Integrative Analysis of Metabolic Signature and Phytohormone Response in Potato Under Heat, Drought and Salt Stresses

Climate change-driven abiotic stresses threaten global potato production, yet stress-specific adaptive mechanisms remain poorly defined. We demonstrate that heat, drought and salt stresses induce fundamentally distinct physiological and biochemical responses in potato plants. Photosynthetic performance and gas exchange showed stress-specific patterns, with heat stress (HS) maintaining elevated carbon metabolism, drought stress (DS) causing severe photosynthetic suppression and water deficit, while salt stress (SS) exhibited intermediate physiological impairment. Secondary metabolite (SM) profiling revealed a corresponding stress-specific signature, where sesquiterpenes (caryophyllene, copaene, humulene) were dramatically elevated under HS but suppressed under DS (which specifically enhanced 1-hexanol and trans-sesquisabinene hydrate), while SS induced copaene and cis-β-farnesene but reduced caryophyllene. Phytohormone analysis demonstrated differential accumulation patterns across stresses: JA, JA-Ile, SA and ABA were maximally elevated under HS, moderately increased under DS, while SS uniquely maintained basal JA/JA-Ile with enhanced SA and ABA. Pharmacological intervention using hormone biosynthesis inhibitors (DIECA, SHAM, Jarin-1, AIP, ABT, fluridone) and exogenous ABA confirmed stress-specific regulatory networks. These findings establish a stress-specific hormone-metabolite regulatory framework, providing a molecular basis for developing climate-resilient potato genotypes.