Plasmid and alfalfa transformation
The Zhongmu No. 1 cultivar was used to generate AtSOAR1(At5g11310) overexpressing transgenic plants. The full-length cDNA ofAtSOAR1 was constructed into a pCAMBIA1300 backbone and drivenCauliflower mosaic virus (CaMV) 35S promoter (Mei et al ., 2014). The construct was introduced into Agrobacterium tumefaciens strain EHA105 and transformed into alfalfa following our previous reports (Zhang and Wang, 2015). Transgenic plants were verified by PCR, RT-PCR, and qRT-PCR using AtSOAR1 gene specific primers (Liu et al., 2019).