Find in Library

Soil salinity is a main abiotic stress in agriculture worldwide. The <i>Na⁺/H⁺</i> antiporters (<i>NHXs</i>) play pivotal roles in intracellular Na⁺ excretion and vacuolar Na⁺ compartmentalization, which are important for plant salt stress resistance (SSR). However, few systematic analyses of <i>NHXs</i> has been reported in allotetraploid rapeseed so far. Here, a total of 18 full-length <i>NHX</i> homologs, representing seven subgroups (<i>NHX1-NHX8</i> without <i>NHX5</i>), were identified in the rapeseed genome (A_nA_nC_nC_n). Number variations of <i>BnaNHXs</i> might indicate their significantly differential roles in the regulation of rapeseed SSR. <i>BnaNHXs</i> were phylogenetically divided into three evolutionary clades, and the members in the same subgroups had similar physiochemical characteristics, gene/protein structures, and conserved Na⁺ transport motifs. Darwin´s evolutionary pressure analysis suggested that <i>BnaNHXs</i> suffered from strong purifying selection. The cis-element analysis revealed the differential transcriptional regulation of <i>NHXs</i> between the model Arabidopsis and <i>B. napus</i>. Differential expression of <i>BnaNHX</i>s under salt stress, different nitrogen forms (ammonium and nitrate), and low phosphate indicated their potential involvement in the regulation of rapeseed SSR. Global landscapes of <i>BnaNHXs</i> will give an integrated understanding of their family evolution and molecular features, which will provide elite gene resources for the genetic improvement of plant SSR through regulating the <i>NHX</i>-mediated Na⁺ transport.