Modification of soybean growth and abiotic stress tolerance by expression of truncated ERECTA protein from Arabidopsis thaliana

ERECTA gene family encodes leucine-rich repeat receptor-like kinases that control major aspects of plant development such as elongation of aboveground organs, leaf initiation, development of flowers, and epidermis differentiation. To clarify the importance of ERECTA signaling for the development of soybean (Glycine max), we expressed the dominant-negative ERECTA gene from Arabidopsis thaliana that is truncated in the kinase domain (AtΔKinase). Expression of AtΔKinase in soybean resulted in the short stature, reduced number of leaves, reduced leaf surface area and enhanced branching in the transgenic plants. The transgenic AtΔKinase soybean plants exhibited increased tolerance to water deficit stress due to the reduction of total leaf area and reduced transpiration compared to the wild-type plants. Production of seeds in AtΔKinase lines was higher compared to wild type at regular conditions of cultivation and after exposure to drought stress. Transgenic seedlings expressing AtΔKinase were also able to withstand salt stress better than the wild-type. Established results demonstrated the significance of native soybean genes (GmER and GmERL) in development and stress response of soybean, and suggested that the truncated ERECTA gene of Arabidopsis thaliana can be used to manipulate the growth and stress response of different crop species.