The Metabolism of a Novel Cytochrome P450 (CYP77B34) in Tribenuron-Methyl-Resistant Descurainia sophia L. to Herbicides with Different Mode of Actions

Abstract

Descurainia sophia L. (flixweeds) is a noxious broad-leaf weed infesting winter wheat fields in China that has evolved high resistance to tribenuron-methyl. In this work, a brand new gene CYP77B34 was cloned from tribenuron-methyl-resistant (TR) D. sophia and transferred into Arabidopsis thaliana, and the sensitivities of Arabidopsis with or without the CYP77B34 transgene to herbicides with a different mode of actions (MoAs) were tested. Compared to Arabidopsis expressing pCAMBIA1302-GFP (empty plasmid), Arabidopsis transferring pCAMBIA1302-CYP77B34 (recombinant plasmid) became resistant to acetolactate synthase (ALS)-inhibiting herbicide tribenuron-methyl, protoporphyrinogen oxidase (PPO)-inhibiting herbicides carfentrazone-ethyl and oxyfluorfen. Cytochrome P450 inhibitor malathion could reverse the resistance to tribenuron-methyl, carfentrazone-ethyl and oxyfluorfen in transgenic Arabidopsis plants. In addition, the metabolic rates of tribenuron-methyl in Arabidopsis expressing CYP77B34 were significantly higher than those in Arabidopsis expressing pCAMBIA1302-GFP. Other than that, the transgenic plants showed some tolerance to very-long-chain fatty acid synthesis (VLCFAs)-inhibiting herbicide pretilachlor and photosystem (PS) II-inhibiting herbicide bromoxynil. Subcellular localization revealed that the CYP77B34 protein was located in the endoplasmic reticulum (ER). These results clearly indicated that CYP77B34 mediated D. sophia resistance to tribenuron-methyl and may have been involved in D. sophia cross-resistance to carfentrazone-ethyl, oxyfluorfen, pretilachlor and bromoxynil.

Cytochrome P450 BsCYP99A44 and BsCYP704A177 Confer Metabolic Resistance to ALS Herbicides in Beckmannia syzigachne

“…Although a large number of genes have been discovered in omics [ 25 , 26 , 27 ], few of them have been identified as being involved in specific herbicide metabolism [ 17 , 28 , 29 ]. The strongest evidence for P450 conferring herbicide resistance is the expression of the P450 allele in herbicide-sensitive individuals or surrogate organisms (such as Arabidopsis ) and screening for reduced susceptibility [ 30 , 31 ]. From this, some P450 genes have been discovered.…”

“…Variants of CYP81A9 (Nsf1) have been reported to be responsible for the metabolism of nicosulfuron in sweet corn [ 32 ]. Higher-expression-level CYP709C56 degrades mesosulfuron-methyl in A. aequalis [ 17 ], and CYP77B34 from Descurainia sophia can confer Arabidopsis resistance to tribenuron-methyl, bromoxynil and pretilachlor [ 30 ]. Weeds are good materials for providing genetic resources for herbicide-resistant crops, and scientists have identified several CYP81A subfamily genes ( CYP81A12, CYP81A14, CYP81A15, CYP81A18, CYP81A21, CYP81A24, and CYP81A63 ) that metabolize herbicides only in E. phyllopogon [ 3 , 15 , 16 , 33 ], and CYP81A68 endows generalist metabolic resistance to penoxsulam and cyhalofop-butyl in Echinochloa crus-galli [ 34 ].…”

Genetic Analysis and Fine Mapping of ZmGHT1 Conferring Glufosinate Herbicide Tolerance in Maize (Zea mays L.)

“…Although phenomena of herbicide resistance have been discovered for decades, and 26 molecular target sites of herbicides have been classified by the Resistance Action Committee ( , accessed on 1 January 2022), new molecular targets and variations involving herbicide resistance are consistently and continuously being discovered [ 38 , 39 , 40 , 41 , 42 , 43 ]. In this study, eight genes located in the mapped interval were functionally annotated, among which Zm00001eb361930 and gene.8455157, possibly encoding a class III aminotransferase and a cationic amino acid transporter, respectively, were detected for expression in the leaves during glufosinate treatment ( Figure 4 ; Table 2 ).…”

An Asp376Glu substitution in ALS gene and enhanced metabolism confers high tribenuron-methyl resistance in Sinapis alba

“…almost remaining unknown. Shen et al, 2022 demonstrated that cyt P450 gen (CYP77B34) was responsible for TM metabolism in D. sophia, also a Brassicaceae weed species.…”

“…Of these, enhanced metabolism is one of the most important mechanisms; this may involve the enhanced activity of cytochrome P450 monooxygenases (P450s), glutathione-Stransferases (GSTs), glucosyltransferases, and ATP-binding cassette transporters (De Prado et al, 2005;Yasuor et al, 2010;Gaines et al, 2020;Palma-Bautista et al, 2020;Dimaano and Iwakami, 2021). Several cases of weeds resistant to ALS-inhibitor herbicides have been confirmed with NTSR mechanisms (mainly metabolism) (Yu and Powles, 2014b;Mei et al, 2017;Wang et al, 2019;Jugulam and Shyam, 2019;Han et al, 2021;Pan et al, 2022;Cao et al, 2022a;Shen et al, 2022;Feng et al, 2022;Lan et al, 2022;Zhao et al, 2022). Enhanced metabolism participates in grassweeds resistant to ALS-inhibiting herbicides, being rarely documented in dicots weeds (Hada et al, 2021).…”