Abstract

Background: Photoperiodic control of development plays a key role in adaptation of plants to seasonal changes. A signaling module consisting of CONSTANS (CO) and FLOWERING LOCUS T (FT) mediates in photoperiodic control of a variety of developmental transitions (e. g., flowering, tuberization, and seasonal growth cessation in trees). How this conserved CO/FT module can mediate in the photoperiodic control of diverse unrelated developmental programs is poorly understood.Results: We show that Like-AP1 (LAP1), a tree ortholog of Arabidopsis floral meristem identity gene APETALA1 (AP1), mediates in photoperiodic control of seasonal growth cessation downstream of the CO/FT module in hybrid aspen. Using LAP1 overexpressors and RNAi-suppressed transgenic trees, we demonstrate that short day (SD)-mediated downregulation of LAP1 expression is required for growth cessation. In contrast with AP1 targets in flowering, LAP1 acts on AINTEGUMENTA-like 1 transcription factor, which is implicated in SD-mediated growth cessation. Intriguingly, unlike AP1 in Arabidopsis, ectopic expression of LAP1 fails to induce early flowering in hybrid aspen trees.Conclusions: These results indicate that AP1 ortholog in trees has acquired a novel function in photoperiodic regulation of seasonal growth. Thus, photoperiodic signaling pathway may have diverged downstream of AP1/LAP1 rather than the CO/FT module during evolution. Moreover, control of flowering by the CO/FT module can be uncoupled from its role in photoperiodic control of seasonal growth in trees. Thus, our findings can explain mechanistically how a conserved signaling module can mediate in the control of a highly diverse set of developmental transitions by a similar input signal, namely photoperiod.

Published in

Current Biology
2014, Volume: 24, number: 7, pages: 717-724
Publisher: CELL PRESS

SLU Authors

• Abdul, Azeez

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Miskolczi, Pal Csaba

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Tylewicz, Szymon

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Bhalerao, Rupali R.

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Biochemistry and Molecular Biology
Cell Biology


Publication identifier

DOI: https://doi.org/10.1016/j.cub.2014.02.037

Permanent link to this page (URI)

https://res.slu.se/id/publ/67907