Screening of differentially expressed genes during the end of endogenous dormancy of flower buds in Prunus armeniaca L.

Abstract

An insufficient endogenous dormancy period of apricot flower buds can result in reduced frost resistance. This is one of the causes of lower fruit yields in certain years. The aim of this work was the analysis of gene expression profiles in flower buds of four apricot cultivars (‘Sundrop’, ‘Stark Early Orange’, ‘Vestar’ and ‘Betinka’) that differ in the duration of their dormancy periods. The investigation was carried out before and during exit of buds from endogenous dormancy. Transcriptomes from bud tissues were analyzed by cDNA amplified fragment length polymorphism. Amplified fragments showing a significant change in their intensity within obtained expression profiles were considered to be derived from genes associated with the exit of flower buds from endogenous dormancy. All selected fragments were sequenced and compared with sequences recorded in public databases, yielding 147 sequences with similarity to previously described genes. The majority of identified genes match with theoretical expectations for events happening in dormant tissues. Moreover, some of the identified genes are included in the category of cellular or physiological processes previously reported to directly influence the exit from endogenous dormancy (e.g. aquaporin, GTP-binding proteins, elongation factor 1-alpha, ATP-dependent ubiquitin, xyloglucan endotransglycosylase hydrolase, and EXGT-A1).