Search

Camelina sativa (L.) Crantz (family Brassicaceae) or false flax, a new oilseed plant for biodiesel and jet fuel production, has been cultivated for centuries in the temperate climate belt of Europe, as an annual summer or winter crop. Camelina is gaining popularity because of its low input requirements and its possibility of being used as a low greenhouse gas emission biofuel crop. Consecutive agronomic trials were carried out in northeast India (Assam), which is characterized by a sub-tropical climate. Three genotypes were used for the study. Comparisons at agronomic, physiological and biochemical levels were carried out. Results demonstrate that Camelina could grow and produce seeds in northeast India only during the winter season (October to March) when precipitation was absent, and the temperature was comparable to that of the temperate European belt in spring-summer. The oil quality and quantities showed small changes and remain in a suitable range for biofuel production. We infer that Camelina sativa has a high level of plasticity and ability to adapt in an area outside of its original habitat and can be cultivated in winter, as a second crop, in northeast India to provide a valuable feedstock for biofuel producers.

Camelina (Camelina sativa (L.) Crantz) is an attractive alternative and sustainable oilseed crop for multipurpose uses, including as a biofuel feedstock. To evaluate the value of C. sativa in Lombardia (north Italy), seven genotypes were cultivated under different climates of two consecutive years and growing seasons; quality and quantity of seed, oil, and flour were analyzed. Genotypes mainly influenced seed weight (0.98-1.56 g/1000 seeds), protein (245-401 mg/g), glucosinolates, and phytic acid. Oil content (27.5%-37.2%) and fatty acid (FA) composition varied with year and growing season among genotypes. Oils were rich in linolenic and linoleic acids (68.4%-80.8%). The monounsaturated acids ranged from 16.4%-25.6%, although erucic acid was much lower at 4.30%. Saturated FAs represented a small fraction. Low free FAs content (0.01%-0.81%) and different amounts of tocopherols (0.44-2.69 ?g/mg) in oils depended on years. Correlations among seed and biochemical traits were found. Genotypes with low protein and high phytic acid contents would not be the best for flour quality. Genotypes showing high levels of protein and C18:3/C18:2 fatty acids ratio could be useful for humans and livestock. Genotype with relatively high C18:1 fatty acid content can be used mainly for biofuel production. Altogether, the data indicated that C. sativa cultivation could be promoted as an economically profitable oilseed crop in north Italian environments. Copyright © Taylor & Francis Group, LLC.

Camelina sativa (L.) Crantz in the last few years is garnering a lot of attention as a biofuel and as raw material for the chemical industry due to its high oil productivity. However the high percentage of polyunsaturated fatty acids of camelina oil (over 50%), which is rich in linolenic acid (37–40%) limits its commercial value and large-scale production. To improve the oil quality and its oxidative stability the methyl esters have been selectively hydrogenated using a non-toxic and non-pyrophoric heterogeneous copper catalyst (Cu/SiO 2 or Cu/Al 2 O 3 ). Our results showed that both catalysts are able to reduce the linolenic acid content below 1% while selectively increasing the monounsaturated one.

Root-knot nematodes (Meloidogyne spp.) are a severe economic constraint of vegetable and industrial crops in the Mediterranean region. The control of these nematodes is necessary to maintain crop yield and quality at economic levels. The use of synthetic pesticides is expensive and polluting. As an alternative, nematodes can be managed by biopesticides. In this study, we evaluated the nematicidal activity of leaf and root meals from Aster caucasicus and A. sedifolius and of the saponins extracted from A. sedifolius on M. incognita and the potato cyst nematode Globodera rostochiensis. Leaf and root meals did not affect root gall index in tomatoes inoculated with M. incognita, while the reproduction of the nematode was reduced by about 97% with 0.5 and 1 g/100 cm3 soil of meals from leaves and roots of A. sedifolius. The effect of A. caucasicus was restricted to leaf meal: the reduction of the nematode eggs per tomato root was 82.3 and 92.7% at 0.5 and 1 g/100 cm3 soil, respectively. When the soil was treated with purified saponins of A. sedifolius at rates from 1.19 to 4.75 mg/100 cm3 soil, the reproduction of the nematode was not affected. Moreover, saponins of A. sedifolius did not show any effect on the viability of second stage juveniles of M. incognita as well as of G. rostochiensis.

Triterpene saponins are a group of bioactive compounds abundant in the genus Medicago, and have been studied extensively for their biological and pharmacological properties. In this article, we evaluated the effects of the ectopic expression of AsOXA1 cDNA from Aster sedifolius on the production of triterpene saponins in barrel medic (Medicago truncatula Gaertn.). AsOXA1 cDNA encodes beta-amyrin synthase, a key enzyme involved in triterpene saponin biosynthesis. One of the four transgenic lines expressing AsOXA1 accumulated significantly larger amounts of some triterpenic compounds in leaf and root than did control plants. In particular, the leaf exhibited significantly higher levels of bayogenin, medicagenic acid and zanhic acid. The amounts of medicagenic acid and zanhic acid, which represent the core of the M. truncatula leaf saponins, were 1.7 and 2.1 times higher, respectively, than the amounts extracted from the control line. In root, the production of bayogenin, hederagenin, soyasapogenol E and 2beta-hydroxyoleanolic acid was increased significantly. The increase in the total amounts of triterpenic compounds observed in the leaves of transgenic lines correlated with the AsOXA1 expression level. Interestingly, the plants expressing AsOXA1 showed, under different growth conditions, improved nodulation when compared with the control line. Nodulation enhancement was also accompanied by a significant change in the soyasapogenol B content. Our results indicate that the ectopic expression of AsOXA1 in barrel medic leads to a greater accumulation of triterpene saponins and enhanced root nodulation.

A genomic DNA library enriched with GA/TC repeats from Camelina sativa variety Calena has been analysed. After sequencing of about 200 randomly selected clones, approximately 60% of them showed to contain simple or compound microsatellites with a high number of repeats. Among all microsatellite markers analysed 15 primer pairs amplified polymorphic fragments. Forty C. sativa accessions of different origin were genotyped with 15 microsatellite markers that generated 134 alleles with an average of 8.93 alleles per locus. The observed heterozygosity (Ho) among the accessions ranged from 0.0 to 0.15 with an average of 0.0370, whereas the average of expected heterozygosity (He) among accessions was 0.2769. The analysis of the average total heterozygosity (HT = 0.651), the intrapopulation genetic diversity (HS = 0.260), the interpopulation genetic diversity (DST = 0.391) and the coefficient of genetic differentiation among populations (GST = 0.574) demonstrated that 57.4% of the genetic diversity is among the accessions, while 42.6% resides within them. Phylogenetic tree of the 40 C. sativa accessions was constructed based on Nei's genetic distance. The UPGMA (Unweighted Pair Group Method with Arithmetic Mean) dendrogram shows, except for CAM108 and CAM170, a clear discrimination among C. sativa accessions grouping them in five subgroups. ANOVA analysis indicates significant differences in some biochemical and agronomic parameters among the C. sativa accessions grouped according to Nei's genetic distance. The result of the Tukey HSD test demonstrated that the A4 subgroup showed a significant higher TWS and linoleic acid (LA) content, while the subgroup A1 showed a significant higher linolenic and lower linoleic acid content compared to the remaining groups.

Several different classes of secondary metabolites, including flavonoids, triterpenoid saponins and quinic acid derivatives, are found in Aster spp. (Fam. Asteraceae). Several Aster compounds revealed biological as well as pharmacological activities. In this work, a phytochemical investigation of A. caucasicus evidenced the presence of quinic acid derivatives, as well as the absence of triterpene saponins. To combine in one species the production of different phytochemicals, including triterpenes, an Agrobacterium-mediated transformation of A. caucasicus was set up to introduce A. sedifolius beta-amyrin synthase (AsOXA1)-encoding gene under the control of the constitutive promoter CaMV35S. The quali-quantitative analysis of transgenic calli with ectopic expression of AsOXA1 showed, in one sample, a negligible amount of triterpene saponins combined with higher amount of quinic acid derivatives as compared with the wild type callus.

Triterpenoid saponins are secondary metabolites showing a remarkable structural variety, as well as notable biological activities. They are synthesised via the isoprenoid pathway by 2,3-oxidosqualene cyclization mediated by oxidosqualene cyclase (OSC) enzymes. In our previous work, three new oleanane-type triterpene saponins (astersedifolioside A–C) were isolated from the aerial tissues of Aster sedifolius L. In this work, the full-length cDNA of a new OSC, designated AsOXA1 , was isolated from A. sedifolius . The AsOXA1 open reading frame consisting of 2286 bp was predicted to encode a protein of 761 amino acid residues. The deduced amino acid sequence of AsOXA1 showed QW and DCTAE motifs which are highly conserved among the known triterpene synthases. In addition, the comparative and phylogenetic analysis evidenced that AsOXA1 was closely related to other plant OSCs, and particularly, β-amyrin synthases including that one of Panax ginseng with which it shared a high degree of identity (79%). Recombinant AsOXA1 has been shown to produce β-amyrin in yeast. RT-PCR analysis evidenced that AsOXA1 was a tissue-specific gene differentially expressed during plant development. Transcripts of AsOXA1 accumulated strongly in leaf at the early reproductive stage but were deficient in root. On the contrary, the accumulation of astersedifoliosides resulted 10-fold higher in roots than in aerial tissues. Molecular and biochemical results have been discussed.

Several different classes of secondary metabolites, including flavonoids, triterpenoid saponins and quinic acid derivatives, are found in Aster spp. (Fam. Asteraceae). Several Aster compounds revealed biological as well as pharmacological activities. In this work, a phytochemical investigation of A. caucasicus evidenced the presence of quinic acid derivatives, as well as the absence of triterpene saponins. To combine in one species the production of different phytochemicals, including triterpenes, an Agrobacterium-mediated transformation of A. caucasicus was set up to introduce A. sedifolius β-amyrin synthase (AsOXA1)-encoding gene under the control of the constitutive promoter CaMV35S. The quali-quantitative analysis of transgenic calli with ectopic expression of AsOXA1 showed, in one sample, a negligible amount of triterpene saponins combined with higher amount of quinic acid derivatives as compared with the wild type callus.