Isolation, expression analysis and chromosomal location of P5CR gene in common wheat (Triticum aestivum L.)

Many organisms, including higher plants, accumulate free proline under osmotic stress. P5CR is the last enzyme in the cascade for proline synthesis. We isolated TaP5CR in wheat with a homologous sequence method. It is 1025 bp in length and contains a complete open reading frame of 864 bp that encodes a polypeptide of 288 amino acids. A Southern blot showed that TaP5CR had more than two copies in wheat. The TaP5CR gene which we isolated was located on chromosome 3D and expressed at much higher levels in radicles, flowers and leaves than other organs. Its expression was upregulated by salt, PEG, ABA and heat stress. TaP5CR overexpression in Arabidopsis can enhance root growth under salt stress and increase proline content and decrease MDA content under NaCl, PEG and ABA stress. The results showed the possibility to use TaP5CR to enhance transgenic Arabidopsis stress tolerance.