## 5 Discussion
(2015), which demonstrated that semi-permeable exposure systems optimize VC diffusion, enhancing plant responses ([PERSON] et al., 2015). Additionally, controlled release systems, including natural polymer-based formulations and volatile encapsulation technologies, may further enhance the targeted and sustained delivery of agrochemicals, improving efficiency and environmental sustainability in large-scale agricultural applications ([PERSON] et al., 2017; [PERSON] et al., 2018; [PERSON] et al., 2019). _Testing the effects of FBs aging_  
Volatile emissions from young (YSFB), mature (MSFB), and waste (WSFB) shiitake FBs were analyzed for their biostimulatory effects. Results showed that YSFB and MSFB showed the strongest impact on dry weight and plant height. Notably, WSFB also promoted significant growth, confirming that FBs retain bioactivity even after mushroom harvesting. These findings suggest that waste shiitake FBs can be repurposed as an economical and sustainable alternative to chemical fertilizers. Moreover, environmental factors such as temperature, humidity, and aging stage may influence VC composition and activity, affecting their biostimulatory potential ([PERSON] et al., 2015). _Testing synthetic volatile compounds_  
Our chemical analysis using HS-SPME-GC-TOF-MS identified 3-octanone, 3-octanol, 1-octen-3-one, and 1-octen-3-ol as predominant VCs. These findings align with previous studies that identified these VCs from mushroom ([PERSON] et al., 2017). Additionally, several studies have cited these compounds as having plant growth promoting and protection ([PERSON] et al., 2017; [PERSON] et al., 2019; [PERSON] et al., 2019). Our findings indicate that 1-octen-3-one and 3-octanol showed potential growth-promoting effects at lower dose rates, while higher dose rates were associated with reduced development or inhibition of growth. 1-octen-3-one enhanced biomass at 1 \(\mu\)L but was inhibitory at greater doses. In contrast, 1-octen-3-ol consistently suppressed plant growth across all tested concentrations. Our findings suggest that while 3-octanone did not show statistically significant differences in its different doses on dry weight, plant height, and root length, it may promote root proliferation at certain doses ([PERSON] et al., 2017). However, at higher concentrations, it might still have the potential to disrupt hormonal balance, possibly leading to growth inhibition. Meanwhile, 1-octen-3-ol remained inhibitory across all tested doses, aligning with previous research that highlights its role as an oxylipin messenger triggering stress-related responses, including the synthesis of methyl jasmonate, indole-3-acetic acid, and gibberellin according to a study by [PERSON] et al. (2019) [PERSON] et al. (2019). While these hormones are essential for plant development, excessive activation of defense mechanisms can shift resource allocation towards stress resistance at the expense of growth, which could explain our results ([PERSON] et al., 2017). The strong inhibitory effect of 1-octen-3-ol in our study further suggests that its role in plant-microbe interactions may be more oriented toward defense priming rather than direct growth promotion. Conversely, 3-octanol, which promoted rice seedling growth at moderate concentrations, is known to influence auxin/cytokinin homeostasis, stimulating lateral root formation while suppressing primary root elongation ([PERSON] et al., 2017). Additionally, it has been shown to enhance plant stress tolerance by modifying root architecture and supporting beneficial microbial interactions ([PERSON] et al., 2017; [PERSON] et al., 2019). Our results indicate that while 3-octanol can be beneficial at appropriate doses, higher concentrations are likely to disrupt this balance, leading to adverse effects on seedling growth. These findings align with studies suggesting that fungal VCs influence plant hormonal balance and stress signaling ([PERSON] et al., 2019; [PERSON] et al., 2019).