Altered cytokinin signaling drives plant drought resilience through lipid remodeling, nutrient homeostasis, cell wall reinforcement, and modulation of biotic stress–associated pathways

Cytokinin signaling regulates abiotic stress tolerance, and modulation of this pathway, including in arr signaling mutants, enhances stress resilience through multiple molecular and physiological mechanisms. Here, we show that under moderate drought conditions, sextuple arr3,4,5,6,8,9 mutants maintained up to 50% greater rosette area than wild-type Col-0 with significantly improved growth trajectories. Integrative analysis of 4706 proteins and 18,008 transcripts, supported by complementary physiological and biochemical measurements, reveal coordinated adaptations linked to enhanced stress tolerance. These include extensive lipid remodeling with selective depletion of polyunsaturated membrane lipids, reinforced redox and protein-homeostasis networks, and improved acquisition of key nutrients (K, P, S, Fe), all contributing to better water balance and cellular stability under drought. Anatomical traits including constitutively reduced stomatal density and 3-fold elevated root lignin content further support decreased water loss and sustained hydraulic function. Cross-omics integration additionally uncovered strong activation of biotic-stress-associated pathways, particularly glucosinolate and jasmonate metabolism, suggesting that reconfigured defense signaling forms an integral part of the drought-adaptive program. Importantly, we identify both previously characterized and novel mechanisms linking cytokinin signaling to drought resilience, including age-dependent regulatory circuits revealed through young-to-old leaf ratio comparisons that recovered stress-tolerance genes absent in conventional analyses. Together, these findings establish cytokinin signaling as a central coordinator of developmental, physiological, and metabolic adjustments shaping plant drought tolerance and position our accelerated drought assay as a robust platform for resolving complex stress-adaptive strategies.