York University researcher Stephen Wright is part of a team of scientists that has identified genes responsible for the domestication of corn – research that will provide important insights in the quest to breed better, higher-yielding crops.
Modern-day corn-on-the-cob, with its plump, juicy kernels, bears little resemblance to the plant from which it was domesticated. In fact, this dietary staple wasn’t always so appealing to human taste buds: when Native Americans first encountered its ancestor, teosinte, they found inedible husks containing single rows of hard, triangular seeds.
The genetic changes that gave rise to these huge alterations had been almost entirely unknown. But Wright and his colleagues have pinpointed many of them using DNA analysis, combining the relatively new science of genomics and a traditional discipline called “population genetics” – the study of genetic variation.
The team of researchers has identified the genes that were preferentially selected by Native Americans 6,000 – 9,000 years ago, during the course of the plant’s domestication. The study revealed that of the 59,000 total genes in the corn genome, approximately 1,200 were preferentially targeted for selection during its domestication. The findings, published in the journal Science, estimate that two to four per cent of the 700 genes they studied contribute to important agricultural traits, including amino acid biosynthesis and plant growth.
“Domestication represents an experiment in evolution lasting thousands of years. The identification of these genes will motivate studies that will provide maize geneticists and breeders with new insights and new tools,” says Wright, a biology researcher in York’s Faculty of Science & Engineering.
The research is a collaborative project between York University, the University of California, Irvine, the US Department of Agriculture, the University of Missouri and the University of Wisconsin.
Right: Stephen Wright
Wright is the recipient of Canada Foundation for Innovation (CFI) funds for the creation of a new laboratory for the study of plant genome evolution and population genomics at York. The facility is used for innovative research combining computer-based analysis of genomes, collection of genome sequence data and theoretical work.