The AtGSTU7 gene influences glutathione-dependent seed germination under ABA and osmotic stress in Arabidopsis.

Glutathione S -transferases (GSTs) play important roles in metabolism and detoxification of plant cells. However, their functions during development are less well understood. Arabidopsis AtGSTU7 (AT2G29420) encodes a Tau class GST. Here we provide the AtGSTU7 was abundantly expressed in seeds and in roots at an early stage of germination. AtGSTU7 expression was repressed by exogenous ABA and promoted by osmotic stress. A null mutant of AtGSTU7 (atgstu7) accumulated higher contents of reduced GSH and decreased amounts of endogenous H 2 O 2 in seedlings. The atgstu7 plants showed decreased osmotic tolerance during seed germination, which was influenced by GSH and ABI3 gene expression. The results suggested that AtGSTU7 involvement in seed germination is mediated by GSH–ROS homeostasis and ABA signaling. • AtGSTU7 gene abundantly expressed in seeds and during seed germination. • AtGSTU7 gene responded to ABA and osmotic stresses. • atgstu7 accumulated reduced GSH and decreased endogenous H 2 O 2. • The atgstu7 plants decreased osmotic tolerance during seed germination influencing by GSH and ABI3 expression. • AtGSTU7 mediated seed germination by regulating GSH–ROS homeostasis and ABA signaling. [ABSTRACT FROM AUTHOR]