The Role of Adenylyl Sulfate Reductase to Abiotic Stress in Tomato

The full-length cDNA of LeAPR1 encoded a protein of 461 amino acid residues, which contained homology with phosphoadenosine phosphosulphate reductase (PAPS reductase) in N-terminal and an adenylylsulfate reductase in N-term and C-terminal. Analysis of the deduced amino acid sequence of LeAPR1 revealed that it shares high sequence identity with potato StAPR (96% identity)(Gene bank accession no. CDC44841). We found that multiple copies of LeAPR1 gene are present in the tomato genome through southern blot using genomic DNA was digested with 3 different restriction enzymes. The expression of LeAPR1 was also examined in various organs and its expression was also detected at high levels in roots and stems. Only high amounts of LeAPR1 transcripts were detected at high transcripts in the leaves at time 0, and then reduced as the plant stressed by the NaCl and abscisic acid (ABA). After 24h treatment of NaCl and ABA were showed increasing patterns of LeAPR1 gene. Time course of LeAPR1 gene expression was examined under oxidative stresses from metyl viologen (MV) and hydrogen peroxide ($H_2O_2$). In the presence of 10 mM $H_2O_2$ and $50\;{\mu}M$ MV, the levels of LeAPR1 transcript in leaves decreased after 1 h, and then increased strongly, peaked at 24 h. Our results indicated that LeAPR1 may play a role function of circadian regulation involved in abiotic stresses signaling pathways.