Functional and Phylogenetic Analysis of the Glutathione Transferase Gene Family in Poplar

摘要

Gene duplication, whether genome-wide or local, plays a major role in plant evolution (reviewed in Flagel and Wendel, 2009). Over the course of evolution, many, perhaps most, duplicate genes (paralogs) are short-lived, losing functionality and ultimately being removed by deletion. However, some duplicates persist, either retaining their full ancestral function, a subset of their ancestral functions (subfunctionalization), or acquiring new functions (neofunctionalization) (reviewed in Demuth and Hahn, 2009). A particular challenge is to understand whether the capacity for sub- and neofunctionalization differs among genes and whether this might explain why only some genes diversify into large gene families. In this issue, Lan et al. (pages 3749–3766) combine thorough molecular evolutionary analysis (reconstruction of the history of gene duplication and assessment of signatures of selection) with expression and functional assays for members of a large gene family, the glutathione S-transferase (GST) gene family in poplar (Populus trichocarpa).