Unraveling the mechanisms of ethylene-induced regulation of energy cane shoot and root development

Energy cane is a bioenergy crop known for its high biomass accumulation, higher fiber content, low management, and growth capacity in more restricted conditions than current sugarcane cultivars. However, during the establishment phase, energy cane exhibits little root formation, which negatively impacts the shoot-to-root ratio. Among the growth regulators, Ethephon stands out as a well-known substance that generates the hormone ethylene, thereby promoting faster sprouting in sugarcane. However, there is no current evidence of its effect on an energy cane cultivar. With this in mind, was conducted an experiment in which was applied Ethephon to sugarcane and energy cane setts and evaluated the sprouting speed of the axillary buds in the two cultivars, as well as their shoot-to-root ratio development for up to 30 days following planting. A significant acceleration in the sprouting speed of sugarcane when Ethephon was applied was observed. However, this effect was not observed in energy cane. Moreover, was observed a noteworthy increase in root length, a concern previously described. Furthermore, analysis of the metabolic profiles of shoots and roots in energy cane showed higher levels of sugars and lipids, and a decrease in a series of amino acids in response to the application of ethylene. These findings suggest that Ethephon may have divergent effects on different cane varieties, shedding new light on the intricate relationship between metabolism and management strategies for energy cane.