PeDREB2a, KcERF enhance drought and salt tolerance in transgenic alfalfa

Alfalfa (Medicago sativa) Zhongmu No.1 was used as the experimental material and leaves were used as explants. The target genes PeDREB2a, KcERF were transferred into alfalfa mediated by Agrobacterium tumefaciens LBA4404. Sixty-six transgenic resistance (Kan) lines were obtained. The positive rate of PCR detection was 93.94%. PeDREB2a and KcERF genes were determined to be single copy in transgenic lines Z6, Z7, and Z9 by digital PCR. RT-PCR showed that the transgene positive plants could be stably expressed at the transcription level. Under normal conditions, the plant height, branch number, and contents of indole acetic acid and cellulose in Z6 and Z7 were significantly higher than those in wild type, and the ethylene content in Z6 and Z7 was significantly lower than that in wild type. With 20% PEG-3350 and 250 mmol·L⁻¹ NaCl stress treatment and physiological indicators, transgenic plants were more resistant under drought and salt stress compared with the wild-type. This provides a new germplasm for further cultivating new alfalfa varieties with stress resistance, high quality, and high yield.