4.6 Review

Which Is Stronger? A Continuing Battle Between Cry Toxins and Insects

Journal

FRONTIERS IN MICROBIOLOGY
Volume 12, Issue -, Pages -

Publisher

FRONTIERS MEDIA SA
DOI: 10.3389/fmicb.2021.665101

Keywords

Bacillus thuringiensis; Cry toxin; receptor; insecticidal mechanism; resistance mechanism

Categories

Funding

  1. National Natural Science Foundation of China [31770087, 31970074]
  2. Cultivation Fund Project of the Fujian Academy of Agricultural Sciences [AGP2018-2]

Ask authors/readers for more resources

This article reviews the insecticidal mechanisms of Bacillus thuringiensis Cry toxins and the resistance mechanisms of insects against Cry toxins, proposing that new models are required to fully describe the complexity of the insecticidal process. Insects mainly employ gene mutations or trans-regulation to reduce effective binding of Cry toxins, with epigenetic mechanisms, host intestinal microbiota, and detoxification enzymes also playing significant roles in resistance. High-throughput sequencing technologies are powerful tools for studying these mechanisms and may facilitate the further development and utilization of Cry toxins.
In this article, we review the latest works on the insecticidal mechanisms of Bacillus thuringiensis Cry toxins and the resistance mechanisms of insects against Cry toxins. Currently, there are two models of insecticidal mechanisms for Cry toxins, namely, the sequential binding model and the signaling pathway model. In the sequential binding model, Cry toxins are activated to bind to their cognate receptors in the mid-intestinal epithelial cell membrane, such as the glycophosphatidylinositol (GPI)-anchored aminopeptidases-N (APNs), alkaline phosphatases (ALPs), cadherins, and ABC transporters, to form pores that elicit cell lysis, while in the signaling pathway model, the activated Cry toxins first bind to the cadherin receptor, triggering an extensive cell signaling cascade to induce cell apoptosis. However, these two models cannot seem to fully describe the complexity of the insecticidal process of Cry toxins, and new models are required. Regarding the resistance mechanism against Cry toxins, the main method insects employed is to reduce the effective binding of Cry toxins to their cognate cell membrane receptors by gene mutations, or to reduce the expression levels of the corresponding receptors by trans-regulation. Moreover, the epigenetic mechanisms, host intestinal microbiota, and detoxification enzymes also play significant roles in the insects' resistance against Cry toxins. Today, high-throughput sequencing technologies like transcriptomics, proteomics, and metagenomics are powerful weapons for studying the insecticidal mechanisms of Cry toxins and the resistance mechanisms of insects. We believe that this review shall shed some light on the interactions between Cry toxins and insects, which can further facilitate the development and utilization of Cry toxins.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available