*4.7. A. rhizogenes-mediated Drought and Salt Stress Assays*

To generate a transgenic line of soybean the amplified cDNA sequence of *GmWRKY12* was constructed into pCAMBIA3301 for an overexpression transgenic line (*35S::GmWRLY12*) and the control was pCAMBIA3301 plant vector with CaMV35S promoter (CK) and two constructs transferred into *A. rhizogenes* strain K599 (NCPPB2659) [69]. Primers are available in Table S4. Williams 82 was cultivated in a 10 × 10 cm flowerpot (vermiculite: nutritious soil is 1:3) for stress experiments (Figure 8A1), soybean seeds were grown under a photoperiod of 16 h light (100 µM photons m−<sup>2</sup> ·s −1 )/8 h dark at 25 ◦C. When plants displayed two cotyledons (Figure 8A1), *A. rhizogenes* strain K599 harboring pCAMBIA3301 (CK) and K599 harboring *35S::GmWRLY12* were injected at the cotyledonary node and/or hypocotyl (Figure 8B1). A plastic cup was used to surround the inoculated soybean seedlings to provide high humidity conditions. After 3 days, nutritious soil was prepared and used to fill the gaps in the plastic cup so that soybean seedlings could grow new roots (Figure 8A2); plants typically need two weeks to generate new roots (2–10 cm) at the infection site (Figure 8B2,B3). The original main roots were removed by cutting from 1 cm below the infection site and the hairy roots of the seedlings were cultivated in nutritious soil with full water and grown with 16 h light (100 µM photons m−<sup>2</sup> ·s −1 )/8 h dark at 25 ◦C for 5 days [70,71]. Each flowerpot cultivated 5 transgenic soybean seedlings and 5 replications of each stress treatment (Figure 8A3). Afterward, the transgenic soybean seedlings were subjected to natural dehydration and 200 mM NaCl for drought and salt stress assays [19,68]. For drought stress assay, both CK and transgenic soybean seedlings were grown without water for 20 days. For salt stress assay, CK and transgenic soybean seedlings were treated with 200 mM NaCl solution for 7 days. There are some Supplement Materials need to prepare for culturing *A. rhizogenes* strain K599 that harbored (*35S::GmWRLY12*) and the control (CK)., eg: Solidified LB medium with streptomycin sulfate (100 mg/L) and Kanamycin solution(100 mg/L) (10 g tryptone, 5 g yeast extract, 10 g NaCl, 15 g agar per liter), Liquid LB medium containing streptomycin sulfate (100 mg/L) and Kanamycin solution (100 mg/L) [69].
