Salomé Prat
Group Leader
Research summary
Work in our group aims to identify which signaling cascades govern etiolated seedling development in the dark and how these cascades are affected by light, with a particular focus in the mechanisms involved in integration of the light signal with the own running developmental programs of the plant. The plant hormones gibberellins (GA) and brassinosteroids(BRs) play a central role in transducing the light signal as judged from the dark de-etiolated phenotype of mutants with a block in the synthesis or response to these hormones.
Publications
Legris M, Nieto C, Sellaro R, Prat S, and Casal JJ. Perception and signaling of light and temperature cues in plants. Plant J. 2017; 90(4):683-697
Abelenda JA, Cruz-Oró E, Franco-Zorrilla, JM and Prat S. Potato StCONSTANS-like1 suppresses storage organ formation by directly activating the FT-like StSP5G repressor. Curr Biol 2016; 26:872-81
Navarro C, Cruz-Oró E and Prat S. Conserved function of FLOWERING LOCUS T (FT) homologues as signals for storage organ differentiation. Curr Opin Plant Biol 2015; 23:45-53
Nieto C, López-Salmerón V, Davière JM and Prat S. ELF3-PIF4 interaction regulates plant growth independently of the Evening Complex. Curr Biol 2015; 25:187-93
Navarro C, Cruz-Oró E, Prat S. Conserved function of FLOWERING LOCUS T (FT) homologues as signals for storage organ differentiation. Curr Opin Plant Biol 2014; 23C: 45-53
Our group is interested in understanding the mechanisms by which hormone signalling controls plant growth and development in response to diurnal photocycles, changes in light spectra, or adverse environmental conditions. Our work focuses on gibberellins (GA), a group of hormones that control plant growth by triggering degradation of the DELLA repressors. We showed that DELLAs inhibit plant GA-regulated gene expression via interaction with PHYTOCHROME-INTERACTING FACTOR 4 and 5 (PIF4 and PIF5). DELLA interaction with the PIF bHLH domain prevents PIF binding to the promoters of their gene targets and suppresses growth. DELLAs also mediate increased tolerance to salt stress via a largely unknown pathway. In genetic screens, we identified several transcription factors whose overexpression confers increased tolerance to salt and drought stress, and which bind the DELLAs. We are currently studying
1. The regulatory pathways controlled by these regulators
2. The molecular mechanisms by which DELLAs modulate activity of these factors
3. DELLA allelic mutations that interfere with PIF interaction but do not alter binding to these stress-related factors
Introduction of these allelic mutations into cultivated species will help to generate new cultivars more tolerant to drought and salt stress, and increase crop production in adverse climate conditions.
Our second line of research is the control of storage organ formation in the potato. We showed that potato tuberization is triggered by a member of the potato FLOWERING LOCUS T (FT) gene family, SP6A. Temperatures >25ºC inhibit storage organ formation by suppressing SP6A expression; this inhibitory effect is reversed by SP6Aox, which highlights the SP6A pathway as one of the primary targets for increased potato productivity. We aim to analyse the signalling events that lead to SP6A suppression at warm temperatures and to identify the SP6A downstream pathway that controls tuber formation and, by extension, storage organ formation in other bulb-, rhizome- or tuberous root-forming species.
