TERMINAL FLOWER1 is a breeding target for a noveleverbearing trait and tailored flowering responses incultivated strawberry (Fragaria × ananassa Duch.)
Koskela, Elli Aurora; Sønsteby, Anita; Flachowsky, Henryk; Heide, Ola M.; Hanke, Magda-Viola; Elomaa, Paula; Hytönen, Timo
Abstract
The effects of daylength and temperature on flowering of the cultivated octoploid strawberry
(Fragaria × ananassa Duch.) have been studied extensively at the physiological level, but
information on the molecular pathways controlling flowering in the species is scarce. The
flowering pathway has been studied at the molecular level in the diploid short-day woodland
strawberry (F. vesca L.), in which the FLOWERING LOCUS T1 (FvFT1)–SUPPRESSOR OF
OVEREXPRESSION OF CONSTANS1 (FvSOC1)–TERMINAL FLOWER1 (FvTFL1) pathway is essential
for the correct timing of flowering. In this work, we show by transgenic approach that the
silencing of the floral repressor FaTFL1 in the octoploid short-day cultivar ‘Elsanta’ is sufficient to
induce perpetual flowering under long days without direct changes in vegetative reproduction.
We also demonstrate that although the genes FaFT1 and FaSOC1 show similar expression
patterns in different cultivars, the regulation of FaTFL1 varies widely from cultivar to cultivar and
is correlated with floral induction, indicating that the transcription of FaTFL1 occurs at least
partially independently of the FaFT1–FaSOC1 module. Our results indicate that changing the
expression patterns of FaTFL1 through biotechnological or conventional breeding approaches
could result in strawberries with specific flowering and runnering characteristics including new
types of everbearing cultivars.
Description
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