Cloning and Expression Analysis of Nitrate Transporter Gene MaNRT2 in Banana under Low Nitrogen Stress

Key words: 
• banana /
• low nitrogen stress /
• nitrate transporter 2 /
• RNA-Seq /
• gene expression analysis

Abstract: Nitrogen is a necessary macro-element for plant growth and development,and is also a key factor limiting plant yield. High affinity nitrate transporter NRT2 is an important protein involved in nitrate nitrogen assimilation. In this study,banana was selected as experimental material,from which a differentially expressed NRT2 gene was identified by Illumina RNA-Seq. The whole c DNA sequence was obtained via PCR. Through bioinformatics,it was predicted that its length was 1 509 bp which encoded 503 amino acids,contained a MFS domain and belonged to NRT2 gene family named as MaNRT2. The results of RNA-Seq and qRT-PCR showed that MaNRT2 was significantly tissue specific,with its expression being higher in root than in leaf. After the banana was treated with low nitrogen stress,the MaNRT2 expression level rose up in leaf but declined in root. This indicated that MaNRT2 gene had close relationship to nitrogen absorption and transport in banana.