Agriculture and Agri-Food Canada

About: Agriculture and Agri-Food Canada is a facility organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Soil water. The organization has 10921 authors who have published 21332 publications receiving 748193 citations. The organization is also known as: Department of Agriculture and Agri-Food.

Agriculture: Feeding the future

Abstract: Humanity depends on fewer than a dozen of the approximately 300,000 species of flowering plants for 80% of its caloric intake. And we capitalize on only a fraction of the genetic diversity that resides within each of these species. This is not enough to support our food system in the future. Food availability must double in the next 25 years to keep pace with population and income growth around the world. Already, food-production systems are precarious in the face of intensifying demand, climate change, soil degradation and water and land shortages. Farmers have saved the seeds of hundreds of crop species and hundreds of thousands of ‘primitive’ varieties (local domesticates called landraces), as well as the wild relatives of crop species and modern varieties no longer in use. These are stored in more than 1,700 gene banks worldwide. Maintaining the 11 international gene-bank collections alone costs about US$18 million a year.

Adaptation and Acclimation of Photosynthetic Microorganisms to Permanently Cold Environments

Abstract: Persistently cold environments constitute one of our world's largest ecosystems, and microorganisms dominate the biomass and metabolic activity in these extreme environments. The stress of low temperatures on life is exacerbated in organisms that rely on photoautrophic production of organic carbon and energy sources. Phototrophic organisms must coordinate temperature-independent reactions of light absorption and photochemistry with temperature-dependent processes of electron transport and utilization of energy sources through growth and metabolism. Despite this conundrum, phototrophic microorganisms thrive in all cold ecosystems described and (together with chemoautrophs) provide the base of autotrophic production in low-temperature food webs. Psychrophilic (organisms with a requirement for low growth temperatures) and psychrotolerant (organisms tolerant of low growth temperatures) photoautotrophs rely on low-temperature acclimative and adaptive strategies that have been described for other low-temperature-adapted heterotrophic organisms, such as cold-active proteins and maintenance of membrane fluidity. In addition, photoautrophic organisms possess other strategies to balance the absorption of light and the transduction of light energy to stored chemical energy products (NADPH and ATP) with downstream consumption of photosynthetically derived energy products at low temperatures. Lastly, differential adaptive and acclimative mechanisms exist in phototrophic microorganisms residing in low-temperature environments that are exposed to constant low-light environments versus high-light- and high-UV-exposed phototrophic assemblages.

Tomato Ve disease resistance genes encode cell surface-like receptors

Abstract: In tomato, Ve is implicated in race-specific resistance to infection by Verticillium species causing crop disease. Characterization of the Ve locus involved positional cloning and isolation of two closely linked inverted genes. Expression of individual Ve genes in susceptible potato plants conferred resistance to an aggressive race 1 isolate of Verticillium albo-atrum. The deduced primary structure of Ve1 and Ve2 included a hydrophobic N-terminal signal peptide, leucine-rich repeats containing 28 or 35 potential glycosylation sites, a hydrophobic membrane-spanning domain, and a C-terminal domain with the mammalian E/DXXXLphi or YXXphi endocytosis signals (phi is an amino acid with a hydrophobic side chain). A leucine zipper-like sequence occurs in the hydrophobic N-terminal signal peptide of Ve1 and a Pro-Glu-Ser-Thr (PEST)-like sequence resides in the C-terminal domain of Ve2. These structures suggest that the Ve genes encode a class of cell-surface glycoproteins with receptor-mediated endocytosis-like signals and leucine zipper or PEST sequences.

Absorption of Anthocyanins from Blueberries and Serum Antioxidant Status in Human Subjects

Abstract: In recent years, numerous studies have shown that the polyphenolics present in fruit and vegetable products exhibit a wide range of biological effects. However, there is little reliable information on the absorption of glycosylated and acylated anthocyanins in humans. In the present study, the absorption of anthocyanins in humans was investigated after the consumption of a high-fat meal with a freeze-dried blueberry powder containing 25 individual anthocyanins including 6 acylated structures. Nineteen of the 25 anthocyanins present in the blueberries were detected in human blood serum. Furthermore, the appearance of total anthocyanins in the serum was directly correlated with an increase in serum antioxidant capacity (ORAC(acetone), P < 0.01). These results show that anthocyanins can be absorbed in their intact glycosylated and possibly acylated forms in human subjects and that consumption of blueberries, a food source with high in vitro antioxidant properties, is associated with a diet-induced increase in ex vivo serum antioxidant status.