From the Field to the Lab: Establishing Different Abscission Potentials in Apple Fruitlets for Transcriptomic and Functional Studies.

Physiological studies of the abscission process in non-model species require a profound knowledge of both the specific characteristics of the crop/variety and the multiple factors that are involved in the induction of the process. The main problem deals with the predictability of the destiny of the abscising organ, that is fundamental in comparative physiological studies aimed at identifying the causal factors preceding the activation of the abscission zones (AZs) and the detachment of the organ. Relevant progress has been made in the last decades regarding the abscission of the apple (Malus domestica L. Borkh) fruitlets, which were shown to be a good model system for these kinds of studies. The present method summarizes the most relevant knowledge regarding the following: (1) the establishment of differentially abscising fruitlet populations in apple; (2) the sampling techniques to adopt for successful collections of suitable samples; (3) a reference protocol for the isolation of total RNA from apple fruitlets' tissues, and (4) the main bioinformatic steps to analyze RNA-Seq data. This method may represent a reliable knowledge base for developing of similar approaches in other crops in future.