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Research in the Fruit Functional Genomics Lab is centred around fundamental advancements in understanding fruit molecular physiology and the use of this knowledge for development of sustainable agricultural practices and cultivars. To those ends we are intrinsically associated with the grapevine breeding platform housed at ARC Nietvoorbij (Stellenbosch), run by our collaborator, Ms Phyllys Burger. We provide molecular support in the way of marker assisted selection to the breeding program as well as work on the development of novel molecular markers for traits of interest.
Till now winegrape breeding has been predominantly focused on the incorporation of mildew resistant genes (typically through introgression with wild Vitis cultivars) to create more sustainable cultivars requiring less fungicide application. In addition to this approach we are interested to identify markers linked to traits sought by both grower and consumers, such as bunch architecture, fruit cracking resistance and flavour production. We make use of forward and reverse genetic approaches to characterise genetic elements associated with these traits and others.
Many fruit quality traits are impacted by regulation of specialised metabolism. We have embarked on several projects involved in the characterisation of genetic elements associated with the metabolic pathways leading to the biosynthesis of wax, terpenes, phenolics and other specialised metabolites. By implementing large scale metabolomic and transcriptomic analyses in grapevine mapping populations we employing quantitative genetic approaches with the aim to create integrated genome-transcriptome-metabolome networks to improve gene identification and characterisation.
In addition to these approaches we make use of targeted functional characterisation of candidate genes. Due to the recalcitrant nature of grapevine regeneration and transformation, we routinely use model species such as tomato and Arabidopsis for gene functional characterisation. However, together with Dr Campa at Stellenbosch University, we are exploring the use of microvine as a tool for functional genomics and accelerating grapevine breeding.
Some of the traits we are most focused on in the group is plant surface formation and grapevine bunch morphology. The fruit surface formation is fundamentally linked to the ripening process, and impacts important traits such as grape berry cracking and apple russet formation. While, in the context of agriculture, despite grapevine bunches being a relatively unique plant structure, and contributing significantly to quality and disease resistance, little is known about the genetic and transcriptomic regulation of its formation.
Plants do not exist in isolation, we therefore study plant-environment interactions are mediated and regulated. We are particularly interested in how volatile compounds are perceived by the plant for the purpose of defence priming and communication as well as the antifungal role played by this class of specialised metabolites. Additionally, we are investigating how plant priming for stress response may be exploited for sustainable agricultural gains as well as how apple bud burst is transcriptionally and hormonally regulated in the context of climate change.