. 2021 Feb 9;10(2):333. doi: 10.3390/plants10020333

Table 3.

Mean amino acid and ammonium concentrations, as well as the glutamine:glutamate and asparagine:aspartate ratio ± standard deviations, in leaves of control, ethephon-treated and naturally senescing Vitis vinifera cv. Riesling vines (n = 4).

	Control (mg kg⁻¹ DM⁻¹)			Ethephon Treatment (mg kg⁻¹ DM⁻¹)			Natural Senescence (mg kg⁻¹ DM⁻¹)
Alanine	50.02	±	8.36 ^a	37.35	±	8.58 ^a	33.24	±	10.63 ^a
Arginine	1.39	±	1.11 ^b	2.95	±	2.21 ^ab	5.66	±	2.60 ^a
Asparagine	0.74	±	0.91 ^b	7.97	±	2.53 ^a	8.83	±	1.51 ^a
Aspartic acid	451.33	±	59.82 ^a	330.91	±	74.54 ^ab	283.44	±	28.31 ^b
Citrulline	0.00	±	0.00 ^a	0.63	±	1.27 ^a	0.91	±	1.82 ^a
Cystine	2.38	±	4.75 ^a	11.52	±	5.11 ^a	10.98	±	4.00 ^a
Glutamic acid	765.06	±	89.73 ^a	387.24	±	78.28 ^b	394.34	±	28.42 ^b
Glutamine	118.78	±	28.32 ^c	531.32	±	26.44 ^a	354.11	±	39.58 ^b
Glycine	15.63	±	3.69 ^a	17.57	±	2.10 ^a	18.28	±	2.38 ^a
Histidine	15.33	±	3.63 ^c	57.07	±	3.08 ^a	33.43	±	2.93 ^b
Isoleucine	20.55	±	5.71 ^c	74.14	±	3.61 ^a	51.29	±	5.14 ^b
Leucine	16.10	±	5.83 ^c	83.22	±	7.41 ^a	65.25	±	6.19 ^b
Lysine	32.84	±	5.45 ^a	15.83	±	6.57 ^b	14.10	±	1.53 ^b
Methionine	1.34	±	1.64 ^c	23.37	±	2.81 ^a	15.48	±	2.82 ^b
Ornithine	0.00	±	0.00 ^a	2.44	±	3.32 ^a	3.08	±	2.22 ^a
Phenylalanine	39.62	±	6.07 ^c	76.19	±	8.44 ^a	55.57	±	4.22 ^b
Proline	7.93	±	1.47 ^b	84.88	±	21.56 ^a	35.84	±	15.75 ^b
Serine	68.05	±	11.36 ^a	57.79	±	6.92 ^a	62.61	±	6.95 ^a
Threonine	34.80	±	4.53 ^c	80.65	±	7.06 ^a	56.78	±	3.03 ^b
Tryptophan	1.62	±	1.19 ^c	95.37	±	19.08 ^a	28.94	±	14.10 ^b
Tyrosine	0.94	±	1.88 ^b	11.93	±	7.91 ^a	6.76	±	3.07 ^ab
Valine	28.70	±	9.92 ^c	99.65	±	9.96 ^a	59.46	±	7.36 ^b
β-Alanine	6.64	±	8.83 ^a	9.63	±	3.24 ^a	13.92	±	4.72 ^a
β-Aminoisobutyric acid	1.48	±	2.96 ^a	0.92	±	1.83 ^a	0.00	±	0.00 ^a
γ-Aminobutyric acid	24.54	±	3.74 ^a	21.01	±	4.02 ^a	20.69	±	2.48 ^a
Total	1705.8	±	175.2 ^b	2121.5	±	176.3 ^a	1633.0	±	48.6 ^b
Ammonium	17.89	±	0.89 ^a	33.75	±	3.37 ^a	14.76	±	17.89 ^a
Glutamine:glutamate *	0.155	±	0.026 ^b	1.421	±	0.336 ^a	0.904	±	0.146 ^a
Asparagine:aspartate *	0.001	±	0.002 ^b	0.025	±	0.007 ^a	0.032	±	0.007 ^a

Treatments with different superscript letters differ significantly with p < 0.05. * The two amino acid ratios are dimensionless parameters.