Flowering induction in juvenile citrus through the constitutive expression of the SFT gene

• Grant number: 16/20981-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2017
• End date: January 31, 2019
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Raquel Luciana Boscariol Camargo
• Grantee: Natalia Cristina Soares
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

The juvenile period in perennial woody plants can be extended, and in citrus, can vary from 6 to 20 years, and has hampered traditional breeding and genetic studies. The flowering process involves a complex network of genes that is shared among different species. Universal florigenic signals triggered by tomato SINGLE FLOWER TRUSS (SFT), a homologue of the Arabidopsis FLOWERING LOCUS T (FT), are graft transmissible and induce flowering. This project aims to reduce the citrus juvenility period by overexpressing SFT gene in rootstocks, so that they can also induce flowering in juvenile scion grafted on them, allowing the study of phenotypic characteristics and favouring breeding. The genetic transformation will be mediate by Agrobacterium tumefaciens GV3101, containing the expression cassette of the SFT gene under control of the CaMV35S constitutive promoter. Epicotyl segments of juvenile plants of the Rangpur lime and Swingle citrumelo are used as explants. Selection of transformants will be made with the antibiotic kanamycin (75mg/L). Transgenic plants will be rooted in vitro and then acclimatized in a greenhouse. Confirmation of genetic transformation will be performed by PCR and phenotypic evaluations. (AU)