Genome-wide identification, characterization, and expression analysis of the MAPK gene family in Nardostachys jatamansi (D. Don) DC

Mitogen-activated protein kinase (MAPK) cascade is a widely distributed signaling pathway, which is involved in growth, development, and stress responses in plants. Nardostachys jatamansi (Caprifoliaceae) is a perennial, high-altitude Himalayan medicinal plant, which experiences varying environmental fluctuations throughout its life span. However, how the fluctuating environment is regulated via MAPKs in high-altitude medicinal plants, such as Nardostachys jatamansi as well as in other members of the Caprifoliaceae family, is poorly understood. In the present study, Lonicera japonica Thunb. (Caprifoliacae) was used as a model for genome-wide understanding of MAPKs in the Caprifoliaceae family; further, Nardostachys jatamansi was used for expression profiling of MAPKs under various growth stages and abiotic stress conditions. Twenty LjMAPKs and 20 NjMAPKs were identified from the Lonicera japonica genome and Nardostachys jatamansi transcriptome database. The identification, characterization, subcellular localization, phylogenetic analysis, chromosomal localization, gene structure, synteny, and cis-acting elements of the LjMAPKs and NjMAPKs gene family were evaluated using in silico approaches. Phylogenetic and other in silico investigations showed maximum similarity between LjMAPKs and NjMAPKs protein sequences. Cis-regulatory elements identified in the promoter region of LjMAPKs included development, light, phytohormone, and stress-responsive elements. Tissue-specific expression profiling showed ubiquitous expression of MAPKs in both L. japonica and N. jatamansi. However, differential transcript abundance was observed in leaf and root tissues of NjMAPKs under varying abiotic stress conditions. The present study’s findings provided a fundamental understanding of MAPKs in L. japonica and N. jatamansi and may contribute towards a better understanding of the molecular mechanisms regulating plant development and abiotic stress response.