## 4 Discussion  
### Mechanism of Iron Transport in Soil and Triticum aestivum L. Plants  
The experimental findings indicate that both the total and effective iron contents in the soil decrease as _Triticum aestivum_ L. grows, whereas the iron content in various parts of the plant continues to accumulate. The correlation analysis indicates that the available iron in soil predominantly influences the aboveground portions of the plant, such as leaves and grains, signifying the migration of iron between the soil and the _Triticum aestivum_ L. plants. In this pot experiment, citric acid was used as a chelating agent ligand. Based on previous data [40], it is presumed that the transport mechanism of iron between the soil and the _Triticum aestivum_ L. plants involves the formation of a cyclic chelate between citric acid and iron ions through carboxyl (COOH) and hydroxyl (OH) coordination groups and its own carbon chain. The strong coordination ability of iron ions enables them to form coordination with the carboxyl and hydroxyl groups in the citric acid ligand. Upon adhering to the root surface, iron ions undergo reduction and degradation on the root surface as a result of the release of H+ and e- by the root system. The iron element is then absorbed into the cells in the form of Fe\({}^{3+}\)[41] and subsequently transported from the roots to the leaves and seeds through the xylem during the growth of _Triticum aestivum_ L.  
Mechanism of Iron Accumulation in Various Parts of Triticum aestivum L. under Iron Deficiency Stress Conditions  
This pot planting experiment, conducted under varying soil iron concentrations, revealed that the element contents in various parts of _Triticum aestivum_ L. do not show a linear relationship with the background gradient. Particularly at the maturity stage, the iron content in various _Triticum aestivum_ L. organs generally displayed an initial in \begin{table}
\begin{tabular}{c c c c c} \hline \hline \begin{tabular}{c} **Concentration** \\ **Gradient** \\ \end{tabular} & \begin{tabular}{c} **Enrichment** \\ **of Root** \\ \end{tabular} & \begin{tabular}{c} **Enrichment** \\ **Coefficient of Stem** \\ \end{tabular} & \
\begin{tabular}{c} **Enrichment** \\ **Coefficient of Seed** \\ \end{tabular} &
\begin{tabular}{c} **Underground to** \\ **Aboveground** \\ **Translocation Factor** \\ \end{tabular} \\ \hline CK & 0.030 & 0.013 & 0.004 & 0.570 \\
4.5 mg/kg & 0.037 & 0.011 & 0.004 & 0.415 \\
7.2 mg/kg & 0.060 & 0.017 & 0.004 & 0.389 \\
10 mg/kg & 0.058 & 0.015 & 0.004 & 0.352 \\
15 mg/kg & 0.039 & 0.010 & 0.004 & 0.356 \\
40 mg/kg & 0.046 & 0.014 & 0.003 & 0.381 \\ Mean & 0.045 & 0.013 & 0.004 & 0.411 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Enrichment coefficient and translocation factor of iron in _Triticum aestivum_ L. plants at the maturity stage. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \begin{tabular}{c} **Concentration** \\ **Gradient** \\ \end{tabular} & \begin{tabular}{c} **Enrichment Coefficient** \\ **of Root** \\ \end{tabular} & \begin{tabular}{c} **Enrichment** \\ **Coefficient of Stem** \\ \end{tabular} & \
\begin{tabular}{c} **Enrichment** \\ **Coefficient of Leaf** \\ \end{tabular} &
\begin{tabular}{c} **Underground to** \\ **Aboveground** \\ **Translocation Factor** \\ \end{tabular} \\ \hline CK & 0.043 & 0.006 & 0.004 & 0.286 \\
4.5 mg/kg & 0.030 & 0.004 & 0.005 & 0.321 \\
7.2 mg/kg & 0.030 & 0.007 & 0.004 & 0.393 \\
10 mg/kg & 0.025 & 0.004 & 0.004 & 0.330 \\
15 mg/kg & 0.030 & 0.003 & 0.004 & 0.248 \\
40 mg/kg & 0.038 & 0.003 & 0.007 & 0.317 \\ Mean & 0.033 & 0.005 & 0.005 & 0.316 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Enrichment coefficient and translocation factor of iron in _Triticum aestivum_ L. plants at the jointing stage. crease followed by a decrease as the soil iron content varied in the sequence of deficient, moderately deficient, medium, moderately adequate, and adequate.