Characterization of the Amaranthus palmeri Physiological Response to Glyphosate in Susceptible and Resistant Populations

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• 作者：Manuel Fernández-Escalada ; Miriam Gil-Monreal ; Ana Zabalza ; Mercedes Royuela
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2016
• 出版时间：January 13, 2016
• 年：2016
• 卷：64
• 期：1
• 页码：95-106
• 全文大小：624K
• ISSN：1520-5118

文摘

The 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.