## 3 Results
### Soluble Carbohydrate Content Analysis in the Roots and Shoots of P. sativum  
Seven soluble carbohydrates (fructose, glucose, sucrose, _myo_-inositol, maltose, galacinol, and raffinose) were detected in the shoot system and six in the root system (galactinol was not detected) after HRGC analysis (Figure 5). In the roots of control plants, the content of monosaccharides (fructose and glucose) and _myo_-inositol decreased during 28 days of the experiment, while in shoots temporarily increased (until the seventh day) and later also decreased but remained at a higher level than in the roots (Figure 5). Similar trends in changes in the contents of sucrose and maltose were found in both shoots and roots (Figure 5). The plant treatment with Cd caused a significant change in the content of all identified carbohydrates in both the root and shoot tissues. Generally, Cd increased levels of sugars in both roots and shoots at each time point of the experiment along with the increasing concentration of Cd (in the case of _myo_-inositol, sucrose, and maltose). Figure 5: The content of soluble carbohydrates in root and shoot tissues of _P. sativum_ plants after 1, 7, and 28 days of treatment with water (control) or cadmium (CdSO\({}_{4}\)) at a concentration in the range of 10–200 \(\upmu\)M. Each value is the mean of three replicates \(\pm\) SD. Different letters represent significant differences \(p<0.01\). Moreover, the increasing concentration of Cd had a significant effect on the expression of enzymes responsible for the synthesis of galactinol and raffinose (Figure 6) and the accumulation of both galactinol and raffinose during the first 7 days after plant treatment with Cd. Analysis of the Accumulation of the Galactinol and Raffinose and the Expression of the PsGoS and PsRS after Cd-Treatment  
Galactinol was not detected in the roots and shoots of control plants and those after one day of Cd treatment (Figure 6). Galactinol was detected solely in Cd-treated shoots, and its content was found to be positively associated with the Cd concentration used during the experiment. After 28 days of Cd treatment, the lowest amount of galactinol was found in the 10 \(\upmu\)M Cd-treated shoot while the highest was in the 50, 100, and 200 \(\upmu\)M Cd-treated shoots. Similarly to galactinol, raffinose in the roots was exclusively detected in Cd-treated plants, with the largest level of raffinose observed after 7 days of Cd treatment in the 100 \(\upmu\)M Cd-treated root and after 28 days of Cd treatment in the 200 \(\upmu\)M Cd-treated roots. The raffinose content in the shoot was nearly five times greater than in the root. The raffinose level in the 100 \(\upmu\)M Cd-treated shoot was higher after 7 days of Cd treatment than in the 10, 200, 50, and control shoots, respectively. Nevertheless, after 28 days of Cd treatment, the maximum amount of raffinose was observed in the 50, 100, and 200 \(\upmu\)M treated shoots (Figure 6A). Figure 6: **(A)**: HRGC profiles of galactinol and raffinose in the root and shoot after 1, 7, and 28 days of cadmium treatment. Each value is the mean of three replicates \(\pm\) SD. Different letters represent significant differences \(p\) < 0.01. **(B)**: Accumulation of _PsGoS_ and _PsRS_ transcripts in the shoots of pea plants after 1 day of Cd treatment. Representative gel of RT PCR for _PsGoS_ and _PsRS_ (_PsEF_ represents a housekeeping control gene; rRNA represents the quality of 1 \(\upmu\)g of the extracted RNA). **(C)**: _PsGoS_ and _PsRS_ mRNA fold changes relative to control (0 \(\upmu\)M CdSO\({}_{4}\)). Following the finding of Cd-dependent changes in raffinose and galactinol levels in pea shoots, we examined the expression of _PsGolS_ and _PsRS_ after 1 day of Cd treatment (Figure 6B). The results of semiquantitative RT-PCR demonstrated that the relatively low level of _PsGolS_ mRNA in the control increased in Cd-treated samples, reaching at least a level threee-fold higher than detected in the control sample.