Biochemical trapping of unidentified events

Basic Data

Photosynthetic Pigments. Tables 2, 3, and 4, respectively, give the results obtained in the various samples. It is noteworthy that, in samples A and B, all classes are decreased in exposed samples by an average coefficient which is similar (p= 0.68) in both younger (0.60 à 0.22) and older leaves (0.66 à 0.075). These coefficients significantly deviate from 1 in both young (p = 4.81) and old leaves (p = 11.99). In sample C (Table 2), levels are decreased by an average factor C/G - 0. 5 8 relative to sample G, considered as reference. This factor, already significant (N = 5; p = 0.056), drops to 0.48 if chlorophyll B (particularly more stable than chlorophyll A) is discarded (N = 4; p = 0.043). In samples H to L, no statistically significant differences could be found.

Table 2. Photosynthetic Pigments in younger and older leaves from exposed (A) and control (B) samples of Medicago minima. Means (nmol per mg) à SD are given from N = 3 determinations.

Younger Leaves Older Leaves
Pigments A B A B

Chlorophyll A 0.58�0.13 0.87�0.19 0.54�0.12 0.81�0.18
Chlorophyll B 0.45�0.10 0.62�0.14 0.37�0.10 0.51�0.11
Pheophytins 0.44�0.10 0.73�0.16 0.20�0.05 0.29�0.06
� Caroten 0.09�0.02 0.21�0.05 0.10�0.02 0.20�0.04
Lutein 0.28�0.06 0.32�0.07 0.24�0.05 0.34�0.08
Violaxanthin 0.03�0.0 0.15�0.03 0.11�0.03 0.17�0.04
Chl.A/Pheo 1.31 1.19 2.70 2.79

Table 3. Photosynthetic pigments in Medicago minima leaves in exposed samples. Means (nanomols per mg) à SD are given from duplicate determinations.

Samples (distances in meters from epicenter)

Pigments C(0) D(1.5) E(2.1) F(3.5) G(10.0)

Chlorophyll A 0.36�0.04 1.10�0.13 1.16�0.14 1.20�0.15 1.30�0.03
Chlorophyll B 0.16�0.02 0.26�0.03 0.25�0.03 0.19�0.03 0.16�0.02
Pheophytins 0.44�0.06 0.71�0.09 0.77�0.10 0.70�0.09 0.52�0.02
� Caroten 0.09�0.02 0.11�0.02 0.12�0.03 0.16�0.03 0.22�0.04
Lutein 0.09�0.02 0.09�0.02 0.12�0.03 0.14�0.04 0.23�0.06
Chl.A/Pheo. 0.82 1.54 1.51 1.71 2.5

Table 4. Photosynthetic pigments in Medicago minima leaves in control samples. Means (nanomols per mg) à SD are given from N = 7 determinations.

Samples (distances in meters from epicenter)
Pigments H(0.5) I(3.8) J(6.0) K(8.8) L(15.4)

Chlorophyll A 0.89�0.42 0.69�0.30 0.69�0.40 0.64�0.20 0.65�0.38
Chlorophyll B 0.45�0.15 0.41�0.10 0.40�0.09 0.40�0.17 0.34�0.17
Pheophytins 1.71�0.54 2.30�0.32 1.83�0.35 1.34�0.26 1.30�0.34
� Caroten 0.37�0.07 0.32�0.08 0.36�0.07 0.25�0.06 0.25�0.07
Lutein 0.72�0.17 0.71�0.19 0.83�0.29 0.62�0.24 0.61�0.15
Chl.A/Pheo. 0.52 0.31 0.38 0.48 0.51

Carbohydrates. Tables 5, 6, and 7, respectively, give the results obtained in the three successive batches of samples, for the sole fractions which have been clearly identified in all cases. The most striking result is the observed increase of glucose concentrations in sample C (+ 158%; p = 0.027) and to a lesser extent in sample D (+32%; p = 0.20) relative to F or G. By contrast, raffinose and sucrose are depressed in sample C relative to sample G (p= 0.03 and 0.04 respectively). This could not be found in plants sampled at D + 730, which proved to be remarkably homogeneous, all along the axis.

Amino Acids. Tables 8, 9, and 10, respectively, give the concentrations of the identified amino acids in the three series of samples. In the first one, it is

TABLE 5

Carbohydrate contents (nmol per mg) in younger and older leaves from exposed (A) and control (B) samples of Medicago minima. Means and SD are given from duplicate determinations. The total value includes an additional 14 unidentified fractions.



Younger Leaves Older Leaves


A B A B

Raffinose 0.06�0.01 0.08�0.01 0.1�0.006 0.1�0.006
Maltose 0.06�0.01 0.08�0.01 0.03�0.002 0.06�0.004
Sucrose 6.1�1.0 4.4�0.7 3.9�0.6 4.8�0.8
Glucose 1.1�0.08 1.5�0.12 1.5�0.12 2.0�0.16
Fructose 0.9�0.05 2.3�0.11 1.0�0.05 1.4�0.07
Total 18.0 13.5 20.2 25.0

TABLE 6

Carbohydrate contents (nmol per mg) of the leaves of Medicago minima in samples C to G. Means and SD are given for 2 determinations. Total includes an additional 14 unidentified fractions.



C D E F G
Epicenter (m): 0 1.5 2.1 3.5 10.0

Raffinose 0.13�0.02 0.31�0.04 0.50�0.06 0.50�0.06 0.40�0.05
Maltose 0.4�0.02 1.4�0.06 1.4�0.06 0.8�0.04 0.6�0.03
Sucrose 1.9�0.11 3.3�0.19 5.5�0.33 4.3�0.26 2.9�0.18
Glucose 23.0�2.5 11.6�1.3 9.7�1.0 8.8�0.9 8.9�1.0
Fructose 5.5�0.3 6.4�0.4 6.1�0.4 6.0�0.4 7.7�0.5
Total 49.0 34.9 39.0 37.4 32.5

TABLE 7

Carbohydrate contents (nmol per mg) of the leaves of Medicago minima in samples H to L. Means and SD are given from duplicate determinations. The total includes an additional 17 unidentified fractions.



H I J K L
Distance from
Epicenter (m):
0.5 3.8 6.0 8.8 15.4

Raffinose 0.04�0.001 0.08�0.003 0.08�0.003 0.21�0.008 0.05�0.002
Maltose 0.2�0.03 0.4�0.06 0.9�0.15 0.6�0.10 0.9�0.14
Sucrose 2.8�0.3 3.1�0.3 4.6�0.6 3.9�0.4 2.6�0.3
Glucose 2.3�0.13 2.3�0.11 3.2�0.18 2.3�0.14 2.6�0.14
Fructose 4.5�0.4 4.9�0.4 6.2�0.5 5.3�0.4 5.8�0.5
Total 23.7 25.8 33.7 29.3 26.9

TABLE 8
Free amino acids content of younger and older leaves of Medicago minima in the First series
(A and B) of experiments. Means and SD (nanomol per mg) are given from duplicate
determinations. (D + 4/D + 15 fom UE).


Younger Leaves Older Leaves


A B A B
Distance from
Epicenter (m):
20 1.5 20 1.5

Lys 0.02�0.007 0.14�0.05 0.012�0.004 0.25�0.08
Arg 0.30�0.09 0.40�0.12 0.07�0.02 0.17�0.05
His 0.04�0.01 0.01�0.002 0.02�0.005 0.07�0.02
Ser 0.45�0.12 0.57�0.15 0.30�0.08 0.20�0.05
Asp 0.04�0.009 0.09�0.02 0.02�0.005 0.03�0.007
Asn 1.60�0.53 0.74�0.24 0.10�0.03 0.35�0.11
Glu + Gln 0.53�0.05 1.44�0.15 0.12�0.01 0.10�0.01
Thr 0.23�0.03 0.23�0.03 0.14�0.02 0.17�0.02
Ala 0.75�0.19 1.70�0.44 1.20�0.31 0.94�0.24
Val 0.80�0.22 0.60�0.17 0.33�0.09 0.29�0.08
Ile 0.24�0.07 0.16� 0.04 0.17�0.05 0.15�0.04
Leu 0.23�0.11 0.25�0.12 0.14�0.06 0.16�0.08
Phe 0.30�0.06 0.21�0.04 0.05�0.01 0.11�0.02
Trp 0.18�0.07 0.31�0.13 0.14�0.06 0.16�0.06
Total* 8.4 10.4 5.2 5.7

* Including an additional 5 unidentified fractions.

TABLE 9

Free amino acids content of Medicago minimaleaves in the second (C to G)

series of samples (D + 40 from observation of the UE)



C D E F G
Distance from
Epicenter (m):
0 1.5 2.1 3.5 10

Lys 0.22�0.015 0.07�0.005 0.08� 0.006 0.12�0.008 0.06�0.004
His + Arg 0.40�0.07 0.16�0.03 0.37�0.07 0.30�0.07 0.27�0.05
Ser 0.48�0.02 0.28�0.01 0.13�0.01 0.41�0.02 0.41�0.02
Asp + Asn 0.25�0.05 0.16�0.03 0.15�0.03 0.24�0.05 0.25�0.05
Glu + Gln 0.63�0.06 0.87�0.08 1.02�0.09 1.15�0.10 1.10�0.10
Thr 0.16�0.04 0.001 . . . 0.001 . . . 0.04�0.01 0.11�0.03
Ala 0.75�0.08 0.98�0.11 0.68�0.07 1.07�0.11 0.45�0.05
Pro 0.01�0.003 0.07�0.02 0.07�0.02 0.12�0.04 0.19�0.06
Val + Met 0.11�0.03 0.24�0.07 0.34�0.10 0.26�0.08 0.30�0.09
Ile 0.11�0.013 0.12�0.014 0.17�0.02 0.19�0.023 0.20�0.024
Leu 0.12�0.03 0.20�0.05 0.15�0.04 0.21�0.05 0.20�0.05
Phe 0.25�0.06 0.45�0.10 0.39�0.09 0.58�0.13 0.26�0.06
Trp 0.09�0.016 0.17�0.031 0.19�0.034 0.24�0.043 0.11�0.020
Total 6.3 7.2 8.1 9.8 8.0

* Including an additional 7 unidentified fractions.

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