Activity of Antioxidant Enzymes in Euphorbia heterophylla Biotypes and their Relation to Cross Resistance to ALS and Protox Inhibitors

Abstract

The characteristics of multiple resistance in Euphorbia heterophylla biotypes to herbicides that are inhibitors of ALS (Acetolactate synthase) and PPO (Protoporphyrinogen oxidase) and their responsible mechanisms are still not completely elucidated. The objectives of this study were to identify cross-resistance to herbicides from different chemical groups of ALS inhibitors (imidazolinones, sulfonylureas, pyrimidyl benzoates and sulfonanilides) and also PPO inhibitors (diphenylethers, phthalamides, oxadiazoles, triazolinones and pyrimidinediones) in E. heterophylla biotypes with multiple resistance to these herbicides; to analyze whether the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) constitute mechanisms that are responsible for the resistance to PPO inhibitors. Initially, the response to doses of herbicides from these different chemical groups was determined, using doses below and above the one recommended for the species. The control of E. heterophylla was determined, estimating the required doses for a 50 and 80% control reduction and calculating the resistance factors. The constitutive and induced activities of the SOD and POD enzymes were also determined. The results confirmed cross-resistance for all chemical groups of ALS and PPO inhibitors in the Bom Sucesso do Sul and Vitorino biotypes. The constitutive and induced activities of the SOD and POD enzymes were superior in plants from the E. heterophylla biotypes Vitorino and Bom Sucesso do Sul, contributing to their resistance to PPO inhibiting herbicides.

Arg-128-Leu target-site mutation in PPO2 evolves in wild poinsettia (Euphorbia heterophylla) with cross-resistance to PPO-inhibiting herbicides

“…For flumioxazin, differences in GR 50 parameters between the two populations were not significant, and thus resistance to flumioxazin was not confirmed in R PPO (Table 1). These results are consistent with other PPO-resistant E. heterophylla populations from Brazil (Trezzi et al 2005(Trezzi et al , 2006Xavier et al 2018). Trezzi et al (2005) studied two populations with high RF to fomesafen (39-and 62-fold) that were controlled with sulfentrazone (600 g ha −1 ) and flumioxazin (50 g ha −1 ) PRE.…”

“…Trezzi et al (2005) studied two populations with high RF to fomesafen (39-and 62-fold) that were controlled with sulfentrazone (600 g ha −1 ) and flumioxazin (50 g ha −1 ) PRE. In a E. heterophylla population from Virotino city, the RF was 15.1-fold for saflufenacil and 4.9-fold for flumiclorac (same chemical group as flumioxazin) (Xavier et al 2018). Regardless of the conditions adopted by different laboratories, the resistance levels and crossresistance patterns primarily depend on the population and its resistance mechanism.…”

Journal of Plant Protection Research

“…Mechanisms that confer tolerance to PPO inhibitors include: the reduction of absorption and translocation (Kilink et al 2011), the increased activity of antioxidant enzymes (Xavier et al 2018), and the rapid herbicide metabolism (Dayan et al 1997;Kilink et al 2011). In pre-emergence application, specific mechanisms capable of interfering with the absorption, translocation and metabolism of herbicidal compounds in plant tissues may contribute to increasing plant tolerance.…”

“…4) and the characteristics of the commercial group, growth habit, and cycle (Table 1). Among the mechanisms considered important for the tolerance of plants to PPO inhibitors are the metabolism of herbicides to less toxic compounds (Dayan et al 1997;Kilink et al 2011), the antioxidative enzyme activity (Xavier et al 2018), and the herbicide absorption and translocation differences (Kilink et al 2011). Probably the mechanisms of tolerance to PPO--inhibiting herbicides mentioned above are not associated with specific morphophysiological characteristics or the center of origin of bean cultivars.…”

Investigation of Euphorbia nivulia-HAM for Enzyme Inhibition Potential in Relation to the Phenolic and Flavonoid Contents and Radical Scavenging Activity

“…Thus, their inhibition could be helpful to counteract these serious pathological disorders [24]. Previous studies have shown that several members of the genus Euphorbia have shown inhibitory activities against a wide range of enzymes, and have proven their potential as a potent enzyme inhibitory therapeutic agent to be used in wide variety of diseases [25,26]. Because of these reasons, the present study was designed to assess phenolic, flavonoid content, in-vitro radical scavenging, and enzyme inhibitory potential of EN using different chemical and biochemical enzymes assays.…”