|
 What makes sweet corn taste so good? It is a single base pair out of the three billion base pairs in the maize genome. The mutant was recognized a century ago and called Sugary1 (Su1). Several years ago Martha James identified the gene (Su1), and then Sherry Whitt collaborated with Bill Tracy to find the nucleotides that make sweet corn throughout the Americas (pdf).
The map indicates were the samples came from, excluding a few samples from the High Andes. It turned out that all of these sweet corns had mutations in the same gene - Su1. But the mutations were in different positions in the same gene. It appears that the Native Americans reselected for sweetness at least five times.  We also found that it was interesting that all North American sweet corns had mutations in same cleft of the isoamylase enzyme. We speculate that mutations in this region allow the enzyme to still work during germination, but it still provides a sweet taste.
|
