S19 - Session O2 - A genome assembly sheds light on dormancy breaking candidate genes of blackcurrant (R. nigrum) buds

Authors: Freya Ziegler *, Anita Sonsteby, Agnieszka Masny, Sonia Osorio-Algar, Björn Usadel

In temperate latitudes of northern and continental Europe, low temperatures during fall and winter frosts are common. To adapt to such climate conditions, woody plant species, like blackcurrant ( Ribes nigrum ), grown in these regions have developed survival strategies, such as cessation of vegetative growth followed in parallel by activation of generative growth and entrance into a state of dormancy, which needs to be broken by the action of low temperature (chilling) during winter. However, the precise molecular mechanisms and genes that may result in breaking of dormancy in blackcurrant remain unclear. RNA-seq and data mining helped us to discover the genes involved in the dormancy breaking of blackcurrant plants and finally elucidate these mechanisms. In this study, blackcurrant plants of cv. Ben Gairn were grown in phytotron daylight compartments at 9°C and 15°C, at natural decreasing autumn daylength for 8 weeks. After treatment, the plants were moved to cold storage at 0°C, in darkness. After 7 and 14 weeks of cold storage, the plants were moved to a greenhouse at 20°C, and 20 h light. After three days of forcing, 3 buds (no. 6, 7 and 8 below the tip) from 3 plants were sampled, flash frozen in liquid nitrogen, and stored in a -80°C freezer until subjected to deep sequencing. In the absence of a reference genome, a draft blackcurrant genome was established and used for analysis of the RNA-seq data. For this purpose, the data were first clustered and subjected to PCA. The first results showed a highly dynamic transcriptomic response and due to these results, candidate genes were selected. Detailed results will be discussed, and we believe that such data can be useful for future studies on dormancy in woody plant species like Ribes. These results could lead to an optimization of blackcurrant production and cultivation processes.