A Comprehensive Assessment of the Effects of Transgenic Cry1Ac/Cry1Ab Rice Huahui 1 on Adult Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae)

PLoS One. 2016 Feb 25;11(2):e0142714. doi: 10.1371/journal.pone.0142714. eCollection 2016.

Abstract

Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae) is a widely distributed coleoptera predator in southern Asia in rice ecosystem, and adult M. discolor feed on both rice pollen and soft-bodied arthropods. Bitrophic bioassay and tritrophic bioassay were conducted to evaluate the potential impact of Cry1Ac/Cry1Ab-expressing rice Huahui 1 and its non-transgenic counterpart Minghui 63 on fitness parameters of adult M. discolor. The results showed that the survival, and fecundity of this beetle' adults were not different when they fed on Bt rice or non-Bt rice pollen or Nilaparvata lugens (Stål) reared on Bt rice or non-Bt rice. Toxicity assessment to ensure M. discolor adults were not sensitive to Cry1Ab or Cry1Ac protein independent from the pollen background, M. discolor adults were fed with an artificial diet containing Cry1Ac, Cry1Ab or both protein approximately 10 times higher concentration than in Huahui 1 rice pollen. No difference was detected for any of the life-table parameters tested between Cry protein-containing and pure diet. Artificial diet containing E-64 (N-(trans-Epoxysuccinyl)-L-leucine 4-guanidinobutylamide) was included as a positive control. In contrast, the pre-oviposition and fecundity of M. discolor were significantly adversely affected by feeding on E-64-containing diet. In both bioassays, the uptakes of Cry protein by adult M. discolor were tested by ELISA measurements. These results indicated that adults of M. discolor are not affected by Cry1Ab- or Cry1Ac-expressing rice pollen and are not sensitive to Cry protein at concentrations exceeding the levels in rice pollen in Huahui1. This suggests that M. discolor adults would not be harmed by Cry1Ac/Cry1Ab rice if Bt rice Huahui 1 were commercialized.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / toxicity
  • Coleoptera / pathogenicity*
  • Coleoptera / physiology
  • Ecosystem
  • Endotoxins / genetics*
  • Endotoxins / toxicity
  • Female
  • Food Chain
  • Hemolysin Proteins / genetics*
  • Hemolysin Proteins / toxicity
  • Male
  • Oryza / genetics*
  • Oryza / parasitology*
  • Pest Control, Biological / methods*
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / parasitology

Substances

  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Endotoxins
  • Hemolysin Proteins
  • insecticidal crystal protein, Bacillus Thuringiensis

Grants and funding

This work was supported by National Important Project of Scientific and Technical Supporting Programs- Transgenic crop’s monitoring and control in crop winter multiplication area (Grant No.2013ZX08012- 004 awarded to Anping Guo) and the Special Fund for Agro-scientific Research in the Public Interest of the people’s Republic of China (Grant No.201403075 awarded to Anping Guo). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.