Journal of Integrative Agriculture ›› 2020, Vol. 19 ›› Issue (6): 1512-1521.DOI: 10.1016/S2095-3119(19)62827-3

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  • 收稿日期:2019-05-14 出版日期:2020-06-01 发布日期:2020-04-26

Characteristics and roles of cytochrome b5 in cytochrome P450-mediated oxidative reactions in Locusta migratoria

LIU Jiao1, 2, ZHANG Xue-yao1, WU Hai-hua1, MA Wen3, ZHU Wen-ya4, Kun-Yan ZHU5, MA En-bo1, ZHANG Jian-zhen1 
  

  1. 1 Institute of Applied Biology, Shanxi University, Taiyuan 030006, P.R.China
    2 College of Life Science, Shanxi University, Taiyuan 030006, P.R.China
    3 Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan 030006, P.R.China
    4 Institute of Plant Protection, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, P.R.China
    5 Department of Entomology, Kansas State University, Manhattan, KS 66506, USA
  • Received:2019-05-14 Online:2020-06-01 Published:2020-04-26
  • Contact: Correspondence MA En-bo, Tel: +86-351-7018871, E-mail: maenbo2003@sxu.edu.cn; ZHANG Jian-zhen, Tel: +86-351-7018871, E-mail: zjz@sxu.edu.cn
  • About author:LIU Jiao, Mobile: +86-15536053652, E-mail: liujiao890408@163.com;
  • Supported by:
    This research was supported by the National Natural Science Foundation of China (31320103921 and 31872010) and the Graduate Outstanding Innovation Project of Shanxi Province, China (2017 BY011).

Abstract:

Cytochrome b5 (Cyt-b5) is a small heme protein and known to be involved in a wide range of biochemical transformations, including cytochrome P450 monooxygenase (CYP)-mediated metabolism of endogenous and exogenous compounds.  Studies on Cyt-b5 are more concentrated in mammals, but are relatively rare in insects.  The characteristics and function of Cyt-b5 from Locusta migratoria have not been described yet.  We sequenced the full-length cDNA sequence of Cyt-b5 from L. migratoria (LmCyt-b5) by reverse transcription-PCR (RT-PCR) based on locust transcriptome database.  The phylogenetic analysis showed that LmCyt-b5 was closely related to the Cyt-b5 from Blattodea.  LmCyt-b5 was highly expressed in ovary, Malpighian tubules, midgut, gastric caeca, and fat bodies.  Silencing of LmCyt-b5 had no effect on the susceptibility of L. migratoria to four different insecticides.  Suppression of LmCyt-b5 or silencing of both LmCyt-b5 and LmCPR did not significantly change the total CYP activity toward the substrate 7-ethoxycoumarin (7-EC).  However, coexpression of LmCYP6FD1 with LmCPR and LmCyt-b5 together in Sf9 cells by using Bac-to-Bac baculovirus expression system significantly increased the catalytic activity of LmCYP6FD1 toward 7-EC as compared with the coexpression of LmCYP6FD1 with cytochrome P450 reductase (LmCPR) or LmCyt-b5 separately.  These results suggest that LmCyt-b5 plays an important role in the catalytic reaction of LmCYP6FD1 toward 7-EC in our in vitro experiments.  Further study is needed to clarify the role of LmCyt-b5 in CYP-mediated catalytic reactions in L. migratoria.
 

Key words: cytochrome b5 ,  cytochrome P450 ,  cytochrome P450 reductase ,  Locusta migratoria ,  RNA interference