Domesticated rice has fatter seed grains with higher starch content than its wild rice relatives -- the result of many generations of preferential seed sorting and sowing. But even though rice was the first crop to be fully sequenced, scientists have only documented a few of the genetic changes that made rice into a staple food for more than half the world's population.
New research now finds that a sizeable amount of domestication-related changes in rice reflects selection on traits that are determined by a portion of the genome that does not transcribe proteins.
Xiaoming Zheng, a biologist with the Institute of Crop Sciences at the Chinese Academy of Agricultural Sciences, is the first author of newly published paper in Science Advances, "Genome-wide analyses reveal the role of non-coding variation in complex traits during rice domestication." Qingwen Yang and Jun Liu, also from the Institute of Crop Sciences in the Chinese Academy of Agricultural Sciences, and Kenneth M. Olsen from Washington University in St. Louis are also communicating authors of this paper.
Noncoding RNAs are suspected to play very important roles in regulating growth and development, but they're only beginning to be characterized.
"Despite almost 20 years of genomics and genome-enabled studies of crop domestication, we still know remarkably little about the genetic basis of most domestication traits in most crop species," said Olsen, professor of biology in Arts & Sciences at Washington University.
"Early studies tended to go for 'low-hanging fruit' -- simple traits that were controlled by just one or two genes with easily identifiable mutations," Olsen said. "Far more difficult is figuring out the more subtle developmental changes that were critical for a lot of the changes during crop domestication.
"This study offers a step in that direction, by examining one regulatory mechanism that has been critical for modulating domestication-associated changes in rice grain development."
(Source: Agriculture and Food News, ScienceDaily. www.sciencedaily.com)