## 3 Results and Discussion
### Elements Concentrations in Leaves of Pumpkin
[77], silver nanoparticles can interfere with cells' biological functions due to two distinct mechanisms. A nanoparticle may be absorbed by a plant cell and start to release silver cations as products of various redox reactions. Cells can also fully absorb nanoparticles in a process known as endocytosis. It is less common in the case of larger nanoparticles due to their size. Once inside a cell, a nanoparticle may release Ag\({}^{+}\) or silver atoms which then bond with proteins and hinder their functional capacity. One of the signs of efficiently working defence mechanisms against oxidative stress is a plant's ability to produce chlorophylls and carotenoids. Chlorophyll particles undergo degradation when a plant is under conditions of abiotic stress caused by absorbing excessive amounts of metals with toxic effects on the plant. In their study, [PERSON] et al. [38] demonstrated that two-week-long exposition of _A. thaliana_ cuttings to AgNPs resulted in a decrease in their Chl \(a\) and Chl \(b\) content. AgNPs applied in concentrations of 0.5 and 3.0 mg.L\({}^{-1}\) significantly reduced the plant's Chl \(a\) content to the level of 60.9% compared to the control in both cases. Moreover, the above concentration of AgNPs (0.5 and 3.0 mg.L\({}^{-1}\)) also triggered a decrease in Chl \(b\) levels. The correlations could be observed between the particular groups: C \(\times\) C (r = \(-\)0.360), L \(\times\) L (r = 0.856), _p \(\times\) p_ (r = 0.982), AgNC \(\times\) AgNC (r = \(-\)0.967) for pots and C \(\times\) C (r = \(-\)0.152), L \(\times\) L (r = 0.971), _p \(\times\) p_ (r = 0.353), AgNC \(\times\) AgNC (r = \(-\)0.086) for dishes (Table 3). Calculations of the correlation coefficients (Table 3) between the values of total chlorophyll and carotenoids revealed no correlation between the Petri dish and pots study groups. As one of the characteristics increased, so did the other, which may suggest that the two are correlated with each other. In the case of seed leaves grown on dishes, no correlation between total chlorophyll _a + b_ and carotenoids was observed. Compared to the controls, a reduction of mean content of chlorophyll _a + b_ in dishes (Figure 4) was observed for L by about 50% and for P by about 35% an increase of AgNC \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multirow{2}{*}{**Research Groups**} & \multicolumn{5}{c}{**Pearson Coefficient r**} \\ \cline{3-6}  & & \multicolumn{4}{c}{**Carotenoids**} \\ \cline{3-6}  & & **C** & **L** & \(p\) & **AgNC** \\ \hline Chlorophyll & C & \(-\)0.360 & 0.603 & \(-\)0.983 & 0.382 \\ Chlorophyll & L & 0.012 & 0.856 & \(-\)0.980 & 0.011 \\ _a + b_ & \(p\) & 0.365 & \(-\)0.599 & 0.982 & \(-\)0.3877 \\ (in leaves dishes) & AgNC & 0.960 & 0.269 & 0.449 & \(-\)0.967 \\ \hline Chlorophyll & C & \(-\)0.152 & 0.749 & \(-\)0.985 & \(-\)0.916 \\ _a + b_ & L & 0.324 & 0.971 & \(-\)0.953 & \(-\)0.625 \\ (in leaves pots) & \(p\) & \(-\)0.943 & \(-\)0.791 & \(-\)0.353 & \(-\)0.223 \\ AgNC & 0.795 & 0.940 & 0.623 & \(-\)0.086 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Pearson correlation coefficient between chlorophyll _a + b_ and carotenoids. by about 38%. With regard to the carotenoids, the decrease was for L and P and increase by AgNc by about 68%, 27% and 79% respectively. Compared to the controls, an increase of mean content of chlorophyll \(a+b\) in pots (Figure 5) was observed for L by about 29%, for P by about 28% and for AgNC by about 47%. With regard to the carotenoids, the increase was observed for L, P and AgNc by about 29%, 55% and 15% respectively. Figure 4: Mean content of chlorophyll \(a+b\) and carotenoids (in seed leaves grown in dishes for 8 days). C—control; L—laser light; \(p\)—magnetic field; AgNC—silver nanocolloid. Different letters a\(\rightarrow\)b—significant differences (\(p\leq 0.05\)), the same letters—no difference between the control. PAR radiation was low (Table 4), ranging from 57 (L, SIII) to 302 umol of photons m\({}^{-2}\) s\({}^{-1}\) (AgNC, SIV).