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ARS Home » Southeast Area » Stoneville, Mississippi » Southern Insect Management Research » Research » Publications at this Location » Publication #295578
Title: Altered gene regulation and potential association with metabolic resistance development to imidacloprid in the tarnished plant bug, Lygus lineolaris

Author
item Zhu, Yu Cheng
item Luttrell, Randall

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2014
Publication Date: 3/20/2014
Publication URL: http://handle.nal.usda.gov/10113/60206
Citation: Zhu, Y., Luttrell, R.G. 2014. Altered gene regulation and potential association with metabolic resistance development to imidacloprid in the tarnished plant bug, Lygus lineolaris. Pest Management Science. 71(1):40-57. doi: 10.1002/ps.3761

Interpretive Summary: Chemical spray on cotton is almost an exclusive method for control of tarnished plant bug (TPB). Frequent use of imidacloprid is a concern for neonicotinoid resistance in this key pest. Information of how and why TPB become less susceptible to imidacloprid is essential for effective monitoring and managing resistance. Novel microarray analysis of 6,688 genes in imidacloprid-selected TPB (Im1500FF) revealed 955 up- and 1277 down-regulated (=2-fold) genes in Im1500FF with 369 and 485 of them annotated. Detection of a large proportion of metabolic genes in both up- and down-regulated genes indicated a significant alternation of metabolic pathways in Im1500FF. Five P450 and 9 esterase genes were significantly up-regulated, and only one esterase gene and no P450 genes were down-regulated. Besides these major metabolic candidate genes that may confer resistance, this study also identified other enzyme-coding genes that may directly or indirectly influence resistance development in TPB. Pathway analyses identified 65 up-regulated cDNAs, that encode 51 different enzymes involved in 62 different pathways, including P450 and esterase genes for drug and xenobiotic metabolisms. Sixty-four down-regulated cDNAs code only 17 enzymes that are associated with only 23 pathways mostly related to food digestions. This study demonstrated a significant change of metabolic processes in imidacloprid-selected TPB, resulting in over-expression of P450 and esterase genes for potential excess detoxification and cross/multiple resistance development. The identification of these and other enzyme genes establishes a foundation to explore the complicity of potential imidacloprid resistance in TPB.

Technical Abstract: Chemical spray on cotton is almost an exclusive method for control of tarnished plant bug (TPB, Lygus lineolaris). Frequent use of imidacloprid is a concern for neonicotinoid resistance in this key pest. Information of how and why TPB become less susceptible to imidacloprid is essential for effective monitoring and managing resistance. Novel microarray analysis of 6,688 genes in imidacloprid-selected TPB (Im1500FF) revealed 955 up- and 1277 down-regulated (=2-fold) genes in Im1500FF with 369 and 485 of them annotated. Detection of a large proportion of metabolic genes in both up- and down-regulated genes indicated a significant alternation of metabolic pathways in Im1500FF. Five P450 and 9 esterase genes were significantly up-regulated, and only one esterase gene and no P450 genes were down-regulated. Besides these major metabolic candidate genes that may confer resistance, this study also identified other enzyme genes, all or most of which were significantly up-regulated, including genes for helicases, phosphodiesterases, ATPases, and kinases. All amylase, anhydrase and glucosidase genes were down-regulated and none were up-regulated in Im1500FF. Most genes coding for carboxylpeptidases, cathepsins, cysteine proteases, lipases, polygalacturonases, and trypsins were down-regulated. Pathway analyses identified 65 up-regulated cDNAs, that encode 51 different enzymes involved in 62 different pathways, including P450 and esterase genes for drug and xenobiotic metabolisms. Sixty-four down-regulated cDNAs code only 17 enzymes that are associated with only 23 pathways mostly related to food digestions. This study demonstrated a significant change of metabolic processes in imidacloprid-selected TPB, resulting in over-expression of P450 and esterase genes for potential excess detoxification and cross/multiple resistance development. The identification of these and other enzyme genes establishes a foundation to explore the complicity of potential imidacloprid resistance in TPB.