSCT1 gene was effective in reducing the sinapine content of Arabidopsis seeds thus defining SCT genes as targets for molecular breeding of low sinapine cultivars of B. napus. Sequence analyses revealed that in the allotetraploid genome of B. napus the gene BnSCT1 represents the C genome homologue from the B. oleracea progenitor whereas BnSCT2 was derived from the Brassica A genome of B. rapa. The BnSCT1 and BnSCT2 loci showed colinearity with the homologous Arabidopsis SNG2 gene locus although the genomic microstructure revealed the deletion of a cluster of three genes and several coding regions in the B. napus genome. PMID:17882453

  9. [Molecular markers linked to mono-dominant genic male sterile gene in rapeseed (Brassica napus L.)].

    PubMed

    Wang, Dao-Jie; Guo, Ai-Guang; Li, Dian-Rong; Tian, Jian-Hua

    2006-10-01

    Bulked segregant analysis (BSA) was used to identify randomly amplified polymorphic DNA (RAPD) markers linked to the MS gene in mono-dominant GMS of rapeseed (Brassica napus L.), which was bred by Hybrid Rapeseed Research Center of Shaanxi Province. A total of 300 random 10-mer oligonucleotide primers were screened on the DNA from fertile and sterile bulks. Primer S(243) (5'CTATGCCGAC3') gave identical 1.5 kb DNA polymorphic segment OPU-03(1500) in the bulk S, but not in the bulk F (Fig.2). The DNAs from individual plants of each bulk and from their sister lines, which were generated from the same original crossing, were then screened with the primer S(243), and the same results were obtained (Figs.3,4). Other types of GMS and CMS were analyzed using primer S(243), and the specific 1.5 kb DNA segment was not found (Fig.5). Therefore, the RAPD marker OPU-03(1500) is linked to the mono-dominant GMS trait in rapeseed. This RAPD marker OPU-03(1500) was cloned into a T-easy vector and sequenced. The sequence here obtained was highly homologous to one of the Arabidopsis DNA sequences. According to this DNA conserved region in different species, we designed a pair of specific primers P1 (5'ATGTCGCTGAGGCCG-AGCAC3') and P2 (5'GGCACACTGTCACG-ATCCTTGG3') and amplified only one specific 2.3 kb DNA fragment in each bulk. There are two mutant loci between the two DNA fragments after sequencing. We designed another pair of specific primers P3 (5'CTCCAGCAGCAGCAGC-AGCCT3') and P4 (5'GCAGGAATGAGAA-CCGTAGG3') according to the DNA sequence at the mutant loci. A specific DNA segment was amplified only in the fertile line but not in the sterile line using the primers P3 and P4 (Fig.6). Therefore the RAPD marker were converted into SCAR marker. Moreover, the SCAR marker detection method was improved (Fig.7).

  10. Identification and characterization of CBL and CIPK gene families in canola (Brassica napus L.)

    PubMed Central

    2014-01-01

    Background Canola (Brassica napus L.) is one of the most important oil-producing crops in China and worldwide. The yield and quality of canola is frequently threatened by environmental stresses including drought, cold and high salinity. Calcium is a ubiquitous intracellular secondary messenger in plants. Calcineurin B-like proteins (CBLs) are Ca2+ sensors and regulate a group of Ser/Thr protein kinases called CBL-interacting protein kinases (CIPKs). Although the CBL-CIPK network has been demonstrated to play crucial roles in plant development and responses to various environmental stresses in Arabidopsis, little is known about their function in canola. Results In the present study, we identified seven CBL and 23 CIPK genes from canola by database mining and cloning of cDNA sequences of six CBLs and 17 CIPKs. Phylogenetic analysis of CBL and CIPK gene families across a variety of species suggested genome duplication and diversification. The subcellular localization of three BnaCBLs and two BnaCIPKs were determined using green fluorescence protein (GFP) as the reporter. We also demonstrated interactions between six BnaCBLs and 17 BnaCIPKs using yeast two-hybrid assay, and a subset of interactions were further confirmed by bimolecular fluorescence complementation (BiFC). Furthermore, the expression levels of six selected BnaCBL and 12 BnaCIPK genes in response to salt, drought, cold, heat, ABA, methyl viologen (MV) and low potassium were examined by quantitative RT-PCR and these CBL or CIPK genes were found to respond to multiple stimuli, suggesting that the canola CBL-CIPK network may be a point of convergence for several different signaling pathways. We also performed a comparison of interaction patterns and expression profiles of CBL and CIPK in Arabidospsis, canola and rice, to examine the differences between orthologs, highlighting the importance of studying CBL-CIPK in canola as a prerequisite for improvement of this crop. Conclusions Our findings indicate that

  11. Transcriptome Analysis Comparison of Lipid Biosynthesis in the Leaves and Developing Seeds of Brassica napus.

    PubMed

    Chen, Jie; Tan, Ren-Ke; Guo, Xiao-Juan; Fu, Zheng-Li; Wang, Zheng; Zhang, Zhi-Yan; Tan, Xiao-Li

    2015-01-01

    Brassica napus seed is a lipid storage organ containing approximately 40% oil, while its leaves contain many kinds of lipids for many biological roles, but the overall amounts are less than in seeds. Thus, lipid biosynthesis in the developing seeds and the leaves is strictly regulated which results the final difference of lipids. However, there are few reports about the molecular mechanism controlling the difference in lipid biosynthesis between developing seeds and leaves. In this study, we tried to uncover this mechanism by analyzing the transcriptome data for lipid biosynthesis. The transcriptome data were de novo assembled and a total of 47,216 unigenes were obtained, which had an N50 length and median of 1271 and 755 bp, respectively. Among these unigenes, 36,368 (about 77.02%) were annotated and there were 109 up-regulated unigenes and 72 down-regulated unigenes in the developing seeds lipid synthetic pathway after comparing with leaves. In the oleic acid pathway, 23 unigenes were up-regulated and four unigenes were down-regulated. During triacylglycerol (TAG) synthesis, the key unigenes were all up-regulated, such as phosphatidate phosphatase and diacylglycerol O-acyltransferase. During palmitic acid, palmitoleic acid, stearic acid, linoleic acid and linolenic acid synthesis in leaves, the unigenes were nearly all up-regulated, which indicated that the biosynthesis of these particular fatty acids were more important in leaves. In the developing seeds, almost all the unigenes in the ABI3VP1, RKD, CPP, E2F-DP, GRF, JUMONJI, MYB-related, PHD and REM transcript factor families were up-regulated, which helped us to discern the regulation mechanism underlying lipid biosynthesis. The differential up/down-regulation of the genes and TFs involved in lipid biosynthesis in developing seeds and leaves provided direct evidence that allowed us to map the network that regulates lipid biosynthesis, and the identification of new TFs that are up-regulated in developing seeds

  12. Transcriptome Analysis Comparison of Lipid Biosynthesis in the Leaves and Developing Seeds of Brassica napus

    PubMed Central

    Chen, Jie; Tan, Ren-Ke; Guo, Xiao-Juan; Fu, Zheng-Li; Wang, Zheng; Zhang, Zhi-Yan; Tan, Xiao-Li

    2015-01-01

    Brassica napus seed is a lipid storage organ containing approximately 40% oil, while its leaves contain many kinds of lipids for many biological roles, but the overall amounts are less than in seeds. Thus, lipid biosynthesis in the developing seeds and the leaves is strictly regulated which results the final difference of lipids. However, there are few reports about the molecular mechanism controlling the difference in lipid biosynthesis between developing seeds and leaves. In this study, we tried to uncover this mechanism by analyzing the transcriptome data for lipid biosynthesis. The transcriptome data were de novo assembled and a total of 47216 unigenes were obtained, which had an N50 length and median of 1271 and 755 bp, respectively. Among these unigenes, 36368 (about 77.02%) were annotated and there were 109 up-regulated unigenes and 72 down-regulated unigenes in the developing seeds lipid synthetic pathway after comparing with leaves. In the oleic acid pathway, 23 unigenes were up-regulated and four unigenes were down-regulated. During triacylglycerol (TAG) synthesis, the key unigenes were all up-regulated, such as phosphatidate phosphatase and diacylglycerol O-acyltransferase. During palmitic acid, palmitoleic acid, stearic acid, linoleic acid and linolenic acid synthesis in leaves, the unigenes were nearly all up-regulated, which indicated that the biosynthesis of these particular fatty acids were more important in leaves. In the developing seeds, almost all the unigenes in the ABI3VP1, RKD, CPP, E2F-DP, GRF, JUMONJI, MYB-related, PHD and REM transcript factorfamilies were up-regulated, which helped us to discern the regulation mechanism underlying lipid biosynthesis. The differential up/down-regulation of the genes and TFs involved in lipid biosynthesis in developing seeds and leaves provided direct evidence that allowed us to map the network that regulates lipid biosynthesis, and the identification of new TFs that are up-regulated in developing seeds

  13. Coordinate changes in gene expression and triacylglycerol composition in the developing seeds of oilseed rape (Brassica napus) and turnip rape (Brassica rapa).

    PubMed

    Vuorinen, Anssi L; Kalpio, Marika; Linderborg, Kaisa M; Kortesniemi, Maaria; Lehto, Kirsi; Niemi, Jarmo; Yang, Baoru; Kallio, Heikki P

    2014-02-15

    Crop production for vegetable oil in the northern latitudes utilises oilseed rape (Brassica napus subsp. oleifera) and turnip rape (B. rapa subsp. oleifera), having similar oil compositions. The oil consists mostly of triacylglycerols, which are synthesised during seed development. In this study, we characterised the oil composition and the expression levels of genes involved in triacylglycerol biosynthesis in the developing seeds in optimal, low temperature (15 °C) and short day (12-h day length) conditions. Gene expression levels of several genes were altered during seed development. Low temperature and short day treatments increased the level of 9,12,15-octadecatrienoic acid (18:3n-3) in turnip rape and short day treatment decreased the total oil content in both species. This study gives a novel view on seed oil biosynthesis under different growth conditions, bringing together gene expression levels of the triacylglycerol biosynthesis pathway and oil composition over a time series in two related oilseed species.

  14. Gene Silencing of BnTT10 Family Genes Causes Retarded Pigmentation and Lignin Reduction in the Seed Coat of Brassica napus

    PubMed Central

    Zhang, Kai; Lu, Kun; Qu, Cunmin; Liang, Ying; Wang, Rui; Chai, Yourong; Li, Jiana

    2013-01-01

    Yellow-seed (i.e., yellow seed coat) is one of the most important agronomic traits of Brassica plants, which is correlated with seed oil and meal qualities. Previous studies on the Brassicaceae, including Arabidopsis and Brassica species, proposed that the seed-color trait is correlative to flavonoid and lignin biosynthesis, at the molecular level. In Arabidopsis thaliana, the oxidative polymerization of flavonoid and biosynthesis of lignin has been demonstrated to be catalyzed by laccase 15, a functional enzyme encoded by the AtTT10 gene. In this study, eight Brassica TT10 genes (three from B. napus, three from B. rapa and two from B. oleracea) were isolated and their roles in flavonoid oxidation/polymerization and lignin biosynthesis were investigated. Based on our phylogenetic analysis, these genes could be divided into two groups with obvious structural and functional differentiation. Expression studies showed that Brassica TT10 genes are active in developing seeds, but with differential expression patterns in yellow- and black-seeded near-isogenic lines. For functional analyses, three black-seeded B. napus cultivars were chosen for transgenic studies. Transgenic B. napus plants expressing antisense TT10 constructs exhibited retarded pigmentation in the seed coat. Chemical composition analysis revealed increased levels of soluble proanthocyanidins, and decreased extractable lignin in the seed coats of these transgenic plants compared with that of the controls. These findings indicate a role for the Brassica TT10 genes in proanthocyanidin polymerization and lignin biosynthesis, as well as seed coat pigmentation in B. napus. PMID:23613820

  15. Systemic Resistance to Powdery Mildew in Brassica napus (AACC) and Raphanus alboglabra (RRCC) by Trichoderma harzianum TH12.

    PubMed

    Alkooranee, Jawadayn Talib; Yin, Yongtai; Aledan, Tamarah Raad; Jiang, Yingfen; Lu, Guangyuan; Wu, Jiangsheng; Li, Maoteng

    2015-01-01

    Trichoderma harzianum TH12 is a microbial pesticide for certain rapeseed diseases. The mechanism of systemic resistance induced by TH12 or its cell-free culture filtrate (CF) in Brassica napus (AACC) and Raphanus alboglabra (RRCC) to powdery mildew disease caused by ascomycete Erysiphe cruciferarum was investigated. In this study, we conducted the first large-scale global study on the cellular and molecular aspects of B. napus and R. alboglabra infected with E. cruciferarum. The histological study showed the resistance of R. alboglabra to powdery mildew disease. The growth of fungal colonies was not observed on R. alboglabra leaves at 1, 2, 4, 6, 8, and 10 days post-inoculation (dpi), whereas this was clearly observed on B. napus leaves after 6 dpi. In addition, the gene expression of six plant defense-related genes, namely, PR-1, PR-2 (a marker for SA signaling), PR-3, PDF 1.2 (a marker for JA/ET signaling), CHI620, and CHI570, for both genotypes were analyzed in the leaves of B. napus and R. alboglabra after treatment with TH12 or CF and compared with the non-treated ones. The qRT-PCR results showed that the PR-1 and PR-2 expression levels increased in E. cruciferarum-infected leaves, but decreased in the TH12-treated leaves compared with leaves treated with CF. The expression levels of PR-3 and PDF1.2 decreased in plants infected by E. cruciferarum. However, expression levels increased when the leaves were treated with TH12. For the first time, we disclosed the nature of gene expression in B. napus and R. alboglabra to explore the resistance pathways in the leaves of both genotypes infected and non-infected by powdery mildew and inoculated or non-inoculated with elicitor factors. Results suggested that R. alboglabra exhibited resistance to powdery mildew disease, and the application of T. harzianum and its CF are a useful tool to facilitate new protection methods for resist or susceptible plants. PMID:26540161

  16. Systemic Resistance to Powdery Mildew in Brassica napus (AACC) and Raphanus alboglabra (RRCC) by Trichoderma harzianum TH12.

    PubMed

    Alkooranee, Jawadayn Talib; Yin, Yongtai; Aledan, Tamarah Raad; Jiang, Yingfen; Lu, Guangyuan; Wu, Jiangsheng; Li, Maoteng

    2015-01-01

    Trichoderma harzianum TH12 is a microbial pesticide for certain rapeseed diseases. The mechanism of systemic resistance induced by TH12 or its cell-free culture filtrate (CF) in Brassica napus (AACC) and Raphanus alboglabra (RRCC) to powdery mildew disease caused by ascomycete Erysiphe cruciferarum was investigated. In this study, we conducted the first large-scale global study on the cellular and molecular aspects of B. napus and R. alboglabra infected with E. cruciferarum. The histological study showed the resistance of R. alboglabra to powdery mildew disease. The growth of fungal colonies was not observed on R. alboglabra leaves at 1, 2, 4, 6, 8, and 10 days post-inoculation (dpi), whereas this was clearly observed on B. napus leaves after 6 dpi. In addition, the gene expression of six plant defense-related genes, namely, PR-1, PR-2 (a marker for SA signaling), PR-3, PDF 1.2 (a marker for JA/ET signaling), CHI620, and CHI570, for both genotypes were analyzed in the leaves of B. napus and R. alboglabra after treatment with TH12 or CF and compared with the non-treated ones. The qRT-PCR results showed that the PR-1 and PR-2 expression levels increased in E. cruciferarum-infected leaves, but decreased in the TH12-treated leaves compared with leaves treated with CF. The expression levels of PR-3 and PDF1.2 decreased in plants infected by E. cruciferarum. However, expression levels increased when the leaves were treated with TH12. For the first time, we disclosed the nature of gene expression in B. napus and R. alboglabra to explore the resistance pathways in the leaves of both genotypes infected and non-infected by powdery mildew and inoculated or non-inoculated with elicitor factors. Results suggested that R. alboglabra exhibited resistance to powdery mildew disease, and the application of T. harzianum and its CF are a useful tool to facilitate new protection methods for resist or susceptible plants.

  17. Systemic Resistance to Powdery Mildew in Brassica napus (AACC) and Raphanus alboglabra (RRCC) by Trichoderma harzianum TH12

    PubMed Central

    Alkooranee, Jawadayn Talib; Yin, Yongtai; Aledan, Tamarah Raad; Jiang, Yingfen; Lu, Guangyuan; Wu, Jiangsheng; Li, Maoteng

    2015-01-01

    Trichoderma harzianum TH12 is a microbial pesticide for certain rapeseed diseases. The mechanism of systemic resistance induced by TH12 or its cell-free culture filtrate (CF) in Brassica napus (AACC) and Raphanus alboglabra (RRCC) to powdery mildew disease caused by ascomycete Erysiphe cruciferarum was investigated. In this study, we conducted the first large-scale global study on the cellular and molecular aspects of B. napus and R. alboglabra infected with E. cruciferarum. The histological study showed the resistance of R. alboglabra to powdery mildew disease. The growth of fungal colonies was not observed on R. alboglabra leaves at 1, 2, 4, 6, 8, and 10 days post-inoculation (dpi), whereas this was clearly observed on B. napus leaves after 6 dpi. In addition, the gene expression of six plant defense-related genes, namely, PR-1, PR-2 (a marker for SA signaling), PR-3, PDF 1.2 (a marker for JA/ET signaling), CHI620, and CHI570, for both genotypes were analyzed in the leaves of B. napus and R. alboglabra after treatment with TH12 or CF and compared with the non-treated ones. The qRT-PCR results showed that the PR-1 and PR-2 expression levels increased in E. cruciferarum-infected leaves, but decreased in the TH12-treated leaves compared with leaves treated with CF. The expression levels of PR-3 and PDF1.2 decreased in plants infected by E. cruciferarum. However, expression levels increased when the leaves were treated with TH12. For the first time, we disclosed the nature of gene expression in B. napus and R. alboglabra to explore the resistance pathways in the leaves of both genotypes infected and non-infected by powdery mildew and inoculated or non-inoculated with elicitor factors. Results suggested that R. alboglabra exhibited resistance to powdery mildew disease, and the application of T. harzianum and its CF are a useful tool to facilitate new protection methods for resist or susceptible plants. PMID:26540161

  18. Helitron-like transposons contributed to the mating system transition from out-crossing to self-fertilizing in polyploid Brassica napus L.

    PubMed Central

    Gao, Changbin; Zhou, Guilong; Ma, Chaozhi; Zhai, Wen; Zhang, Tong; Liu, Zhiquan; Yang, Yong; Wu, Ming; Yue, Yao; Duan, Zhiqiang; Li, Yaya; Li, Bing; Li, Jijun; Shen, Jinxiong; Tu, Jinxing; Fu, Tingdong

    2016-01-01

    The mating system transition in polyploid Brassica napus (AACC) from out-crossing to selfing is a typical trait to differentiate it from their diploid progenitors. Elucidating the mechanism of mating system transition has profound consequences for understanding the speciation and evolution in B. napus. Functional complementation experiment has shown that the insertion of 3.6 kb into the promoter of self-incompatibility male determining gene, BnSP11-1 leads to its loss of function in B. napus. The inserted fragment was found to be a non-autonomous Helitron transposon. Further analysis showed that the inserted 3.6 kb non-autonomous Helitron transposon was widely distributed in B. napus accessions which contain the S haplotype BnS-1. Through promoter deletion analysis, an enhancer and a putative cis-regulatory element (TTCTA) that were required for spatio-temporal specific expression of BnSP11-1 were identified, and both might be disrupted by the insertion of Helitron transposon. We suggested that the insertion of Helitron transposons in the promoter of BnSP11-1 gene had altered the mating system and might facilitated the speciation of B. napus. Our findings have profound consequences for understanding the self-compatibility in B. napus as well as for the trait variations during evolutionary process of plant polyploidization. PMID:27650318

  19. Selection and evaluation of novel reference genes for quantitative reverse transcription PCR (qRT-PCR) based on genome and transcriptome data in Brassica napus L.

    PubMed

    Yang, Hongli; Liu, Jing; Huang, Shunmou; Guo, Tingting; Deng, Linbin; Hua, Wei

    2014-03-15

    Selection of reference genes in Brassica napus, a tetraploid (4×) species, is a very difficult task without information on genome and transcriptome. By now, only several traditional reference genes which show significant expression differentiation under different conditions are used in B. napus. In the present study, based on genome and transcriptome data of the rapeseed Zhongshuang-11 cultivar, 14 candidate reference genes were screened for investigation in different tissues, cultivars, and treated conditions of B. napus. These genes were as follows: ELF5, ENTH, F-BOX7, F-BOX2, FYPP1, GDI1, GYF, MCP2d, OTP80, PPR, SPOC, Unknown1, Unknown2 and UBA. Among them, excluding GYF and FYPP1, another 12 genes, were identified to perform better than traditional reference genes ACTIN7 and GAPDH. To further validate the accuracy of the newly developed reference genes in normalization, expression levels of BnCAT1 (B. napus catalase 1) in different rapeseed tissues and seedlings under stress conditions were normalized by the three most stable reference genes PPR, GDI1, and ENTH and little difference existed in normalization results. To the best of our knowledge, this is the first time B. napus reference genes have been provided with the help of complete genome and transcriptome information. The new reference genes provided in this study are more accurate than previously reported reference genes in quantifying expression levels of B. napus genes.

  20. Methylene blue adsorption onto swede rape straw (Brassica napus L.) modified by tartaric acid: equilibrium, kinetic and adsorption mechanisms.

    PubMed

    Feng, Yanfang; Zhou, Hui; Liu, Guohua; Qiao, Jun; Wang, Jinhua; Lu, Haiying; Yang, Linzhang; Wu, Yonghong

    2012-12-01

    The aim of this study was to develop a promising and competitive bioadsorbent with the abundant of source, low price and environmentally friendly characters to remove cationic dye from wastewater. The swede rape straw (Brassica napus L.) modified by tartaric acid (SRSTA) was prepared, characterized and used to remove methylene blue (MB) from aqueous solution at varied operational conditions (including MB initial concentrations, adsorbent dose, etc.). Results demonstrated that the equilibrium data was well fitted by Langmuir isotherm model. The maximum MB adsorption capacity of SRSTA was 246.4 mg g(-1), which was comparable to the results of some previous studied activated carbons. The higher dye adsorption capacity could be attributed to the presence of more functional groups such as carboxyl group on the surface of SRSTA. The adsorption mechanism was also discussed. The results indicate that SRSTA is a promising and valuable absorbent to remove methylene blue from wastewater.

  1. Modification of (137)Cs transfer to rape (Brassica napus L.) phytomass under the influence of soil microorganisms.

    PubMed

    Pareniuk, O; Shavanova, K; Laceby, J P; Illienko, V; Tytova, L; Levchuk, S; Gudkov, I; Nanba, K

    2015-11-01

    After nuclear accidents, such as those experienced in Chernobyl and Fukushima, microorganisms may help purify contaminated soils by changing the mobility of radionuclides and their availability for plants by altering the physical and chemical properties of the substrate. Here, using model experiments with quartz sand as a substrate we investigate the influence of microorganisms on (137)Cs transfer from substrate to plants. The highest transition of (137)Cs from substrate to plants (50% increase compared to the control) was observed after Brassica napus L. seeds were inoculated by Azotobacter chroococcum. The best results for reducing the accumulation of (137)Cs radionuclides (30% less) were noted after the inoculation by Burkholderia sp.. Furthermore, Bacillus megaterium demonstrated an increased ability to accumulate (137)Cs. This research improves our prediction of the behavior of radionuclides in soil and may contribute towards new, microbiological countermeasures for soil remediation following nuclear accidents. PMID:26210686

  2. Altered Fruit and Seed Development of Transgenic Rapeseed (Brassica napus) Over-Expressing MicroRNA394.

    PubMed

    Song, Jian Bo; Shu, Xia Xia; Shen, Qi; Li, Bo Wen; Song, Jun; Yang, Zhi Min

    2015-01-01

    Fruit and seed development in plants is a complex biological process mainly involved in input and biosynthesis of many storage compounds such as proteins and oils. Although the basic biochemical pathways for production of the storage metabolites in plants are well characterized, their regulatory mechanisms are not fully understood. In this study, we functionally identified rapeseed (Brassica napus) miR394 with its target gene Brassica napus leaf curling responsiveness (BnLCR) to dissect a role of miR394 during the fruit and seed development. Transgenic rapeseed plants over-expressing miR394 under the control of the cauliflower mosaic virus 35S promoter were generated. miR394 over-expression plants exhibited a delayed flowering time and enlarged size of plants, leaf blade, pods and seed body, but developed seeds with higher contents of protein and glucosinolates (GLS) and lower levels of oil accumulation as compared to wild-type. Over-expression of miR394 altered the fatty acid (FA) composition by increasing several FA species such as C16:0 and C18:0 and unsaturated species of C20:1 and C22:1 but lowering C18:3. This change was accompanied by induction of genes coding for transcription factors of FA synthesis including leafy cotyledon1 (BnLEC1), BnLEC2, and FUSCA3 (FUS3). Because the phytohormone auxin plays a crucial role in fruit development and seed patterning, the DR5-GUS reporter was used for monitoring the auxin response in Arabidopsis siliques and demonstrated that the DR5 gene was strongly expressed. These results suggest that BnmiR394 is involved in rapeseed fruit and seed development.

  3. Quantitative trait loci for thermal time to flowering and photoperiod responsiveness discovered in summer annual-type Brassica napus L.

    PubMed

    Nelson, Matthew N; Rajasekaran, Ravikesavan; Smith, Alison; Chen, Sheng; Beeck, Cameron P; Siddique, Kadambot H M; Cowling, Wallace A

    2014-01-01

    Time of flowering is a key adaptive trait in plants and is conditioned by the interaction of genes and environmental cues including length of photoperiod, ambient temperature and vernalisation. Here we investigated the photoperiod responsiveness of summer annual-types of Brassica napus (rapeseed, canola). A population of 131 doubled haploid lines derived from a cross between European and Australian parents was evaluated for days to flowering, thermal time to flowering (measured in degree-days) and the number of leaf nodes at flowering in a compact and efficient glasshouse-based experiment with replicated short and long day treatments. All three traits were under strong genetic control with heritability estimates ranging from 0.85-0.93. There was a very strong photoperiod effect with flowering in the population accelerated by 765 degree-days in the long day versus short day treatments. However, there was a strong genetic correlation of line effects (0.91) between the long and short day treatments and relatively low genotype x treatment interaction indicating that photoperiod had a similar effect across the population. Bivariate analysis of thermal time to flowering in short and long days revealed three main effect quantitative trait loci (QTLs) that accounted for 57.7% of the variation in the population and no significant interaction QTLs. These results provided insight into the contrasting adaptations of Australian and European varieties. Both parents responded to photoperiod and their alleles shifted the population to earlier flowering under long days. In addition, segregation of QTLs in the population caused wide transgressive segregation in thermal time to flowering. Potential candidate flowering time homologues located near QTLs were identified with the aid of the Brassica rapa reference genome sequence. We discuss how these results will help to guide the breeding of summer annual types of B. napus adapted to new and changing environments.

  4. Altered Fruit and Seed Development of Transgenic Rapeseed (Brassica napus) Over-Expressing MicroRNA394.

    PubMed

    Song, Jian Bo; Shu, Xia Xia; Shen, Qi; Li, Bo Wen; Song, Jun; Yang, Zhi Min

    2015-01-01

    Fruit and seed development in plants is a complex biological process mainly involved in input and biosynthesis of many storage compounds such as proteins and oils. Although the basic biochemical pathways for production of the storage metabolites in plants are well characterized, their regulatory mechanisms are not fully understood. In this study, we functionally identified rapeseed (Brassica napus) miR394 with its target gene Brassica napus leaf curling responsiveness (BnLCR) to dissect a role of miR394 during the fruit and seed development. Transgenic rapeseed plants over-expressing miR394 under the control of the cauliflower mosaic virus 35S promoter were generated. miR394 over-expression plants exhibited a delayed flowering time and enlarged size of plants, leaf blade, pods and seed body, but developed seeds with higher contents of protein and glucosinolates (GLS) and lower levels of oil accumulation as compared to wild-type. Over-expression of miR394 altered the fatty acid (FA) composition by increasing several FA species such as C16:0 and C18:0 and unsaturated species of C20:1 and C22:1 but lowering C18:3. This change was accompanied by induction of genes coding for transcription factors of FA synthesis including leafy cotyledon1 (BnLEC1), BnLEC2, and FUSCA3 (FUS3). Because the phytohormone auxin plays a crucial role in fruit development and seed patterning, the DR5-GUS reporter was used for monitoring the auxin response in Arabidopsis siliques and demonstrated that the DR5 gene was strongly expressed. These results suggest that BnmiR394 is involved in rapeseed fruit and seed development. PMID:25978066

  5. Altered Fruit and Seed Development of Transgenic Rapeseed (Brassica napus) Over-Expressing MicroRNA394

    PubMed Central

    Song, Jian Bo; Shu, Xia Xia; Shen, Qi; Li, Bo Wen; Song, Jun; Yang, Zhi Min

    2015-01-01

    Fruit and seed development in plants is a complex biological process mainly involved in input and biosynthesis of many storage compounds such as proteins and oils. Although the basic biochemical pathways for production of the storage metabolites in plants are well characterized, their regulatory mechanisms are not fully understood. In this study, we functionally identified rapeseed (Brassica napus) miR394 with its target gene Brassica napus LEAF CURLING RESPONSIVENESS (BnLCR) to dissect a role of miR394 during the fruit and seed development. Transgenic rapeseed plants over-expressing miR394 under the control of the cauliflower mosaic virus 35S promoter were generated. miR394 over-expression plants exhibited a delayed flowering time and enlarged size of plants, leaf blade, pods and seed body, but developed seeds with higher contents of protein and glucosinolates (GLS) and lower levels of oil accumulation as compared to wild-type. Over-expression of miR394 altered the fatty acid (FA) composition by increasing several FA species such as C16:0 and C18:0 and unsaturated species of C20:1 and C22:1 but lowering C18:3. This change was accompanied by induction of genes coding for transcription factors of FA synthesis including LEAFY COTYLEDON1 (BnLEC1), BnLEC2, and FUSCA3 (FUS3). Because the phytohormone auxin plays a crucial role in fruit development and seed patterning, the DR5-GUS reporter was used for monitoring the auxin response in Arabidopsis siliques and demonstrated that the DR5 gene was strongly expressed. These results suggest that BnmiR394 is involved in rapeseed fruit and seed development. PMID:25978066

  6. Metabolic Characteristics in Meal of Black Rapeseed and Yellow-Seeded Progeny of Brassica napus-Sinapis alba Hybrids.

    PubMed

    Jiang, Jinjin; Wang, Yue; Xie, Tao; Rong, Hao; Li, Aimin; Fang, Yujie; Wang, Youping

    2015-01-01

    Breeding of yellow-seeded rapeseed (Brassica napus) is preferred over black-seeded rapeseed for the desirable properties of the former. This study evaluated the metabolites and nutritive values of black-seeded rapeseed meal and yellow-seeded meal from the progeny of a B. napus-Sinapis alba hybrid. Yellow-seed meal presented higher protein (35.46% vs. 30.29%), higher sucrose (7.85% vs. 7.29%), less dietary fiber (26.19% vs. 34.63%) and crude fiber (4.56% vs. 8.86%), and less glucosinolates (22.18 vs. 28.19 μmol/g) than black-seeded one. Amounts of ash (3.65% vs. 4.55%), phytic acid (4.98% vs. 5.60%), and total polyphenols (2.67% vs. 2.82%) were decreased slightly in yellow-seeded meal compared with black-seeded meal. Yellow-seeded meal contained more essential amino acids than black-seeded meal. Levels of the mineral elements Fe, Mn, and Zn in yellow-seeded meal were higher than black-seeded meal. By contrast, levels of P, Ca, and Mg were lower in yellow-seeded meal. Moreover, yellow-seeded meal showed lower flavonol (kaempferol, quercetin, isorhamnetin, and their derivatives) content than black-seeded meal. Comparison of metabolites between yellow and black rapeseed confirmed the improved nutritional value of meal from yellow-seeded B. napus, and this would be helpful to the breeding and improvement of rapeseed for animal feeding. PMID:26633322

  7. Physiological and molecular analyses of black and yellow seeded Brassica napus regulated by 5-aminolivulinic acid under chromium stress.

    PubMed

    Gill, Rafaqat A; Ali, Basharat; Islam, Faisal; Farooq, Muhammad A; Gill, Muhammad B; Mwamba, Theodore M; Zhou, Weijun

    2015-09-01

    Brassica napus L. is a promising oilseed crop among the oil producing species. So, it is prime concern to screen the metal tolerant genotypes in order to increase the oilseed rape production through the utilization of pollutant soil regimes. Nowadays, use of plant growth regulators against abiotic stress is one of the major objectives of researchers. In this study, an attempt was carried out to analyze the pivotal role of exogenously applied 5-amenolevulinic acid (ALA) on alleviating chromium (Cr)-toxicity in black and yellow seeded B. napus. Plants of two cultivars (ZS 758 - a black seed type, and Zheda 622 - a yellow seed type) were treated with 400 μM Cr with or without 15 and 30 mg/L ALA. Results showed that exogenously applied ALA improved the plant growth and increased ALA contents; however, it decreased the Cr concentration in B. napus leaves under Cr-toxicity. Moreover, exogenous ALA reduced oxidative stress by up-regulating antioxidant enzyme activities and their related gene expression. Further, results suggested that stress responsive protein's transcript level such as HSP90-1 and MT-1 were increased under Cr stress alone in both cultivars. Exogenously applied ALA further enhanced the expression rate in both genotypes and obviously results were found in favor of cultivar ZS 758. The ultrastructural changes were observed more obvious in yellow seeded than black seeded cultivar; however, exogenously applied ALA helped the plants to recover their cell turgidity under Cr stress. The present study describes a detailed molecular mechanism how ALA regulates the plant growth by improving antioxidant machinery and related transcript levels, cellular modification as well as stress related genes expression under Cr-toxicity.

  8. Metabolic Characteristics in Meal of Black Rapeseed and Yellow-Seeded Progeny of Brassica napus-Sinapis alba Hybrids.

    PubMed

    Jiang, Jinjin; Wang, Yue; Xie, Tao; Rong, Hao; Li, Aimin; Fang, Yujie; Wang, Youping

    2015-01-01

    Breeding of yellow-seeded rapeseed (Brassica napus) is preferred over black-seeded rapeseed for the desirable properties of the former. This study evaluated the metabolites and nutritive values of black-seeded rapeseed meal and yellow-seeded meal from the progeny of a B. napus-Sinapis alba hybrid. Yellow-seed meal presented higher protein (35.46% vs. 30.29%), higher sucrose (7.85% vs. 7.29%), less dietary fiber (26.19% vs. 34.63%) and crude fiber (4.56% vs. 8.86%), and less glucosinolates (22.18 vs. 28.19 μmol/g) than black-seeded one. Amounts of ash (3.65% vs. 4.55%), phytic acid (4.98% vs. 5.60%), and total polyphenols (2.67% vs. 2.82%) were decreased slightly in yellow-seeded meal compared with black-seeded meal. Yellow-seeded meal contained more essential amino acids than black-seeded meal. Levels of the mineral elements Fe, Mn, and Zn in yellow-seeded meal were higher than black-seeded meal. By contrast, levels of P, Ca, and Mg were lower in yellow-seeded meal. Moreover, yellow-seeded meal showed lower flavonol (kaempferol, quercetin, isorhamnetin, and their derivatives) content than black-seeded meal. Comparison of metabolites between yellow and black rapeseed confirmed the improved nutritional value of meal from yellow-seeded B. napus, and this would be helpful to the breeding and improvement of rapeseed for animal feeding.

  9. Oxidative injury and antioxidant enzymes regulation in arsenic-exposed seedlings of four Brassica napus L. cultivars.

    PubMed

    Farooq, Muhammad A; Li, Lan; Ali, Basharat; Gill, Rafaqat A; Wang, Jian; Ali, Shafaqat; Gill, Muhammad B; Zhou, Weijun

    2015-07-01

    Environmental contamination due to arsenic (As) has become a major risk throughout the world; this affects plant growth and productivity. Its accumulation in food chain may pose a severe threat to organisms. The present study was carried out to observe the toxic effects of As (0, 50, 100, and 200 μM) on physiological and biochemical changes in four Brassica napus cultivars (ZS 758, Zheda 619, ZY 50, and Zheda 622). Results showed that As toxicity provoked a significant inhibition in growth parameters of B. napus cultivars and this reduction was more obvious in cultivar Zheda 622. The highest concentration of MDA, H2O2, and O2 (-) contents in both leaf and root tissues were observed at 200 μM As level, and a gradual decrease was observed at lower concentrations. Increasing As concentration gradually decreased chlorophyll and carotenoids contents. Activity of antioxidant enzymes such as SOD, CAT, APX, GR, and GSH was positively correlated with As treatments in all cultivars. The microscopic study of leaves and roots at 200 μM As level showed the disorganization in cell organelles. Disturbance in the morphology of chloroplast, broken cell wall, increase in size, and number of starch grains and immature nucleus were found in leaf ultrastructures under higher concentration of As. Moreover, damaged nucleus, diffused cell wall, enlarged vacuoles, and a number of mitochondria were observed in root tip cells at 200 μM As level. These results suggest that B. napus cultivars have efficient mechanism to tolerate As toxicity, as evidenced by an increased level of antioxidant enzymes.

  10. Integration of a constraint-based metabolic model of Brassica napus developing seeds with 13C-metabolic flux analysis

    DOE PAGES

    Hay, Jordan O.; Shi, Hai; Heinzel, Nicolas; Hebbelmann, Inga; Rolletschek, Hardy; Schwender, Jorg

    2014-12-19

    The use of large-scale or genome-scale metabolic reconstructions for modeling and simulation of plant metabolism and integration of those models with large-scale omics and experimental flux data is becoming increasingly important in plant metabolic research. Here we report an updated version of bna572, a bottom-up reconstruction of oilseed rape (Brassica napus L.; Brassicaceae) developing seeds with emphasis on representation of biomass-component biosynthesis. New features include additional seed-relevant pathways for isoprenoid, sterol, phenylpropanoid, flavonoid, and choline biosynthesis. Being now based on standardized data formats and procedures for model reconstruction, bna572+ is available as a COBRA-compliant Systems Biology Markup Language (SBML) modelmore » and conforms to the Minimum Information Requested in the Annotation of Biochemical Models (MIRIAM) standards for annotation of external data resources. Bna572+ contains 966 genes, 671 reactions, and 666 metabolites distributed among 11 subcellular compartments. It is referenced to the Arabidopsis thaliana genome, with gene-protein-reaction (GPR) associations resolving subcellular localization. Detailed mass and charge balancing and confidence scoring were applied to all reactions. Using B. napus seed specific transcriptome data, expression was verified for 78% of bna572+ genes and 97% of reactions. Alongside bna572+ we also present a revised carbon centric model for 13C-Metabolic Flux Analysis (13C-MFA) with all its reactions being referenced to bna572+ based on linear projections. By integration of flux ratio constraints obtained from 13C-MFA and by elimination of infinite flux bounds around thermodynamically infeasible loops based on COBRA loopless methods, we demonstrate improvements in predictive power of Flux Variability Analysis (FVA). In conclusion, using this combined approach we characterize the difference in metabolic flux of developing seeds of two B. napus genotypes contrasting in starch

  11. Comparative genomic analysis of duplicated homoeologous regions involved in the resistance of Brassica napus to stem canker.

    PubMed

    Fopa Fomeju, Berline; Falentin, Cyril; Lassalle, Gilles; Manzanares-Dauleux, Maria J; Delourme, Régine

    2015-01-01

    All crop species are current or ancient polyploids. Following whole genome duplication, structural and functional modifications result in differential gene content or regulation in the duplicated regions, which can play a fundamental role in the diversification of genes underlying complex traits. We have investigated this issue in Brassica napus, a species with a highly duplicated genome, with the aim of studying the structural and functional organization of duplicated regions involved in quantitative resistance to stem canker, a disease caused by the fungal pathogen Leptosphaeria maculans. Genome-wide association analysis on two oilseed rape panels confirmed that duplicated regions of ancestral blocks E, J, R, U, and W were involved in resistance to stem canker. The structural analysis of the duplicated genomic regions showed a higher gene density on the A genome than on the C genome and a better collinearity between homoeologous regions than paralogous regions, as overall in the whole B. napus genome. The three ancestral sub-genomes were involved in the resistance to stem canker and the fractionation profile of the duplicated regions corresponded to what was expected from results on the B. napus progenitors. About 60% of the genes identified in these duplicated regions were single-copy genes while less than 5% were retained in all the duplicated copies of a given ancestral block. Genes retained in several copies were mainly involved in response to stress, signaling, or transcription regulation. Genes with resistance-associated markers were mainly retained in more than two copies. These results suggested that some genes underlying quantitative resistance to stem canker might be duplicated genes. Genes with a hydrolase activity that were retained in one copy or R-like genes might also account for resistance in some regions. Further analyses need to be conducted to indicate to what extent duplicated genes contribute to the expression of the resistance phenotype

  12. Comparative Transcriptome Analysis of Primary Roots of Brassica napus Seedlings with Extremely Different Primary Root Lengths Using RNA Sequencing.

    PubMed

    Dun, Xiaoling; Tao, Zhangsheng; Wang, Jie; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

    2016-01-01

    Primary root (PR) development is a crucial developmental process that is essential for plant survival. The elucidation of the PR transcriptome provides insight into the genetic mechanism controlling PR development in crops. In this study, we performed a comparative transcriptome analysis to investigate the genome-wide gene expression profiles of the seedling PRs of four Brassica napus genotypes that were divided into two groups, short group (D43 and D61), and long group (D69 and D72), according to their extremely different primary root lengths (PRLs). The results generated 55,341,366-64,631,336 clean reads aligned to 62,562 genes (61.9% of the current annotated genes) in the B. napus genome. We provide evidence that at least 44,986 genes are actively expressed in the B. napus PR. The majority of the genes that were expressed during seedling PR development were associated with metabolism, cellular processes, response to stimulus, biological regulation, and signaling. Using a pairwise comparison approach, 509 differentially expressed genes (DEGs; absolute value of log2 fold-change ≥1 and p ≤ 0.05) between the long and short groups were revealed, including phytohormone-related genes, protein kinases and phosphatases, oxygenase, cytochrome P450 proteins, etc. Combining GO functional category, KEGG, and MapMan pathway analyses indicated that the DEGs involved in cell wall metabolism, carbohydrate metabolism, lipid metabolism, secondary metabolism, protein modification and degradation, hormone pathways and signaling pathways were the main causes of the observed PRL differences. We also identified 16 differentially expressed transcription factors (TFs) involved in PR development. Taken together, these transcriptomic datasets may serve as a foundation for the identification of candidate genes and may provide valuable information for understanding the molecular and cellular events related to PR development. PMID:27594860

  13. Comparative Transcriptome Analysis of Primary Roots of Brassica napus Seedlings with Extremely Different Primary Root Lengths Using RNA Sequencing

    PubMed Central

    Dun, Xiaoling; Tao, Zhangsheng; Wang, Jie; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

    2016-01-01

    Primary root (PR) development is a crucial developmental process that is essential for plant survival. The elucidation of the PR transcriptome provides insight into the genetic mechanism controlling PR development in crops. In this study, we performed a comparative transcriptome analysis to investigate the genome-wide gene expression profiles of the seedling PRs of four Brassica napus genotypes that were divided into two groups, short group (D43 and D61), and long group (D69 and D72), according to their extremely different primary root lengths (PRLs). The results generated 55,341,366–64,631,336 clean reads aligned to 62,562 genes (61.9% of the current annotated genes) in the B. napus genome. We provide evidence that at least 44,986 genes are actively expressed in the B. napus PR. The majority of the genes that were expressed during seedling PR development were associated with metabolism, cellular processes, response to stimulus, biological regulation, and signaling. Using a pairwise comparison approach, 509 differentially expressed genes (DEGs; absolute value of log2 fold-change ≥1 and p ≤ 0.05) between the long and short groups were revealed, including phytohormone-related genes, protein kinases and phosphatases, oxygenase, cytochrome P450 proteins, etc. Combining GO functional category, KEGG, and MapMan pathway analyses indicated that the DEGs involved in cell wall metabolism, carbohydrate metabolism, lipid metabolism, secondary metabolism, protein modification and degradation, hormone pathways and signaling pathways were the main causes of the observed PRL differences. We also identified 16 differentially expressed transcription factors (TFs) involved in PR development. Taken together, these transcriptomic datasets may serve as a foundation for the identification of candidate genes and may provide valuable information for understanding the molecular and cellular events related to PR development.

  14. Continuous expression in tobacco leaves of a Brassica napus PEND homologue blocks differentiation of plastids and development of palisade cells.

    PubMed

    Wycliffe, Paul; Sitbon, Folke; Wernersson, Jonny; Ezcurra, Inés; Ellerström, Mats; Rask, Lars

    2005-10-01

    Brassica napus complementary deoxyribonucleic acid (cDNA) clones encoding a DNA-binding protein, BnPEND, were isolated by Southwestern screening. A distinctive feature of the protein was a bZIP-like sequence in the amino-terminal portion, which, after expression in Escherichia coli, bound DNA. BnPEND transcripts were present in B. napus roots and flower buds, and to a lesser extent in stems, flowers and young leaves. Treatment in the dark for 72 h markedly increased the amount of BnPEND transcript in leaves of all ages. Sequence comparison showed that BnPEND was similar to a presumed transcription factor from B. napus, GSBF1, a protein deduced from an Arabidopsis thaliana cDNA (BX825084) and the PEND protein from Pisum sativum, believed to anchor the plastid DNA to the envelope early during plastid development. Homology to expressed sequence tag (EST) sequences from additional species suggested that BnPEND homologues are widespread among the angiosperms. Transient expression of BnPEND fused with green fluorescent protein (GFP) in Nicotiana benthamiana epidermal cells showed that BnPEND is a plastid protein, and that the 15 amino acids at the amino-terminal contain information about plastid targeting. Expression of BnPEND in Nicotiana tabacum from the Cauliflower Mosaic Virus 35S promoter gave stable transformants with different extents of white to light-green areas in the leaves, and even albino plants. In the white areas, but not in adjacent green tissue, the development of palisade cells and chloroplasts was disrupted. Our data demonstrate that the BnPEND protein, when over-expressed at an inappropriate stage, functionally blocks the development of plastids and leads to altered leaf anatomy, possibly by preventing the release of plastid DNA from the envelope.

  15. Comparative Transcriptome Analysis of Primary Roots of Brassica napus Seedlings with Extremely Different Primary Root Lengths Using RNA Sequencing.

    PubMed

    Dun, Xiaoling; Tao, Zhangsheng; Wang, Jie; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

    2016-01-01

    Primary root (PR) development is a crucial developmental process that is essential for plant survival. The elucidation of the PR transcriptome provides insight into the genetic mechanism controlling PR development in crops. In this study, we performed a comparative transcriptome analysis to investigate the genome-wide gene expression profiles of the seedling PRs of four Brassica napus genotypes that were divided into two groups, short group (D43 and D61), and long group (D69 and D72), according to their extremely different primary root lengths (PRLs). The results generated 55,341,366-64,631,336 clean reads aligned to 62,562 genes (61.9% of the current annotated genes) in the B. napus genome. We provide evidence that at least 44,986 genes are actively expressed in the B. napus PR. The majority of the genes that were expressed during seedling PR development were associated with metabolism, cellular processes, response to stimulus, biological regulation, and signaling. Using a pairwise comparison approach, 509 differentially expressed genes (DEGs; absolute value of log2 fold-change ≥1 and p ≤ 0.05) between the long and short groups were revealed, including phytohormone-related genes, protein kinases and phosphatases, oxygenase, cytochrome P450 proteins, etc. Combining GO functional category, KEGG, and MapMan pathway analyses indicated that the DEGs involved in cell wall metabolism, carbohydrate metabolism, lipid metabolism, secondary metabolism, protein modification and degradation, hormone pathways and signaling pathways were the main causes of the observed PRL differences. We also identified 16 differentially expressed transcription factors (TFs) involved in PR development. Taken together, these transcriptomic datasets may serve as a foundation for the identification of candidate genes and may provide valuable information for understanding the molecular and cellular events related to PR development.

  16. Comparative genomic analysis of duplicated homoeologous regions involved in the resistance of Brassica napus to stem canker

    PubMed Central

    Fopa Fomeju, Berline; Falentin, Cyril; Lassalle, Gilles; Manzanares-Dauleux, Maria J.; Delourme, Régine

    2015-01-01

    All crop species are current or ancient polyploids. Following whole genome duplication, structural and functional modifications result in differential gene content or regulation in the duplicated regions, which can play a fundamental role in the diversification of genes underlying complex traits. We have investigated this issue in Brassica napus, a species with a highly duplicated genome, with the aim of studying the structural and functional organization of duplicated regions involved in quantitative resistance to stem canker, a disease caused by the fungal pathogen Leptosphaeria maculans. Genome-wide association analysis on two oilseed rape panels confirmed that duplicated regions of ancestral blocks E, J, R, U, and W were involved in resistance to stem canker. The structural analysis of the duplicated genomic regions showed a higher gene density on the A genome than on the C genome and a better collinearity between homoeologous regions than paralogous regions, as overall in the whole B. napus genome. The three ancestral sub-genomes were involved in the resistance to stem canker and the fractionation profile of the duplicated regions corresponded to what was expected from results on the B. napus progenitors. About 60% of the genes identified in these duplicated regions were single-copy genes while less than 5% were retained in all the duplicated copies of a given ancestral block. Genes retained in several copies were mainly involved in response to stress, signaling, or transcription regulation. Genes with resistance-associated markers were mainly retained in more than two copies. These results suggested that some genes underlying quantitative resistance to stem canker might be duplicated genes. Genes with a hydrolase activity that were retained in one copy or R-like genes might also account for resistance in some regions. Further analyses need to be conducted to indicate to what extent duplicated genes contribute to the expression of the resistance phenotype

  17. Oxidative injury and antioxidant enzymes regulation in arsenic-exposed seedlings of four Brassica napus L. cultivars.

    PubMed

    Farooq, Muhammad A; Li, Lan; Ali, Basharat; Gill, Rafaqat A; Wang, Jian; Ali, Shafaqat; Gill, Muhammad B; Zhou, Weijun

    2015-07-01

    Environmental contamination due to arsenic (As) has become a major risk throughout the world; this affects plant growth and productivity. Its accumulation in food chain may pose a severe threat to organisms. The present study was carried out to observe the toxic effects of As (0, 50, 100, and 200 μM) on physiological and biochemical changes in four Brassica napus cultivars (ZS 758, Zheda 619, ZY 50, and Zheda 622). Results showed that As toxicity provoked a significant inhibition in growth parameters of B. napus cultivars and this reduction was more obvious in cultivar Zheda 622. The highest concentration of MDA, H2O2, and O2 (-) contents in both leaf and root tissues were observed at 200 μM As level, and a gradual decrease was observed at lower concentrations. Increasing As concentration gradually decreased chlorophyll and carotenoids contents. Activity of antioxidant enzymes such as SOD, CAT, APX, GR, and GSH was positively correlated with As treatments in all cultivars. The microscopic study of leaves and roots at 200 μM As level showed the disorganization in cell organelles. Disturbance in the morphology of chloroplast, broken cell wall, increase in size, and number of starch grains and immature nucleus were found in leaf ultrastructures under higher concentration of As. Moreover, damaged nucleus, diffused cell wall, enlarged vacuoles, and a number of mitochondria were observed in root tip cells at 200 μM As level. These results suggest that B. napus cultivars have efficient mechanism to tolerate As toxicity, as evidenced by an increased level of antioxidant enzymes. PMID:25752633

  18. Citric acid enhances the phytoextraction of chromium, plant growth, and photosynthesis by alleviating the oxidative damages in Brassica napus L.

    PubMed

    Afshan, Sehar; Ali, Shafaqat; Bharwana, Saima Aslam; Rizwan, Muhammad; Farid, Mujahid; Abbas, Farhat; Ibrahim, Muhammad; Mehmood, Muhammad Aamer; Abbasi, Ghulam Hasan

    2015-08-01

    Chromium (Cr) toxicity is widespread in crops grown on Cr-contaminated soils and has become a serious environmental issue which requires affordable strategies for the remediation of such soils. This study was performed to assess the performance of citric acid (CA) through growing Brassica napus in the phytoextraction of Cr from contaminated soil. Different Cr (0, 100, and 500 μM) and citric acid (0, 2.5, and 5.0 mM) treatments were applied alone and in combinations to 4-week-old seedlings of B. napus plants in soil under wire house condition. Plants were harvested after 12 weeks of sowing, and the data was recorded regarding growth characteristics, biomass, photosynthetic pigments, malondialdehyde (MDA), electrolytic leakage (EL), antioxidant enzymes, and Cr uptake and accumulation. The results showed that the plant growth, biomass, chlorophyll contents, and carotenoid as well as soluble protein concentrations significantly decreased under Cr stress alone while these adverse effects were alleviated by application of CA. Cr concentration in roots, stem, and leaves of CA-supplied plant was significantly reduced while total uptake of Cr increased in all plant parts with CA application. Furthermore, in comparison with Cr treatments alone, CA supply reduced the MDA and EL values in both shoots and roots. Moreover, the activity of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) in shoots and roots markedly increased by 100 μM Cr exposure, while decreased at 500 μM Cr stress. CA application enhanced the activities of antioxidant enzymes compared to the same Cr treatment alone. Thus, the data indicate that exogenous CA application can increase Cr uptake and can minimize Cr stress in plants and may be beneficial in accelerating the phytoextraction of Cr through hyper-accumulating plants such as B. napus. PMID:25850739

  19. The infection processes of Sclerotinia sclerotiorum in cotyledon tissue of a resistant and a susceptible genotype of Brassica napus

    PubMed Central

    Garg, Harsh; Li, Hua; Sivasithamparam, Krishnapillai; Kuo, John; Barbetti, Martin J.

    2010-01-01

    Background and Aims Sclerotinia sclerotiorum can attack >400 plant species worldwide. Very few studies have investigated host–pathogen interactions at the plant surface and cellular level in resistant genotypes of oilseed rape/canola (Brassica napus). Methods Infection processes of S. sclerotiorum were examined on two B. napus genotypes, one resistant cultivar ‘Charlton’ and one susceptible ‘RQ001-02M2’ by light and scanning electron microscopy from 2 h to 8 d post-inoculation (dpi). Key Results The resistant ‘Charlton’ impeded fungal growth at 1, 2 and 3 dpi, suppressed formation of appresoria and infection cushions, caused extrusion of protoplast from hyphal cells and produced a hypersensitive reaction. At 8 dpi, whilst in ‘Charlton’ pathogen invasion was mainly confined to the upper epidermis, in the susceptible ‘RQ001-02M2’, colonization up to the spongy mesophyll cells was evident. Calcium oxalate crystals were found in the upper epidermis and in palisade cells in susceptible ‘RQ001-02M2’ at 6 dpi, and throughout leaf tissues at 8 dpi. In resistant ‘Charlton’, crystals were not observed at 6 dpi, whereas at 8 dpi they were mainly confined to the upper epidermis. Starch deposits were also more prevalent in ‘RQ001-02M2’. Conclusions This study demonstrates for the first time at the cellular level that resistance to S. sclerotiorum in B. napus is a result of retardation of pathogen development, both on the plant surface and within host tissues. The resistance mechanisms identified in this study will be useful for engineering disease-resistant genotypes and for developing markers for screening for resistance against this pathogen. PMID:20929899

  20. Physiological and molecular analyses of black and yellow seeded Brassica napus regulated by 5-aminolivulinic acid under chromium stress.

    PubMed

    Gill, Rafaqat A; Ali, Basharat; Islam, Faisal; Farooq, Muhammad A; Gill, Muhammad B; Mwamba, Theodore M; Zhou, Weijun

    2015-09-01

    Brassica napus L. is a promising oilseed crop among the oil producing species. So, it is prime concern to screen the metal tolerant genotypes in order to increase the oilseed rape production through the utilization of pollutant soil regimes. Nowadays, use of plant growth regulators against abiotic stress is one of the major objectives of researchers. In this study, an attempt was carried out to analyze the pivotal role of exogenously applied 5-amenolevulinic acid (ALA) on alleviating chromium (Cr)-toxicity in black and yellow seeded B. napus. Plants of two cultivars (ZS 758 - a black seed type, and Zheda 622 - a yellow seed type) were treated with 400 μM Cr with or without 15 and 30 mg/L ALA. Results showed that exogenously applied ALA improved the plant growth and increased ALA contents; however, it decreased the Cr concentration in B. napus leaves under Cr-toxicity. Moreover, exogenous ALA reduced oxidative stress by up-regulating antioxidant enzyme activities and their related gene expression. Further, results suggested that stress responsive protein's transcript level such as HSP90-1 and MT-1 were increased under Cr stress alone in both cultivars. Exogenously applied ALA further enhanced the expression rate in both genotypes and obviously results were found in favor of cultivar ZS 758. The ultrastructural changes were observed more obvious in yellow seeded than black seeded cultivar; however, exogenously applied ALA helped the plants to recover their cell turgidity under Cr stress. The present study describes a detailed molecular mechanism how ALA regulates the plant growth by improving antioxidant machinery and related transcript levels, cellular modification as well as stress related genes expression under Cr-toxicity. PMID:26079286

  1. Integration of a constraint-based metabolic model of Brassica napus developing seeds with 13C-metabolic flux analysis

    PubMed Central

    Hay, Jordan O.; Shi, Hai; Heinzel, Nicolas; Hebbelmann, Inga; Rolletschek, Hardy; Schwender, Jorg

    2014-01-01

    The use of large-scale or genome-scale metabolic reconstructions for modeling and simulation of plant metabolism and integration of those models with large-scale omics and experimental flux data is becoming increasingly important in plant metabolic research. Here we report an updated version of bna572, a bottom-up reconstruction of oilseed rape (Brassica napus L.; Brassicaceae) developing seeds with emphasis on representation of biomass-component biosynthesis. New features include additional seed-relevant pathways for isoprenoid, sterol, phenylpropanoid, flavonoid, and choline biosynthesis. Being now based on standardized data formats and procedures for model reconstruction, bna572+ is available as a COBRA-compliant Systems Biology Markup Language (SBML) model and conforms to the Minimum Information Requested in the Annotation of Biochemical Models (MIRIAM) standards for annotation of external data resources. Bna572+ contains 966 genes, 671 reactions, and 666 metabolites distributed among 11 subcellular compartments. It is referenced to the Arabidopsis thaliana genome, with gene-protein-reaction (GPR) associations resolving subcellular localization. Detailed mass and charge balancing and confidence scoring were applied to all reactions. Using B. napus seed specific transcriptome data, expression was verified for 78% of bna572+ genes and 97% of reactions. Alongside bna572+ we also present a revised carbon centric model for 13C-Metabolic Flux Analysis (13C-MFA) with all its reactions being referenced to bna572+ based on linear projections. By integration of flux ratio constraints obtained from 13C-MFA and by elimination of infinite flux bounds around thermodynamically infeasible loops based on COBRA loopless methods, we demonstrate improvements in predictive power of Flux Variability Analysis (FVA). Using this combined approach we characterize the difference in metabolic flux of developing seeds of two B. napus genotypes contrasting in starch and oil content. PMID

  2. Citric acid enhances the phytoextraction of chromium, plant growth, and photosynthesis by alleviating the oxidative damages in Brassica napus L.

    PubMed

    Afshan, Sehar; Ali, Shafaqat; Bharwana, Saima Aslam; Rizwan, Muhammad; Farid, Mujahid; Abbas, Farhat; Ibrahim, Muhammad; Mehmood, Muhammad Aamer; Abbasi, Ghulam Hasan

    2015-08-01

    Chromium (Cr) toxicity is widespread in crops grown on Cr-contaminated soils and has become a serious environmental issue which requires affordable strategies for the remediation of such soils. This study was performed to assess the performance of citric acid (CA) through growing Brassica napus in the phytoextraction of Cr from contaminated soil. Different Cr (0, 100, and 500 μM) and citric acid (0, 2.5, and 5.0 mM) treatments were applied alone and in combinations to 4-week-old seedlings of B. napus plants in soil under wire house condition. Plants were harvested after 12 weeks of sowing, and the data was recorded regarding growth characteristics, biomass, photosynthetic pigments, malondialdehyde (MDA), electrolytic leakage (EL), antioxidant enzymes, and Cr uptake and accumulation. The results showed that the plant growth, biomass, chlorophyll contents, and carotenoid as well as soluble protein concentrations significantly decreased under Cr stress alone while these adverse effects were alleviated by application of CA. Cr concentration in roots, stem, and leaves of CA-supplied plant was significantly reduced while total uptake of Cr increased in all plant parts with CA application. Furthermore, in comparison with Cr treatments alone, CA supply reduced the MDA and EL values in both shoots and roots. Moreover, the activity of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) in shoots and roots markedly increased by 100 μM Cr exposure, while decreased at 500 μM Cr stress. CA application enhanced the activities of antioxidant enzymes compared to the same Cr treatment alone. Thus, the data indicate that exogenous CA application can increase Cr uptake and can minimize Cr stress in plants and may be beneficial in accelerating the phytoextraction of Cr through hyper-accumulating plants such as B. napus.

  3. Comparative Transcriptome Analysis of Primary Roots of Brassica napus Seedlings with Extremely Different Primary Root Lengths Using RNA Sequencing

    PubMed Central

    Dun, Xiaoling; Tao, Zhangsheng; Wang, Jie; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

    2016-01-01

    Primary root (PR) development is a crucial developmental process that is essential for plant survival. The elucidation of the PR transcriptome provides insight into the genetic mechanism controlling PR development in crops. In this study, we performed a comparative transcriptome analysis to investigate the genome-wide gene expression profiles of the seedling PRs of four Brassica napus genotypes that were divided into two groups, short group (D43 and D61), and long group (D69 and D72), according to their extremely different primary root lengths (PRLs). The results generated 55,341,366–64,631,336 clean reads aligned to 62,562 genes (61.9% of the current annotated genes) in the B. napus genome. We provide evidence that at least 44,986 genes are actively expressed in the B. napus PR. The majority of the genes that were expressed during seedling PR development were associated with metabolism, cellular processes, response to stimulus, biological regulation, and signaling. Using a pairwise comparison approach, 509 differentially expressed genes (DEGs; absolute value of log2 fold-change ≥1 and p ≤ 0.05) between the long and short groups were revealed, including phytohormone-related genes, protein kinases and phosphatases, oxygenase, cytochrome P450 proteins, etc. Combining GO functional category, KEGG, and MapMan pathway analyses indicated that the DEGs involved in cell wall metabolism, carbohydrate metabolism, lipid metabolism, secondary metabolism, protein modification and degradation, hormone pathways and signaling pathways were the main causes of the observed PRL differences. We also identified 16 differentially expressed transcription factors (TFs) involved in PR development. Taken together, these transcriptomic datasets may serve as a foundation for the identification of candidate genes and may provide valuable information for understanding the molecular and cellular events related to PR development. PMID:27594860

  4. Tight regulation of the interaction between Brassica napus and Sclerotinia sclerotiorum at the microRNA level.

    PubMed

    Cao, Jia-Yi; Xu, You-Ping; Zhao, Li; Li, Shuang-Sheng; Cai, Xin-Zhong

    2016-09-01

    MicroRNAs (miRNAs) 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, b