Comparative genome-wide analysis of the NRAMP gene family in chickpea (Cicer arietinum L.) associated with heavy metal stress tolerance

Abstract

Chickpea (Cicer arietinum L.), a widely cultivated legume, is valued for its high protein and mineral content. However, its production has been inconsistent in recent years, largely due to biotic and abiotic stresses and limited genetic diversity. Micronutrient deficiencies, particularly of iron and zinc, remain a global challenge and are often referred to as “hidden hunger”. The NRAMP (natural resistance- associated macrophage protein) gene family plays a crucial role in the uptake and transport of heavy metals such as cadmium (Cd), zinc (Zn), copper (Cu), lead (Pb), iron (Fe), and manganese (Mn), and contributes significantly to plant responses under heavy metal stress conditions. In this study, a genome-wide analysis was conducted to identify and characterize NRAMP genes in the chickpea genome using bioinformatics approaches. Multiple sequence alignment was performed using the ClustalW method in MEGA 7 to examine conserved residues across NRAMP proteins from Cicer arietinum, Nicotiana attenuata, Arabidopsis thaliana, Oryza sativa, Solanum lycopersicum, and Solanum tuberosum. A total of nine NRAMP genes were identified in chickpea. The phylogenetic analysis grouped these genes into five distinct clades. Additionally, physicochemical profiling revealed that Ca-NRAMP6 has the longest protein sequence, while Ca-NRAMP4 has the highest number of exons and introns. Protein interaction analysis indicated that only CaNRAMP 6 has a strong interaction with other proteins.