The Tamarix ferritin gene confers low-iron tolerance in transgenic tobacco

Abstract

Ferritin is one of the important proteins that respond to various stresses in Tamarix androssowii. We cloned a full-length cDNA sequence of a ferritin gene from T. androssowii, named “TaFer1” (GenBank accession number: AB275873), and overexpressed it in tobacco to examine its functions. The transgenic tobacco plants were confirmed by both northern and western blots, indicating that the TaFer1 gene was expressed in transgenic tobacco plants. Interestingly, the expression of tobacco endogenous NtFer1 gene increased significantly in accordance with TaFer1 gene. Evidence from bacterial two-hybrid experiments demonstrated that there were strong interactions between different ferritin subunits, which suggested that the subunit of TaFer1 participated in the protein complex of ferritin that usually contains 24 subunits. Under low-iron condition, the transgenic tobacco showed a higher tolerance that is manifested in the significant increases of ferric reductase activity, iron concentration, chlorophyll concentration, plant height, and fresh weight than that of non-transgenic plants. The results of the present study suggested that the characterization of Tamarix ferritin gene and the interactions between exogenous and endogenous ferritins may increase our understanding of the molecular functions of the Tamarix ferritin gene and find a solution to prevent iron deficiency.