It has been shown that epigenetics allows plants to adapt to environmental stress, and may ‘prime’ them to respond more rapidly to the same stress in the future.
This project aims to determine if long-term epigenetic memory of stress is passed on to cuttings taken in grapevine propagation and the applicability of using these cuttings in grapevine breeding.
Epigenetics refers to the expression of genes in cells. The DNA sequence itself is not altered, but a chemical modification occurs to turn the gene ‘on’ or ‘off’.
These modifications survive cell division and can be passed onto the next generation.
Epigenetic memory could therefore be used to enhance plant resilience, while maintaining a level of plasticity which tends to be lost in lengthy conventional genetic breeding programmes.
For seed-propagated plants, the maintenance of epigenetic memory of stress has been shown to improve the offspring’s tolerance to stress. However, grapevines are propagated vegetatively and little is known on how vegetative propagation affects the epigenetic memory and long-term maintenance of stress-induced epigenetic modifications.
This research will build on the previous Wine Australia-funded incubator project (UA 1402), where a significant number of stress-induced epigenetic changes were maintained after plants reached physiological recovery once stress was discontinued; suggesting that epigenetic memory of stress is maintained in the grapevine.
This project will analyse to what extent the epigenetic memory of drought and heat stress (individually and combined) is maintained three and four years after discontinuation of the experienced stress.
Cuttings of Cabernet Sauvignon, exposed to stress in 2013 and analysed in the incubator project, will be re-exposed to stress and subject to analyses of physiological traits, epigenetic modification of genes and gene expression profiles (using established techniques).
In addition, the stressed plants will be propagated vegetatively using two methods, namely cuttings and layering, and analysed to test the heritability and durability of the epigenetic changes.
The generation of new insights in the regulation of plant stress tolerance will provide tools to develop novel strategies for crop improvement. Priming donor plants before propagation could enhance water use efficiency and heat tolerance of new propagules, revolutionising breeding of grapevine varieties.