Dormancy release in almond by metabolomic analyses

Dormancy release is a prerequisite for flowering in temperate fruit trees as Prunus species. It is known that metabolites play a key role in dormancy release. Therefore, in this study, flower buds from four different almond (Prunus dulcis (Miller) D.A. Webb) cultivars (‘Desmayo Largueta’, ‘Antoñeta’, ‘Penta’ and ‘Tardona’), with different chilling requirements and flowering times, were analyzed in an UPLC-QTOF equipment, obtaining the fingerprinting of every single sample. The spectra of those metabolites with the most significant variation along the different states from dormancy to dormancy release, which in the North Hemisphere were from November to February, were subjected to the Metlin, HMDB and KEGG databases. These analyses not only allow the putative identification of the compounds but also to the different pathways involved. Interestingly, some of those pathways, such as the abscisic acid biosynthetic pathway, just varied in one of the late-flowering varieties. Nevertheless, it was the glutathione metabolism that varied in all the varieties. Moreover, it has been seen that some fatty acids suffered a sharp decrease in the earliest-flowering varieties, while some oligopeptides showed a huge decrease in the late-flowering species. This is a stepping stone in the development of dormancy-associated biomarkers in temperate fruit tree species.