Genome-Wide Characterization of High-Affinity Nitrate Transporter 2 (NRT2) Gene Family in <i>Brassica napus</i>

oleh: Run-Jie Du, Ze-Xuan Wu, Zhao-Xi Yu, Peng-Feng Li, Jian-Yu Mu, Jie Zhou, Jia-Na Li, Hai Du

Format: Article
Diterbitkan: MDPI AG 2022-04-01

Deskripsi

Nitrate transporter 2 (NRT2) plays an essential role in Nitrogen (N) uptake, transport, utilization, and stress resistance. In this study, the NRT2 gene family in two sequenced <i>Brassica napus</i> ecotypes were identified, including 31 genes in ‘Zhongshuang11’ (<i>BnaZSNRT2s</i>) and 19 in ‘Darmor-<i>bzh</i>’ (<i>BnaDarNRT2s</i>). The candidate genes were divided into three groups (Group I−III) based on phylogenetic analyses, supported by a conserved intron-exon structure in each group. Collinearity analysis revealed that the large expansion of <i>BnaZSNRT2s</i> attributed to allopolyploidization of ancestors <i>Brassica rapa</i> and <i>Brassica oleracea</i>, and small-scale duplication events in <i>B. napus</i>. Transcription factor (TF) binding site prediction, <i>cis</i>-element analysis, and microRNA prediction suggested that the expressions of <i>BnaZSNRT2s</i> are regulated by multiple factors, and the regulatory pattern is relatively conserved in each group and is tightly connected between groups. Expression assay showed the diverse and differentiated spatial-temporal expression profiles of <i>BnaZSNRT2s</i> in Group I, but conserved patterns were observed in Group II/III; and the low nitrogen (LN) stress up-regulated expression profiles were presented in Group I−III, based on RNA-seq data. RT-qPCR analyses confirmed that <i>BnaZSNRT2.5A-1</i> and <i>BnaZSNRT2.5C-1</i> in Group II were highly up-regulated under LN stress in <i>B. napus</i> roots. Our results offer valid information and candidates for further functional <i>BnaZSNRT2s</i> studies.