Heterologous expression of Arabidopsis SOS3 increases salinity tolerance in Petunia

Salinity stress is one of the most important rising problems worldwide. It significantly reduces plant growth and development, mainly by provoking excessive uptake of ions such as Na⁺. The Salt Overly Sensitive (SOS) machinery is a well-known signaling pathway that help plants to maintain ion homeostasis by reducing Na⁺ accumulation in plant cells. Overexpression of key components of this pathway has been reported to increase salinity stress tolerance in some plant species.

In this study, SOS3 cDNA isolated from Arabidopsis seedlings was transferred into the Petunia genome by two common plant transformation methods, Agrobacterium and biolistic gun. Transgene integration and expression in putative lines were evaluated by PCR and RT-PCR techniques. In vitro and greenhouse evaluation of transgenic plants for salt tolerance showed that, compared to the wild type, transgenic plants overexpressing AtSOS3 gene exhibit enhanced salt tolerance in response to high NaCl concentrations.

These results not only demonstrate the potential of SOS pathway components to improve salt tolerance in Petunia, but also provide more evidence for functional conservation of the SOS salt tolerance signaling pathway among different plant families.