Vacuolar invertase knockout enhances drought tolerance in potato plants

Drought stress is one of the most critical abiotic constraints limiting crop productivity worldwide, exacerbated by ongoing climate change and increasingly frequent extreme weather events. Stomatal regulation and osmoprotective sugar accumulation are critical adaptive mechanisms for plant survival under drought stress. Here, we characterize the enhanced drought resilience observed in CRISPR/Cas9-mediated potato, mutants in their vacuolar invertase gene (StVInv). Knockout plants exhibited improved performance under progressive drought stress and during rewatering drought, maintaining higher stomatal conductance, elevated transpiration rates, and superior photosynthetic efficiency compared to wild-type (WT) plants. These improved performance under similar transpiration rate led to higher agronomic water-use efficiency (AWUE) in stvinv plants resulting in greater biomass production despite reduced water availability. Metabolomic profiling revealed distinct adaptive strategies; stvinv plants preferentially accumulated galactinol and raffinose, indicating enhanced raffinose family oligosaccharide (RFO) metabolism. Furthermore, stvinv plants displayed lower levels of abscisic acid (ABA) and its catabolites under drought, suggesting a moderated ABA response facilitating a more risk-taking growth strategy that supports sustained growth and physiological stability. Our findings identify targeted metabolic and hormonal adjustments underlying drought resilience in potato plant, offering promising strategies for enhancing crop performance under water-limited conditions.