Comparison of salt tolerance between Cichorium intybus L. transformed with AtNHX1 or HvBADH1

Drought and salinity are two major limiting factors of plant growth and agricultural productivity. An efficient way to improve salt tolerance of plants is by expression of the Na+/H+ antiporter gene AtNHX1 from Arabidopsis thaliana, introduced via genetic transformation. Similarly, expression of the coding genes of betaine aldehyde dehydrogenase (BADH) cloned from Graminaceous or Chenopodiaceous weeds appears to increase salt tolerance of plants. Unlike AtNHX1 gene, the transformation of BADH genes additionally enhances osmotic stress tolerance to the transformants. To better understand the differences of their capacities in promoting plant salt tolerance, the HvBADH1 gene from Hulless barley and the AtNHX1 gene, were introduced into a glycophyte species Cichorium intybus L. We investigated the traits of osmotic adjustment and antioxidation ability in the transformed plants under salt stress condition. The results indicated that both AtNHX1 and HvBADH1-transformed plants showed similar Na+ and K+ accumulations, but HvBADH1-transformed plants exhibited better osmotic adjustments to salt stress. And the AtNHX1 overexpression lines exhibited superior membrane protection and relative calli growth, delivering better NaCl tolerance to the plants under conditions of severe salt stress.