Alteration of TAC1 expression in Prunus species leads to pleiotropic shoot phenotypes

Abstract

Fruit trees: Slimmer trees for denser planting Peach and plum trees grow tall and slim when the TAC1 gene is mutated, permitting higher-density planting in orchards. Branches of peach trees with the “pillar” trait grow more “up” than “out”, reducing each tree’s footprint. Chris Dardick at the Appalachian Fruit Research Station in West Virginia and co-workers previously traced the trait to mutation of TAC1. However, the effects of TAC1 mutation on tree shape in other species remains poorly understood. Dardick and co-workers investigated the effects of knocking out TAC1 in peach and plum trees. In both species, trees were narrower, but fruit yield was unchanged. Both species also showed other effects, including differences in trunk and branch thickness; these effects differed between peach and plum. These data may help in breeding of more upright fruit trees, improving fruit yield per acre.