Analysis of MADS-box genes expression patters during fruit development in Citrus sinensis

Author(s)

Pedro Araújo

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2010-04-02

Examining board members

Marcelo Carnier Dornelas; Sandra Maria Carmello Guerreiro; Adriana Pinheiro Martinelli

• Advisor: Marcelo Carnier Dornelas

Abstract

Fruit development is extensively studied in the model plant Arabidopsis thaliana and a number of genes is being related to the control of fruit ontogenesis and ripening. The FRUITFULL (FUL) and SHATTERPROOF (SHP) genes, which belong to the MADS-box multigenic family are, in large part, responsible for determining the identity of the Arabidopsis dry fruit tissues. Homologs to these genes have been described for species harbouring fleshy fruits, but the expression patterns and biological functions for these genes during fruit development are unknown. Sequences showing similarity to FUL and SHP were found at the database of the CitEST Project (expressed sequence tags in Citrus). Since Citrus fruits are fleshy and do not have the same structures of the Arabidopsis fruits, we decided to characterize in detail the development of fruits in Citrus sinensis and Citrus reticulata and to study the possible functions of FUL and SHP homologues during the development of C. sinensis fruits. These sequences were characterized by bioinformatic's tools and phylogenetic analysis. The use of light and scanning electron microscopy (SEM) techniques allowed the morpho-anatomical characterization of Citrus fruit development. The RT-PCR results showed a preferential expression of FUL and SHP in developing fruits. The in situ hybridization results showed that the C. sinensis homolog of the FUL gene is differentially expressed in the secretory cells of the oil cavity as well as in the juice vesicles, epicarp, mesocarp and endocarp tissues. The homolog of the SHP gene also expressed in epicarp, mesocarp, endocarp and juice vesicles. All the results taken together might contribute to a better understanding of the processes involved in Citrus fruit development. (AU)