GENOME-WIDE ANALYSIS AND EXPRESSION PROFILING OF POTASSIUM TRANSPORT RELATED GENES IN Solanum tuberosum

Potassium (K+) is one of the vital macronutrients for the plant kingdom. It constitutes almost 10% of total plant biomass. Therefore, it is evident that K+ takes part in diverse biological processes throughout plant life. A number of molecular and functional studies have demonstrated the existence of a very organized system for K+ uptake and transport in model plants. However, very scanty information is available related to the potassium transport system in Solanum tuberosum. Current study involves genome wide identification, in silico characterization and expression analysis of K+ transport related genes in S. tuberosum. In this study, we identified 43 genes encoding transporters and channels involved in potassium transport. These genes were categorized on the basis of their conserved motifs and domain structure. There are twenty three potassium transorters (1 HKT, 4 KEAs and 18 KUP/HAK/KTs) and twenty channels (5 KCOs/TPKs and 15 Shakers). Chromosomal positioning of these genes showed that these genes are randomly spread over all the 12 chromosomes of S. tuberosum. The phylogenetic analysis showed that K+ transporters and channels in S. tuberosum are orthologous to genes that are in charge of K+ transport in Arabidopsis thaliana and Solanum lycopersicum. To validate the in silico data, we performed expression analysis of these genes under salinity stress. Some genes were differentially expressed in response to salt stress, which indicates the significance of these genes for stress response of S. tuberosum. Current study is the first insight into the potassium transport system in S. tuberosum and it will work as a baseline for functional analysis of these genes.