Molecular Characterization and Promoter Analysis of Novel Sugar Transporter Gene ScERD6 in Sugarcane

Abstract

Plant sugar transporters are key physiological elements in transporting sucrose and sensing specific sucrose signals. A knockoff of the novel sugar transporter gene (ScERD6) was developed by RACE-PCR from sugarcane, which incorporated an ORF of 1521 bp encoding a protein of 506 amino acids. The isolated ScERD6 gene was measured by 4722 bp DNA and containing 17 exons and 16 introns. It was found that the ScERD6 only had one transcript, and the ScERD6 protein consisted of potentially 12 transmembrane domains, belonging to sugar transporter protein. The promoter sequence was cloned by using genome walking, which included CAAT-boxes and TATA-boxes, as well as specific acting elements such as cis-regulatory elements involved in hormone response, seed development, environmental stresses, ACES, G-box, I-box, L-box, and rbcS-CMA7 light response element, etc. The treatments with 15% PEG and 6 °C stress can induce the expression of ScERD6 in the leaf, root, and stem. But ScERD6 expression in stem was different from that in leaf and root of sugarcane. Real-time PCR analysis uncovered the presence of ScERD6 in roots, stems, leaves, inflorescence, and buds, excessively, and the highest transcript level was observed in inflorescence, and the lowest in roots, while the average was detected in the stem. This finding predicted an important role of this gene in reproductive and floral development.