## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Protein ID**} & \multirow{2}{*}{**Protein Name**} & \multirow{2}{*}{**Peptide Sequence**} & \multicolumn{3}{c}{**Log2 Protein Abundance**} \\ \cline{3-6}  & & & **WT** & **RI1-2** & **RI1-3** \\ \hline O24230 & Expansin-B2 & MAGASAK & 14.52 & 0 & 14.70 \\ Q6 ZJJ0 & Beta-galactosidase 11 & DLHHALR & 13.7 & 13.2 & 0 \\ Q2 QNS6 & Cellulose synthase-like protein D4 & LLIAIRLVALGFFLAWRIR & 12.93 & 13.19 & 0 \\ Q5Z6E5 & Cellulose synthase-like protein D5 & ICYIQFPQRFEGIDPSDR & 10.74 & 0 & 13.02 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._scavenging during stress responses. Overexpression of _TERF1_ in tobacco increased the expression of the oxidative-related genes--not only the _GPX_ gene that catalyzes oxidative reactions but also the _VTC1_ gene in the AsA biosynthesis pathway. This finding suggests that the AsA and GPX coordinates function in the regulation of ROS detoxification. For this reason, decreasing the expression of _VTC1_ gene could affect the transcript level of genes related to oxidative stress, such as _GPX_[55; 56]. AsA, which is a multifunctional molecule that plays a significant role in plant growth and development, including enzymes, is involved in multiple biological processes, photosynthesis, ROS scavenging and tolerance against both abiotic and biotic stresses [1; 57; 5]. The rice genome consists of three homologs of _OsVTC1_ gene. Among these homologs, _OsVTC1_-_1 is associated with the greatest AsA production in rice leaves, whereas _OsVTC1_-_3 plays a role in AsA synthesis in roots [8]. Our results were in agreement with a previous report [8]. The expression levels of genes in the L-galactose pathway in roots were quite low as compared to leaf levels, implying that rice synthesizes AsA mainly in leaves [15]. The amount of AsA was highest at the top and decreased down to the base of leaves. AsA is synthesized in all parts of leaves (and other parts of the plants). It has a concentration of more than 20 mM in chloroplasts [5]. This study showed that AsA accumulated more in the top of the leaves. It could possibly be related to higher light intensity because AsA acts as a photoprotectant during light exposure. Moreover, AsA acts as an electron donor in photosynthesis, while monodehydroascorbate acts as an electron acceptor [2]. It is involved in the removal of H\({}_{2}\)O\({}_{2}\) generated by photoreduction and photorespiration [53]. Therefore, the AsA was accumulated in the area of plants that are exposed to higher light intensity. Supporting again in leaves contained a high amount of AsA but low in roots. Similarly, [PERSON] et al. [58] showed that AsA activities of _Moringa oleifera_, Lam were high in leaves, followed by stems and stalks, respectively. The total AsA contents were the highest in flowering buds, then siliques and leaves, but low in stems [59]. In addition, the absence of AsA content was observed in seeds. To maintain metabolic activity at a low level, dry seed avoids its reduced form (AsA), and comprises only the oxidized form; dehydroascorbic acid (DHA) [60; 61]. According to the comparative anatomical characteristics between _OsVTC1_-_1 RNAi lines and WT plants in rice under a light microscope, the results revealed that the leaf anatomical parameters were altered in _OsVTC1_-_1 RNAi lines. The decrease in size of parenchyma, large and small vascular bundles of RNAi lines reflect the roles of AsA in its photosynthetic tissue and vascular system. This is because leaf parenchyma generally contains abundant chloroplast, which is a source of high AsA accumulation [1; 2]. In Arabidopsis, AsA was detected not only in parenchyma cells but also in xylem and phloem elements [62]. Moreover, AsA has been known to be required for vascular development at the different stages of xylem and phloem in larch (_Larix sibirica_ Ldb.) and pine (_Pinus sylvestris_ L.) trees [63].