邻苯二甲酸二(2-乙基己基)酯胁迫下不同水稻品种生理与代谢响应OA

To elucidate the physiological toxicity and underlying metabolic regulatory mechanisms of di(2-ethylhexyl)phthalate(DEHP)in different rice genotypes,hydroponic experiments were conducted to assess the effects of DEHP exposure on seedlings of an inbred indica cultivar(NX24)and a three-line hybrid indica cultivar(TYHZ).Untargeted metabolomics was employed to characterize genotype-specific metabolic response profiles.DEHP exposure markedly inhibited root growth in both genotypes(maximum reduction of 36.94%)and suppressed biomass accumulation.DEHP also induced genotype-specific oxidative stress responses:hydrogen peroxide content increased significantly in NX24(by 43.61%),whereas malondialdehyde levels were significantly elevated in TYHZ(by 36.69%).Distinct antioxidant systems were mobilized to counteract oxidative damage:superoxide dismutase activity in NX24 was strongly induced(an increase of 90.06%),while catalase activity in TYHZ was markedly enhanced(by 447.70%).Metabolomic pathway analysis revealed that under DEHP stress,NX24 primarily activated metabolic routes associated with cellular homeostasis,reactive oxygen species scavenging,and energy metabolism,notably sphingolipid metabolism,plant hormone signal transduction,flavonoid biosynthesis,and pantothenate and CoA biosynthesis.In contrast,TYHZ responded primarily by upregulating pathways implicated in reinforcing physical barriers(cutin,suberin,and wax biosynthesis)and maintaining membrane integrity and signaling(linoleic acid metabolism).Collectively,DEHP exerts substantial phytotoxic effects on rice seedlings,with divergent coping strategies observed between genotypes.NX24 relies predominantly on modulation of secondary metabolism and hormone signaling,whereas TYHZ preferentially enhances its physical barriers and membrane integrity.