## 4 Results
### Comparison of Fungi Bed Exposure Methods  
To investigate the effects of different exposure methods of shitake FBs VCs, we encased FBs in gas-permeable polymer films. Rice seedlings were exposed to shitake FBs (60 g) wrapped in gas-permeable polymer films of HDPE, PVC, or left unwrapped, and placed unwrapped in open Petri dishes (OPD). Figure 4A clearly shows the distinctive effects of different exposure methods of shitake FBs (60 g) on rice seedling growth and biomass accumulation, favoring the OPD method. Figure 3: Dose–response effects of shitake fungi bed VCs on rice seedling growth and biomass accumulation. (**A**) Representative images of rice seedlings after 14 days of non-contact exposure to varying quantities (0–60 g) of shitake fungi bed substrates (scale bar = 5 cm is shown as white bar at the right). (**B**) Dry weight of rice seedlings. (**C**) Plant height. (**D**) Root length. Different letters (a, b, c, d) indicate statistically significant differences between treatments (Tukey’s test, \(p\) < 0.05). Data are presented as mean \(\pm\) SD (n = 5). Error bars indicate the standard deviation (\(\pm\)SD). The results demonstrate a clear variation in growth parameters, including dry weight, plant height, and root length, depending on the exposure method employed. Seedlings exposed to the OPD method showed the highest dry weight (38.4 \(\pm\) 8.17 mg, labeled a, Figure 4B), which was significantly greater than the control (20.2 \(\pm\) 3.77 mg, labeled c, \(p\) = 0.0019, Mean Diff. = \(-\)18.2, 95% CI: 8.01, 28.39) and the HDPE method (27.2 \(\pm\) 3.11 mg, labeled b, c, \(p\) = 0.0126). The PVC method also significantly increased dry weight (31.0 \(\pm\) 3.79 mg, labeled a, b, \(p\) = 0.0007, Mean Diff. = \(-\)10.8, 95% CI: [3.72, 17.88]), though to a lesser extent than OPD. Plant height followed a similar trend, with seedlings under the OPD method achieving the tallest average height (34.2 \(\pm\) 3.75 cm, labeled a, Figure 4C), which was significantly higher than the control (26.5 \(\pm\) 5.10 cm, labeled b, \(p\) = 0.0227, Mean Diff. = 7.7, 95% CI: [\(-\)0.13, 15.23]). The PVC method resulted in moderate increases in plant height (32.3 \(\pm\) 3.28 cm, labeled a, b, \(p\) = 0.0664, Mean Diff. = 5.8, 95% CI: [\(-\)1.28, 12.88]),  
Figure 4: Effect of different exposure methods of shitake fungi bed-derived VCs on rice seedling growth and biomass accumulation. (**A**) Representative image of rice seedlings exposed to shitake fungi beds (60 g) using HDPE wrapping (HDPE), PVC wrapping (PVC), and open Petri dish (OPD) methods compared to the control (scale bar = 5 cm is shown as white bar at the right). (**B**) Dry weight (mg) of rice seedlings. (**C**) Plant height (cm) of rice seedlings. (**D**) Root length (cm) of rice seedlings. Different letters (a, b, c) indicate statistically significant differences among treatments (Tukey’s test, \(p\) < 0.05). Data are presented as mean \(\pm\) SD (n = 5). Error bars indicate the standard deviation (\(\pm\)SD). whereas the HDPE method (26.2 \(\pm\) 2.63 cm, labeled b) showed no significant difference compared to the control (\(p\) = 0.8880, Mean Diff. = \(-\)0.3, 95% CI: [\(-\)6.74, 6.14]). In contrast, root length exhibited no significant differences across treatments. The control group maintained an average root length of 7.8 \(\pm\) 1.62 cm (labeled a, Figure 4D). Seedlings in the HDPE method (7.62 \(\pm\) 2.12 cm, \(p\) = 0.8709, Mean Diff. = 0.20, 95% CI: [\(-\)3.08, 2.68]), PVC method (6.38 \(\pm\) 1.07 cm, \(p\) = 0.6354, Mean Diff. = 1.26, 95% CI: [\(-\)0.49, 3.01]), and OPD method (6.74 \(\pm\) 1.66 cm, \(p\) = 0.7355, Mean Diff. = 1.08, 95% CI: [\(-\)1.04, 3.20]) showed no significant deviations from the control, suggesting that root growth is less responsive to VCs exposure. These findings clearly indicate that the OPD method is the most effective for enhancing rice seedling growth and biomass accumulation, with significant increases observed in both dry weight and plant height compared to other exposure methods.