SCI1 Is a Direct Target of AGAMOUS and WUSCHEL and Is Specifically Expressed in the Floral Meristematic Cells

Author(s):Show less -

Cruz, Joelma O. ^{[1, 2]} ; San Martin, Juca A. B. ^{[2, 3]} ; Lubini, Greice ^{[1, 2]} ; Strini, Edward J. ^{[1, 2]} ; Sobral, Romulo ^[4] ; Pinoti, Vitor F. ^{[1, 2]} ; Ferreira, Pedro B. ^{[1, 2]} ; Thome, Vanessa ^{[1, 2]} ; Quiapim, Andrea C. ^[2] ; Dornelas, Marcelo C. ^[5] ; Pranchevicius, Maria Cristina S. ^[6] ; Madueno, Francisco ^[7] ; Costa, M. Manuela R. ^[4] ; Goldman, Maria Helena S. ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Fac Med Ribeirao Preto, PPG Genet, Ribeirao Preto - Brazil

^[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Pret, Dept Biol, Ribeirao Preto - Brazil

^[3] Consejo Nacl Invest Cient & Tecn, Inst Bot Darwin, Acad Nacl Ciencias Exactas Fis & Nat, San Isidro - Argentina

^[4] Univ Minho, Plant Funct Biol Ctr, Biosyst & Integrat Sci Inst, Braga - Portugal

^[5] Univ Estadual Campinas, Inst Biol, Dept Biol Vegetal, Campinas - Brazil

^[6] Univ Fed Sao Carlos, Dept Genet & Evolucao, Sao Carlos - Brazil

^[7] Univ Politecn Valencia, CSIC, Inst Biol Mol & Celular Plantas, Valencia - Spain

• Document type: Journal article
• Source: FRONTIERS IN PLANT SCIENCE; v. 12, MAR 18 2021.
• Web of Science Citations: 0

Abstract

The specified floral meristem will develop a pre-established number of floral organs and, thus, terminate the floral meristematic cells. The floral meristematic pool of cells is controlled, among some others, by WUSCHEL (WUS) and AGAMOUS (AG) transcription factors (TFs). Here, we demonstrate that the SCI1 (Stigma/style cell-cycle inhibitor 1) gene, a cell proliferation regulator, starts to be expressed since the floral meristem specification of Nicotiana tabacum and is expressed in all floral meristematic cells. Its expression is higher in the floral meristem and the organs being specified, and then it decreases from outside to inside whorls when the organs are differentiating. SCI1 is co-expressed with N. tabacum WUSCHEL (NtWUS) in the floral meristem and the whorl primordia at very early developmental stages. Later in development, SCI1 is co-expressed with NAG1 (N. tabacum AG) in the floral meristem and specialized tissues of the pistil. In silico analyses identified cis-regulatory elements for these TFs in the SCI1 genomic sequence. Yeast one-hybrid and electrophoresis mobility shift assay demonstrated that both TFs interact with the SCI1 promoter sequence. Additionally, the luciferase activity assay showed that NAG1 clearly activates SCI1 expression, while NtWUS could not do so. Taken together, our results suggest that during floral development, the spatiotemporal regulation of SCI1 by NtWUS and NAG1 may result in the maintenance or termination of proliferative cells in the floral meristem, respectively. (AU)

• FAPESP's process: 19/24774-1 - The importance of the SCI1 gene in the floral meristem, its transcriptional regulation and evolutionary conservation
• Grantee: Maria Helena de Souza Goldman
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/20486-3 - Deciphering SCI1, its expression during flower development and mechanisms of action for the control of cell proliferation
• Grantee: Maria Helena de Souza Goldman
• Support Opportunities: Regular Research Grants