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- Tylewicz, Szymon, et al.
(författare)
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Dual role of tree florigen activation complex component FD in photoperiodic growth control and adaptive response pathways
- 2015
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 112, s. 3140-3145
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Tidskriftsartikel (refereegranskat)abstract
- A complex consisting of evolutionarily conserved FD, FLOWERING LOCUS T (FT) proteins is a regulator of floral transition. Intriguingly, FT orthologs are also implicated in developmental transitions distinct from flowering, such as photoperiodic control of bulbing in onions, potato tuberization, and growth cessation in trees. However, whether an FT-FD complex participates in these transitions and, if so, its mode of action, are unknown. We identified two closely related FD homologs, FD-like 1 (FDL1) and FD-like 2 (FDL2), in the model tree hybrid aspen. Using gain of function and RNAi-suppressed FDL1 and FDL2 transgenic plants, we show that FDL1 and FDL2 have distinct functions and a complex consisting of FT and FDL1 mediates in photoperiodic control of seasonal growth. The downstream target of the FT-FD complex in photoperiodic control of growth is Like AP1 (LAP1), a tree ortholog of the floral meristem identity gene APETALA1. Intriguingly, FDL1 also participates in the transcriptional control of adaptive response and bud maturation pathways, independent of its interaction with FT, presumably via interaction with ABSCISIC ACID INSENSITIVE 3 (ABI3) transcription factor, a component of abscisic acid (ABA) signaling. Our data reveal that in contrast to its primary role in flowering, FD has dual roles in the photoperiodic control of seasonal growth and stress tolerance in trees. Thus, the functions of FT and FD have diversified during evolution, and FD homologs have acquired roles that are independent of their interaction with FT.
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| 2. |
- Tylewicz, Szymon
(författare)
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Molecular analysis of growth cessation and dormancy in hybrid aspen
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Perennial plants such as trees living in temperate zones experience extreme changes in temperature during summers and winters. In order to survive, shoot apical and cambial meristem undergo a transition from active growth to dormant state, well in advance of winter onset. The transition between an active growth and dormancy involves physiological and developmental processes such as bud formation, acquisition of cold hardiness that are underpinned by massive changes transcriptional and metabolic programs. The studies of this thesis provide an insight into the molecular regulation underlying the photoperiodic control of growth cessation, adaptive response and acquisition of dormancy in model tree hybrid aspen. Our data show that components of flowering pathway i.e. LAP1 and FDL1 have evolved new functions to mediate in SD-control of growth cessation and adaptive response. Furthermore, we found that FIE, a component of evolutionary conserved PRC2 complex, in concert with Abscisic Acid (ABA) are key regulators of dormancy in Populus. We demonstrate that an interplay between these two components and yet another chromatin remodelling factor PICKLE is necessary for the development of dormancy. In summary, this thesis sheds new light on molecular regulation of activity-dormancy cycle in hybrid aspen. Our better understanding of how trees regulate growth cessation, adaptive response and dormancy may be useful to devise strategies to engineer trees with altered activity-dormancy traits in order to improve their productivity under the impending climate change.
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