Stress memory increases cane yield and juice quality of field-grown sugarcane.

Intergenerational drought memory has been studied in several sexually reproducing plant species, but the occurrence of this phenomenon and the potential effects on yield of clonal plants are unknown. We investigated the effects of intergenerational drought memory on productivity of sugarcane propagules obtained from plants previously stressed at two phenological stages. Firstly, IACCTC07-8008 (drought tolerant) and IACSP95-5000 (high-yielding) cultivars were grown under well-hydrated conditions (group W) or subjected to three cycles of water deficit through water withholding during the tillering (group T) or maturation (group M) stage. Then, propagules from these three groups were grown under field conditions. Propagules from groups T and M of IACCTC07-8008 showed enhanced photosynthesis, attributed to increased stomatal conductance, photochemical activity, Rubisco carboxylation, and a larger root system. Group M of IACCTC07-8008 exhibited reduced ascorbate peroxidase activity, leading to increased HO concentration without causing oxidative damage. This group also showed improved juice quality - such a higher sucrose content. The stalk yield, shoot biomass, leaf area index and tiller density of the group M of IACCTC07-8008 and group T of IACSP95-5000 were increased as a consequence of intergenerational drought memory. Although both cultivars have "inherited" drought memory, our findings suggest that parental stress memory varies between cultivars and phenological stages in sugarcane. This research is the first to demonstrate the impact of intergenerational drought memory on yield and juice quality in field-grown sugarcane, providing valuable insights for enhancing drought tolerance strategies in sugarcane production, with significant potential benefits for the industry.