Effect of exogenous γ-aminobutyric acid (GABA) and nutrients on growth and quality of <i>Glechoma longituba</i> (Nakai) Kupr

ABSTRACT Medicinal plants play a crucial role in both traditional and modern medicine. As demand continues to grow, the requirements for their yield and quality are becoming stringent. Exogenous γ -aminobutyric acid (GABA) has been indicated to enhance plant stress resistance; however, its effects on the yield and quality of medicinal plants, as well as whether soil nutrient conditions modulate these effects remain unclear. We experimented to examine the effects of GABA (0, 2, 10 and 50 mL · L −1 ) and nutrients (0, 1, 5 and 10 mL · L −1 ) on the growth and contents of the main active constituents (chlorogenic acid and total flavonoids) and nutrition (soluble sugar and protein) of a typical medicinal plant Glechoma longituba . The addition of GABA significantly increased the biomass of G. longituba . Still, it decreased the contents of chlorogenic acid and total flavonoids, while not affect soluble sugar and protein content. The addition of nutrients increased the biomass of G. longituba , reduced the contents of chlorogenic acid and total flavonoids, yet increased the soluble sugar content. Our results highlight that the application of GABA and nutrients can boost the biomass of G. longituba but may compromise its quality. This provides valuable experimental evidence for optimising the cultivation practices of medicinal plants.