The Durum Wheat Group 3 Lea Protein (TdLEA3) Confers Abiotic Stress Tolerance and Ensures Antibacterial and Antifungal Activities In Vitro

Heterologous expression has been frequently used to elucidate the protein function in vivo. Here, we overexpressed the durum wheat protein TdLEA3 in Escherichia coli BL21 cells to explore the protective effects of this protein in a prokaryotic system. The results showed that BL21/TdLEA3 cells confer a better tolerance to different types of abiotic stress (NaCl, KCl, PEG, H2O2, 45°C and –20°C), compared to E. coli cells overexpressing the empty vector pET28a (considered as control). These results were correlated with the viability of E. coli overexpressing TdLEA3, under the same stress conditions. In the second part, we have exhibited that TdLEA3 protein is also involved in biotic stress tolerance. We used the purified protein for antibacterial and antifungal tests. Results proved that the protein exerted an antibacterial effect on certain Gram(‒) and Gram(+) bacterial strains such as E. coli, Pseudomonas syringea, Micrococcus luteus, Enterrococcus fecalis, Bacillus cerius, Staphylococcus aureus and Salmonella enteric. TdLEA3 had also an antifungal potential on the Fusaruim graminearum. These results confirm the potential role of TdLEA3 in stress defense.