Molecular Cloning, Expression Pattern of Multidrug Resistance Associated Protein 1 (Mrp1, Abcc1) Gene, and the Synergistic Effects of Verapamil on Toxicity of Two Insecticides in the Bird Cherry‐oat Aphid

Abstract

The ATP-binding cassette (ABC) transporters are important transmembrane proteins encoded by a supergene family. The majority of ABC proteins are primary active transporters that bind and hydrolyze ATP to mediate the efflux of a diverse range of substrates across lipid membranes. In this study, we cloned and characterized a putative multidrug resistance associated protein 1 (MRP1) from Rhopalosiphum padi encoded by ABCC1. Structural analysis showed that this protein has structural features typical of the ABC transporter family. Phylogenetic analysis indicated that the amino acid sequence was highly similar that of the corresponding protein from Acyrthosiphon pisum. Real-time quantitative polymerase chain reaction (PCR) analysis showed that ABCC1 was expressed throughout all R. padi developmental stages, with the highest level of expression in the fourth larval instar. We also examined ABCC1 expression in four different tissue types and found that it was most highly expressed in the midgut. Exposing R. padi to imidacloprid and chlorpyrifos increased ABCC1 expression. Furthermore, ABCC1 expression was higher in the imidacloprid-resistant (IR) and chlorpyrifos-resistant (CR) strains than in an insecticide-susceptible strain (SS) of R. padi. Exposing R. padi to verapamil in combination with insecticides significantly increased the toxicity of the insecticides. The respective synergy factor of CR and IR R. padi strain was 1.33 and 1.26, which was lower than that (2.72 and 1.64, respectively) of the SS. Our results clarify the biological function of ABCC1 in R. padi, particularly its role in insecticide resistance, and suggest novel strategies for pest management that use ABC transporter inhibitors to increase the effectiveness of insecticides.

Characterisation of imidacloprid resistance in the bird cherry‐oat aphid, Rhopalosiphum padi, a serious pest on wheat crops

“…The down‐regulation of the nAChR subunits could be a possible mechanism of resistance of R. padi to neonicotinoids, although more studies need to be performed to confirm this mechanism. Previously, we found that the ATP‐binding cassette (ABC) transporter ABCC1 was up‐regulated in the imidacloprid‐resistant R. padi strain, and imidacloprid induced the transcription of ABCC1 , indicating a role of ABCC1 in the efflux of insecticides in R. padi ; nevertheless the precise role of ABCC1 in the insecticide resistance remains to be further determined …”

“…Previously, we found that the ATP-binding cassette (ABC) transporter ABCC1 was up-regulated in the imidacloprid-resistant R. padi strain, and imidacloprid induced the transcription of ABCC1, indicating a role of ABCC1 in the efflux of insecticides in R. padi; nevertheless the precise role of ABCC1 in the insecticide resistance remains to be further determined. 64…”

The ABCB Multidrug Resistance Proteins Do Not Contribute to Ivermectin Detoxification in the Colorado Potato Beetle, Leptinotarsa decemlineata (Say)

“…Verapamil was used to inhibit the activity of ABC transporters at the protein level to verify if phenotypic changes caused by direct transporter inhibition would be similar to those caused by transcript downregulation. Verapamil is a common pharmacological inhibitor of ABC transporters used to test ABC transporter activity in a variety of organisms, including insects [17][18][19][20][21]23,24,[26][27][28][29][30]. In most species, verapamil produces a synergistic effect with insecticide in both resistant and sensitive populations.…”

“…MDR proteins have been intensively studied in humans because upregulation of MDR genes confers the multidrug resistance phenotype to cancer cells [16], but since they are highly conserved between organisms, their function is now being explored with respect to insect defenses against [17][18][19][20][21][22][23], and resistance to [24][25][26][27][28][29][30], insecticides. The development of insecticide resistance is frequently driven by amplified levels of natural defense processes, including those of both detoxification and excretion [31].…”

Increased Expression of Plasma-Induced ABCC1 mRNA in Cystic Fibrosis

“…Since the cloning of ABCC1 in the early 90s [ 17 , 18 , 19 ], progress has been made towards establishing a functional relationship between ABCC1 and CFTR . For example, functional complementation of dysfunctional CFTR by ABCC1 following chemotherapy that resulted in increased expression of ABCC1 was associated with improved lung function in a CF patient [ 15 ].…”