Role of Cytochrome P-450s in Herbicide Metabolism and Selectivity and Multiple Herbicide Metabolizing Cytochrome P-450 Activities in Maize

Safeners recruit multiple signalling pathways for the orchestrated induction of the cellular xenobiotic detoxification machinery in Arabidopsis

“…The selective action of safeners may rather be determined by the specificity of the detoxifying enzymes, resulting in a higher herbicide metabolizing activity in grass crops as compared with dicots. Indeed, variation in substrate specificity of GSTs and P450s in different plant species can result in herbicide selectivity (Barrett et al 1997;Van Eerd et al 2003;Yuan et al 2007;Zhang et al 2007a). Furthermore, GSTs with herbicidedetoxifying activity were shown to result in herbicide tolerance in dicots when overexpressed in appropriate tissues (Jepson et al 1997;Skipsey et al 2005;Benekos et al 2010), and the development of herbicide resistance in weeds is often because of increased activities of specific P450s (Siminszky 2006).…”

Detoxification without Intoxication: Herbicide Safeners Activate Plant Defense Gene Expression

“…Plant P450 proteins are encoded by very large and diverse multigene families consisting of approximately 350 genes in rice and 250 genes in Arabidopsis (Arabidopsis thaliana), whose protein products are involved in numerous processes such as secondary product biosyntheses, fatty acid metabolism, and hormone homeostasis . The primary metabolism of herbicides from several important chemical classes is mediated by P450 activities, often leading to crop selectivity (Barrett et al, 1997), and the relationships between the physiological and detoxicative roles of individual P450 isoforms and herbicide selectivity in rice and maize are becoming more clear (Barrett, 2000;Persans et al, 2001;Pan et al, 2006;Nordby et al, 2008). There is ample circumstantial evidence from in vivo metabolism studies and experiments with isolated microsomes that P450 activities are induced by safeners.…”

New methods for haploid selection in maize

“…F l hybrids from the cross of GA209 and bentazon-tolerant inbreds inherited bentazon tolerance but sustained some minor damage from bentazon treatment. The ben1 gene also governed sensitivity to nicosulfuron (Barrett et al, 1997). Green (1998) published data on the inbred F2, and mapped a gene for sensitivity to rimsulfuron (another sulfonylurea herbicide) to the short arm of chromosome 5 (Williams et al, 2005).…”

“…F l hybrids from crosses of GA209 and bentazon-tolerant inbreds were tolerant despite of minor injury. The ben1 gene also caused sensitivity to nicosulfuron (Barrett et al 1997).…”