Researchers say they have unravelled the genetic code of the rapeseed plant, and say it could lead to better tasting vegetables.
Genomics researchers of the University of Arizona's iPlant collaborative, housed in the BIO5 Institute, have helped unravel the genetic code of the rapeseed plant, most noted for a variety whose seeds are made into canola oil.
The sequencing effort provides scientists and breeders with a map they can use to home in on certain genes and, by extension, the plant's metabolic pathways. For example, they could strive to create a cultivar of broccoli that's not bitter, or tweak the lipid biosynthesis pathway to favourably modify the oil content in rapeseed.
Being able to modify the content of bitter-tasting compounds has implications beyond what meets the tongue, because in most plants, those chemicals also confer defence against pests.
In addition, they help scientists better understand how plant genomes evolve in the context of domestication.
Brassica plants have been bred all over the world for centuries and resulted in produce and products diverse enough for supermarkets to place them across several different aisles. Broccoli, cauliflower, Brussels sprouts, Chinese cabbage, turnip, collared greens, mustard, canola oil – all these are different incarnations of the same plant genus, Brassica.
'Whole-genome sequencing efforts like this one allow us to address two fundamental questions,' said Eric Lyons, an assistant professor in the School of Plant Sciences at the University of Arizona, who led the study. 'How does the genetic information stored in the genome help us understand the functions of the organism, and what does the structure of the genome tell us about the evolution of genomes in general?'
The endeavour, which was led by institutions in France, Canada, China and U.S., revealed that the rapeseed (or Brassica napus) genome contains a large number of genes – more than 100,000 – due to the fact that it arose from a merger between two parent species, Brassica rapa (Chinese cabbage) and Brassica oleracea, a cultivar that includes broccoli, cauliflower, Brussels sprouts, collard greens and others.
'The Brassica group is extremely versatile with regard to human use,' he said. 'In all of the cultivars, we find something to eat. The genome defines what Brassicas are. It also defines what kids hate to eat,' Lyons added. 'The bitterness in some cultivars such as broccoli or Brussels sprouts comes from a class of compounds called glucosinolates, and we find that precisely those genes that code for those compounds were lost from the rapeseed genome.'
The sequencing effort provides scientists and breeders with a map they can use to home in on certain genes and, by extension, the plant's metabolic pathways.
For example, they could strive to create a cultivar of broccoli that's not bitter, or tweak the lipid biosynthesis pathway to favourably modify the oil content in rapeseed.
Being able to modify the content of bitter-tasting compounds has implications beyond what meets the tongue, because in most plants, those chemicals also confer defence against pests.
