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    • Keywords


      Duplication; evolution; gene expression; glutamate decarboxylase; soybean

    • Abstract


      Glutamate decarboxylase (GAD) is an enzyme that catalyses the conversion of L-glutamate into 𝛾-aminobutyric acid (GABA), which is a four-carbon non-protein amino acid present in all organisms. Although plant GAD plays important roles in GABA biosynthesis, our knowledge concerning GAD gene family members and their evolutionary relationship remains limited. Therefore, in this study, we have analysed the evolutionary mechanisms of soybean GAD genes and suggested that these genes expanded in the soybean genome partly due to segmental duplication events. The approximate dates of duplication events were calculated using the synonymous substitution rate, and we suggested that the segmental duplication of GAD genes in soybean originated 9.47 to 11.84 million years ago (Mya). In addition, all segmental duplication pairs (GmGAD1/3 and GmGAD2/4) are subject to purifying selection. Furthermore, GmGAD genes displayed differential expression either in their transcript abundance or in their expression patterns under abiotic stress conditions like salt, drought, and cold. The expression pattern of paralogous pairs suggested that they might have undergone neofunctionalization during the subsequent evolution process. Taken together, our results provide valuable information for the evolution of the GAD gene family and represent the basis for future research on the functional characterization of GAD genes in higher plants.

    • Author Affiliations


      Tae Kyung Hyun1 2 Seung Hee Eom1 2 Xiao Han3 Ju-Sung Kim4 5

      1. Division of Applied Life Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, Republic of Korea
      2. These authors contributed equally to the work.
      3. Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
      4. Majors in Plant Resource and Environment, College of Agriculture & Life Sciences, SARI, Jeju National University, Jeju 690-756, Republic of Korea
      5. The Research Institute for Subtropical Agriculture and Biotechnology, Jeju National University, Jeju, Republic of Korea
    • Dates

    • Supplementary Material

  • Journal of Biosciences | News

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