## 3 Results and Discussion
### Use of SLD as an Antifungal Agent on Corn Kernels: Raised Bed Analysis (Large Scale)  
Antifungal efficacy of SLD was examined further in large containers (16 cm \(\times\) 20 cm \(\times\) 10 cm) for scaling up. As shown in Figure 3, application of SLD at 0.5 to 1.0 mM in the large containers completely inhibited the growth of _A. flavus_ and/or seedborne fungal contaminants, while no treatment control (seedborne contaminants or _A. flavus_ at 0.0 mM) allowed the growth of fungi. As determined in Petri plate assay (Section 3.3 above), SLD at 0.5 to 1.0 mM also inhibited seed germination (tested in the large containers). We examined further the \"fungal burden on the surfaces\" of corn kernels after SLD treatment (See Figure 3). As shown in Figure 4, corn kernels treated with 0.5 to 1.0 mM of SLD prevented the survival of _A. flavus_ or seedborne filamentous fungi (after 1:1, 1:10, 1:100 dilutions), while only some \"yeast-like\" contaminants (seedborne) were detected from the same seeds (1:1 (no dilution)); however, no indication of any microbial survival was determined with 1:10 and 1:100 dilution, respectively. In comparison, high level of fungal contamination was detected in the control groups, viz., no SLD treatments (seedborne contaminants or _A. flavus_ only). Therefore, results indicated that the effect of SLD antifungal activity (against _A. flavus_ or seedborne filamentous fungi) seemed \"fungicidal\" where no filamentous fungi was survived after SLD fumigation. If necessary, standard methods such as modified protocols developed by the Clinical and Laboratory Standards Institute (CLSI) could be applied for the precise determination of fungistatic or fungicidal characteristic of SLD [71; 72]. Future in-depth study is also necessary to confirm (1) the antifungal efficacy of SLD against broad spectrum of fungal pathogens/contaminants such as azole fungicide-resistant aspergillic recently identified in California tree nut farms [73], and (2) the effectiveness of SLD (as fumigant) for the sterilization of internal seeds when seeds are stored in piles. Use of 4-Isopropyl-3-Methylphenol (413M) as an Antifungal and Anti-Aflatoxigenic Agent on Corn Kernels  
Next, 413M was tested as an antifungal agent against _A. flavus_ or seedborne fungi-contaminated on corn kernels. As shown in Figure 5a, 413M exerted antifungal activity at or above 0.8 mM (tested up to 1.0 mM) without affecting seed germination, possibly being less redox-active than SLD. However, compared to SLD, 413M did not completely inhibit the growth of fungi on corn seeds at the highest concentrations tested (namely, 0.8-1.0 mM). The effect of 413M on AF production by _A. flavus_ and _A. parasiticus_ was examined further at higher concentrations (0.5 to 1.5 mM). As shown in Figure 5b, there was an incremental increase in anti-aflatoxigenic activity of 413M as the concentration of the compound increased (from 0.5 to 1.5 mM); complete inhibition of AF production was achieved in both _A. flavus_ and _A. parasiticus_ at 1.0 to 1.5 mM of 413M. Figure 4: Fungal burden on seed surface after SLD treatment. Figure 3: Antifungal activity of SLD tested at large scale. Overcoming Fluidoxosil Tolerance of Mitogen-Activated Protein Kinase (MAPK) Mutants of P. expansum by 4I3M  
_Penicillium expansum_ FR2 is a MAPK pathway mutant involved in oxidative stress signaling [49], thus showing tolerance to FLU, whereas it is more susceptible to oxidative stress reagents compared to the parental, wild-type strain. Using _P. expansum_ (W1; wild type, parental strain) and FR2 (oxidative/osmotic stress MAPK mutant) as a \"model\" filamentous/mycotogenic (producing toxic patulins) fungal system, we examined the capability of 4I3M for overcoming FLU tolerance of _P. expansum_ FR2. We tried to confirm the antifungal potential of 4I3M as a \"redox-active\" compound by targeting FR2. As shown in Figure 6, 4I3M at as low as 0.75 mM overcame FLU tolerance of _P. expansum_ FR2. Of note, _P.