La cameline, Camelina sativa (Brassicaceae), fait aujourd'hui l'objet d'un regain d'intérêt. Il s'agit d'une plante aux vocations multiples (bioénergétique, industrielle, alimentaire), aux exigences agronomiques faibles et qui semble peu sujette aux attaques de ravageurs phytophages.Trois objectifs visant à appréhender la complexité des interactions multitrophiques autour de la cameline ont été définis au cours de ce travail de thèse. Le premier visait à déterminer le rôle de la cameline en tant que réservoir à pucerons ravageurs. Les deux autres reposaient sur les études des impacts des pratiques culturales (fertilisation azotée, culture en association) et des virus de plantes, sur les interactions tritrophiques cameline/pucerons/parasitoïdes. Les premiers résultats ont permis de montrer que la cameline pouvait être considérée comme plante réservoir pour différentes espèces de pucerons ravageurs présents dans les paysages agricoles du nord de la France, qu'il s'agisse d'espèces inféodées aux Brassicaceae (Brevicoryne brassicae), d'espèces polyphages (Myzus persicae, Aphis fabae) ou encore d'espèces spécialistes des Poaceae (Rhopalosiphum padi). En ce qui concerne les deux pratiques culturales étudiées, l'association de la cameline avec la fèverole a engendré des effets délétères sur le contrôle biologique du puceron Aphis fabae par le parasitoïde Aphidius matricariae. Le comportement des femelles A. matricariae ne semble pas satisfaire à la théorie de "l’optimal foraging". En parallèle, des effets de la fertilisation azotée ont été observés sur les trois niveaux trophiques et ont varié en fonction de la dose apportée à la plante et du degré de spécialisation du puceron. Ainsi, notre étude montre que les pratiques culturales peuvent avoir des répercussions importantes de type "bottom-up" sur les niveaux trophiques supérieurs. Enfin, nous avons montré un impact des deux virus de plantes étudiés qui s'est révélé variable non seulement en fonction du mode mais aussi de l'efficacité de la transmission par le puceron-vecteur. Ce dernier travail a également permis de mettre en évidence des effets "bottom-up" d'un virus sur le comportement de sélection de l'hôte par un parasitoïde de puceron mais aussi sur la physiologie des partenaires appartenant aux trois niveaux trophiques. En effet, les performances du puceron-vecteur sur la plante infectée semblent améliorées alors que celles du parasitoïde sont altérées, ce qui pourrait se traduire par une meilleure propagation du virus. Ces travaux soulignent l'importance de la prise en compte des relations multitrophiques avant la (ré-) introduction d’une espèce de plante dans les agro-écosystèmes, et en particulier l'intérêt d'identifier les risques associés en termes de pression de ravageurs et de pathogènes / Camelina (Camelina sativa, Brassicaceae) has recently received great attention as an alternative oil-seed crop presenting various (bioenergetic, industrial, alimentary) advantages, requiring low agronomic inputs and exhibiting few attacks by phytophagous insects.In this thesis, three objectives have been defined to understand the complexity of the multi-trophic interactions involving camelina. The first one was to determine the role of camelina as a reservoir of aphid pests. The other two were based on the study of the effects of cultural practices (nitrogen fertilization, mixed crops) and plant viruses on the tritrophic interactions involving camelina, aphids and parasitoids.Results have shown that camelina could be considered as a plant reservoir for various aphid pest species occurring in the agricultural landscape of northern France, among which were found not only species usually restricted to Brassicaceae (Brevicoryne brassicae), but also polyphagous species (Myzus persicae, Aphis fabae) and specialists of Poaceae (Rhopalosiphum padi). Regarding the two studied agricultural practices, the association of camelina with faba bean induced deleterious effects on the biological control of the aphid Aphis fabae by the parasitoid Aphidius matricariae. The behavior of parasitoid females did not seem in line with the "optimal foraging" theory. In addition, several effects of nitrogen fertilization have been observed on the three trophic levels depending on both the dose given to the plant and the degree of specialization of the aphid. Thus, our study has shown that cultural practices could have significant "bottom-up" impacts on higher trophic levels. Finally, we have shown the two studied plant viruses had an impact which not only varied depending on the virus mode of transmission by the vector but also according to its transmission efficiency. This work also revealed the existence of "bottom-up" effects of a virus on the host selection behavior by an aphid parasitoid as well as on the physiology of the partners belonging to three trophic levels. Indeed, the performance of the aphid vector was improved on the infected plant whereas that of the parasitoid was impaired, which could lead to a better spread of the virus.This work highlights not only the importance of taking into account the associated multi-trophic relations before the (re-) introduction of a plant species within agro-ecosystems but also the importance of identifying the risks in terms of pests and pathogens pressure

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Food Science." Includes bibliographical references (p. 165-170).

Brassica carinata (A.) Braun and Camelina sativa (L.) Crantz are two re-emerging oilseed crops of the Brassicaceae family that are being adapted for cultivation in western Canada. Both seeds of these species reportedly accumulate considerable amounts of sulfur-containing secondary metabolites called glucosinolates. The purpose of the current work was to gain knowledge of the occurrence and distribution of glucosinolates during primary processing of these oilseeds, including during pressing and dehulling. In the first study, a reversed phase HPLC method was developed for the analysis of sinigrin, the major glucosinolate in B. carinata. Both C18 columns selected were able to separate the compound with an isocratic eluent containing 100% tetramethylammonium bromide (10 mM, pH 5) delivered at 1 mL/min at a column temperature of 25oC. These chromatographic conditions were applied and sinigrin concentration of whole B.carinata seed was estimated to be 29 μg/mg. Average matrix effect was estimated to be 104% that was caused by other components in the B. carinata seed matrix. In the second study, high concentrations of glucosinolates were detected and identified in fractions of C. sativa seeds using HPLC-ESI-MS. Methods for extraction, isolation, and purification of three individual glucosinolates from these fractions are reported. Quantitation of total glucosinolates was performed on proton NMR using DMF as an internal standard. Quantitation of individual glucosinolates was achieved by using MS extracted ion chromatogram data. Total glucosinolates were found in C. sativa whole seed at a concentration of 14 μg/mg, and glucocamelinin, the major glucosinolate, constituted 65% of the total amount. In addition, a dehulling treatment was applied to C. sativa seeds, from which both oil content and crude protein content increased after dehulling of the seeds.

Master of Science / Department of Biological & Agricultural Engineering / Donghai Wang / Gums are water-soluble polysaccharides used in many industrial and food applications because of their functions such as thickening, gelling, emulsification, adhesion, and encapsulation. Interactions between gums are conducted to enhance functional properties of finished products and reduce processing costs. In this study, camelina gum, from the oil-seed plant Camelina sativa, is characterized by carbohydrate composition and morphological, thermal, and rheological properties. Interactions with xanthan gum, galactomannans guar gum, and locust bean gum (LBG) are also studied. Camelina gum is composed of arabinose, rhamnose, galactose, glucose, xylose and mannose; according to high-performance anion exchange chromatography analysis. Scanning electron microscopy and transmission electron microscopy images showed camelina gum with fibrillar structure and intermeshed network. Camelina gum solutions exhibited a shear thinning flow behavior in a range of concentrations (0.1% to 2.0% w/w) and shear rate (0.001 sˉ¹ to 3000 sˉ¹). Camelina gum is temperature independent at temperature ranges from 4 °C to 90 °C. The apparent viscosity increased as gum concentration increased. Mechanical properties of camelina gum demonstrated viscoelastic behavior with entangled molecular chains. Interaction of camelina gum with monovalent salt NaCl significantly reduced the viscosity of camelina gum solution at 1% when NaCl concentration increased. Camelina gum is soluble in water up to 60% ethanol content, in which the rheological properties do not significantly differ from camelina gum in water solution only. A synergy with xanthan and galactomannans was determined. All mixtures exhibited shear-thinning flow behavior, solid-like behavior at low frequencies, and liquid-like behavior at high frequencies. For camelina-galactomannans mixtures, synergistic interactions occurred in LBG-camelina mixtures at ratios of 1:1 and 3:1. For xanthan-camelina mixture, maximum synergy was observed at the ratio 1:1. Synergistic effects of gum mixtures suggest dependency on the ratios and chemical structures of the gums. The effect of temperature on apparent viscosity of mixtures is not significant. Results showed that camelina gum can be used for commercial applications.

Doctor of Philosophy / Department of Agronomy / Nathan O. Nelson / Augustine K. Obour / Emerging sustainability issues with summer-fallow period has prompted producers to identify fallow replacement crops in wheat (Triticum aestivum) production systems. Camelina [Camelina sativa (L.) Crantz] has been identified as a potential fallow replacement crop in the semiarid Great Plains. Camelina has uses in animal and human nutrition, biofuel production, and bio-based products. Three field experiments were conducted to develop production recommendations for camelina in wheat production systems in the semiarid Great Plains. In the first study, three camelina cultivars were evaluated in mid-March (March 17, 2014; March 18, 2015), early-April (April 3, 2013; April 1, 2014 and 2015), and mid-April (April 16, 2013; April 15, 2014 and 2015) at Hays, KS. Findings from this study showed delaying camelina planting until early- or mid-April resulted in 34% increase in seed yield. Planting date affected oil concentration, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and linolenic acid concentration. The concentrations of SFA, MUFA, PUFA, linoleic acid, and linolenic acid were also different among cultivars. A second study was conducted to evaluate the response of camelina to nitrogen (N), and sulfur (S) fertilizer application. Nitrogen rates (0, 22, 45 and 90 kg ha⁻¹), and S rates (0 and 20 kg ha⁻¹) were applied in a randomized complete block design with a split-plot arrangement. The main plots were S application rates and the subplot factor was N rates. Sulfur application did not affect seed yield, oil, protein, or seed nutrient concentration. The agronomic optimum N rate was 49 kg N ha⁻¹, however, the economic optimum N rate ranged from 25 to 31 kg N ha⁻¹ based on current N fertilizer cost, and camelina seed price. Nitrogen application had no effect on SFA, MUFA, and PUFA. Moderate N application increased seed calcium (Ca) concentration, whereas higher N rate increased zinc (Zn), and manganese (Mn) concentration in the seed. There was a general negative relation between N application with copper (Cu), and molybdenum (Mo) in camelina seed. Our study shows that camelina needed to be applied with a minimum of 25 kg N ha⁻¹ for optimum production. A third study investigated effects of crop rotation on crop yield, soil water, soil CO₂ flux, and soil health in wheat-camelina rotation systems. Rotation systems in this study were wheat-fallow (W-F), wheat-sorghum (Sorghum bicolor) -fallow (W-S-F), wheat-spring camelina (W-SC), and wheat-sorghum-spring camelina (W-S-SC). Crop rotation had no effect on sorghum grain yield. However, winter wheat yield decreased by 15% when fallow was replaced by camelina in the rotation system. Camelina yield in W-SC was 2-fold greater than that in W-S-SC. Soil water content in the more intensified rotations were less than rotations with fallow, irrespective of sampling period. Soil pH, phosphorus (P), and total nitrogen (TN) were not different among rotation systems. Nonetheless, soil profile N, soil organic carbon (SOC), microbial biomass carbon and N (MBC and MBN), and potentially mineralizable nitrogen (PMN) were different among rotation systems. Soil particle aggregation increased with increasing cropping intensity. This suggests improved soil structure with cropping intensification.

Master of Science / Biochemistry and Molecular Biophysics Interdepartmental Program / Timothy P. Durrett / Using vegetable oils directly as an alternative biofuel presents several problems as such oils typically possess poor fuel qualities including high viscosity, low volatility, and poor cold temperature properties. The ornamental shrub Euonymus alatus produces unusual acetyl-1,2-diacyl-sn-glycerols (acetyl-TAGs) that have an acetyl group in the sn-3 position instead of a long chain fatty acid. The presence of this sn-3 acetyl-group give acetyl-TAGs properties desirable for biofuels, such as reduced viscosity, comparted to the normal long chain triacyglycerols found in most vegetable oils. Acetyl-TAGs are synthesized by the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) and Euonymus fortunei diacylglycerol acetyltransferase (EfDAcT) enzymes. Both enzymes catalyze the transfer of an acetyl group from acetyl-CoA to diaclglycerol (DAG) to produce acetyl-TAGs. Previous work demonstrated that expression of EaDAcT combined with the suppression of a diacylglycerol aceyltransferase (DGAT1) in Camelina sativa led to seeds with 85 mol % acetyl-TAGs. Increasing acetyl-TAG levels further was explored using two strategies. Over expression of citrate lyase to increase the pool of acetyl-CoA to be used as a substrate for the acetyltransferase enzymes failed to increased levels of acetyl-TAGs. A second approach involved expressing EfDAcT in Camelina sativa. EfDAcT has demonstrated higher activity in vitro and in vivo and its expression in yeast leads to approximately 50 % higher levels of acetyl-TAGs compared to EaDAcT. The expression of EfDAcT coupled with the suppression of DGAT1 in Camelina sativa resulted in 90 mol % acetyl-TAGs in the transgenic seeds. Levels of EfDAcT protein analyzed in developing transgenic Camelina sativa seeds across a 40 day time period were highest at 15 and 20 days after flowering. Following these time points acetyl-TAG accumulation increased rapidly, coinciding with the higher enzyme expression levels. The optimization of additional promoters to ensure expression of EfDAcT in the last half of seed development could represent another way to further increase acetyl-TAGs in the future.

To better understand the nature and function of N-acylethanolamines (NAEs) in Camelina sativa, we used mass spectrometry analysis to identify and quantify NAE types in developing seeds, desiccated seeds and seedlings. Developing seeds showed a differential increase in individual NAE species and an overall increase in NAE content with seed development and maturation. The NAE composition in mature, desiccated seeds mostly reflected the total fatty acid composition in the seed tissues, except for a noted absence of 11-eicosenoic (20C monounsaturated) fatty acid in the NAE pool. During seed stratification and seedling growth, individual NAE species were depleted at similar rates. Simulated drought treatments during seedling development resulted in a significant rise in NAE levels for the major 18C NAE types compared with untreated seedlings. Arabidopsis and Camelina mutants with reported altered fatty acid profiles were analyzed for their NAE compositions; both Arabidopsis and Camelina had relatively similar changes between compositions of total seed fatty acids and NAEs. Furthermore, seeds were analyzed from transgenic Arabidopsis and Camelina with engineered, non-native, long-chain polyunsaturated fatty acids (18C, 20C and 22C), and the results showed the production of novel N-acylphosphatidylethanolamines (presumed precursors of NAEs) and NAEs with the same long acyl chains. These results demonstrate i) that NAE levels change dramatically with seed and seedling development in Camelina, ii) that NAE levels in Camelina seedlings can be elevated in response to environmental stress, and iii) that the pool of NAEs can be manipulated by making alterations to seed fatty acid compositions, some of which may have promise for the production of novel, bioactive NAEs.

Doctor of Philosophy / Department of Grain Science and Industry / X. Susan Sun / Oilseed protein is a promising renewable source to be used as the replacement of petroleum-based materials for adhesion purpose, and it has drawn increasing attention since soy-based adhesives were developed for wood glues. However, soy protein comprises a portion of humans’ diets, thereby creating competition between utilization of soy protein for protein-based products or human food. Therefore, alternative bio-resources must be discovered. Proteins from camelina sativa provide such potential. Similar to other protein-based polymers, low mechanical strength and poor water resistance are the major drawbacks limiting camelina protein’s further applications. In this research, camelina protein (CP) was modified by unfolding, crosslinking, and co-polymerization treatment for improved flow-ability, adhesion properties and water resistance, which facilitates the industrialization of camelina as an alternative to soy-based adhesives. The physicochemical properties and microstructures of CP were also investigated. To increase the reactivity of CP adhesive, the first step is to denature the folded structure of native proteins. Camelina protein was extracted from defatted camelina meal through alkali solubilization and acid precipitation and modified with varying amount of NaHSO₃ (0-12% of the protein dry base) and Gdm.Cl (0-250% of the protein dry base). NaHSO₃ treatment broke the disulfide bonds of the CP and thus increased its free sulfhydryl content and surface hydrophobicity. As NaHSO₃ concentration increased, the viscosity, elastic modulus (G') and water resistant of NaHSO₃-modified camelina protein (SMCP) dispersion decreased, and the protein became hydrophobic. Gdm.Cl treatment broke the CPI’s hydrogen bonds but decreased their surface hydrophobicity. Similarly, viscosity, G', and water resistant of Gdm.Cl-modified camelina protein (GMCP) dispersions decreased as Gdm.Cl increased and protein became to aggregate. The reducing effect of NaHSO₃ was more obvious than Gdm.Cl to disrupt CPI’s intermolecular protein interaction but less obvious than Gdm.Cl to reduce the viscosity and water resistant. To further increase the CP’s water resistance, a coupling agent, Ethyl-3-(3-dimethyl-aminopropyl-1-carbodiimide) (EDC), was applied to stabilize the protein structure by crosslinking the free carboxyl groups and amino groups. The cross-linked CP exhibited increased molecular weight and particle size. Microstructures of modified CP also became rigid and condensed. Accordingly, CP’s increased intermolecular protein interaction resulted in its higher elastic modulus, viscosity and water resistance. The ultrasound pretreatment further increased the crosslink degree of CP, which resulted in protein’s increased aggregation behaviors and compact micro-structures. Consequently, the elastic modulus, viscosity, and water resistance of CP increased accordingly. Copolymerization with hydrophobic enhancers was also an effective method to improve CP’s water resistance. In this study, kraft lignin was oxidized by H₂O₂ and then copolymerized with CP as wood adhesives, which exhibited increased wet strength. In the presence of ultrasound irradiation, the H₂O₂-depolymerized kraft lignin exhibited reduced particle size, thermal stability and increased content of hydroxyl groups. Fluorescence spectroscopy analysis revealed that after coupling with pristine or de-polymerized lignin, CP exhibited increased hydrophobicity due to lignin’s increased reactivity with camelina protein. Accordingly, the water resistance of CP-based adhesives improved. In the optimized condition, when CP was copolymerized with ultrasound-induced oxidized lignin, it had increased wet shear adhesion strength from 0.28 MPa to 1.43 MPa, with wood panels passing the three-cycle water soaking test.

The study is aimed to determine the role of avocado DGAT1 and PDAT1 in seed oil synthesis. Triacylglycerol (TAG) has a nutritional and industrial value and is essential for plant growth. DGAT1 and PDAT1 catalyze the final step of TAG Assembly. We hypothesized that both PaPDAT1 and PaDGAT1, although predominantly expressed in non-seed tissues, could contribute to oil accumulation in seeds. Agrobacterium transformants with PaPDAT1 and PaDGAT1 cloned in pCAMBIA were generated to test this. Subsequently, the Agrobacterium-mediated transformation of Arabidopsis mutant lines and camelina was carried out by floral dipping. The T1 camelina seeds expressing the genes of interest were selected using fluorescence screening. Homozygous T3 lines were generated. The transgenic camelina seeds were evaluated for TAG content and fatty acid composition relative to wild-type seeds. Line D1 3-3-2 expressing PaDGAT1 and line P1 7-8 expressing PaPDAT1 showed a significant increase in C18:1 compared to the wild type.

Three experiments compared ruminal, physiological, and performance responses of beef steers consuming hay ad libitum and receiving grain-based supplements with (CAM) or without (CO) inclusion of camelina meal. In Exp. 1, 9 steers fitted with ruminal cannulas received CAM (2.04 kg of DM/d) or CO (2.20 kg of DM/d). Steers receiving CAM had reduced (P = 0.01) total DMI and tended to have reduced (P = 0.10) forage DMI compared to CO. No treatment effects were detected (P ≥ 0.35) for ruminal hay degradability parameters. In Exp. 2, 14 steers receiving CAM (1.52 kg of DM/d) or CO (1.65 kg of DM/d) were assigned to corticotropin-releasing hormone (CRH; 0.1 μg/kg of BW) and thyrotropin-releasing hormone (TRH; 0.33 μg/kg of BW) challenges. Steers receiving CAM had greater (P < 0.05) serum concentrations of PUFA compared to CO prior to challenges. Upon CRH infusion, mean plasma ceruloplasmin concentrations increased at a lesser rate in CAM compared with CO (P < 0.01). Upon TRH infusion, no treatment effects were detected (P ≥ 0.55) for serum TSH, T₃, and T₄. In Exp. 3, 60 steers were allocated to 20 drylot pens. Pens were randomly assigned to receive CAM (2.04 kg of DM/steer daily) or CO (2.20 kg of DM/steer daily) during preconditioning (PC; d -28 to 0). On the morning of d 0, steers were transported for 24 h. Upon arrival from transport on d 1, pens were randomly assigned to receive, in a 2 x 2 factorial arrangement, CAM or CO during feedlot receiving (FR; d 1 to 29). During PC, CAM had reduced (P < 0.01) forage and total DMI, and tended to have reduced (P = 0.10) ADG compared to CO. Plasma linolenic acid concentrations increased during PC for CAM, but not for CO (P = 0.02). Steers that received CAM during FR had greater (P < 0.05) mean plasma concentrations of PUFA, and reduced mean rectal temperature and concentrations of haptoglobin and ceruloplasmin during FR compared to CO. Therefore, camelina supplementation reduced forage and total DMI, did not alter thyroid gland function, increased PUFA concentrations in blood, and attenuated the acute-phase protein reaction elicited by neuroendocrine stress responses. In conclusion, camelina meal is a feasible ingredient to reduce stress-induced inflammatory reactions and potentially promote cattle welfare and productivity in beef operations. / Graduation date: 2012