Isolation Phosphoglycerate Dehydrogenase gene from Aeluropus littoralis halophyte plant and functional analysis of T-DNA mutant in Arabidopsis thaliana

Bioinformatic analysis plays an important role in the study of genes and the prediction of their function in response to stresses. Halophyte Aeluropus littoralis, a valuable genetic resource for identifying genes involved in plant tolerance to abiotic stresses. In this study, Phosphoglycerate Dehydrogenase (PGDH) gene as the first important enzyme in the synthesis of serine, was Isolated based on EST sequence from plant Aeluropus littoralis in salinity using by the RLM-RACE method. By overlapping the 3’ and EST sequences, a 1506 bp fragment including the ORF region (1268 nucleotides) and 3’UTR region (238 nucleotides) were obtained. The phylogenetic analysis of AlPGDH was done with other ortholog genes in different plants and its homologs were identified. Based on phylogram, the high degree of homology was observed between AlPGDH gene and other homologous genes from monocot cereals such as sorghum, foxtail millet and rice. The AtPGDH co-expression network analysis showed the important role of the PGDH gene in biosynthetic pathways, including amino acid synthesis, secondary metabolites synthesis and the pathway of glycine, serine and threonine metabolism, and its expression analysis indicated that the expression was increased in different stresses. The Phenotyping of the Arabidopsis knockout mutants for PGDH gene in NaCl and PEG stress condition indicated that the growth characteristics were significantly reduced in compared to the control plant, which could be confirmed the role of this gene in the response to salt and drought stress. The findings of this study reveal the functional characteristics of AlPGDH gene, phenotypic changes in AtPGDH mutant plants in exposure to salt and drought stress, and its possible role in increasing plant tolerance to stress.