Hedley, P.E., Russell, J.R., Jorgensen, L., Gordon, S., Morris, J.A., Hackett, C.A., Cardle, L. and Brennan, R.M.
BMC Plant Biology 10, 202.
The detrimental effects of mild winter temperatures on the consistency of cropping of blackcurrant (Ribes nigrum L.) in parts of Europe have led to increasing interest in the genetic control of dormancy break in this species. The aim of this study was to examine patterns of gene expression in leaf buds of blackcurrant and to identify the key differential changes in these profiles around the time of budbreak.
Using leaf bud tissue of blackcurrant, a cDNA library was generated as a source of blackcurrant ESTs for construction of a custom microarray, which was then used to examine gene expression during dormancy release, and to identify the key differential changes in expression around the time of budbreak. Lowest levels of differential expression were detected in early stages of dormancy, increasing to reach a maximum around budbreak. Unigenes with significantly changing gene expression profiles were clustered and evidence is provided for the transient expression of genes previously associated with dormancy processes in other species. Expression profiling identified candidate genes associated with budbreak, and these genes were mapped onto a blackcurrant genetic linkage map containing budbreak-related QTL. Three genes, associated with calcium signalling, beta-tubulin and acetyl CoA carboxylase activities, were found to co-localise with budbreak QTL.
This study provides insight into the genetic control of dormancy transition in blackcurrant, identifying key changes in gene expression around budbreak. Genetic mapping of ESTs enabled the identification of genes which co-localise with previously-characterised blackcurrant QTL, and it is concluded that these genes have probable roles in the dormancy and budbreak processes, and can therefore provide a basis for the development of genetic markers for future breeding deployment.