The team made a comparison of the microRNA populations of high-yielding indica rice lines, of wild rice and other traditional rice varieties. They found that one microRNA species, miR397, accumulated to high levels in the flag leaves of wild rice, but were very low in other plants analyzed. They also found that miR397 silenced several members of the laccase gene family, which encode proteins that promote woody tissue formation for mechanical strength. By silencing a subset of these genes, miR397 greatly reduced the formation of woody tissue.
Using genetic engineering techniques, the researchers expressed the gene coding for miR397 in domesticated rice, which resulted to plants that were more similar to wild rice plants than to domesticated ones, with long, spindly stems; narrow, short leaves; few flowering structures; and hardly any rice grains. These findings suggest the involvement of miRNAs in rice domestication, particularly in boosting rice production.