Aflatoxin control through transgenic approaches

Abstract

Control of preharvest aflatoxin contamination of susceptible crops such as corn, cotton, peanut, and tree nuts is possible through time-consuming and expensive agronomic practices. Breeding for disease-resistant crops is also very time consuming and does not lend itself readily to combat the evolution of new virulent fungal races. Moreover, availability of known genotypes with natural resistance to mycotoxin-producing fungi is a prerequisite for the successful breeding program. While it is possible to identify a few genotypes of corn or peanuts that are naturally resistant to Aspergillus, we do not know whether these antifungal factors are specific to Aspergillus flavus. In crops like cotton, there are no known varieties naturally resistant to Aspergillus spp. So far, the best options available to us are through biocontrol and/or genetic engineering. Availability of transgenic varieties with antifungal traits is extremely valuable as a breeding tool. Use of fungicides or chemicals can add to the cost of production. Moreover, the growing concerns regarding environmental safety and groundwater quality demand less dependence on agrochemicals. Disease-resistant transgenic crops would not only control mycotoxin-producing organisms such as A. flavus, A. parasiticus and Fusarium spp. but also other microbial (fungal, bacterial, and viral) diseases that cause significant economic losses in crop production. Above all, transgenic crops resistant to aflatoxin-producing fungi offer the promise of negating the adverse effects caused by the toxin on immunocompromised humans and animals. This review explores recent advances regarding genetic engineering approaches towards the control of aflatoxin contamination using native and heterologous genes.

Keywords::

• Aflatoxin
• Aspergillus
• biotechnology
• genetic engineering
• mycotoxin
• transgenic crops

Acknowledgments

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.