Arabidopsis EARLY FLOWERING3 increases salt tolerance by suppressing salt stress response pathways

3 years ago

Arabidopsis EARLY FLOWERING3 increases salt tolerance by suppressing salt stress response pathways

Selin Bülbül, Giltsu Choi, Yasuhito Sakuraba, Nam-Chon Paek, Weilan Piao

Arabidopsis EARLY FLOWERING3 (ELF3) functions in modulating light input to the circadian clock, as a component of ELF3-ELF4-LUX ARRHYTHMO (LUX) evening complex. However, the role of ELF3 in stress responses remains largely unknown. In this study, we show that ELF3 enhances plants’ resilience to salt stress: ELF3-overexpressing (ELF3-OX) plants are salt-tolerant while elf3 mutants are more sensitive to salt stress. Expression of many salt stress- and senescence-associated genes are altered in elf3-1 and ELF3-OX plants compared to wild type. During salt stress, ELF3 suppresses factors that promote salt stress response pathways, mainly GIGANTEA (GI), at the post-translational level, and PHYTOCHROME INTERACTING FACTOR4 (PIF4), at the transcriptional level. To enhance the salt stress response, PIF4 directly downregulates the transcription of JUNGBRUNNEN1 (JUB1/ANAC042), encoding a transcription factor that upregulates the expression of stress tolerance genes, DREB2A and DELLA. Furthermore, PIF4 directly upregulates the transcription of ORESARA1 (ORE1/ANAC092) and SAG29, positive regulators of salt stress response pathways. Based on our results, we propose that ELF3 modulates key regulatory components in salt stress response pathways at the transcriptional and posttranslational levels. This article is protected by copyright. All rights reserved.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1111/tpj.13747