Several recent studies have shown that glyphosate and its metabolite, aminomethylphosphonic acid (AMPA), resist rapid degradation and, therefore, can accumulate in plants. Continuing our previous research, we aimed to investigate the effect of indirectly spraying glyphosate on leaves and soil on non-target plants in the case of Helianthus annuus L. The plants were treated with glyphosate in their 5–6 leaf stages, the effects of which were assessed two weeks later from a morphological and histological point of view, as an evaluation of the residues of glyphosate and its metabolite, AMPA. They had an effect on both treated groups. In the case of the morphological parameters (plant height, number of leaves, and fresh and dried root and green mass), the data of the treated plants were statistically lower than in the case of the control group. The epidermis and the transport tissue system were damaged, and tissue death was observed in plants exposed to glyphosate. Both compounds were detected in all plant parts (roots, stems, lower leaves, and upper leaves), well above the limit of detection (0.025 mg/kg) and limit of quantitation 0.075 mg/kg showing a statistical difference with the control plants. This proved that glyphosate is incorporated into the plant organism even when applied indirectly.

Mycotoxin production by aflatoxin B1 (AFB1) -producing Aspergillus flavus Zt41 and sterigmatocystin (ST) -hyperproducer Aspergillus creber 2663 mold strains on corn and rice starch, both of high purity and nearly identical amylose-amylopectin composition, as the only source of carbon, was studied. Scanning electron microscopy revealed average starch particle sizes of 4.54 ± 0.635 µm and 10.9 ± 2.78 µm, corresponding to surface area to volume ratios of 127 1/µm for rice starch and 0.49 1/µm for corn starch. Thus, a 2.5-fold difference in particle size correlated to a larger, 259-fold difference in surface area. To allow starch, a water-absorbing powder, to be used as a sole food source for Aspergillus strains, a special glass bead system was applied. AFB1 production of A. flavus Zt41 was determined to be 437.6 ± 128.4 ng/g and 90.0 ± 44.8 ng/g on rice and corn starch, respectively, while corresponding ST production levels by A. creber 2663 were 72.8 ± 10.0 µg/g and 26.8 ± 11.6 µg/g, indicating 3–fivefold higher mycotoxin levels on rice starch than on corn starch as sole carbon and energy sources. Key points: • A glass bead system ensuring the flow of air when studying powders was developed. • AFB1 and ST production of A. flavus and A. creber on rice and corn starches were studied. • 3–fivefold higher mycotoxin levels on rice starch than on corn starch were detected.

Aflatoxin B1 (AFB1), a highly potent Group 1 human carcinogen produced by Aspergillus flavus (A. flavus), poses a significant contamination risk to corn silage, a threat that is further intensified by rising global temperatures. This study aimed to characterize the combined effects of temperature and co-inoculation with the lactic acid bacterium Limosilactobacillus fermentum (L. fermentum) on AFB1 production and the expression of key biosynthetic genes in A. flavus colonizing corn silage. Corn silage was incubated at 20 °C, 30 °C, and 37 °C with and without L. fermentum. Using qRT-PCR and HPLC, we found that elevated temperatures, particularly 37 °C, strongly induced the expression of the aflatoxin biosynthetic cluster, including the regulatory gene aflR and structural genes such as omtA and ordA. Co-inoculation with L. fermentum consistently reduced in the final AFB1 concentration by approximately 50–60% at all three temperatures. Molecular analysis revealed that this reduction was associated with transcriptional repression at 30 °C and 37 °C. L. fermentum consistently and markedly down-regulated the expression of aflR and all structural genes. A particularly pronounced suppression was observed for the late-pathway gene ordA at 30 °C. These findings provide molecular evidence supporting the incorporation of selected L. fermentum strains into silage inoculant formulations to mitigate the AFB1 risk under high-temperature conditions.