Genome-wide identification of potassium transporters and channels in Malus domestica genome

Potassium (K⁺) is an essential nutrient for plants. It contributes to most physiological and biochemical pathways for plant metabolism, growth, and development. It is the most available plant nutrient, comprising 10-15% of plant weight. Plants have a sophisticated system of K⁺ transporters and channels for distribution in plant body. Apple is one of the most consumed fruits in the world. Its fruit quality and yield are positively affected by K⁺. However, limited information is available about K⁺ transport systems in Apple. In this study, 47 candidate genes (26 K⁺ transporters and 21 K⁺ channels) have been identified in Apple (Malus domestica) genome. The phylogenetic comparisons with other plants (Glycine max, Arabidopsis thaliana, and Oryza sativa) indicated that the K⁺ transport system is much conserved among different plants. The analysis of Gene structure showed the presence of specific introns and exon patterns for these gene families. Transcriptomic data analysis and RT-qPCR demonstrated significant variations in the transcript abundance of these genes in response to abiotic stresses. The current project represents the first report about the K⁺ transport system in Apple. Therefore, it may act as a starting point for further functional characterizations.