biostudies-literatureUnknown66(21)Rinne PLTree architecture develops over time through the collective activity of apical and axillary meristems. Although the capacity of both meristems to form buds is crucial for perennial life, a comparative analysis is lacking. As shown here for hybrid aspen, axillary meristems engage in an elaborate process of axillary bud (AXB) formation, while apical dominance prevents outgrowth of branches. Development ceased when AXBs had formed an embryonic shoot (ES) with a predictable number of embryonic leaves at the bud maturation point (BMP). Under short days, terminal buds (TBs) formed an ES similar to that of AXBs, and both the TB and young AXBs above the BMP established dormancy. Quantitative PCR and in situ hybridizations showed that this shared ability and structural similarity was reflected at tJournal of experimental botany6745-60https://www.ebi.ac.uk/biostudies/studies/S-EPMC4623686biostudies-literatureLong and short photoperiod buds in hybrid aspen share structural development and expression patterns of marker genes.PMC4623686Vahala JRuonala RKangasjarvi Jvan der Schoot CPaul LKRinne PLfalseLong and short photoperiod buds in hybrid aspen share structural development and expression patterns of marker genes.Tree architecture develops over time through the collective activity of apical and axillary meristems. Although the capacity of both meristems to form buds is crucial for perennial life, a comparative analysis is lacking. As shown here for hybrid aspen, axillary meristems engage in an elaborate process of axillary bud (AXB) formation, while apical dominance prevents outgrowth of branches. Development ceased when AXBs had formed an embryonic shoot (ES) with a predictable number of embryonic leaves at the bud maturation point (BMP). Under short days, terminal buds (TBs) formed an ES similar to that of AXBs, and both the TB and young AXBs above the BMP established dormancy. Quantitative PCR and in situ hybridizations showed that this shared ability and structural similarity was reflected at t2015-01-01T00:00:00Z2015 Nov2025-04-21T20:25:40.417Z2019-03-27T02:00:55ZS-EPMC46236862624866610.1093/jxb/erv380