Figure 1.
Phenotype of Arabidopsis thaliana plants subjected to IM-enantiomer treatment.
A. Photograph of the control and plants treated by R-, S-IM and the racemic mixture; The relative inhibition rate of root elongation of A. thaliana is shown in B–D, after 2, 3 and 4 weeks of IM exposure, respectively. * represents a statistically significant difference (of p<0.05), when compared to that of S-IM exposed plants; ** represents a statistical significance at the p<0.01 level.
Table 1.
The effect of IM enantiomers on fresh weight (FW), malondialdehyde (MDA) and water content (WC).
Figure 2.
The effect of IM enantiomers on ALS activity in vitro and amino acid content.
A. The effect of IM enantiomers on ALS activity in vitro; B. Amino acid content of Arabidopsis thaliana after 4 weeks of exposure. * or ** indicate that the numbers are significantly higher than those of the wild-type plants (p<0.05 or 0.01, respectively). # or ## indicate that the numbers are significantly different compared to those of S-IM-exposed plant (p<0.05 or 0.01, respectively).
Figure 3.
The superoxide anion accumulation after 4 weeks of IM-enantiomer treatment.
A. A plantlet stained with NBT; B. A leaf stained with NBT; C. The colorimetric quantification of NBT-formazan production in plant extracts. ** indicates that the numbers are significantly higher than those of the control plants (p<0.01). # indicates that the numbers are significantly higher than those of S-IM-exposed plant (p<0.05). FW, fresh weight.
Figure 4.
Hydrogen peroxide accumulation after 4 weeks of IM-enantiomer treatment.
A. A plantlet stained with DAB; B. A root stained with DAB.
Figure 5.
Changes of chloroplasts in A. thaliana after 4 weeks of IM-enantiomer treatment.
A. Mesophyll cell structure; B. Chloroplast structure; C. Grana lamella structure; D. Number of chloroplast and starch granule per cell. cp, chloroplast; sg, starch granule; g, grana; thy, thylakoid. * or **represents a statistically significant difference of p<0.05 or 0.01, respectively, when compared to that of control.
Figure 6.
Plants stained for the presence of starch with iodine after 4 weeks of IM exposure.
A. Plants harvested at the end of the light; B. Plants harvested at the end of the dark.
Figure 7.
The diurnal changes of the starch content after 4 weeks of IM exposure.
The white and black solid bars indicate the time of the light and dark period, respectively.
Figure 8.
The diurnal changes of glucose, maltose, sucrose and fructose content after 4 weeks exposure.
A. glucose content; B. maltose content; C. sucrose content; D. fructose content. The white and black solid bars indicate the time of the light and dark period, respectively.
Figure 9.
The gene expression of antioxidant enzyme in A. thaliana after 3 weeks of IM exposure.
A. Gene expression of superoxide dismutase (SOD) and catalase (CAT); B. Gene expression of ascorbate peroxidase (APX); C. Gene expression of glutathione peroxidase (GPX). Values were normalized against actin 2 as housekeeping gene, and represent relative mean mRNA expression value ±SEM of 3 individuals. * or ** represents a statistically significant difference when compared to that of the control (p<0.05 or 0.01, respectively). # or ## represents a statistically significant difference when compared to S-IM-exposed plants (p<0.05 or 0.01, respectively).
Figure 10.
The gene expression of antioxidant enzyme in A. thaliana after 4 weeks of IM exposure.
A. Gene expression of superoxide dismutase (SOD) and catalase (CAT); B. Gene expression of ascorbate peroxidase (APX); C. Gene expression of glutathione peroxidase(GPX). Values were normalized against actin 2 as housekeeping gene, and represent relative mean mRNA expression value ±SEM of 3 individuals. * or ** represents a statistically significant difference when compared to that of the control (p<0.05 or 0.01, respectively). # or ## represents a statistically significant difference when compared to S-IM-exposed plants (p<0.05 or 0.01, respectively).
Figure 11.
The activity of antioxidant enzyme in A. thaliana after 3 and 4 weeks exposure. *
A. The activity of superoxide dismutase (SOD); B. The activity of catalase (CAT); C. The activity of ascorbate peroxidase (APX); D. The activity of glutathione peroxidase(GPX). * or ** represents a statistically significant difference when compared to that of the control (p<0.05 or 0.01, respectively). # or ## represents a statistically significant difference when compared to S-IM-exposed plants (p<0.05 or 0.01, respectively).