Diurnal metabolism of energy-cane and sugarcane: A metabolomic and non-structural carbohydrate analysis

Energy-cane is a cross breed between commercial sugarcane and S. spontaneum, a hybrid that has higher fiber content, low sucrose and greater productivity compared to commercial sugarcane hybrids. It has been recently shown that diurnal and seasonal changes impact several physiological characteristics of sugarcane. However, little is known about how the diurnal cycle affects the production of carbohydrates and metabolites in energy cane. In the present study, we investigate the diurnal cycle of adult sugarcane and energy-cane by analyzing the carbohydrates and metabolites profiles of leaves and internodes. Our results show fluctuations in the soluble sugars content (sucrose, glucose and fructose) and the metabolites profile throughout of day, which indicates different growth strategies and carbon use among these cultivars. In addition, a high concentration of starch was observed in the mature internodes of energy-cane. Some biological pathways related to biomass production, such as the phenylpropanoid pathway, were more active in energy-cane compared to sugarcane. Our results reveal that sugarcane and energy-cane metabolism are different throughout the day, a better understanding of the metabolism of these cultivars opens the possibility of creating more efficient plants through breeding.