Heterologous overexpression of Lithospermum erythrorhizon LeERF-1 gene increases drought and pathogen resistance in Arabidopsis

Ethylene-responsive transcription factors (ERFs) belonging to the AP2/ERF family have diverse functions in plants. However, the functions of LeERF-1, a member of ERF family from the medicinal plant Lithospermum erythrorhizon, remain unclear. In this study, by cloning the promoter of LeERF-1, we found that the promoter region contained a number of potential regulatory motifs related to drought and pathogen resistances. Further transgenic studies showed that the heterologous overexpression of LeERF-1 in Arabidopsis displayed phenotypes of higher survival ratio, lower root inhibition rate, slow water loss in leaf discs, and smaller stomatal apertures under drought stress, compared with wild type (WT) of Arabidopsis. LeERF-1 transgenic Arabidopsis also displayed fewer chlorotic symptoms, lower incidence rates, and lower levels of bacterial proliferation on leaves after the inoculation of bacterial pathogen compared with WT. These results suggested that LeERF-1 can also confer drought and pathogen resistances. Our work provided a candidate gene with remarkable potential use in genetic engineering for stress resistance improvement in plants.