## 3 Results  
### Comparison of OCT Structural Images and bOCT Biospeckle Contrast Images after AMD Exposure for 1 h  
The OCT images of the Kaiware daikon seeds exposed under different AMD concentrations of the control, 40 mL/L, and 80 mL/L AMD after an exposure of 1 h to AMD are shown in Figure 2a-c with logarithmic intensity scale. Reflectivity signals of the OCT images can visualize the internal laminar structure of the seed. Bright regions correspond to stronger OCT reflectivity signal, while dark regions correspond to reduced reflectivity. At the very top, the seed coat and the epidermis can be seen with greater reflectivity. There is also noise related to strong scattering due to the inhomogeneous nature of the structures within the measurement volume determined by the coherence of the source. The scattered light interferes to produce a granular pattern called biospeckles, that changes with time due to the activity within the seed tissue. From a series of OCT frames acquired in a few seconds, the bOCT images were calculated across the acquisition period under each of the conditions, namely, the control, 40 mL/L AMD, and 80 mL/L AMD, and are, respectively, shown in Figure 2d-f. As can be seen in Figure 2a-c, there are no differences seen in the structural images with the change of AMD concentrations. On the other hand, comparing the biospeckle images obtained under  
Figure 2: Cross sections of OCT structural (top row) and bOCT (bottom row) images after just an hour of AMD exposure for (**a**,**d) 0 mL/L or the control, (**b**,**e**) 40 mL/L and (**c**,**f**) 80 mL/L. different conditions, a clear difference could be seen. In the bOCT images, red regions correspond to higher temporal variation while blue regions correspond to lower temporal fluctuation. There are more red regions in the bOCT images for seeds exposed to AMD than those of the control. Moreover, the bOCT image of seed in 80 mL/L AMD (Figure 2f) has more red parts than those exposed to 40 mL/L AMD (Figure 2e). Comparison of Biospeckle Contrast of Seeds after AMD Exposure for 1 h and Germination Percentage within 48 h  
The bOCT images can be used to know the trend of changes between different treatments, and further quantitative analysis of the bOCT images can be performed to analyze the significant differences between different treatments. Figure S1 shows the OCT structure images, obtained by averaging 100 OCT (x-z) scans. A total of six specific rectangular localized regions, namely the regions of interest (ROIs), were selected in the region close to the seed coat and from the slightly deeper region. The depth of the selected ROIs is within 240 \(\upmu\)m below seed surface; the choice of ROIs is well within the sensitivity limits of the system. The biospeckle contrast of each ROI was obtained by Equation (3) in the method section, and six ROIs were averaged to obtain the average value of the biospeckle contrast of each seed (Figure S1). Next, six seeds were measured for each treatment. A grand average of the biospeckle contrast calculated from six seeds was calculated and is shown in Figure 3.  
In the figure, the biospeckle contrast values of the seeds under different treatments showed significant differences: 80 mL/L > 40 mL/L > control. The results indicate that the activity of the seeds was significantly different from that of the control after 1 h of AMD treatment, and the contrast of the seeds under 80 mL/L AMD treatment was significantly higher than that under 40 mL/L AMD. Next, we compared the contrast with the germination rate. The germination could be affected by many factors such as humidity and light levels. The structure of the seed changes dynamically during germination, and this is dependent on the pH of the medium used for germination. Environmental stress or stimulation, such as the presence of AMD, can affect the metabolic rate, organelle morphology, and locomotion rate of seeds and plants [32].