In Silico And Expression Analysis Of Delta(1)-Pyrroline-5-Carboxylate Synthetase In Rice Seedlings Under Nacl Stress

The synthesis of proline, an osmolyte, is one of the stress response mechanisms of the plants. Glutamate is converted to proline by the activity of the enzyme Delta(1)-pyrroline-5-carboxylate synthetase (P5CS). We have analyzed the gene (p5cs) behind this enzyme to study the relationship between the expression of p5cs and the proline content of different rice genotypes. The shoots of the genotypes showing salt tolerance (SR26B and Nonabokhra) revealed a significant positive correlation between the elevated expression of p5cs and proline level, while the roots showed insignificant correlation. Danaguri, a rice landrace, on the contrary, showed a negative correlation between the expression of p5cs and proline in both shoots and roots.The salt-sensitive rice genotype (IR64) indicated a positive correlation between the expression of p5cs and proline in both shoots and roots. Considering a feedback inhibition of the activity of P5CS by proline, we performed in silico molecular docking experiment. We observed a very close competition between the binding sites of P5CS with glutamate, the substrate and proline, the product.