Search

Your search keyword '"Humphreys, D Gavin"' showing total 16 results
Start Over Author "Humphreys, D Gavin"
16 results on '"Humphreys, D Gavin"'

7. Highly predictive SNP markers for efficient selection of the wheat leaf rust resistance gene Lr16

Author

Kassa, Mulualem T., primary, You, Frank M., additional, Hiebert, Colin W., additional, Pozniak, Curtis J., additional, Fobert, Pierre R., additional, Sharpe, Andrew G., additional, Menzies, James G., additional, Humphreys, D. Gavin, additional, Rezac Harrison, Nicole, additional, Fellers, John P., additional, McCallum, Brent D., additional, and McCartney, Curt A., additional

Published
2017
Full Text
View/download PDF

8. A review of wheat leaf rust research and the development of resistant cultivars in Canada

Author

McCallum, Brent D., primary, Hiebert, Colin W., additional, Cloutier, Sylvie, additional, Bakkeren, Guus, additional, Rosa, Silvia B., additional, Humphreys, D. Gavin, additional, Marais, G. Francois, additional, McCartney, Curt A., additional, Panwar, Vinay, additional, Rampitsch, Christof, additional, Saville, Barry J., additional, and Wang, Xiben, additional

Published
2016
Full Text
View/download PDF

9. The role of abscisic acid and its catabolic genes in the regulation of wheat seed dormancy and germination

Author

Jordan, Mark C. (Plant Science) Humphreys, D. Gavin (Plant Science) Schroeder, Dana (Biological Science) Spaner, Dean (University of Alberta), Ayele, Belay T. (Plant Science), Chitnis, Vijaya, Jordan, Mark C. (Plant Science) Humphreys, D. Gavin (Plant Science) Schroeder, Dana (Biological Science) Spaner, Dean (University of Alberta), Ayele, Belay T. (Plant Science), and Chitnis, Vijaya

Abstract

Common wheat is the one of the most important cereal crop in the world. Pre-harvest sprouting (PHS) is one of the major problems affecting wheat yield and quality in Canada and globally. The occurrence of PHS is closely associated with the level of seed dormancy, and abscisic acid (ABA) plays a pivotal role in the regulation of seed dormancy. The catabolism of ABA plays a crucial role for maintaining its homeostasis in plant tissues, including seeds, and this reaction is mediated primarily by ABA 8' hydroxylase, an enzyme encoded by genes designated as CYP707A. This study identified the three homeologues of TaCYP707A1 from Canadian wheat genotypes with contrasting PHS phenotype, and comparison of their genomic sequences indicated the presence of allelic and other variations. Analysis of the total expression of TaCYP707A1 in different wheat tissues revealed that it is predominantly expressed in seeds during maturation, and genomic contribution of transcripts to the total expression of TaCYP707A1 are shown to vary with tissues and genotypes. Ectopic expression of TaCYP707A1 in Arabidopsis demonstrated its function in regulating seed ABA level and dormancy. Furthermore, the spatiotemporal expression patterns of TaCYP707A1 along with TaCYP707A2 in the seeds of the wheat genotypes studied suggest that both genes are involved in the regulation of seed ABA and dormancy levels, however, TaCYP707A1 appears to play a major role. The findings of this thesis also show that the role of ABA in inhibiting the germination of wheat seed is partly mediated by transcriptional regulation of genes involved in the metabolic and signaling pathways of brassinosteroids, ethylene and cytokinin, which in turn suggests changes in the contents and responses of seeds to these particular phytohormones.

Published
2014

11. Application of molecular markers to wheat breeding in Canada

Author

Randhawa, Harpinder S., primary, Asif, Muhammad, additional, Pozniak, Curtis, additional, Clarke, John M., additional, Graf, Robert J., additional, Fox, Stephen L., additional, Humphreys, D. Gavin, additional, Knox, Ron E., additional, DePauw, Ron M., additional, Singh, Asheesh K., additional, Cuthbert, Richard D., additional, Hucl, Pierre, additional, and Spaner, Dean, additional

Published
2013
Full Text
View/download PDF

16. Genetic variation of seed dormancy in wheat (Triticum aestivum L.) is mediated by transcriptional regulation of abscisic acid metabolism and signaling.

Author

Rehal, Pawanpuneet K., Tuan, Pham Anh, Nguyen, Tran-Nguyen, Cattani, Douglas J., Humphreys, D. Gavin, and Ayele, Belay T.

Subjects
*GENETIC variation, *SEED dormancy, *GENETIC transcription regulation, *ABSCISIC acid, *WHEAT, *WHEAT seeds, *DORMANCY in plants
Abstract

Abscisic acid (ABA) regulates seed dormancy and therefore preharvest sprouting (PHS) in wheat. This study investigated the contribution of transcriptional regulation of ABA metabolism and signaling genes to genetic variation in dormancy of wheat seeds. Our results showed that genetic variation in seed dormancy is highly correlated with ABA content (r > 0.86), which, in turn, was closely associated with the expression levels of ABA biosynthesis genes, TaNCED1 (r = 0.78) and TaNCED2 (r = 0.67). A relatively lower correlation was observed between ABA content and the expression levels of ABA catabolism genes, TaCYP707A1 (r = 0.51) and TaCYP707A2 (r = 0.57). The expression level of TaABI5 exhibited strong associations with the levels of ABA (r = 0.8) and seed dormancy (r > 0.9), indicating the importance of seed ABA sensitivity in mediating genetic variation in dormancy. Furthermore, high positive correlations were prevalent between the expression patterns of TaABI5 and TaNCED1 (r = 0.91) or TaNCED2 (r = 0.82). Overall, ou r results implicated the significance of TaNCED s and TaABI5 in regulating genetic variation in ABA level and sensitivity and thereby seed dormancy, highlighting the potential use of these genes to develop molecular markers for incorporating PHS resistance in wheat. • ABA underlies genetic variation of seed dormancy in wheat. • Seed ABA levels are regulated mainly by expression of TaNCED1 and TaNCED2 genes. • Transcriptional regulation TaABI5 mediates seed ABA sensitivity. • Seed dormancy is not associated with seed coat pigmentation. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results