Cloning and functional characterization of a tau class glutathione transferase associated with haloxyfop‐P‐methyl resistance in Digitaria sanguinalis

Abstract

AbstractBackgroundHaloxyfop‐P‐methyl, an acetyl‐CoA carboxylase (ACCase)‐inhibiting herbicide, has been extensively used to control grass weeds. Widespread use of haloxyfop‐P‐methyl in cotton fields in China has led to the development of glutathione transferase (GST)‐mediated resistance in Digitaria sanguinalis. An RNA‐seq analysis identified DsGSTU1, a tau class glutathione transferase from the D. sanguinalis transcriptome as a potential candidate. Here, we cloned DsGSTU1 from D. sanguinalis young leaf tissues and subsequently characterized DsGSTU1 by a combination of sequence analysis, as well as functional heterologous expression in rice.RESULTSThe full‐length coding DNA sequence (CDS) of DsGSTU1 is 717 bp in length. Higher DsGSTU1 expression was observed in haloxyfop‐P‐methyl‐resistant (HR) D. sanguinalis than in haloxyfop‐P‐methyl‐susceptible (HS) plants. Overexpression of the DsGSTU1 gene was confirmed by transformation into the wild‐type (WT) Nipponbare rice with pBWA(V)HS, a recombinant expression vector. GST activity in transgenic rice seedlings was 1.18–1.40‐fold higher than the WT rice seedlings before and after haloxyfop‐P‐methyl treatment, respectively. Additionally, transgenic rice seedlings overexpressing DsGSTU1 were less sensitive to haloxyfop‐P‐methyl.CONCLUSIONOur combined findings suggest that DsGSTU1 is involved in metabolic resistance to haloxyfop‐P‐methyl in D. sanguinalis. A better understanding of the major genes contributing to herbicide‐resistant D. sanguinalis facilitates the development of resistance management strategies for this global invasive grass weed. © 2023 Society of Chemical Industry.