Fernández Escalada, ManuelGil Monreal, MiriamZabalza Aznárez, AnaRoyuela Hernando, Mercedes2017-04-112017-04-1120160021-8561 (Print)1520-5118 (Electronic)10.1021/acs.jafc.5b04916https://academica-e.unavarra.es/handle/2454/24071Incluye 2 ficheros de datosThe herbicide glyphosate inhibits the plant enzyme 5-enolpyruvylshikimate3-phosphate synthase (EPSPS) in the aromatic amino acid (AAA) biosynthetic pathway. The physiologies of an Amaranthus palmeri population exhibiting resistance to glyphosate by EPSPS gene amplification (NC-R) and a susceptible population (NC-S) were compared. The EPSPS copy number of NC-R plants was 47.5-fold the copy number of NC-S plants. Although the amounts of EPSPS protein and activity were higher in NC-R plants than in NC-S plants, the AAA concentrations were similar. The increases in total free amino acid and in AAA contents induced by glyphosate were more evident in NC-S plants. In both populations, the EPSPS protein increased after glyphosate exposure, suggesting regulation of gene expression. EPSPS activity seems tightly controlled in vivo. Carbohydrate accumulation and a slight induction of ethanol fermentation were detected in both populations.application/pdfapplication/zipeng© 2015 American Chemical SocietyCarbohydrate accumulationEthanol fermentationFree amino acid accumulationHerbicide resistancePhysiological effectsinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess