Whole-genome duplication (WGD), or polyploidy, is a major force in plant genome evolution. A duplicate of all genes is present in the genome immediately following a WGD event. However, the evolutionary mechanisms responsible for the loss of, or retention and subsequent functional divergence of polyploidy-derived duplicates remain largely unknown. Recently, Dr. Qing-Yin Zeng's group from the Institute of Botany, Chinese Academy of Sciences, revealed the evolutionary and functional dynamics of polyploidy-derived duplicate genes. Plant glutathione S-transferase (GST) genes play important roles in stress tolerance and detoxification metabolism. Dr. Qing-Yin Zeng and his collaborators reconstructed the evolutionary history of the GST gene family from the soybean genome, and identified 72 GST duplicated gene pairs formed by a recent Glycine-specific WGD event occurring approximately 13 Mya. They found that 72% of duplicated GST gene pairs experienced gene losses or pseudogenization, whereas 28% of GST gene pairs have been retained in the soybean genome. The GST pseudogenes were under relaxed selective constraints, whereas functional GSTs were subject to strong purifying selection. The polyploidy-derived GST duplicates show the divergence in enzymatic activities. Nonsynonymous substitutions of key amino acid sites play an important role in the divergence of enzymatic functions of polyploidy-derived GST duplicates. These findings have been published in Molecular Biology and Evolution (http://mbe.oxfordjournals.org/content/early/2015/08/17/molbev.msv156.full),
Whole-genome duplication (WGD), or polyploidy, is a major force in plant genome evolution. A duplicate of all genes is present in the genome immediately following a WGD event. However, the evolutionary mechanisms responsible for the loss of, or retention and subsequent functional divergence of polyploidy-derived duplicates remain largely unknown. Recently, Dr. Qing-Yin Zeng's group from the Institute of Botany, Chinese Academy of Sciences, revealed the evolutionary and functional dynamics of polyploidy-derived duplicate genes. Plant glutathione S-transferase (GST) genes play important roles in stress tolerance and detoxification metabolism. Dr. Qing-Yin Zeng and his collaborators reconstructed the evolutionary history of the GST gene family from the soybean genome, and identified 72 GST duplicated gene pairs formed by a recent Glycine-specific WGD event occurring approximately 13 Mya. They found that 72% of duplicated GST gene pairs experienced gene losses or pseudogenization, whereas 28% of GST gene pairs have been retained in the soybean genome. The GST pseudogenes were under relaxed selective constraints, whereas functional GSTs were subject to strong purifying selection. The polyploidy-derived GST duplicates show the divergence in enzymatic activities. Nonsynonymous substitutions of key amino acid sites play an important role in the divergence of enzymatic functions of polyploidy-derived GST duplicates. These findings have been published in Molecular Biology and Evolution (http://mbe.oxfordjournals.org/content/early/2015/08/17/molbev.msv156.full),