Groat oil content and composition are important quality traits in oats (Avena sativa L). These traits are controlled by many genes with additive effects. The chromosomal regions containing these genes, known as quantitative trait loci (QTL), can be discovered through their close association with markers. This study investigated total oil content and fatty acid components in an oat breeding population derived from a cross between high oil ('Dal') and low oil ('Exeter') parents. A genetic map consisting of 475 DArT (Diversity Array Technology) markers spanning 1271.8 cM across 40 linkage groups was constructed. QTL analysis for groat oil content and composition was conducted using grain samples grown at Aberdeen, ID in 1997. QTL analysis for multiple agronomic traits was also conducted using data collected from hill plots and field plots in Ottawa, ON in 2010. QTLs for oil content, palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3) were identified. Two of the QTLs associated with oil content were also associated with all of the fatty acids examined in this study, and most oil-related QTL showed similar patterns of effect on the fatty acid profile. These results suggest the presence of pleiotropic effects on oil-related traits through influences at specific nodes of the oil synthesis pathway. In addition, 12 QTL-associated markers (likely representing nine unique regions) were associated with plant height, heading date, lodging, and protein content. The results of this study will provide information for molecular breeding as well as insight into the genetic mechanisms controlling oil biosynthesis in oat.

Groat oil content and composition are important quality traits in oats (Avena sativa L). These traits are controlled by many genes with additive effects. The chromosomal regions containing these genes, known as quantitative trait loci (QTL), can be discovered through their close association with markers. This study investigated total oil content and fatty acid components in an oat breeding population derived from a cross between high oil ('Dal') and low oil ('Exeter') parents. A genetic map consisting of 475 DArT (Diversity Array Technology) markers spanning 1271.8 cM across 40 linkage groups was constructed. QTL analysis for groat oil content and composition was conducted using grain samples grown at Aberdeen, ID in 1997. QTL analysis for multiple agronomic traits was also conducted using data collected from hill plots and field plots in Ottawa, ON in 2010. QTLs for oil content, palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3) were identified. Two of the QTLs associated with oil content were also associated with all of the fatty acids examined in this study, and most oil-related QTL showed similar patterns of effect on the fatty acid profile. These results suggest the presence of pleiotropic effects on oil-related traits through influences at specific nodes of the oil synthesis pathway. In addition, 12 QTL-associated markers (likely representing nine unique regions) were associated with plant height, heading date, lodging, and protein content. The results of this study will provide information for molecular breeding as well as insight into the genetic mechanisms controlling oil biosynthesis in oat.

Soybean (Glycine max (L.) Merr) is the largest oil and protein crop in the world and it is grown for both oil and protein. To address the needs of both the edible oil market and industrial applications of soybean oil, fatty acid modification has been a focus of soybean breeding programs. Natural variation, mutagenesis and genetic engineering have been used to alter the fatty acid profile. Several genes, mostly desaturases, have been associated with altered fatty acid profiles but enzymes in the Kennedy Pathway have yet to be studied as another source of genetic variation for altering the fatty acid profiles. The Kennedy Pathway is also known as the oil producing pathway and consists of four enzymes: glycerol-3-phosphate acyltransferase (G3PAT); lysophosphatidic acid acyltransferase (LPAAT); phosphatidic acid phosphatase (PAP); and diacylglycerol acyltransferase 1 (DGAT1). The starting material for this pathway is glycerol-3-phosphate, which is produced from glycerol by glycerol kinase (GK), and the product of this pathway is triacylglycerol (TAG). The overall objective of this study was to elucidate the role that the Kennedy Pathway plays in determining the fatty acid profile in two ways: (1) sequencing the transcribed region of the genomic genes encoding the enzymes of GK, G3PAT, LPAAT, and DGAT1 in soybean genotypes with altered fatty acid profiles; and (2) studying their expression over seed development, across three growing temperatures. The genetic material for the study consisted of four soybean genotypes with altered fatty acid profile: RG2, RG7, RG10, and SV64-53. Results from sequencing showed that the mutations identified in G3PAT, LPAAT, and DGAT1 in the four soybean genotypes did not explain the differences in the fatty acid profiles. The expression of G3PAT, LPAAT, and DGAT1 over seed development showed that G3PAT had the lowest levels, followed by LPAAT, then DGAT1, across the growing temperatures. The differences in expression among genotypes corresponded to differences in fatty acid accumulation, suggesting that expression rather than genetic mutations in the transcribed region of the genes influenced the fatty acid profile of the genotypes in this study. In conclusion, the enzymes of the Kennedy Pathway appear to contribute to the altered fatty acid profiles observed in the soybean mutant genotypes. / Ontario Ministry of Economic Development and Innovation (formerly Ontario Ministry of Research and Innovation), BioCar Initiative, Grain Farmers of Ontario, SeCan

Groat oil content and composition are important quality traits in oats (Avena sativa L). These traits are controlled by many genes with additive effects. The chromosomal regions containing these genes, known as quantitative trait loci (QTL), can be discovered through their close association with markers. This study investigated total oil content and fatty acid components in an oat breeding population derived from a cross between high oil ('Dal') and low oil ('Exeter') parents. A genetic map consisting of 475 DArT (Diversity Array Technology) markers spanning 1271.8 cM across 40 linkage groups was constructed. QTL analysis for groat oil content and composition was conducted using grain samples grown at Aberdeen, ID in 1997. QTL analysis for multiple agronomic traits was also conducted using data collected from hill plots and field plots in Ottawa, ON in 2010. QTLs for oil content, palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3) were identified. Two of the QTLs associated with oil content were also associated with all of the fatty acids examined in this study, and most oil-related QTL showed similar patterns of effect on the fatty acid profile. These results suggest the presence of pleiotropic effects on oil-related traits through influences at specific nodes of the oil synthesis pathway. In addition, 12 QTL-associated markers (likely representing nine unique regions) were associated with plant height, heading date, lodging, and protein content. The results of this study will provide information for molecular breeding as well as insight into the genetic mechanisms controlling oil biosynthesis in oat.

The biofuel market is dominated by ethanol and biodiesel derived from cellulosic and lipid-based biomass crops. This is largely due to the relatively low costs and reliability of production. At present, production of non-food plant-derived oils for biofuel production in the U.S. is minimal. A research team from the Commonwealth Scientific and Industrial Research Organization (CSIRO), an independent Australian federal government research institution, has developed an efficient transgenic system to engineer oil production in tobacco leaves. This novel system is comprised of multiple transgenes that direct the endogenous metabolic flux of oil precursors towards triacylglycerol (TAG) production. Additional genes were incorporated to store and protect the accumulated oil in vegetative tissues. Preliminary greenhouse tests by the CSIRO research group indicated an oil content of > 30% by dry weight (DW) in tobacco leaf lamina. Here we evaluated two transgenic lines against a non-transgenic control in 2017 and 2018 in greenhouse and field production systems. The 2017 pilot study showed that the high leaf-oil tobacco line was viable and will grow in the field in Kentucky. Chemical analyses revealed significantly higher oil content compared to the non-transgenic control despite several logistical setbacks. These promising discoveries prompted the deployment of additional transgenic line assessments and further data validation in 2018. Line evaluations in 2018 revealed that the LEC2:WRI1:DGAT:OLE transgenic line had the highest leaf oil content (≥ 19.3% DW-1) compared to both the WRI1:DGAT:OLE transgenic line (≤ 5.6% DW-1) and non-transgenic control (≤ 2.1% DW-1). The results of this research will contribute to the successful development of transgenic tobacco lines engineered to accumulate high concentrations of TAG in the leaves.

Les Streptomyces sont des bactéries filamenteuses du sol à Gram +. Elles sont connues pour leur capacité à produire des métabolites secondaires utiles en médecine et en agriculture. S. coelicolor et S. lividans sont des souches modèles phylogénétiquement proches. Elles ont cependant des capacités contrastées à accumuler des lipides de réserve de la famille des triacylglycérol (TAG) et produire des métabolites secondaires alors qu’elles possèdent des voies de biosynthèse similaires pour ces deux types de molécules. En présence de glucose, S. coelicolor produit des niveaux élevés de métabolites secondaires spécifiques et son contenu en TAG est faible alors que c'est le contraire chez S. lividans. En revanche, en présence de glycérol, les deux souches accumulent une quantité de TAG similaire mais S. coelicolor produit aussi des métabolites secondaires. Le but de la présente thèse était de déterminer les caractéristiques métaboliques différentielles qui sous-tendent les différentes capacités biosynthétiques de ces deux souches modèles. Pour ce faire, une analyse protéomique comparative sans marquage des souches cultivées en milieu R2YE liquide ou solide en présence de glucose ou de glycérol comme principales sources de carbone a été réalisée en utilisant la technique de chromatographie liquide couplée à de la Spectrométrie de Masse en tandem (LC-MS / MS). Au total, 2024 et 4372 protéines ont été identifiées à partir des cultures liquides et solides, représentant 24% et 50% du protéome théorique. Les études en liquide ont révélé que le métabolisme de S. lividans était principalement glycolytique alors que le métabolisme de S. coelicolor était principalement oxydatif. Elles ont également indiqué que ces caractéristiques pourraient être liées au catabolisme préférentiel des acides aminés par rapport au glucose chez S. coelicolor par rapport à S. lividans. De plus, cette thèse constitue la première analyse protéomique du métabolisme de ces deux souches modèles en présence de glycérol. / Streptomyces are filamentous Gram+ soil bacteria well known for their ability to produce secondary metabolites useful in medicine and agriculture. S. coelicolor and S. lividans are phylogenetically closely-related model strains but they have contrasted abilities to accumulate storage lipids of the TriAcylGlycerol (TAG) family and to produce secondary metabolites whereas they possess similar pathways for the biosynthesis of these molecules. In the presence of glucose, S. coelicolor produces high levels of specific secondary metabolites and its TAG content is low whereas it is the opposite for S. lividans. In contrast, in the presence of glycerol, the two strains accumulated similar amount of TAG but S. coelicolor still produces secondary metabolites. The aim of the present thesis was to determine the differential metabolic features supporting such different biosynthetic abilities. To do so, a comparative label-free shotgun proteomic analysis of the strains grown in liquid or solid R2YE media with glucose or glycerol as main carbon sources was carried out using Liquid chromatography−tandem mass spectrometry (LC−MS/MS). A total of 2024 and 4372 proteins were identified in liquid and solid cultures, representing 24% and 50% of the theoretical proteome, respectively. These studies revealed that S. lividans metabolism was mainly glycolytic whereas S. coelicolor metabolism was mainly oxidative. They also suggested that these features might be related to the preferential catabolism of amino acids over glucose of S. coelicolor compared to S. lividans. Furthermore, this thesis constituted the first proteomic analysis of the metabolism of these two model strains in the presence of glycerol. / Streptomyces es un género de bacterias filamentosas Gram+ provenientes del suelo que son conocidas por su capacidad para producir metabolitos secundarios útiles en la medicina y agricultura. S. coelicolor y S. lividans son cepas modelo filogenéticamente próximas que presentan capacidades opuestas para acumular lípidos de reserva de la familia de los triglicéridos (TAG) y para producir metabolitos secundarios en tanto que ambas cepas poseen rutas metabólicas idénticas para la biosíntesis de éstas moléculas. En presencia de glucosa, S. coelicolor produce altos niveles de metabolitos secundarios específicos y su contenido de TAG es bajo mientras que en S. lividans el comportamiento es opuesto. Sin embargo, en presencia de glicerol, ambas cepas acumulan cantidades similares de TAG y S. coelicolor produce metabolitos secundarios. El objetivo de ésta tesis fue de determinar las características metabólicas que distinguen las diferentes capacidades biosintéticas mencionadas previamente. Por esto, un análisis protéomico comparativo sin marcaje de tipo “shotgun” fue realizado con las dos cepas cultivadas en medio R2YE líquido y sólido usando glucosa o glicerol como fuentes principales de carbono mediante Cromatografía Líquida en “tándem” acoplada a Espectrometría de Masas (LC-MS/MS). Un total de 2024 y 4372 proteínas fueron identificadas en cultivos en medio líquido y sólido, representando 24% y 50% del proteoma teórico, respectivamente. El presente estudio demostró que el metabolismo de S. lividans fue principalmente glicolítico mientras que el metabolismo de S. coelicolor fue principalmente oxidativo. También se sugiere que éstas características pueden estar relacionadas con la preferencia catabólica de aminoácidos sobre el catabolismo de glucosa de S. coelicolor comparada con S. lividans. Además, la presente tesis constituye el primer análisis proteómico del metabolismo de éstas dos cepas modelo en presencia de glicerol.