Analysis of Amino acid levels
Amino acid (AAs) levels were analyzed via HPLC in WT and twoCsGGCT2;1 OE lines #102 and #103 under MS control and AsIII treatment. Glycine (Gly), cysteine (Cys), and glutamate (Glu) are three constituent amino acids of GSH. Therefore, we analyzed the level of all amino acids in WT and OE lines under normal and AsIII stress conditions. No significant differences in the levels of Cys and Glu were observed in WT and OE lines under normal and AsIII treatment (Figure 7 c&d). However, under AsIII treatment, their levels increased relative to normal non-stress conditions. Still, within treatments, there were no significant difference in the levels of Cys and Glu between WT and OE lines (Figure 7c&d). For Gly, the CsGGCT2;1 OE lines had 15-30% less than the WT under normal conditions. Though Gly levels increased by 45-140% in all plants in response to AsIII, relative to MS control, again there were no significant differences in Gly content between WT and OE lines (Figure 7e).
For glutamine (Gln), there was no significant difference between WT and OE lines under MS control. Under AsIII treatment, Gln content was 18-21% lower in OE lines than WT plants (Figure 7f). Further, no significant differences were found in serine, arginine, threonine, alanine, prolines, tryptophane, ornithine, and lysine (Figure S2). For Asp and GABA, other than line #103 on MS control, CsGGCT2;1 OE lines had lower levels in both MS and AsIII treatments. No difference was observed for isoleucine (Ile) between WT and OE lines growing on MS control, but in response to AsIII treatment, OE lines had lower levels than WT. For phenylalanine (Phe) and histidine (His), higher levels were observed in OE lines relative to WT under MS control, but under AsIII, there was no significant differences in either AA (Figure S2).