ThGRF5, a 14-3-3 protein, acts as a positive regulator of salt tolerance in Tamarix hispida

The 14-3-3 proteins, also known as General Regulatory Factors (GRFs), are a family of highly conserved acidic proteins that mediate cellular processes and plant stress adaptation through protein-protein interactions. In this study, 9 GRF genes (ThGRF1-ThGRF9) were isolated and characterized from the halophytic species Tamarix hispida.

qRT-PCR analyses showed that all nine ThGRFs responded to multiple stress response pathways. In particular, the expression levels of ThGRF4 and ThGRF5 were significantly upregulated in T. hispida roots under salt stress, suggesting their potential involvement in salt stress responses. Furthermore, an overexpression vector of ThGRF5 was constructed and transiently transformed into T. hispida. Biochemical staining and physiological parameter analyses showed that overexpression of ThGRF5 increased antioxidant enzyme activity, decreased MDA content and electrolyte leakage by decreasing the accumulation of ROS, thereby improving tolerance to salt stress.

These results suggested that ThGRF5 might play an important physiological role in salt tolerance in transgenic T. hispida plants. This study provides a foundation for further elucidation of salt tolerance mechanisms involving ThGRF5 in T. hispida.