%0 Journal Article
%T The role of the Arabidopsis FUSCA3 transcription factor during inhibition of seed germination at high temperature
%A Rex S Chiu
%A Hardeep Nahal
%A Nicholas J Provart
%A Sonia Gazzarrini
%J BMC Plant Biology
%D 2012
%I BioMed Central
%R 10.1186/1471-2229-12-15
%X In this study, we present evidence for a role of FUS3 in delaying seed germination at supraoptimal temperatures that would be lethal for the developing seedlings. During seed imbibition at supraoptimal temperature, the FUS3 promoter is reactivated and induces de novo synthesis of FUS3 mRNA, followed by FUS3 protein accumulation. Genetic analysis shows that FUS3 contributes to the delay of seed germination at high temperature. Unlike WT, seeds overexpressing FUS3 (ML1:FUS3-GFP) during imbibition are hypersensitive to high temperature and do not germinate, however, they can fully germinate after recovery at control temperature reaching 90% seedling survival. ML1:FUS3-GFP hypersensitivity to high temperature can be partly recovered in the presence of fluridone, an inhibitor of ABA biosynthesis, suggesting this hypersensitivity is due in part to higher ABA level in this mutant. Transcriptomic analysis shows that WT seeds imbibed at supraoptimal temperature activate seed-specific genes and ABA biosynthetic and signaling genes, while inhibiting genes that promote germination and growth, such as GA biosynthetic and signaling genes.In this study, we have uncovered a novel function for the master regulator of seed maturation, FUS3, in delaying germination at supraoptimal temperature. Physiologically, this is important since delaying germination has a protective role at high temperature. Transcriptomic analysis of seeds imbibed at supraoptimal temperature reveal that a complex program is in place, which involves not only the regulation of heat and dehydration response genes to adjust cellular functions, but also the activation of seed-specific programs and the inhibition of germination-promoting programs to delay germination.Seed maturation begins during mid-embryogenesis and controls important traits, including seed quality and viability. In Arabidopsis, during mid-embryogenesis the embryo accumulates storage compounds, such as seed storage proteins (SSP) and lipids, which a
%K High temperature
%K FUSCA3
%K Seed germination
%K Hormones
%K ABA
%K Transcriptome
%U http://www.biomedcentral.com/1471-2229/12/15