Genome-wide identification and expression analysis of yellow stripe-like (YSL) genes in Nicotiana tabacum

Abstract Iron (Fe) and copper (Cu) are crucial micronutrients for plant growth and development. The yellow stripe-like (YSL) proteins play a vital role in the absorption and transport of metal chelates in plants. The YSL genes in tobacco have not been systematically identified and characterized. This study aims to explore the YSL genes in Nicotiana tabacum. A comprehensive set of 17 NtYSL genes were identified and classified into four distinct clades on the phylogenetic tree. The gene structures, characterized by the length and distribution of exons and introns, and protein motifs are relatively conserved. Genomic localization analysis revealed that the NtYSL genes are unevenly distributed across 15 chromosomes, with 11 pairs of homeologous loci identified within the genome. To investigate the functionality of these genes, we analyzed their expression levels in shoots and roots under Fe- and Cu-deficient conditions by real-time quantitative reverse transcription PCR (qRT-PCR), finding that several NtYSL genes are responsive to Cu deficiency or Fe deficiency. This study provides a systematic characterization of the NtYSL gene family in Nicotiana tabacum and offers insights into their potential roles in Fe and Cu homeostasis.