Metabolic response to cold and freezing of Osteospermum ecklonis overexpressing Osmyb4

We examined the phenotypic adaptation of transgenic plants to cold and freezing stress. We also analysed the ability of wild-type and transgenic Osteospermum to accumulate several solutes, such as proline, amino acids and sugars. Using nuclear magnetic resonance, we outlined the metabolic profile of this species under normal growth conditions and under stress for the first time. Indeed, we found that overexpression of Osmyb4 improved the cold and freezing tolerance and produced changes in metabolite accumulation, especially of sugars and proline. Based on our data, it could be of agronomic and economic interest to use this gene to produce Osteospermum plants capable of growing in open field, even during the winter season in climatic zone Z9.