The lectin gene TRpL1 of tetraploid Robinia pseudoacacia L. response to salt stress

Lectins are natural proteins in animals, plants, and microorganisms and can be divided into 12 families. These lectins play important roles in various environmental stresses. Some polyploid plants show tolerance to environmental stresses and to insect pests. However, the mechanism of stress tolerance is unclear. Tetraploid Robinia pseudoacacia (4x) under salt stress showed higher tolerance than diploid R. pseudoacacia (2x). As lectin can improve stress tolerance, it was questioned whether the stress resistance of polyploid plants was related to the lectin protein. In this study, salt resistance of lectin gene TRpL1 was verified by its over-expression in plants. In addition, salt resistance of lectin protein by E. coli strains was detected. The data revealed that the over-expression transgenic plants of TRpL1 showed better salt tolerance than control plants under salt stress, and the TRpL1-expressing strain also grew better in the medium with added NaCl. Therefore, tetraploid plants can resist salt stress through TRpL1 protein regulation.