3-Dichloroacetyl oxazolidine protect maize from imazethapyr herbicide injury

Abstract

Safeners are an important tool used to ensure the safe using of herbicide. The objective of this paper was to investigate the protective effect of four 3-dichloroacetyl oxazolidine safeners (3-dichloroacetyl-2,2-dimethyl-1,3-oxazolidine [R-28725], racemate of 3-dichloroacetyl-2,2-dimethyl-4-ethyl-1,3-oxazolidine, and its two chiral stereoisomers) in reducing the injury caused by imazethapyr. Physiological and biochemical tests were conducted under laboratory condition, by using seed treatment with safeners and soil treatment with imazethapyr, respectively. The interaction of two safeners (R-28725 and R-stereoisomer) and imazethapyr reduced the injury of maize significantly, and also increased glutathione content, activity of glutathione S-transferases, and activity of acetolactate synthase in maize. When induced by R-stereoisomer, the GSH content in root and in shoot increased 100.7% and 73.6%, respectively. When induced by R-28725, the GST activity in vivo increased threefold and the GST activity in vitro more than doubled. The kinetic parameter Vmax of GST in the maize treated with R-28725 and R-stereoisomer increased by 102.2% and 81.9%, respectively, compared with the control. The results also showed that R-28725 and R-stereoisomer induced glutathione S-transferases affinity for the substrate of conjugation reaction significantly.

Evaluating the effects of manual hoeing and selective herbicides on maize (Zea mays L.) productivity and profitability

“…On the latter crop, imazethapyr combined with imazapyr does not influence yield regardless of the sensitivity of the crop to this herbicide and the timing of application in non-asphyxiating soil [ 68 ]. In certain cases, imazethapyr or herbicides of the same family can induce low yields on maize crops when applied without an antioxidant safener [ 69 ] or in submerged rice cultivation whose anaerobic conditions slowed down the biodegradation of imazethapyr, thus accelerating its strong accumulation in the soil solution [ 70 ] which can induce other symptoms such as morpho-anatomical deformations of the root system of maize installed in sandy loam soil, slightly alkaline and poor in organic matter [ 71 ].…”