Investigation of Aspergillus flavus Infection and Aflatoxin Accumulation in Pulses During Growth and Development

Abstract

Aflatoxins (AFL) are mycotoxins produced by Aspergillus flavus that pose major risks to food safety. This study evaluated fungal growth and AFL production in planta across the following five pulse species: chickpeas ( Cicer arietinum L .), lentils ( Lens culinaris Medik .), peas ( Pisum sativum L .), soybeans ( Glycine max L .), and with corn ( Zea mays L .) as a susceptible reference host. Plants were grown in a greenhouse and arranged in a 5 × 2 factorial completely randomized design (CRD) with crop species and inoculation treatment as factors. Each crop had 10 mock‐inoculated plants and 10 plants inoculated with A. flavus strain AF‐70 expressing green fluorescent protein (GFP). Fungal colonization was monitored using GFP imaging, and toxin levels (AFB 1 , AFB 2 , cyclopiazonic acid [CPA], α‐aflatrem, aflavarin, and ditryptophenaline [DTP]) were quantified at 7 days after inoculation and at physiological maturity. Corn accumulated the highest AFL (20,639 ng/g AFB 1; 6146/g AFB 2 ), representing a ~7‐fold and ~6‐fold higher concentration than chickpeas (2548 ng/g AFB 1 ; 900 ng/g AFB 2 ) ( p  < 0.0001). Soybeans showed intermediate contamination (1807 ng/g AFB 1 ; 584 ng/g AFB 2 ), while lentils and peas accumulated minimal AFL (< 63 ng/g AFB 1 and AFB 2 ). GFP imaging of lentils and chickpeas showed early fungal colonization, yet corn exhibited the strongest fluorescence at maturity. Secondary metabolite profiles showed high α‐aflatrem, CPA, and DTP in corn, elevated aflavarin in chickpeas, and limited production in lentils and peas. These findings demonstrate fungal colonization and mycotoxin contamination are not consistently coupled across hosts and highlight key food safety implications, as well as validating earlier studies.