Arabidopsis NAC transcription factor JUB1 regulates GA/BR metabolism and signalling

0467800 - ÚEB 2017 RIV GB eng J - Journal Article
Shahnejat-Bushehri, S. - Tarkowská, Danuše - Sakuraba, Y. - Balazadeh, S.
Arabidopsis NAC transcription factor JUB1 regulates GA/BR metabolism and signalling.
Nature Plants. Roč. 2, č. 3 (2016), č. článku 16013. ISSN 2055-026X. E-ISSN 2055-0278
R&D Projects: GA MŠMT LK21306; GA MŠMT(CZ) LO1204; GA ČR GA14-34792S
Institutional support: RVO:61389030
Keywords : gibberellins * brassinosteroids * signalling
Subject RIV: EF - Botanics
Impact factor: 10.300, year: 2016

Gibberellins (GAs) and brassinosteroids (BRs) are important phytohormones that control plant development and responses to environmental cues by involving DELLA proteins and BRASSINAZOLE-RESISTANT1 (BZR1) respectively as key transcription factors. Here, we reveal a new role for JUNGBRUNNEN1 (JUB1) as a transcriptional regulator of GA/BR signalling in Arabidopsis thaliana. JUB1 directly represses the hormone biosynthesis genes GA3ox1 and DWARF4 (DWF4), leading to reduced levels of GAs and BRs and typical GA/BR deficiency phenotypes exhibiting short hypocotyls, dwarfism, late flowering and male sterility. JUB1 also directly represses PHYTOCHROME INTERACTING FACTOR4 (PIF4), a transcription factor connecting hormonal and environmental stimuli. On the other hand, JUB1 activates the DELLA genes GA INSENSITIVE (GAI) and RGA-LIKE 1 (RGL1). In addition, BZR1 and PIF4 act as direct transcriptional repressors upstream of JUB1, establishing a negative feedback loop. Thus, JUB1 forms the core of a robust regulatory module that triggers DELLA accumulation, thereby restricting cell elongation while concomitantly enhancing stress tolerance.
Permanent Link: http://hdl.handle.net/11104/0265840