<i>LmGSTF3</i> Overexpression Enhances Cadmium Tolerance in <i>Lemna minor</i>

Glutathione S-transferase (GST) has been established to play an important role in regulating the responses of plants to stress, although its function and mechanisms of action in the cadmium (Cd)-tolerant <i>Lemna minor</i> remain unclear. In this study, we sought to identify a Cd-responsive <i>GST</i> gene from <i>Lemna minor</i> for functional analysis and mechanistic characterization. We accordingly identified a member of the <i>GST</i> gene family, <i>LmGSTF3</i>, which plays a positive role in adaptation of <i>Lemna minor</i> to Cd. Having successfully obtained overexpressing (OE) strains via genetic transformation, we established that these strains were characterized by elevated Cd tolerance compared with the wild-type strain, as evidenced by significant increases in growth rate, chlorophyll content, antioxidant enzyme activities, and Cd removal rate. At the transcriptome level, the OE strains were found to have a stronger regulatory ability in response to Cd, particularly with respect to photoprotection, antioxidant defense, and glycolytic metabolism, which may be key factors contributing to the Cd tolerance of <i>Lemna minor</i>. Our findings provide a basis for further elucidating the biochemical and molecular mechanisms underlying the Cd tolerance conferred by <i>GST</i> genes in <i>Lemna minor</i> and will potentially contribute to the utilization of <i>Lemna minor</i> in remediating aquatic pollution.