NON-INVASIVE CHARACTERIZATIONOF AFLATOXIN-STRESSED WHEAT SEEDSUSING 2D EPR IMAGING AND EEM FLUORESCENCE SPECTROSCOPY

Abstract

In this work, two non-invasive and independent methods for the characterization of aflatoxin-stressed wheat seeds were applied.Aflatoxins (AFs) are secondary toxic fungi metabolites, which exhibit hazardous effects on plants (phytotoxic), as well as on humans and animals. First, for 2D EPR imaging, we used 3-CP spin probe for the estimation of changes in the redox state of the aflatoxin-stressed seed. On the other side, an excitation-emission fluorescence approach was used to evaluate the spectral profiles of the key biological molecules. We determined their areas and the ratio of the two emission peaks at 355 nm (Ex 290) and 430 nm (Ex 350), corresponding to protein and phenol emission, respectively. Our results showed that the ratio of the two peaks (p/f) decreased in the presence of AFs. Both methods revealed to be useful for the rapid, non-invasive assessment of the seeds' stress state induced by AFs.