# Potential Mechanisms Underlying the Minimal Impact of Cry1Ab1 Protein on Myzus persicae

## TL;DR

This study explores why the Cry1Ab1 protein from Bt crops has little effect on the green peach aphid, Myzus persicae.

## Contribution

The study identifies molecular and structural reasons for the minimal impact of Cry1Ab1 on a non-target insect.

## Key findings

- Cry1Ab1 had no significant effect on the survival or development of Myzus persicae.
- Fewer binding proteins were identified for Cry1Ab1 compared to other Cry proteins.
- Structural differences in Domain III of Cry1Ab1 likely reduce its binding efficiency to M. persicae.

## Abstract

Transgenic crops have been commercially cultivated for nearly three decades, leading to increasing concerns about their environmental safety, particularly their effects on non-target organisms. This study investigated the underlying mechanisms behind the lack of impact of the Cry1Ab1 protein on the Myzus persicae. The Cry1Ab1 protein showed no significant impact on the survival and development of M. persicae. Compared to other Cry protein, fewer Cry1Ab1-binding proteins were identified including beta-actin, ATP synthase subunit alpha, and GPN-loop GTPase 2. Transcriptomic analysis showed that a small set of pathways, mainly involved in immune defense, were temporarily enriched at 24 h after exposure to the Cry1Ab1 protein, while no significant pathways were enriched at 48 h in M. persicae. The results suggest that the Cry1Ab1 protein has a transient and minimal impact on M. persicae. Further structural comparisons between Cry1Ab1 and other Cry proteins (e.g., Cry1Ac) revealed significant differences in Domain III, which likely reduced the binding efficiency and impact on M. persicae’s metabolism and biological traits. This study provides valuable insights into the molecular and functional mechanisms behind the ineffectiveness of Cry1Ab1 on M. persicae and contributes to the safety evaluation of Bt for non-target organisms.