Brassica Oil Research Articles

Protist ubiquitin ligase effector PbE3-2 targets cysteine protease RD21A to impede plant immunity.

Clubroot, caused by the soil-borne protist pathogen Plasmodiophora brassicae, is one of the most devastating diseases of Brassica oil and vegetable crops worldwide. Understanding the pathogen infection strategy is crucial for the development of disease control. However, because of its obligate biotrophic nature, the molecular mechanism by which this pathogen promotes infection remains largely unknown. P. brassicae E3 ubiquitin ligase 2 (PbE3-2) is a Really Interesting New Gene (RING)-type E3 ubiquitin ligase in P. brassicae with E3 ligase activity in vitro. Yeast (Saccharomyces cerevisiae) invertase assay and apoplast washing fluid extraction showed that PbE3-2 harbors a functional signal peptide. Overexpression of PbE3-2 in Arabidopsis (Arabidopsis thaliana) resulted in higher susceptibility to P. brassicae and decreases in chitin-triggered reactive oxygen species burst and expression of marker genes in salicylic acid signaling. PbE3-2 interacted with and ubiquitinated host cysteine protease RESPONSIVE TO DEHYDRATION 21A (RD21A) in vitro and in vivo. Mutant plants deficient in RD21A exhibited similar susceptibility and compromised immune responses as in PbE3-2 overexpression plants. We show that PbE3-2, which targets RD21A, is an important virulence factor for P. brassicae. Two other secretory RING-type E3 ubiquitin ligases in P. brassicae performed the same function as PbE3-2 and ubiquitinated RD21A. This study reveals a substantial virulence functional role of protist E3 ubiquitin ligases and demonstrates a mechanism by which protist E3 ubiquitin ligases degrade host immune-associated cysteine proteases to impede host immunity.

Comparison of some species in genus Brassica cultivated on clay loamy soils under semi-arid agroecosystem for suitability to biodiesel production

ABSTRACT Instead of using canola purelines, the use of other species in genus Brassica will be a novel concept to obtain sustainable biodiesel production. This study compares the crude oil percentage, fatty acid composition, and biodiesel characteristics of spring and autumn sown Brassica juncea, B. rapa ssp. oleifera, Sinapis alba, B. nigra purelines appropriateness for biodiesel production. The results indicated that crude oil percentage and fatty acid composition are significantly affected by an interaction between years × genotypes. The crude oil percentage in all species in genus Brassica changed between 14.31 and 30.46% in spring crops and 22.29 and 36.88% in autumn crops. Erucic acid (C22:1; 10.2–42.8%), oleic acid (C18:1; 14.2–34.9%), and linoleic acid (C18:2; 6.8–25.1%) were identified as major fatty acids in all genotypes. Technical features of biodiesel produced by transesterification of species in genus Brassica oil such as acid value (0.18–0.50 mg KOH g−1), water content (110–480 mg kg−1), iodine value (97.30–119.89 g iodine 100 g−1), cold filter plugging point (−5–5°C), flash point (170–205°Ϲ), and glyceride (0.003–0.46% mm−1). These values indicated that regardless of the time of sowing, these lines are appropriate for biodiesel production in accordance with the TS EN 14,214 standards. Br2 (B. rapa ssp. oleifera) autumn and Bj3 (B. juncea) spring crops are preferable compared to other genotypes to achieve higher yield and quality. Therefore, these genotypes are recommended for further evaluation and sustainable biodiesel production.

Fatty Acid Composition and Oxidative Potential of Food Products Prepared Using Low Erucic Brassica Oils

Fatty Acid Composition and Oxidative Potential of Food Products Prepared Using Low Erucic Brassica Oils

The Use of Genetic and Gene Technologies in Shaping Modern Rapeseed Cultivars (Brassica napus L.).

Since their domestication, Brassica oilseed species have undergone progressive transformation allied with the development of breeding and molecular technologies. The canola (Brassica napus) crop has rapidly expanded globally in the last 30 years with intensive innovations in canola varieties, providing for a wider range of markets apart from the food industry. The breeding efforts of B. napus, the main source of canola oil and canola meal, have been mainly focused on improving seed yield, oil quality, and meal quality along with disease resistance, abiotic stress tolerance, and herbicide resistance. The revolution in genetics and gene technologies, including genetic mapping, molecular markers, genomic tools, and gene technology, especially gene editing tools, has allowed an understanding of the complex genetic makeup and gene functions in the major bioprocesses of the Brassicales, especially Brassica oil crops. Here, we provide an overview on the contributions of these technologies in improving the major traits of B. napus and discuss their potential use to accomplish new improvement targets.

Improved Brassica oleracea JZS assembly reveals significant changing of LTR-RT dynamics in different morphotypes.

Brassica oleracea is an important vegetable crop that has provided ancestor genomes of the two most important Brassica oil crops, Brassica napus and Brassica carinata. The current B. oleracea reference genome (JZS, also named 02-12) displays problems of large mis-assemblies, low sequence continuity, and low assembly integrity, thus limiting genomic analysis. We reported an updated assembly of the B. oleracea reference genome (JZS v2) obtained through single-molecule sequencing and chromosome conformation capture technologies. We assembled an additional 83.16Mb of genomic sequences, and the updated genome features a contig N50 size of 2.37Mb, representing an ~ 88-fold improvement. We detected a new round of long terminal repeat retrotransposon (LTR-RT) burst in the new assembly. Comparative analysis with the reported genome sequences of two other genomes of B. oleracea (TO1000 and HDEM) identified extensive gene order and gene structural variation. In addition, we found that the genome-specific amplification of Gypsy-like LTR-RTs occurred around 0-1 million years ago (MYA). In particular, the athila, tat, and Del families were extensively amplified in JZS around 0-1 MYA. Moreover, we identified that the syntenic genes were modified due to the insertion of genome-specific LTR-RTs. These results indicated that the genome-specific LTR-RT dynamics were associated with genome diversification in B. oleracea.

Tribological and rheological properties of palm and brassica oil with inclusion of CuO and TiO2 additives

In the present study, tribological properties of vegetable oil addition of nanoparticles have been carried out using pin on disc tribometer. Vegetable oils are Palm oil and Brassica oil are used in tribological test. Copper oxide (Cuo) nanoparticles and Titanium oxide (Tio2) nanoparticles are used as additives on weight percentage of 0.1% and 0.5%. From the study it was perceived that Palm oil with 0.5% Cuo based lubricant sample illustrations significantly reduce in coefficient of friction and wear than rest of lubricant samples. Viscosity and thermal conductivity properties also increase with increasing nanoparticles concentrations in vegetable oils (palm and Brassica). SEM (Scanning Electron Microscopy) images shows the worn surface of pin materials.

First Report of Sclerotinia subarctica nom. prov. (Sclerotinia sp. 1) Causing Stem Rot on Turnip Rape (Brassica rapa subsp. oleifera) in Norway

During August 2013, white-grayish lesions, typical of Sclerotinia stem rot, had developed around leaf axils on the stems of turnip rape ‘Pepita’ in a field at the NIBIO research station Apelsvoll in Oppland County, Norway. Sclerotia were collected from inside infected turnip rape stubble and from harvested seeds, surface sterilized, bisected, and placed onto potato dextrose agar (PDA). Following 1 to 2 days incubation at 20°C, fast-growing white mycelium characteristic of Sclerotinia was observed, and within 5 to 7 days, new sclerotia had started to develop. Sclerotia size and growing pattern although variable was characteristic of S. sclerotiorum. DNA extraction, PCR amplification, and sequencing of the ITS regions of the rDNA was then carried out for 20 isolates. BLASTn analysis of 475 bp amplicons showed that 15 isolates were S. sclerotiorum, while five were identified as S. subarctica (previously called Sclerotinia sp 1; Holst-Jensen et al. 1998; Winton et al. 2006, 2007), with 100% identity to a U.K. S. subarctica isolate (Clarkson et al. 2010). A representative ITS region sequence was deposited in GenBank (accession no. KX929095). The identity of the S. subarctica isolates was further confirmed by the lack of a 304-bp intron in the LSU rDNA compared with S. sclerotiorum (Holst-Jensen et al. 1998), which was visualized by PCR amplification and gel electrophoresis. Sclerotia of two S. subarctica isolates were placed on PDA and incubated for 7 days. Agar plugs of actively growing mycelium were used for the pathogenicity testing of spring oilseed rape plants (‘Mosaik’) in the greenhouse. Plants were inoculated at growth stage BBCH 57/59 (preflowering) and BBCH 64 (40% of flowers open) by attaching two PDA plugs of actively growing mycelium per main stems with small needles, using four plants per treatment. Noninoculated PDA agar plugs were attached to the control plants. The experiment was repeated three times. Symptoms typical of stem rot appeared after 1 to 2 weeks of incubation at 16 to 20°C, 100% relative humidity. Stems started to develop white lesions with fluffy mycelium around the inoculation sites. Control plants did not show the characteristic symptoms for Sclerotinia infection. After senescence of the plants, sclerotia were collected from inside the stems and cultured on PDA. White mycelium started to grow after 1 to 2 days and new sclerotia were formed within 7 days, similar to the ones used for producing the initial isolate. Brassica oil seed crops are cultivated as important break crops in the cereal-based production system in Norway and can be severely affected by Sclerotinia stem rot. The disease is observed in all regions where Brassica oil seed crops are grown, and in severe cases, a reduction in oilseed yield of 25% has been recorded in untreated control treatments of fungicide trials. Although S. subarctica has been previously reported on wild hosts (Holst-Jensen et al. 1998), this is the first report of the pathogen on a crop plant in Norway. In the United Kingdom, Clarkson et al. (2010) demonstrated pathogenicity of S. subarctica isolated from Ranunculus acris on oilseed rape. As symptoms for S. subarctica and S. sclerotiorum are indistinguishable, S. subarctica might be present undetected in many farmer fields.

The Plasmodiophora brassicae genome reveals insights in its life cycle and ancestry of chitin synthases

Plasmodiophora brassicae causes clubroot, a major disease of Brassica oil and vegetable crops worldwide. P. brassicae is a Plasmodiophorid, obligate biotrophic protist in the eukaryotic kingdom of Rhizaria. Here we present the 25.5 Mb genome draft of P. brassicae, developmental stage-specific transcriptomes and a transcriptome of Spongospora subterranea, the Plasmodiophorid causing powdery scab on potato. Like other biotrophic pathogens both Plasmodiophorids are reduced in metabolic pathways. Phytohormones contribute to the gall phenotypes of infected roots. We report a protein (PbGH3) that can modify auxin and jasmonic acid. Plasmodiophorids contain chitin in cell walls of the resilient resting spores. If recognized, chitin can trigger defense responses in plants. Interestingly, chitin-related enzymes of Plasmodiophorids built specific families and the carbohydrate/chitin binding (CBM18) domain is enriched in the Plasmodiophorid secretome. Plasmodiophorids chitin synthases belong to two families, which were present before the split of the eukaryotic Stramenopiles/Alveolates/Rhizaria/Plantae and Metazoa/Fungi/Amoebozoa megagroups, suggesting chitin synthesis to be an ancient feature of eukaryotes. This exemplifies the importance of genomic data from unexplored eukaryotic groups, such as the Plasmodiophorids, to decipher evolutionary relationships and gene diversification of early eukaryotes.

Effect of Water Deficiency and Potassium Application on Plant Growth, Osmolytes and Grain Yield of Brassica Napus Cultivars

Abstract One of the major issues with brassica oil seed production is the water requirement of the brassica crop. To address the problem, field experiments were conducted to evaluate the effect of potassium (K) and water deficiency levels on canola (Brassica napus L.). Analysis of the data revealed that application of K, irrigation and interactions between irrigation and cultivar (I x C), irrigation and potassium (I x K), potassium and cultivar (K x C), and irrigation and cultivar and potassium (I x C x K) had a significant (p < 0.05) effect on shoot proline content, relative water content, plant fresh weight and grain yield. Potassium application, irrigation and interaction between I x C, K x C, and I x C x K had a significant (p < 0.05) effect on shoot sugar content. Water deficiency increased shoot proline and sugar contents and decreased relative water content. Potassium application increased shoot proline level in a dose dependent manner. Minimum proline and sugar contents and maximum relative water content, plant fresh and dry weight and yield were obtained when 100% irrigation was applied. Maximum grain yield was obtained upon application of 100% irrigation in combination with 120 kg ha−1 K.

Correlations between Tocopherol and Fatty Acid Components in Germplasm Collections of Brassica Oilseeds

To date, little is known about the correlations among the tocopherol (T) and fatty acid (FA) components in rapeseed oils. In the current study, a germplasm collection of landraces from the species Brassica juncea , Brassica rapa , and Brassica napus and a collection of low erucic acid (EA) breeding lines from B. napus were analyzed for FA and T contents. In the groups comprising landraces, the most notable correlation was the significantly positive one between α-T and the sum of C18:1 and C18:2, whereas neither positive correlations were found between α-T and C18:3 nor were positive correlations observed between α-T and very long chain FAs (VLCFA). Hardly any association between γ-T and FA components was observed, indicating the possible function of α-T beyond its antioxidant property. The complexity of correlation between T and FA components in Brassica oils may arise from the role of α-T in the FA metabolism of endoplasmic reticulum (ER).

The genome of the mesopolyploid crop species Brassica rapa

We report the annotation and analysis of the draft genome sequence of Brassica rapa accession Chiifu-401-42, a Chinese cabbage. We modeled 41,174 protein coding genes in the B. rapa genome, which has undergone genome triplication. We used Arabidopsis thaliana as an outgroup for investigating the consequences of genome triplication, such as structural and functional evolution. The extent of gene loss (fractionation) among triplicated genome segments varies, with one of the three copies consistently retaining a disproportionately large fraction of the genes expected to have been present in its ancestor. Variation in the number of members of gene families present in the genome may contribute to the remarkable morphological plasticity of Brassica species. The B. rapa genome sequence provides an important resource for studying the evolution of polyploid genomes and underpins the genetic improvement of Brassica oil and vegetable crops.

PP 1/153 (3): Control of lodging and growth regulation in brassica oil crops

Specific scopeThis standard describes the conduct of trials for the efficacy evaluation of plant growth regulators used for manipulation of canopy structure, winter hardiness or the control of lodging in brassica oil crops.Specific approval and amendmentFirst approved in 1989–09.Revision approved in 2010–09.

Comparing regional risks in producing turnip rape and oilseed rape – Today in light of long-term datasets

Finland is the only country in which summer turnip rape (Brassica rapa L.) is predominant over oilseed rape (Brassica napus L.) as an oil crop. However, farmer interest in growing oilseed rape has increased significantly over recent years. Accordingly, this study aims to compare the regional risks of producing turnip rape and oilseed rape in order to avoid setbacks in Finnish vegetable oil production. This study is especially topical because the cultivated area of Brassica oil crops is projected to double in the near future and recent years have particularly favoured oilseed rape production and farmers have been encouraged to replace turnip rape with oilseed rape. Using information gained through this risk assessment, changes in oil crop production can be managed in a more economically sustainable way. In this study we used long-term datasets from MTT Agrifood Research Finland (MTT Official Variety Trials for 1976–2005) and the Finnish Meteorological Institute (regional datasets for temperature accumulation and occurrence of frosts at late seed ripening for 1971–2000). According to the results of this risk assessment, sustainable and economically feasible oil crop production in Finland must currently be based primarily on turnip rape. Oilseed rape is, however, likely to become increasingly important, but in the most favourable fields of the southernmost production regions. However, it was evident that comparison of yield values is very sensitive to variety differences for the most critical yield parameters. Hence, when introducing new oilseed rape varieties it is particularly important that they always have equal or better seed yield and seed chlorophyll content than the recently introduced, markedly improved oilseed rape varieties. This will reduce economic risks for farmers.

Survival and reproduction of some blue-green and green algae as affected by sewage water, fertilizer factory effluent, brassica oil, phenol, toluene and benzene

Fourteen blue-green and green algae survived for widely different time periods ranging between 22-102 d in control culture medium. Irrespective of their long or short survival period in control cultures, their pro- or eukaryotic nature, their different morphological types or natural habitats, they all survived for a short time period ranging between 3-8 d in sewage water, 5-10 d in fertilizer factory effluent, (1/4)-2 d in brassica oil, (1/2)-2 d in phenol, 1-3 d in toluene, and 1-4 d in benzene (showing the relative toxicity of different chemicals to different algae, and the antialgal nature of brassica oil). Dilution decreased the toxicity of these agents very little, indicating that they all were very toxic to algae. None of the agent induced the formation of any reproductive or dormant cells. Sewage water, fertilizer factory effluent, brassica oil and/or benzene favored the formation of necridia cells in Phormidium bohneri, P. foveolarum, Microcoleus chthonoplastes, Lyngbya birgei, and L. major filaments. Scenedesmus quadricauda shed off all spines earlier, Hormidium flaccidum fragmented less or not at all, Scytonema millei formed no false branch and heterocyst, Aphanothece pallida and Gloeocapsa atrata cells did not divide, Cosmarium granatum cells did not form any zygospore and Oedogonium sp. not any oogonia-like cells under all or most of treatments with 25-100 % sewage water, 1-100 % fertilizer factory effluent, 1-100 % brassica oil, 25-100 % phenol, toluene and benzene.

Novel seed oil types of Ethiopian mustard with high levels of polyunsaturated fatty acids

Oils rich in polyunsaturated fatty acids linoleic acid and linolenic acid have important industrial applications, both as drying oils in the manufacture of paints and coatings as well as in formulation of pharmaceuticals and nutraceuticals. However, no oil types with high levels of polyunsaturation have been developed so far in Brassica oilseed crops. The objective of the present research was to select for high levels of linoleic acid and linolenic acid in Ethiopian mustard ( Brassica carinata A. Braun). Selection started from the F 3 (S 0) seed generation of crosses involving the high oleic acid, high erucic acid line N2-3591, the low linolenic, high erucic acid line HF-186, and the zero erucic acid line 25X-1. The analysis of individual S 0 seeds showed ranges of variation with maximum levels of 68.9% linoleic acid and 36.4% linolenic acid. Selection for increased levels of linoleic acid resulted in a S 1:2 high linoleic acid line BC-HL that showed average linoleic acid contents of 62.5%, 58.3%, and 59.6%, respectively in three contrasting environments, compared to 47.8%, 45.8%, and 52.1%, respectively in a high linoleic acid check line. Selection for increased levels of linolenic acid resulted in a S 1:2 high linolenic acid line BC-HLN that showed average linolenic acid contents of 27.1%, 25.8%, and 26.3%, respectively in the mentioned environments, compared to 23.9%, 21.2%, and 19.4%, respectively in a high linolenic acid check line. Both lines developed in the present research possess novel fatty acid profiles not available so far in Brassica oilseed crops and they may contribute to broaden the potential of Brassica oils for industrial applications.

Phytotoxicity assessment

Phytotoxicity assessment

Weeds in brassica oil crops

Weeds in brassica oil crops

Weed suppression in mixed cropped grain peas and false flax (Camelina sativa)

SummaryMixed cropping peas with false flax, a brassica oil seed crop, in additive arrangements had a significant suppressive effect on weed coverage (63% in 2003 and 52% in 2004), compared with the monocropped pea plots. Weed suppression by false flax was apparently restricted to the establishment phase, because effects were significant against the key annuals Fallopia convolvulus, Sonchus oleraceus and Matricaria recutita, but ineffective towards the major perennials Cirsium arvense and Elytrigia repens. Relatively higher yields in mixed stands with calculated land equivalent ratios (LER) of 1.43 (2003) and 1.98 (2004) were the result of low monocrop yields mainly related to weed pressure not only in pea but also in false flax. Partial LERs were in favour of peas, demonstrating a balanced but asymmetric complementarity of the components, with peas as the main and false flax as the minor crop component. The role of false flax in row‐cropped peas can be characterized as both a smother crop and weed antagonist with no obvious indications for allelopathic traits. Weed suppression was probably achieved by a mutually enhanced competitiveness of both crop components, indicating a mechanism based on resource allocation, but further research is needed for a better understanding of weed‐suppressive traits in pea–false flax mixed cropping systems.

Modification of Brassica Oil Using Conventional and Transgenic Approaches

ABSTRACTModifying the fatty acid composition of Brassica seed oil to increase its value as a nutritional or as an industrial oil has been a major objective in Brassica breeding programs worldwide. The conventional approach to fatty acid modification has explored natural or induced mutations occurring in the same plant species or close relatives within the Brassica genus. These mutations have been shown to be associated with a few enzymes in the biosynthetic pathway of the fatty acids. Several types of Brassica oil with significantly altered levels of the long chain fatty acid erucic acid (C22:1) and medium chain fatty acids such as oleic acid (C18:1) and linolenic acid (C18:3) have been developed for different end uses through conventional breeding. When the necessary genetic variation is not available within Brassica species, gene transfer by genetic transformation has been applied, as this approach is not restricted by the sexual incompatibility barrier across species. The fatty acids targeted by the transgenic approach included fatty acids with various carbon chain lengths ranging from C8 to C22, with different numbers of double bonds, and with various functional groups such as epoxy and hydroxy fatty acids. A commercial specialty oil with high level of a novel fatty acid, lauric acid (C12:0), was produced as a result of the transfer of a FatB thioesterase gene from a distantly related plant species that produces seed oil with high level of this unusual fatty acid. Considerable progress has been achieved in altering the relative levels of the fatty acids found in Brassica oils for increased health and economic benefits and in developing Brassica oils which contain other unusual fatty acids, mainly through genetic transformation. Although the use of natural or induced mutations in the fatty acid biosynthesis within Brassica remains a valid option for oil modification, the transgenic approach will play an increasingly important role in the development of Brassica oils with altered novel fatty acid composition.

Breeding for Improved Oil Quality in Brassica Oilseed Species

Abstract Oil quality in vegetable oils is determined by both nutritional and functional aspects, which are, in turn, primarily determined by the fatty acid profile (i.e., fatty acid composition) of the oil. The naturally occurring fatty acid composition of Brassica oils has been extensively modified using conventional plant breeding and biotechnology-based techniques to create unique and improved quality vegetable oils. New Brassica cultivars displaying a wide range of edible oil qualities have been developed, and commercialized in recent years. Improved Brassica cultivars which produce an industrial oil have also been developed and commercialized in the last two decades. World vegetable oil markets are highly competitive, so the steady improvement in oil quality of the Brassica oilseeds is essential to maintain or increase market share, and/or to create new niche markets. The main challenges facing Brassica oilseed breeders are (1) to determine the desirable fatty acid profiles of the oil for each end-us...