Monitoring dormancy release in fruit trees and ornamentals by RNA sequencing and its implications for horticulture
Dormancy, as it occurs in many perennial plants, is characterised by the temporal absence of growth. One of the major factors that overcomes dormancy and stimulates flowering, is the exposure to low temperature. Suboptimal flowering is often caused by poor accumulation of chilling hours and is frequently observed in warmer geographical regions. The number and size of geographical regions suffering from suboptimal flowering is likely to increase as a consequence of global warming. Insight in the underlying processes enables growers to take measures that support optimal release from dormancy. Transcriptome analysis, using next generation sequencing, provides in depth insight in underlying processes and their timing. In kiwifruit (Actinidia spp.), upon analysing data from several seasons in both New Zealand and Italy, distinct Gene Ontology categories could be recognised related to dormancy release, such as cell wall metabolism, stress response and polysaccharide catabolism. Subsequent comparison of relevant genes from kiwifruit to the transcriptomes of another important fruit crop, sweet cherry (Prunus avium) and an ornamental, Viburnum opulus, revealed conserved genes. Regulated genes included a dormancy associated MADS-box transcription factor, a dehydration stress related galactinol synthase and several genes involved in abscisic acid regulated processes. The approach presented here opens possibilities to effectively compare genes involved in dormancy release across species, thereby increasing insight in relevant conserved processes. Moreover, such genes can be used as indicators to define the exact physiological stage crops are in.
Balk, P.A., Hoeberichts, F.A., Verhoef, N., Schumacher-Strijker, A.M. and Aanhane, T.G.M. (2018). Monitoring dormancy release in fruit trees and ornamentals by RNA sequencing and its implications for horticulture. Acta Hortic. 1229, 35-42
RNA sequencing, dormancy release, kiwifruit, sweet cherry, Viburnum