Cloning and expression analysis of two novel Prxs genes from Tamarix hispida.

Peroxiredoxins (Prxs) are important antioxidant enzymes in nearly all plant tissues. To characterize their functions under abiotic stress, two Prx cDNA sequences were isolated from the cDNA library of Tamarix hispida, named ThPrx1 and ThPrx2 respectively. ThPrx1 is partial cDNA, while ThPrx2 is complete gene. Bioinformatics analysis showed that the two ThPrx sequences were highly homologous to other Prx genes from other plants, and ThPrx1 and ThPrx2 belong to the PrxⅡ and 2-Cys Prx subfamilies, respectively. Under different abiotic stresses(NaCl, PEG, CdCl2, low temperature and ABA), gene expression of ThPrx1 and ThPrx2 was investigated by using realtime quantitative RTPCR in roots and leaves. The results showed that ThPrx1 and ThPrx2 had different expression patterns under varied abiotic stresses. The mRNA levels of ThPrx1 in roots were upregulated under NaCl, PEG, and ABA treatments. ThPrx1 mRNA levels in both leaves and roots were downregulated under CdCl2 and low temperature stresses. The expression of ThPrx2 mRNA decreased during low temperature treatment, but the expression of ThPrx2 mRNA varied under other treatments. Our results demonstrate that ThPrx1 and ThPrx2 are two novel Prx genes, and they might play roles during different abiotic stress scenarios.