Characterization of regulatory elements in citrus derived promoters

• Grant number: 14/25077-9
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: July 01, 2015
• End date: March 31, 2016
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Beatriz Madalena Januzzi Mendes
• Grantee: Lígia Erpen
• Supervisor: Manjul Dutt
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: University of Florida, Gainesville (UF), United States
• Associated to the scholarship: 13/19700-2 - Citrus sinensis constitutive gene promoters: isolation and evaluation of its efficiency on uidA gene expression in Solanum lycopersicum and Citrus sinensis, BP.DR

Abstract

Transgenic technology can provides genetic solutions to major problems affecting citrus species. The success of gene transfer technologies depends on the selection of appropriate promoter that induces expression of transgene at desired levels. Among the promoters usually employed, there is the constitutive promoter CaMV35S isolated from the Cauliflower Mosaic Virus characterized by the ability to induce strong expression of the transgene. However, new approaches for plant transformation (intragenesis and cisgenesis) requires use of genetic material derived from the species itself or related species. Thus, it is necessary to increase the availability of well characterized constitutive promoters derived from citrus for genetic transformation. The objective of the doctorate project is to identify and isolate constitutive promoters of Citrus sinensis as an alternative to CaMV35S promoter. Hence, the promoter region of the citrus genes GAPDH (glyceraldehyde-3-phosphate dehydrogenase), EF1-± (elongation factor 1-±) and CYP (cyclophilin) were isolated and inserted into a transformation vector fused to the reporter gene uidA (GUS). The promoter constructs were evaluated in citrus plants and had the ability to drive GUS gene expression. To complement the research, is important to characterize the cis-regulatory elements of these promoters. This characterization would be done by deletion analysis. This information is fundamental for understanding gene expression levels according to the biological condition which the plants will be submitted and will define the minimum size required to the promoter provide the desired effect on gene expression. (AU)