Isolation and Identification of a Peroxidase (TcPOD1) of Tamarix chinensis, a Gene in the Phenylalanine Metabolic Pathway, and Its Potential Role in Salt Tolerance

Salt tolerance in plants is becoming an increasingly sought after trait as the salinity of soils are increasing around the globe and threatening the availability of agricultural land. Tamarix chinensis is a halophytic plant native to China that is prolific in many different soil environments, including soils of high salinity. However, the salt tolerance mechanisms within this species and its relatives are still poorly understood. In previous studies, it has been shown that enzymes involved in the phenylalanine metabolic pathway are up regulated under salt stress conditions. In this present study, the sequence of a secretory peroxidase gene (TcPOD1) from the phenylalanine metabolic pathway was cloned from T. chinensis using RNA Ligase Mediated Rapid amplification of cDNA ends polymerase chain reaction. The sequence was then analyzed using bioinformatical tools to predict its protein structure. Furthermore, the predicted protein was compared with other peroxidases to elucidate its role in salt tolerance mechanisms. The results showed that TcPOD1 has very strong predicted structural similarities to other salt tolerance-associated plant peroxidases. The results also support that TcPOD1 from T. chinensis is homologous to the salt tolerance gene ThPOD5 in T. hispida. The evidence presented here suggests that TcPOD1 is a valuable gene for the genetic engineering of plants for salt tolerance. This may ultimately lead to the expansion of useable land for more abundant and efficient production of plants for food and other resources.