Table 1 Effects of exogenous chitosan (CTS) on changes in sucrose content, fructose content, glucose content, sucrose synthase (SS) activity, sucrose phosphate synthase (SPS) activity, invertase activity, total amino acids (TAA) content, free proline (Pro) content, glutamic acid (Glu) content, γ-aminobutyric acid (GABA) content, pyruvic acid (PA) content, and pyruvate kinase (PK) activity in leaves of creeping bentgrass under normal and salt stress conditions at 24 d. Same letters indicate no significant difference (n = 4, and p ≤ 0.05). C, control; C + CTS, control pretreated with CTS; S, salt stress; S + CTS, salt-stressed plants pretreated with CTS

Sucrose content (mg g^− 1 DW)

12.45 + 1.09 d

21.88 + 4.51 c

36.05 + 3.22 b

63.43 + 8.58 a

Fructose content (mg g^− 1 DW)

9.51 + 1.55 c

3.46 + 0.65 d

28.66 + 0.29 a

23.71 + 0.70 b

Glucose content (μmol g^− 1 DW)

7.79 + 0.85 c

5.44 + 0.48 c

41.27 + 1.60 a

25.83 + 2.27 b

SS activity (μg min⁻¹ mg^− 1 Prot)

0.89 + 0.06 c

1.01 + 0.06 bc

1.16 + 0.05 b

1.54 + 0.01 a

SPS activity (μg min⁻¹ mg^− 1 Prot)

29.08 + 1.82 c

18.67 + 1.51 c

127.26 + 7.28 a

67.40 + 3.85 b

Invertase activity (μg min⁻¹ mg^− 1 Prot)

627.50 + 12.71 a

643.37 + 12.70 a

425.33 + 10.28 b

353.93 + 9.64 c

TAA content (μmol mg⁻¹ Prot)

54.19 + 6.54 c

62.27 + 5.99 c

114.75 + 7.09 b

137.53 + 3.06 a

Free Pro content (μg g⁻¹ DW)

1.06 + 0.31 c

0.85 + 0.09 c

4.87 + 0.31 a

3.15 + 0.07 b

Glu content (μg g⁻¹ DW)

374.00 + 5.19 b

332.85 + 5.46 c

386.48 + 9.42 b

412.71 + 3.08 a

GABA content (μmol mg⁻¹ DW)

821.47 + 18.74 b

895.28 + 10.92 a

414.45 + 9.18 d

536.65 + 20.73 c

PA content (μg mg⁻¹)

155.99 + 13.40 b

158.34 + 17.79 b

207.39 + 11.26 a

208.77 + 5.50 a

PK activity (nmol⁻¹ min ^− 1 mg Prot)

299.15 + 7.17 c

280.86 + 6.46 c

635.5 + 19.61 b

689.03 + 12.33 a