Pool of Resistance Mechanisms to Glyphosate in Digitaria insularis

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• 作者：Leonardo Bianco de Carvalho ; Pedro Luis da Costa Aguiar Alves ; Fidel Gonz谩lez-Torralva ; Hugo Enrique Cruz-Hipolito ; Antonia Mar铆a Rojano-Delgado ; Rafael De Prado ; Javier Gil-Humanes ; Francisco Barro ; Mar铆a Dolores Luque de Castro
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2012
• 出版时间：January 18, 2012
• 年：2012
• 卷：60
• 期：2
• 页码：615-622
• 全文大小：321K
• 年卷期：v.60,no.2(January 18, 2012)
• ISSN：1520-5118

文摘

Digitaria insularis biotypes resistant to glyphosate have been detected in Brazil. Studies were carried out in controlled conditions to determine the role of absorption, translocation, metabolism, and gene mutation as mechanisms of glyphosate resistance in D. insularis. The susceptible biotype absorbed at least 12% more ¹⁴C-glyphosate up to 48 h after treatment (HAT) than resistant biotypes. High differential ¹⁴C-glyphosate translocation was observed at 12 HAT, so that >70% of the absorbed herbicide remained in the treated leaf in resistant biotypes, whereas 42% remained in the susceptible biotype at 96 HAT. Glyphosate was degraded to aminomethylphosphonic acid (AMPA), glyoxylate, and sarcosine by >90% in resistant biotypes, whereas a small amount of herbicide (up to 11%) was degraded by the susceptible biotype up to 168 HAT. Two amino acid changes were found at positions 182 and 310 in EPSPS, consisting of a proline to threonine and a tyrosine to cysteine substitution, respectively, in resistant biotypes. Therefore, absorption, translocation, metabolism, and gene mutation play an important role in the D. insularis glyphosate resistance.

Keywords:

N-phosphonomethylglycine; EPSPS; weed resistance; mechanisms of resistance; sourgrass