<Note>Architectural morphogenesis of poplar grown in a shortened annual cycle system

Abstract

Tree architecture is an important feature of plant environmental adaptation and affects many aspects of forestry, as well as both timber and orchard fruit production. However, studying tree architecture indoors in standard lab environments is challenging due to the large size and long growth cycles of trees. Here, we developed miniaturized poplar trees with branching architecture similar to field-grown trees by using a shortened annual cycle system. Control poplars grown under typical fixed conditions in a growth room had no branches and formed simple shapes consisting of a single stem and leaves. We observed simultaneous breaking of dormancy of several buds resulting in such architectural complexity. Our results suggest that apical dominance is lost in the shortened annual system as dormancy is broken. In contrast, apical dominance persisted in control trees grown under typical fixed conditions.