*4.1. Plant Growth Conditions and Stress Treatments*

Maize (Inbred line B73) growth conditions and stress treatments were performed according to Wang et al. [45]. The hydroponically cultured 3-leaf stage seedlings were used. For drought treatments, the seedlings were placed on a clean bench and subjected to dehydration (at 28 ◦C, with a relative humidity of 40–60%). Samples were exposed for 0, 5 h, and 24 h, at which the relative leaf water contents were measured (RLWC) to be 98%, 70%, and 60%, respectively, in the drought-treated leaf samples. ABA and PEG treatments were applied by immersing the seedlings in 100 µM ABA or 10% PEG 6000. All leaf samples from a minimum of 3 seedlings were immediately frozen in liquid nitrogen, then stored at −80 ◦C, prior to RNA isolation. The *Arabidopsis thaliana* ecotype Col-0 was used in this study. Seeds were grown on the Murashige and Skoog (MS) medium with an addition of 3% sucrose and 0.6% agar (pH 5.8). Drought treatment was applied to the 3-week-old seedlings by removing them from the MS medium plates and desiccating them on Whatman 3MM paper, on a clean bench, for 0 h and 3 h, respectively.
