Abstract

The signalling pathways that control seasonal modulation of carbon metabolism in perennial plants are poorly understood. Using genetic, metabolic and natural variation approaches, we identify factors mediating photoperiodic control of storage lipid accumulation in the model tree hybrid aspen (Populus tremula x tremuloides).We characterized lipid accumulation in transgenic hybrid aspen with impaired photoperiodic and hormonal responses. Genome-wide association mapping was performed in Swedish aspen (P.tremula) genotypes to determine genetic loci associated with genotype variation in lipid content.Our data show that the storage lipid triacylglycerol (TAG) accumulates in cambial meristem and pith rays of aspen in response to photoperiodic signal controlling growth cessation and dormancy induction. We show that photoperiodic control of TAG accumulation is mediated by the FLOWERING LOCUS T/CONSTANS module, which also controls the induction of growth cessation. Hormonal and chromatin remodelling pathways also contribute to TAG accumulation by photoperiodic signal. Natural variation exists in lipid accumulation that is controlled by input from multiple loci.Our data shed light on how the control of storage metabolism is temporally coordinated with growth cessation and dormancy by photoperiodic signal, and reveals that storage lipid accumulation between seeds and perennating organs of trees may involve distinct regulatory circuits.

Keywords

abscisic acid (ABA); dormancy; flowering time; growth cessation; lipid biosynthesis; photoperiod; trees; triacylglycerol

Published in

New Phytologist
2018, Volume: 219, number: 2, pages: 619-630

SLU Authors

• Grimberg, Åsa

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

• Lager, Ida

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

• Marttila, Salla

  • Department of Plant Protection Biology, Swedish University of Agricultural Sciences
    

• Ingvarsson, Pär

  • Department of Plant Biology, Swedish University of Agricultural Sciences
    

• Bhalerao, Rishikesh P.

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

UKÄ Subject classification

Cell Biology
Genetics
Biochemistry and Molecular Biology


Publication identifier

DOI: https://doi.org/10.1111/nph.15197

Permanent link to this page (URI)

https://res.slu.se/id/publ/97253