The objective of this paper is to research the effects of CdCl 2 treatment on mineral elements and amino acids in leaves of Malus hupehensis var. pingyiensis. The seedlings of Malus hupehensis var. pingyiensis with 6 leaf were cultured in 1/2 Hoagland nutrient solutions of different CdCl 2 treatments (0, 0.5, 5 and 10 mg·L -1), respectively. The mineral elements and amino acids of the leaves in Malus hupehensis var. pingyiensis were measured in the day 30. Compared with the control (0 mg·L -1 CdCl 2), the treatments significantly decreased the contents of Mg, Fe and Zn in the tested leaves and obviously increased the contents of Cd in the experimental leaves. As to Ca and Mn, low concentration Cd treatment (0.5 mg·L -1 CdCl 2) promoted their absorption, however, high concentration Cd treatments (5 and 10 mg·L -1 CdCl 2) inhibited their absorption. The metabolism pathway and content of amino acids in the Malus hupehensis var. pingyiensis leaves under Cd treatment were modified, the content of amino acids in the glycolate pathway became larger than that in control, the content of amino acids in the pyruvic acid synthesis pathway and tyrosine and phenylalanine became smaller than that in control, the content of other amino acids also had made a certain degree change. The results provided the important basis for safety production and quality evaluation of leaves in Malus hupehensis var. pingyiensis.
The content of Cd released by people in the world in the near 50 years reached about 22,000 t [
According to the test method [
According to the test method [
The content of amino acids including aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, cysteine, valine, methionine, isoleuci, leucine, tyrosine, phenylalanine, histidine, lysine and arginine in the Malus hupehensis var. pingyiensis leaves was measured according to the test method [
The data in the article were completed with Excel statistical software 2003 and SPSS 17.0 statistical software package, the significant difference was conducted by Duncan’s new multiple range method.
The effects of CdCl2 treatment on the absorption of different mineral elements had a certain degree of difference. As far as Ca and Mn were concerned, 0.5 mg∙L−1 CdCl2 treatment promoted the absorption of the two kinds of elements, however, their absorption was restrained by CdCl2 treatments with the increase Cd concentration. For comparison with Mn, the inhibition degree of Ca affected by Cd treatment was larger. Moreover, the content of Cd in the leaves in different Cd treatments became significantly increase than that in control (0 mg∙L−1 CdCl2 treatment), the content of Mg, Fe and Zn in the leaves was obvious smaller than that in the control with the increase Cd concentration (
It was shown in the
Treatment concentration (mg∙L−1) | Ca (mg∙kg−1) | Mg (mg∙kg−1) | Fe (mg∙kg−1) | Zn (mg∙kg−1) | Mn (mg∙kg−1) | Cd (mg∙kg−1) |
---|---|---|---|---|---|---|
0 | 8342 ± 278b | 2790 ± 72a | 122 ± 4a | 24.8 ± 0.6a | 28.1 ± 1.9b | 1.4 ± 0.2d |
0.5 | 8735 ± 106a | 1983 ± 58b | 118 ± 3a | 21.9 ± 1.1b | 30.0 ± 3.3a | 2.6 ± 0.3c |
5 | 7825 ± 166c | 1743 ± 67c | 104 ± 3b | 17.8 ± 0.6c | 26.2 ± 1.3c | 13.7 ± 0.3b |
10 | 6981 ± 94d | 1557 ± 31d | 95 ± 3c | 11.4 ± 0.4d | 26.7 ± 2.1c | 15.8 ± 0.4a |
Duncan’s multiple test, different letter in the brackets indicated the significant differences among the different treatments in the same time, small letter stand for 5% level.
Type of amino acids | Content of amino acids | |||
---|---|---|---|---|
0 mg∙L−1 CdCl2 treatment | 0.5 mg∙L−1 CdCl2 treatment | 5 mg∙L−1 CdCl2 treatment | 10 mg∙L−1 CdCl2 treatment | |
aspartic acid | 1.70 | 1.38 | 1.01 | 0.97 |
threonine | 0.28 | 0.30 | 0.31 | 0.33 |
serine | 0.29 | 0.31 | 0.35 | 0.33 |
glutamic acid | 0.76 | 1.06 | 1.17 | 1.30 |
proline | 0.39 | 0.63 | 0.25 | 0.78 |
glycine | 0.26 | 0.31 | 0.34 | 0.33 |
alanine | 0.29 | 0.33 | 0.36 | 0.34 |
cysteine | 1.48 | 1.34 | 1.43 | 1.99 |
valine | 0.87 | 0.85 | 0.80 | 1.05 |
methionine | 1.34 | 1.07 | 1.20 | 1.57 |
isoleuci | 0.72 | 0.70 | 0.71 | 0.88 |
leucine | 0.81 | 0.85 | 0.88 | 1.09 |
tyrosine | 0.26 | 0.24 | 0.27 | 0.27 |
phenylalanine | 0.21 | 0.20 | 0.23 | 0.21 |
histidine | 0.37 | 0.16 | 0.14 | 0.41 |
lysine | 0.52 | 0.38 | 0.31 | 0.52 |
arginine | 0.59 | 0.51 | 0.37 | 0.45 |
essential amino acids | 4.75 | 4.35 | 4.44 | 5.65 |
non-essential amino acids | 6.39 | 6.27 | 5.69 | 7.17 |
Total amino acids | 11.14 | 10.62 | 10.13 | 12.82 |
Low Cd concentration treatment reduced the content of the essential amino acids and non-essential amino acids in human body by 4.67%, 9.07%, respectively. However, high Cd concentration treatment (10 mg∙L−1 CdCl2) raised the content of the total amino acids in Malus hupehensis var. pingyiensis leaves. In all, the effects of Cd treatment on amino acids metabolism pathway had obvious variation.
Mineral elements in plant are the important component of plant leaf, which affect the production capacity and quality of plant. The content of mineral elements in plant leaf was influenced by soil type, soil water, heavy metal content, plant varieties and so on. Seasonal variations of leaf element content had existed in plant [
Cd is one kind of important pollution sources for soil, it affected growth, quality, element absorption and distribution of plants. In the paper, the lower concentration CdCl2 treatment (0.5 mg∙L−1) promoted the absorption of Ca and Mn in the Malus hupehensis var. pingyiensis leaves, the results were not consisted with the report [
Content and types of Amino acids in plant tissues determined plant product quality. Amino acids content was affected by plant population, varieties, weather condition, soil type, heavy metal and other factors [
1) The contents of mineral elements in the experimental leaves with different Cd treatments significantly varied. The effects of different Cd treatments on absorption of Ca and Mn were different. 0.5 mg∙L−1 CdCl2 treatment promoted the absorption of Ca and Mn, higher concentration Cd treatment (5 mg∙L−1, 10 mg∙L−1) decreased the absorption of Ca and Mn in the Malus hupehensis var. pingyiensis leaves. All the Cd treatments reduced the contents of Mg, Fe, Zn and Cd in the tested leaves.
2) Lower Cd concentration treatment reduced the content of the essential amino acids and non-essential amino acids in human body, by 4.67%, 9.07%, respectively. Higher Cd concentration treatment (10 mg∙L−1 CdCl2) raised the content of the total amino acids in Malus hupehensis var. pingyiensis leaves. The effects of Cd treatment on amino acids metabolism pathway had obvious difference.
This work was supported by “five-twelfth” Nation Science and Technology Support Program of China (Grant No. 2014BAD16B02).
Wang, L., Fan, W.G., Ma, K.X., Liu, J., Chen, S., Du, M.Y., Qiang, W. and Yang, H.Q. (2018) Change of Mineral Elements and Amino Acids in Malus hupehensis var. pingyiensis Leaves under Cd Treatment. Agricultural Sciences, 9, 221-227. https://doi.org/10.4236/as.2018.92016