Implicación de los esfingolipidos en el proceso de abscisión del fruto en olivo

Abstract

Plant organs abscission is regulated by complex signaling networks that mediate development and environmental responses. In olive (Olea europaea L.), abscission of fruit is associated with changes in sphingolipid long-chain bases (LCB) in the abscission zone (AZ), showing a specific association between the dihydroxylated LCB sphinganine (d18:0) and the olive fruit abscission. The main goal of this work is to gain knowledge on the molecular mechanisms involved in the fruit abscission in olive, broadening our research into the role of sphingolipids using pharmacological and transcriptomic approaches. Here, firstly, we reported hormonal and transcriptome changes in olive fruit with respect to their AZ at the last stage of ripening when natural fruit abscission occurs. These transcriptomic data allowed for the identification of unique and common transcriptional signatures related to cell wall modification; plant hormone metabolism and signaling; vesicle trafficking; and ion fluxes between the fruit tissues. Subsequently, to understand the differential signaling involved in fruit and leaf abscission in olive, we reported transcriptional characterization of the olive AZs of fruit and leaf in response to d18:0 treatment. We reported identification of specific markes of the AZ of fruit and novel regulators of olive fruit abscission signaling. Our results provide new insight into the biology of olive fruit abscission and this will enable the development of new strategies for the selective control of the fruit abscission in olive, facilitating mechanical harvest of the crop and reducing costs without tree defoliation.