August 01, 2009, Ottawa, Ontario
It takes decades of conventional breeding techniques to cultivate better plant varieties, especially when complex traits are controlled by more than one gene and genetic activity is little understood. But all that could soon change. Combining the strengths of genomics and bioinformatics, scientists at the NRC Plant Biotechnology Institute (NRC-PBI) in Saskatoon are breaking new ground in developing crop varieties with improved agronomical and nutritional traits.
"Although we’ll always need conventional breeding techniques, genomics-based approaches stand to revolutionize the selective breeding process," says Dr. Faouzi Bekkaoui, a senior researcher at NRC-PBI. He leads the Biorenewable Oil for Food and Fuel research team. With support from the NRC Genomics and Health Initiative, this team has been characterizing selected genes involved in the seed development and metabolism of canola.
NRC bioinformatics experts have developed techniques and databases to assemble and analyze genomic data, and apply cutting-edge algorithms to discover gene-gene associations, gene-metabolite associations and gene networks, as well as to produce modelling.
With the rapid progress in DNA sequencing technology and bioinformatics, researchers will be able to sequence and analyze the DNA of numerous genomes in even shorter periods of time.
NRC-PBI has been studying oilseed crop genomics for the last six years. "We’ve gained considerable knowledge about the relationship between genes and the biochemical and molecular factors that regulate seed development and composition," says Dr. Bekkaoui. "Our goal is to identify all the genes and their functions in canola, and genetically manipulate them to produce even greater gains."
Some of the genes studied are known to regulate embryo development or photosynthesis, and therefore growth. Other genes help canola to produce more branching or stronger roots, or increase its tolerance to a saline environment or drought. Yet others control seed dormancy and germination, flowering, and the size and oil content of seeds.
The Biorenewable Oil for Food and Fuel research team aims to characterize the genes expressed in canola seed and produce transgenic plant lines that 'over-express' (i.e. express multiple copies of) the genes controlling growth, seed yield, vigour and other characteristics that could increase economic yield.
To help isolate genes of interest, the team has developed more than 430,000 "expressed sequence tags" (ESTs), an instrumental step in gene discovery and gene sequence determination. In addition, the team further characterized the ESTs using DNA arrays, in order to understand gene expression under specific growth conditions. Their goal is to strengthen certain plant characteristics through genetic manipulation, creating prototypes that can be tested in the lab and later in the field.
Last summer, the NRC team collaborated with Agriculture and Agri-Food Canada to test five canola prototypes in field studies. Two of the five prototypes delivered promising results. They flowered 10 days earlier than control plants — allowing their seeds to develop earlier in the season before hot temperatures could adversely affect oil content and yield. The varieties also produced larger seeds, which enhances seed vigour. Another prototype yielded 2 to 8 percent more oil than the control plants ? good news for the industry, since each percentage increase creates an additional $75 million in related economic activity.
Oilseed crops, such as canola, play an important role in meeting the global demand for food and biofuels. Canola already contributes close to $14 billion to Canada’s economy ? a figure that could grow considerably if NRC succeeds in cultivating new lines of higher yielding canola.
