SELF PRUNING 3C is a flowering repressor that modulates seed germination, root architecture, and drought responses

Authors: MOREIRA, JULIENE DOS REI - Universidade Federal De Vicosa; QUINONES, ALJANDRA - Universidade Federal De Vicosa; LIRA, BRUNO - Universidad De Sao Paulo; ROBLEDO, JESSENIA - Universidade Federal De Vicosa; Curtin, Shaun; VICENTE, MATEUS - Universidad De Sao Paulo; RIBEIRO, DIMAS - Universidade Federal De Vicosa; RYNGAJLLO, MALGORZATA - Max Planck Institute Of Molecular Plant Physiology; JIMÉNEZ-GÓMEZ, JOSE - Agro Paris Tech; PEREIRA PERES, LÁZARO - Universidad De Sao Paulo; ROSSI, MAGDALENA - Universidad De Sao Paulo; ZSÖGÖN, AGUSTIN - Universidade Federal De Vicosa

Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2022
Publication Date: 6/17/2022
Citation: Moreira, J., Quinones, A.L., Lira, B.S., Robledo, J., Curtin, S.J., Vicente, M.H., Ribeiro, D.M., Ryngajllo, M., Jiménez-Gómez, J., Pereira Peres, L.E., Rossi, M., Zsögön, A. 2022. SELF PRUNING 3C is a flowering repressor that modulates seed germination, root architecture, and drought responses. Journal of Experimental Botany. 73(18):6226-6240. https://doi.org/10.1093/jxb/erac265.
DOI: https://doi.org/10.1093/jxb/erac265

Interpretive Summary: Plant breeders have improved many plants by selecting for desirable traits such as fruit size, color and shape, along with changes in shoot architecture, alterations in flowering time, reduction of seed dispersal and dormancy, and modifications in roots. Some of the genes that control domestication and improvement traits have been identified. The CETS gene family is important in domestication traits in tomato but the role of some members of the family remain unexplored. We found that one member of the family, SP3C, acts as a flowering repressor, regulates seed germination and modulates root growth. We show that sp3c mutant plants have accelerated seed germination and increased root length with reduced lateral branching and in SP3C over-expression transgenic lines opposite effects were observed. These discoveries provide new insights into the role of these genes play for agronomically relevant traits. Considering the large expansion of CETS in many species and evidence that these genes can regulate important physiological processes under stressful environmental conditions, this study adds to the catalog of genes known to control agronomically important traits for improvement of tomato and other crop plants.

Technical Abstract: The genetic basis of many agronomically important traits has been unveiled and in different crops involves allelic variation in members of the CETS (CENTRORADIALIS, TERMINAL FLOWER 1, SELF PRUNING) gene family. CETS genes encode phosphatidylethanolamine binding proteins (PEBPs) that have a central role in the control of flowering time control as florigenic and anti-florigenic signals. The great expansion of CETS genes in many species suggests that the functions of this family go beyond flowering control. Here, we characterized the tomato SELF PRUNING 3C (SP3C) gene, and show that besides acting as a flowering repressor it also regulates seed germination and modulates root growth. We show that loss of SP3C function in CRISPR/Cas9-generated mutant lines accelerates seed germination and increases root length but with lower root side branching. Higher SP3C expression in transgenic lines promotes the opposite effects and also improves tolerance to water stress in seedlings. These discoveries provide new insights into the role of SP paralogs in agronomically relevant traits, such as seed germination and root development, and support future exploration of the involvement of CETS genes in abiotic stress responses.