Abstract
The identification and characterization of transcripts involved in flower organ development, plant reproduction and metabolism represent key steps in plant phenotypic and physiological pathways, and may generate high-quality transcript variants useful for the development of functional markers. This study was aimed at obtaining an extensive characterization of the olive flower transcripts, by providing sound information on the candidate MADS-box genes related to the ABC model of flower development and on the putative genetic and molecular determinants of ovary abortion and pollen-pistil interaction. The overall sequence data, obtained by pyrosequencing of four cDNA libraries from flowers at different developmental stages of three olive varieties with distinct reproductive features (Leccino, Frantoio and Dolce Agogia), included approximately 465,000 ESTs, which gave rise to more than 14,600 contigs and approximately 92,000 singletons. As many as 56,700 unigenes were successfully annotated and provided gene ontology insights into the structural organization and putative molecular function of sequenced transcripts and deduced proteins in the context of their corresponding biological processes. Differentially expressed genes with potential regulatory roles in biosynthetic pathways and metabolic networks during flower development were identified. The gene expression studies allowed us to select the candidate genes that play well-known molecular functions in a number of biosynthetic pathways and specific biological processes that affect olive reproduction. A sound understanding of gene functions and regulatory networks that characterize the olive flower is provided.
Highlights
Olive (Olea europaea L.) is a wind pollinated, andromonoecious species whose cluster inflorescences are paniculate
This study was aimed at obtaining an extensive characterization of the olive flower transcripts, by providing sound information on the candidate MADSbox genes related to the ABC model of flower development and on the putative genetic and molecular determinants of ovary abortion and pollen-pistil interaction
The results demonstrated that OeLTP1, OeLTP2, OeLTP3 and OeLTP4 possess a pistil-specific expression pattern, whereas the mRNA levels of OeLAT52, OeNTP, OePME1, OePME2, OeOLE and OeβGLU were much higher in the anthers compared to the pistils, in accordance to their function
Summary
Olive (Olea europaea L.) is a wind pollinated, andromonoecious species whose cluster inflorescences are paniculate The hermaphrodite flower consists of a small, greenish calyx, four white petals, two stamens with large anthers and one single pistil with a bilobed stigma, a short style and a bilocular ovary with four ovules [3]. Studies on the genetic determinants of flower development and plant reproduction have not yet been conducted in olive; the results from other plants provided a wide variety of candidates that might have utility in this species. In the last two decades, studies on MADS-box genes disclosed the importance of these determinants in flower and fruit development of different plant species, as they exert a wide range of functions, including the development of reproductive structures, the control of flowering time and vegetative development [7]. Starch grains are observable in the stigma, style, ovary wall and ovule integument, while starch is not detected in the pistil of staminate flowers, suggesting a correlation with the ovary abortion of olive flowers [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
