Evaluation of salinity tolerance in two transgenic poplar lines harboring TaWCS120 and HvDHN5 genes

Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch of the Russian Academy of Sciences, 132, Lermontov Street, Irkutsk, 664033, Russia

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Abstract

In present study, salinity tolerance was evaluated in two transgenic Populus berolinensis lines harboring the TaWCS120 and HvDHN5 dehydrin genes under in vitro sodium chloride (NaCl) stress. Two experimental setups assessed the effects of NaCl on rooting ability under salinization and post-rooting growth in transgenic poplars. NaCl concentrations ranging from 25 to 200 mM revealed dose-dependent impacts on root formation and plant growth in both control and transgenic lines. At 25 mM NaCl, no visible effects were observed across all lines during rooting. At 50 mM NaCl, rooting remained unaffected, but growth suppression occurred in control and TaWCS120-transgenic plants, whereas HvDHN5 transgenics exhibited normal phenotypes. Higher NaCl levels progressively inhibited root formation and growth in controls and TaWCS120 lines, while HvDHN5-transgenic poplars showed enhanced resistance. Exposure experiments further confirmed superior NaCl tolerance in rooted HvDHN5 plants, which survived 150 mM with viable shoots—unlike controls, which suffered lethal effects. Agrobacterium-mediated transformation with these dehydrin genes thus increased salinity resistance, with the most pronounced effects in HvDHN5-expressing lines from barley. Based on these findings, new genetically modified plants may be generated using TaWCS120 and HvDHN5 genes from wheat (Triticum aestivum) and barley (Hordeum vulgare) to enhance salinity tolerance of the target plants important for both wood industry and agriculture.