Structural and Expression Analysis of Salinity Stress Responsive Phosphoserine Phosphatase from Brassica juncea (L.)

Abstract

Plants exposed to environment generally encounter various abiotic stresses which include drought, salinity, mineral deficiency, high and low temperature leading to reduction in growth and productivity. Phosphoserine phosphatase (EC 3.1.3.3) belongs to Haloacid Dehalogenase (HAD) superfamily and it catalyzes the last step in the phosphorylated pathway for the biosynthesis of L-Ser. In the present investigation, the full-length cDNA coding for phosphoserine phosphatase was cloned and purified from Brassica juncea L. Sequence analysis indicates that it encodes a protein of 296 amino acids and revealed high homology to PSP of Arabidopsis thaliana. Multiple sequence alignment analysis showed the presences of the three short conserved sequence motifs. Molecular modelling of BjPSP showed core α/β domain of Rossmann fold which is the characteristic of members of HAD superfamily. Western blot analysis showed that the level of BjPSP protein increased under different concentration of salinity stresses indicating its possible role during salinity stress in B. juncea L.