Molecular characterization and hormonal regulation of a sterile male mutant in tomato plant (Solanum lycopersicum L. cv Micro-Tom) involving the transformation of stamens into pistils and petals into sepals

• Grant number: 16/02415-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2016
• End date: December 31, 2016
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Lázaro Eustaquio Pereira Peres
• Grantee: Rodolfo Augusto Maniero
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Genetic and molecular studies in several species of model plants have led to a broadly accepted model for the development of each floral whorl based on the combined activity of functions from the so called "ABC" genes. Based on the ABC model, the variations in floral organ architecture amongst species might be due to the existence of either duplications or gene loss and functional diversification in the MADS-box transcription factor family type MIKCC, which are involved on the determination of flower meristem and floral organ identity. In tomato plants (Solanum lycopersicum L.), four genes MADS-box from class B specify the identity of petals and stamens during the development of floral organs. Some tomato plant mutants that show total or partial homeotic conversion in the second (petals) and third (stamens) whorls have been previously described as showing allelic differences with distinct phenotypes for petal and stamen identity. Molecular analysis of these mutants indicated that specific alterations in MADS-box genes from class B affect petals and stamens identity in a distinct manner. Moreover, the signaling with other class B genes and/or plant hormones might cause variations in identity of flower organs in tomato plants. With regard to the essentiality of MADS-box genes for floral organ identity specification in tomato plants, the present scientific project aims to perform the molecular and functional characterization of genes associated with the formation of petals and stamens in the spontaneous mutant tomato plant as known as castrato (cst), having Micro-Tom (MT) as background, through the identification of possible mutations in one or more genes (Tomato APETALA3, Tomato MADS-box gene 6, Tomato PISTILLATA e Solanum lycopersicum GLOBOSA) which encode for MADS proteins type B. Besides that, hormonal regulation in cst mutants will be assayed by using reporter transgenic lines so that MADS transcription factors and plant hormone can be better comprehended during floral organ development in tomato plants. (AU)