Li 6800 portable photosynthetic system

Photosynthetic parameters were measured on the third fully expanded leaf of each plant after 15 days (S2) for control (CK), drought acclimation (DA), and non-acclimation (NA) plants. The measurements were taken at 9:00 AM and 11:00 AM using an LI-6800 portable photosynthetic system (LI-COR Inc., Lincoln, NE, USA). The light-saturation point was set to µmol (photon) m -2 s -1 to measure the net photosynthetic rate and stomatal conductance using the methods reported by Du et al. (2020a) and Li et al. (2017) . The ambient temperature of each measured millet leaf was set to 30 °C. The CO 2 concentration was 400 µmol (CO 2 ) mol -1 , the relative humidity was 60%-65%, and the airflow was 500 µmol. For tissue relative water contents (RWC), the leaves and roots of CK, DA, and NA-treated plants were sampled. Fresh weights were immediately taken, and the samples were incubated in distilled water for 4 h with vigorous shaking. The turgid weights (TW) were measured after 4 h, and the tissue samples (leaf and roots) were oven-dried at 60 °C for 48 h, after which the dry weights (DW) were recorded. Tissue RWC was estimated using the equation.