Gamma-aminobutyric acid (GABA) improves the cadmium phytoremediation capacity of Galinsoga parviflora Cav.

Abstract

ABSTRACT Gamma-aminobutyric acid (GABA) is a signalling substance that related to the stress condition. To improve the cadmium (Cd) phytoremediation capacity of hyperaccumulator Galinsoga parviflora Cav., the effects of exogenous GABA on the Cd accumulation of G. parviflora were studied. The treatment of Cd (0.1 mg/L) decreased the biomass and photosynthetic pigment content of G. parviflora, indicating that Cd treatment produced stress to G. parviflora. Under Cd stress, exogenous GABA increased the biomass and photosynthetic pigment content of G. parviflora to some extent, and the applications of GABA at 1 and 2 g/L increased the shoot biomass by 10.36% and 28.83%, respectively, compared with Cd treatment. Exogenous GABA also increased the Cd content, bioconcentration factor, and Cd extraction of G. parviflora. The applications of GABA at 1 and 2 g/L increased the shoot Cd content by 13.39% and 16.53%, respectively, and increased the shoot Cd extraction by 25.25% and 49.83%, respectively, compared with Cd treatment. Therefore, GABA can alleviate Cd stress to G. parviflora and improve its phytoremediation capacity.