Transgenic Arabidopsis thaliana plants expressing the 1-aminocyclopropane-1-carboxylate deaminase
gene (ACCD) of Trichoderma asperellum ACCC30536 (TaACCD) were created and their growth performance
was assessed under normal and salt stress conditions. In order to characterize their growth, root length,
root number, fresh weight (FW), relative water content (RWC), seed production, and seed number were
measured. Under normal growing condition, all growth parameters except for dry weight (DW) of the
transgenic plants increased significantly compared to WT plants. Furthermore, the transgenic line also
exhibited higher tolerance and faster growth than WT plants in the presence of 150 mM NaCl. The
increased salt stress tolerance of the transgenic plants is attributed to a greater RWC, root weight, root
length, root number and FW under salt stress, and to reduced reactive oxygen species (ROS) level, cell
death and electrolyte leakage compared to WT plants. The reduction in ROS levels could be explained by
increased activity of several antioxidant enzymes, including peroxidase (POD), superoxide dismutase
(SOD), and catalase (CAT). Thus, we propose that heterologous expression of TaACCD could be used to
improve salt stress tolerance in plants.