亚硒酸钠对红甜菜次生代谢产物的调控效应OA

Selenium is a non-essential but beneficial trace element for plants.Appropriate amounts of selenium can enhance the stress resistance of plants and be converted into organic selenium and stored in plant tissues.Secondary metabolites of plants are non-essential compounds for plant growth and development,including flavonoids,polyphenols,alkaloids,terpenoids,etc.,which are synthesized by plants under environmental stress or at specific growth stages.To clarify the regulatory patterns of sodium selenite on secondary metabolites in red beet,red beet seedlings were sprayed with different concentrations of sodium selenite(0,1.0,and 3.0 mg/L).The contents of major secondary metabolites were determined by ultraviolet spectrophotometry,high-perform-ance liquid chromatography,and ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),and differential metabolites were screened.The results showed that low concentration of sodium sel-enite(1.0 mg/L)significantly promoted the accumulation of total flavonoids,total phenols,total tri terpenoids,and betaine,with the largest increase in the 1.0 mg/L treatment group(total flavonoids+32.5％,total phenols+28.3％,total triterpenoids+25.7％,betaine+31.2％).High concentration(3.0 mg/L)inhibited the synthesis of flavonoids and phenolic substances.A total of 326 metabolites were identified by UPLC-MS/MS,and 89 differential metabolites(56 up-regulated and 33 down-regulated)were screened in the 1.0 mg/L treatment group.The up-regulated products were mainly flavonoids(quercetin,kaempferol),phenolic acids(caffeic acid,chlorogenic acid),and triterpenoids(oleanolic acid).This study revealed the concentration-de-pendent regulatory characteristics of sodium selenite on secondary metabolism in red beet and provided metabolic-level evidence for understanding its regulatory mechanism.