Overexpression of the chloride channel gene (GmCLC1) from soybean increases salt tolerance in transgenic Populus deltoides × P. euramericana 'Nanlin895'.

The GmCLC1 encodes a vacuolar Cl- transporter protein that sequesters ions from the cytoplasm to the vacuole, thereby reducing the toxic effects of salt stress. We constructed aGmCLC1 overexpression vector, pGWB402O, and introduced it into poplar hybrid, Populus deltoides x P. euramericana 'Nanlin895', by Agrobacterium tumefaciens-mediated transformation. PCR and Southern blot analyses showed that GmCLC1 was integrated into the genome of the hybrid poplar line. When transgenic plants overexpressing GmCLC1 were subjected to salt stress, the contents of soluble protein and photosynthetic pigments and the activity of antioxidant enzymes (POD and SOD) were increased, and the MDA concentrations were significantly decreased in transgenic lines compared with the control lines. Also, the defoliation rates of the transgenic plants were significantly lower than that of the control plants. These results suggest that overexpression of GmCLC1 plays a significant role in improving salt tolerance of poplars, reducing damage to membrane structures, and enhancing osmotic adjustment and antioxidative enzyme regulation during salt stress.