Abstract
Woody perennials adapt their genetic traits to local climate conditions. Day length plays an essential role in the seasonal growth of poplar trees. When photoperiod falls below a given critical day length, poplars undergo growth cessation and bud set. A leaf-localized mechanism of photoperiod measurement triggers the transcriptional modulation of a long distance signaling molecule, FLOWERING LOCUS T (FT). This molecule targets meristem function giving rise to these seasonal responses. Studies over the past decade have identified conserved orthologous genes involved in photoperiodic flowering in Arabidopsis that regulate poplar vegetative growth. However, phenological and molecular examination of key photoperiod signaling molecules reveals functional differences between these two plant model systems suggesting alternative components and/or regulatory mechanisms operating during poplar vegetative growth. Here, we review current knowledge and provide new data regarding the molecular components of the photoperiod measuring mechanism that regulates annual growth in poplar focusing on main achievements and new perspectives.
Highlights
Shoot apical growth in poplar is extremely sensitive to day length (Howe et al, 1995)
When photoperiod falls below a critical day length (CDL), these events come to a halt and this phenomenon is known as growth cessation (Weiser, 1970; Thomas and Vince-Prue, 1997)
We describe that by comparing diurnal gene expression with height-associated single nucleotide polymorphism (SNP) genes, we here identified GIGANTEA (GI) and FLAVIN BINDING, KELCH REPEAT, F-BOX1 (FKF1), already shown to be involved in poplar seasonal growth (Ding et al, 2018), along with new candidate orthologous genes to Arabidopsis flowering time regulators
Summary
Shoot apical growth in poplar is extremely sensitive to day length (Howe et al, 1995). Poplar annual growth is controlled by a photoperiodic time measurement (PTM) mechanism. Similar night break experiments have been found to accelerate Arabidopsis flowering under conditions of short days (Reed et al, 1994) Such responses to night break experiments suggest that poplar shoot growth and Arabidopsis flowering share a similar photoperiod regulation mechanism. Photoperiodic Time Measurement in Poplar suggested that the genetic control of Arabidopsis flowering time and poplar shoot apical growth is conserved (Böhlenius et al, 2006; Hsu et al, 2011; Ding et al, 2018). The genes VERNALIZATION INDEPENDENCE 4 and 5 (VIP4 and VIP5), AGAMOUS-LIKE (AG-like) and TERMINAL FLOWER 2 (TFL2) associated with the vernalization pathway in Arabidopsis, show robust diurnal rhythms of mRNA accumulation in poplar, suggesting their potential role as photoperiodic regulators of poplar shoot apical growth
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
