## 3 Results and Discussion
### Effect of SA Seed Priming on the Phenolics Composition
Besides, the extracts contained other flavonoids as minor components: apigenin-6,8-di-C-glucoside (peak 14, \(\lambda_{\rm max}\) at 256, 354 nm, [M-H]\({}^{-}\) at \(m/z\) 593]; rutin ([M-H]\({}^{-}\) at \(m/z\) 609\(\rightarrow\)301 and luteolin-7-O-rutinose ([M-H]\({}^{-}\) at \(m/z\) 593\(\rightarrow\)285 eluted in peaks 15 and 17, respectively). Hydroxycinnamic acids (HCA) were also major phenolic constituents in _S. carnosa_ leaves of both varieties. Overall, in plants grown under optimal Fe supply (control), caffe acid (peak 12, [M-H]\({}^{-}\) at \(m/z\) 179) and its derivatives, including four caffeoylglucaric acids isomers (eluted in peaks 4, 5, 6, and 8, of [M-H]\({}^{-}\) at \(m/z\) 371) and two caffeoylquinic acid isomers (peaks 7 and 11, [M-H]\({}^{-}\) at \(m/z\) 353), were detected, together with a fertile acid derivative, namely ferulolylglucaric acid (peak 13 [M-H]\({}^{-}\) at \(m/z\) 385 \(\rightarrow\) 209, 353, 191). The phenolic components in plants grown under deficient conditions (D, D+SA) corresponded to those grown in the presence of Fe (C, C+SA), regardless significant variations on their levels (Table 5). In accordance with the results relative to TPC and TFC (Table 4), the gathered data indicated that, under complete medium primed with SA (C+SA), _S. carnosa_ SK increased greatly the biosynthesis of HCA, compared to C plants. Moreover, when grown under Fe deficiency, SK did not show a significant change of its phenolic compound levels compared to C, contrarily to KA that was characterized by a significant decrease of HCA and flavonoid amount (32% and 16%, respectively in D versus C, respectively). Under this deficiency, soaking with SA did not reverse the levels of HCA in KA, but again, a slight improvement of phenolic contents was observed in SK cultivar (11% and 19% for HCA and flavonoids, respectively). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Peak** & **Rt (min)** & **Amax** & **[M-H]\({}^{-}\)** & **Main MS Fragments** & **Probable Compound** \\ \hline
1 & 1.4 & 224 & 133 & 155, 73 & Malic acid \\
2 & 1.8 & 258 & 191 & 127, 173, 111, 85, 93 & Quinic acid \\
3 & 1.8 & 258 & 191 & 111, 173, 67 & Citric acid \\
4 & 2.6 & 290 sh, 324 & 371 & 209, 353, 191 & Caffeoylglucaric acid (isom 1) \\
5 & 3.3 & 295 sh, 325 & 371 & 209, 353, 191 & Caffeoylglucaric acid (isom 2) \\
6 & 4.2 & 295 sh, 325 & 371 & 209, 353, 191 & Caffeoylglucaric acid (isom 3) \\
7 & 5.0 & 295 sh, 325 & 353 & 191, 179, 173 & Caffeoylquinic acid (isom 1) \\
8 & 5.5 & 289 sh, 323 & 371 & 209, 353, 191 & Caffeoylglucaric acid (isom 4) \\
9 & 5.8 & 279 & 209 & 191, 193 & Glucaric acid \\
10 & 6.0 & 279 & 323 & 119, 113, 101, 143, 179 & Unknown \\
11 & 7.8 & 297 sh, 322 & 353 & 191, 179, 161, 135 & Caffeoylquinic acid (isom 2) \\
12 & 8.7 & 298 sh, 327 & 179 & 135, 179 & Caffeic acid \\
13 & 8.9 & 221, 326 & 385 & 191, 367, 209, 281 & Feruloylglucaric acid \\
14 & 9.7 & 234, 273, 324 & 593 & 473, 503, 353, 575,383 & Apigenin-6,8-di-C-glucose \\
15 & 11.6 & 256, 356 & 609 & 301 & Rutin \\
16 & 12.1 & 221, 280 & 289 & 245, 205, 203 & Epicatechin \\
17 & 12.4 & 268 sh, 341 & 593 & 285 & Luteolin-7-O-rutinose \\
18 & 15.8 & ND & 327 & 309, 291, 239, 171 & Unknown \\
19 & 16.7 & ND & 267 & 193, 135 & Unknown \\
20 & 16.9 & ND & 327 & 309, 291, 293, 171 & Unknown \\
21 & 20.7 & ND & 823 & 171, 193 & Unknown \\
22 & 20.5 & 247, 285 & 987 & ND & Unknown \\
23 & 21.2 & 254, 281 & 831 & ND & Unknown \\ \hline \hline \end{tabular} ND—Not detected; sh—UV shoulder.  
\end{table} 
Table 4: Identification of UHPLC eluting fractions by UHPLC-DAD-MS\({}^{\rm n}\) of _Sulla carnosa_ hydro-methanonic extracts. Phenolics were described as the major classes of organic ligands displayed by strategy I plants under Fe deficient conditions. In this respect, caffeic acid and ferulic acid were previously proposed to sustain Fe reduction from ferrihydrite [32]. Other phenolics such as quercetin, myricetin and rutin were also implicated in the increase of Fe uptake, mainly through the stimulation of Fe reduction mechanism [33; 34].