Bioinformatics study of LEA proteins involved in tolerance to drought stress in barley (Hordium vulgare L.) and rice (Oryza sativa L.)

Late embryonic accumulating proteins (LEAs) are proteins that involved in reducing Cellular injuries associated with dehydration and preventing cellular proteins from aggregation due to osmotic stress and freezing. Increased expression of some genes encoding these proteins has led to increased resistance to stresses such as dehydration, cold and salinity in many plants. Analysis of biological data with the using of bioinformatics tools plays an important role in the study of genes and proteins and predicts their function in response to the stress.

In this study, in order to study of LEA proteins in two important grasses (tolerant and sensitive to drought), the interest sequences are obtained from different data bases and the phylogeny tree are drown using ClustalW software. After the investigation of classes in different groups, the short sequences deleted and some sequences were selected. The information about sequence characteristics, their motifs, prediction of intracellular location, analysis of hydrogen and non-hydrogen bands and prediction of biological process and molecular activity obtained using ProtParam, EXPASY, MEME and SMART, Wolf PSORT, PIC, WHAT IF databases and Blast2GO software. The 3D structure of these proteins was modeled using Discovery studio, HyperChem, MODELLER v10 and SPDBV software.

The results were grouped the proteins into seven distinct groups with the highest number of sequences in dehydrin group. Most proteins had small size with less than 30 kDa. Also, the most sequences showed high surface charge, because of their hydrophilicity and flexible structure to form a chaperone structure to protect the cell membrane from stress. The study of intracellular location showed that most of proteins are located in the cell nucleus. Also, the motif study demonstrated the conserved sequences among members of the same group. The prediction of molecular activity and biology indicated the role of these proteins in the tolerance to the stress including drought and protein folding through bindings or catalytic activity.  

Barley as a stress-resistant plant mainly involved the dehydrin sequences and rice as a stress-sensitive plant mainly contains the LEA4 and LEA2 sequences.