Exogenous γ-Aminobutyric Acid (GABA) Enhanced Response to Abiotic Stress in <i>Hypsizygus marmoreus</i> by Improving Mycelial Growth and Antioxidant Capacity
Zhi Cao,
Hongyu Chen,
Chenli Zhou,
Ming Gong,
Yan Li,
Youran Shao,
Yingying Wu,
Dapeng Bao
Affiliations
Zhi Cao
School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
Hongyu Chen
National Engineering Research Center of Edible Fungi, Key Laboratory of Applied Mycological Resources and Utilization of Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
Chenli Zhou
National Engineering Research Center of Edible Fungi, Key Laboratory of Applied Mycological Resources and Utilization of Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
Ming Gong
National Engineering Research Center of Edible Fungi, Key Laboratory of Applied Mycological Resources and Utilization of Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
Yan Li
National Engineering Research Center of Edible Fungi, Key Laboratory of Applied Mycological Resources and Utilization of Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
Youran Shao
National Engineering Research Center of Edible Fungi, Key Laboratory of Applied Mycological Resources and Utilization of Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
Yingying Wu
National Engineering Research Center of Edible Fungi, Key Laboratory of Applied Mycological Resources and Utilization of Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
Dapeng Bao
School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
γ-Aminobutyric (GABA) acid is a nutrient and signaling molecule existing in many plants, participating in the regulation of metabolism and various physiological activities. Two strains of Hypsizygus marmoreus (a white variety and a brown variety) were investigated to study the impact of exogenous GABA on mycelial growth and the response to stress. Mycelial growth, microscopic morphology, antioxidant profile, and gad2 expression in H. marmoreu were investigated under salt, dehydration, or cold stress. The results indicated that 5 mM GABA stimulated mycelial growth under standard cultivation conditions, whereas GABA addition over 10 mM hindered the growth. Under salt, dehydration, or cold stress, treatment with 5 mM GABA significantly enhanced the mycelial growth rate and density of both H. marmoreus strains by promoting front hyphae branching. Meanwhile, the activities of key antioxidant enzymes such as peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) were enhanced by GABA, thereby augmenting the defensive network against abiotic stress. Additionally, gad2 expression and GABA concentration were increased under abiotic stresses as a resistance regulation response. The exogenous addition of GABA strengthened the upregulation of gad2 expression and GABA production. These findings indicated that exogenously adding low concentrations of GABA effectively enhanced the mycelial growth and antioxidant profile of H. marmoreus, thereby improving its resistance against stresses.
