Mg-deficientconditions
The control treatment contained 0.5 mM Mg and 2.0 mM K, whereas the magnesium deficiency treatment  contained 0.1 mM Mg, supplied as MgCl6HO and potassium excess teratment contained 6.0 mM K, suplied as KCl. Six pots per treatment were used, with two plants per pot. Seedlings underwent a gradual acclimation to the nutrient solution (1/4 strength for 18 days, 1/2 strength for 4 days, and 3/4 strength for 4 days). After this 26-day acclimation period, plants were maintained for 143 days in full-strength nutrient solution under a controlled 12/12 h light/dark photoperiod. Total RNA was extracted from 36 samples (six biological replicates per treatment) obtained from secondary roots and mature leaves under control and magnesium deficiency conditions and K excess. Extraction was performed using the RNeasy Plant Mini Kit (Qiagen), followed by DNase treatment with TURBO DNA-free (Thermo Fisher Scientific). RNA integrity was verified by 1.5% agarose gel electrophoresis, and concentration was determined using a Qubit fluorometer and a NanoDrop ND-1000 spectrophotometer (Thermo Fisher Scientific). Samples were subsequently sent to Macrogen Inc. for library preparation and sequencing. Libraries were constructed using the TruSeq Stranded mRNA Library Prep kit, following the manufacturers reference guide (#1000000040498 v00).