Metabolomic changes in potato(Solanum tuberosum L.)under different drought stress levels

LIU Yaqi; SU Riguga; LIU Sujun

doi:10.13522/j.cnki.ggps.2025267

Abstract：[Objective]Drought is one of the major abiotic stresses limiting potato growth and yield in many regions.Understanding metabolic responses of potato to drought is essential for elucidating the mechanisms underlying its adaptation to drought and breeding drought-resistant cultivar,but it remains elusive.This paper aims to fill this knowledge gap.[Method]The experiment was conducted in pots using the Jizhangshu 12 variety as the model plant.There were three irrigation treatments by controlling soil moisture in the root zone at 35%-40%(T1),15%-20%(T2)of the field capacity.The control was maintaining the soil moisture at 65%-70%of the field capacity for 14 days(CK).During the experiment,we measured various metabolite profiles and the associated metabolic pathways in the different treatments.[Result]In T1,there were 39 metabolites that showed significant differences from those in CK,including 20 upregulated and 19 downregulated metabolites,involved in 29 metabolic pathways.In T2,there were 158 metabolites that differed significantly from those in CK,including 67 upregulated and 91 downregulated,involved in 61 metabolic pathways.There were 37 metabolites that differed significantly between T1 and T2,including 26 upregulated and 11 downregulated,involved in 47 metabolic pathways.Among the top 20 metabolites in T1 and T2,which differed from those in CK,seven were upregulated:diosgenin-3-O-glucosyl-(1→4)-rhamnosyl-(1→4)-rhamnosyl-(1→2)-glucoside,deltonin,protodioscin,3-O-glucosyl-(1→2)-xylosyl-(1→3)-glucosyl-(1→4)-galactoside-diosgenin,5(6)-ene-spirost-3-ol-3-O-glucosyl-(1→4)-[rhamnosyl-(1→2)]-galactoside,5,6-dihydrosolanidine,and pseudoprotodioscin;three were downregulated:N-(4′-O-glycosyl)-feruloyl spermidine,machilin D,and usnic acid.In T1,differentially accumulated metabolites were mainly enriched in 29 pathways,including metabolic pathways,biosynthesis of secondary metabolites,phenylpropanoid biosynthesis,amino acid biosynthesis,and flavonoid biosynthesis,while in T2,they were significantly enriched in 47 pathways,primarily metabolic pathways,biosynthesis of secondary metabolites,biosynthesis of cofactors,amino acid biosynthesis,and 2-oxocarboxylic acid metabolism.[Conclusion]Drought significantly altered metabolite composition and metabolic pathways in potato plants,especially under severe drought stress.Steroidal saponins and flavonoids were identified as potential positive biomarkers associated with drought resistance,whereas phenolic amides and sesquiterpene lactones showed negative responses to drought stress.These findings suggest that potatoes activate multiple metabolic pathways to mitigate drought effects and maintain physiological stability,providing insight into the metabolic mechanisms underlying drought tolerance.