Objective  Bioinformatics and expression of NRAT1 gene of the ornamental Hydrangea macrophylla plants that tend to accumulate aluminum (Al), a growth-limiting heavy metal in acidic soil, were studied to understand the physiology of the plant on Al-tolerance.

  Method  The RNA of H. medalensis cv. Laybla was extracted for RT-PCR to detect the real-time expression and cloned for bioinformatic analysis to determine the molecular structure of NRAT1.

  Result  The cloned macrophage gene obtained in the lab revealed that the gene had a 1 881 bp open reading frame and encoded 548 amino acids. A multiple sequence analysis showed it to be highly conservative with 12 transmembrane structures located on the plasma or vacuole membrane. The secondary and tertiary structures of the hydrophobic protein were obtained. RT-PCR indicated that NRAT1 was expressed in the roots, stems and leaves of H. macrophylla, and the expressions increased initially to peak in 2h followed by a decline with time to a levered low level. After 12h under Al-stress, the expression was completely inhibited. Among the three issues, the roots had the highest expression and were affected the most by the stress.

  Conclusion  The NRAT1 gene expression was up-regulated in Hydrangea macrophylla immediately upon the exposure to Al. The gene was positively confirmed to participate in the absorption and transport of Al ions playing an important role in the heavy metal accumulation in the plants.