Abstract
During autumn and early winter, buds and apices of fruit trees enter dormancy in response to low temperatures and short days. This dormancy is eventually overcome by prolonged exposure to cold, allowing growth to resume in spring, triggered by longer days and warmer temperatures. Environmental cues, such as winter and spring temperatures, which control these phenology patterns, are being altered by climate change, posing a threat to yield. However, our ability to breed new fruit tree cultivars is hindered by our lack of knowledge regarding the molecular and genetic mechanisms underlying these economically significant environmental responses, particularly how trees detect and respond to temperature changes.The FruitFlow project (https://www.suscrop.eu/projects-second-call/fruitflow) brings together an international consortium of five academic and three commercial partners to address these issues for two important fruit tree crops: apple (Malus domestica) and peach (Prunus persica). In the FruitFlow project, we aim to develop novel technologies and knowledge for predicting and promoting flower and fruit production. To achieve this, we have firstly acquired data on the seasonal behavior of diverse panels of apple and peach varieties. Statistical and machine learning methods have been tested to predict the flowering behavior of cultivars in different environments using aerial images and NIRS data. Secondly, we have identified genetic associations between the flowering behavior of apple and peach cultivars and polymorphisms in their genomes. Genome-Wide Association Studies (GWAS) were performed to identify polymorphisms associated with loci and candidate genes regulating bud dormancy and bud break (Watson et al., 2024). Thirdly, the metabolic content of apple and peach buds was analyzed between December and February to identify small molecules whose intensities could predict different stages of the dormancy cycle. Proteins interacting with these metabolites were identified through proteomics and computational methods. These data were also used to generate machine-learning-based predictive models of dormancy traits. Fourthly, the functions of proteins identified as interacting with small molecules or from previous studies are being tested through reverse genetics or transgenic approaches using perennial plant models such as poplar trees and Arabis alpina. Fifthly,chemicals identified as accumulating at different stages of the dormancy process were tested for their capacity to stimulate bud break or flowering of apple and peach through direct application.In this communication, we will present an overview of the FruitFlow project, with special emphasis on some significant results which increase the fundamental knowledge on bud dormancy and budbreak in fruit trees and could contribute to solving an important current problem in European Agriculture.