Fig. 1. RGB images of Arabidopsis phenotypes
(a)—(f): Col-0 ecotype on 0~5 days of drought stress;(g)—(l): OSCA1 mutant genotypes on 0~5 days of drought stress

Fig. 2. The relationship between water content of Arabidopsis thaliana and the number of days post drought stress
Gray color represents Col-1 and white color represents OSCA1; Changes are represented by the mean±standard deviation; * and ** represent the degree of significant differences based on Duncan test (* represents 0.03<p<0.05; ** represents 0.01<p<0.03)

Fig. 3. Mean spectra of all Arabidopsis canopy (20 mm·s^-1)

Fig. 4. PLSR model results for different moving speeds with full spectra
(a): 20 mm·s^-1; (b): 30 mm·s^-1; (c): 40 mm·s^-1

Fig. 5. The variation of spatial resolution caused by different scanning speed
(a): 20 mm·s^-1; (b): 30 mm·s^-1; (c): 40 mm·s^-1

Fig. 6. The performance of PLSR models of different scanning speed based on optimal wavelengths
(a): 20 mm·s^-1; (b): 30 mm·s^-1; (c): 40 mm·s^-1

Table 1. The performance of PLSR model based on different spectral pretreatment methods (20 mm·s^-1)

Table 2. The summary of optimal wavelengths based on Successive projection algorithm (SPA)