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Quizalofop‐ p ‐ethyl resistance in Polypogon fugax involves glutathione S‐transferases
Author(s) -
Chen Wen,
Wu Lamei,
Wang Junzhi,
Yu Qin,
Bai Lianyang,
Pan Lang
Publication year - 2020
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.5931
Subject(s) - population , canola , biology , glutathione , biochemistry , botany , enzyme , medicine , environmental health
Background Asia minor bluegrass ( Polypogon fugax ) is one of the main weeds invading Chinese canola fields. The P. fugax resistant population SC‐R, which survived quizalofop‐ p ‐ethyl at the field‐recommended rate (67.5 g ha −1 ), was collected from a canola field in Qingsheng County in China. The present study aimed to (1) characterize the SC‐R resistance pattern to acetyl‐CoA carboxylase (ACCase)‐inhibiting herbicides, and (2) investigate the mechanism of quizalofop‐ p ‐ethyl resistance in this population. Results Dose–response studies showed that resistance to quizalofop‐ p ‐ethyl and haloxyfop occurred in the SC‐R population. Four transcripts/genes encoding the plastidic ACCase carboxyl‐transferase domain were isolated from the P. fugax plants. No mutations in the four ACCase genes were detected in the SC‐R population compared to the SC‐S population. Pre‐treatment with the known glutathione S‐transferase (GST) inhibitor 4‐chloro‐7‐nitrobenzoxadiazole (NBDCl), reversed resistance to quizalofop‐ p ‐ethyl and partially reversed resistance to haloxyfop‐R‐methyl in the resistant population (SC‐R). However, the cytochrome P450 inhibitor malathion did not reverse the resistance. There was no difference in basal GST activity (using CDNB as a substrate), but there was higher inducible GST activity in SC‐R relative to SC‐S. Two GST genes, GST2c and GSTL3 , were constitutively overexpressed in the resistant SC‐R population. Conclusion This study confirmed that resistance to quizalofop‐ p ‐ethyl in the resistant P. fugax population is likely nontarget‐site based involving GST, and this resistance mechanism also partially confers haloxyfop‐ R ‐methyl resistance. © 2020 Society of Chemical Industry