GABA	γ-aminobutyric acid
PEG-6000	polyethylene glycol-6000
SOD	superoxide dismutase
CAT	catalase
POD	peroxidase
APX	ascorbate peroxidase
DR	dehydroascorbate reductase
GR	glutathione reductase
MR	monodehydroascorbate reductase
RWC	relative water content
WUE	water use efficiency
Pn net	photosynthetic rate
EL	electrolyte leakage
OP	osmotic potential
OA	osmotic adjustment
Chl	total chlorophyll
TCA	tricarboxylic acid
NO	nitric oxide
NOA	NO-associated protein
NR	nitrate reductase
NiR	nitrite reductase
Glu	glutamate
GS	glutamine synthetase
GOGAT	glutamate synthase
GDH	glutamate dehydrogenase
GAD	glutamate decarboxylase
PGRs	plant growth regulators
ROS	reactive oxygen species
MDA	malondialdehyde
O2−	superoxide anion
H2O2	hydrogen peroxide