The chromium (Cr⁶⁺) toxicity mechanisms have not been fully revealed yet in plants mainly due to its complex electronic chemistry. Both putrescine (PUT) and glutathione (GSH) are reported to be involved in plethora of plant cellular processes. Therefore, we hypothesized that exogenous individual or co-application of PUT and GSH could alleviate the Cr⁶⁺ stress in genetically diverse canola cultivars. The seed priming with GSH (0.1 mM) alleviated inhibitory effects of Cr⁶⁺ on root growth, and thus plants raised from GSH-treated seed had higher leaf chlorophyll a contents (78, 69 and 82%, in Shiralee, Rainbow and Dunkled cultivar, respectively), carotenoids contents, stem phenolics, root GSH, leaf and root NO concentration. The foliar treatment with PUT caused 37 and 11.9% decrease in the accumulation of Cr in shoot of Shiralee and Dunkled, respectively. Overall, the results suggested that seed priming with GSH regulated leaf photosynthetic pigments to cope with Cr⁶⁺ shock at early growth stage whereas foliar treatment with PUT decreased Cr transport to the shoot, and thus increased tolerance at later growth stage irrespective of cultivars.

铬（Cr ⁶⁺）在植物中的毒性机制尚未完全揭示，主要是由于其复杂的电子化学。据报道，腐胺 (PUT) 和谷胱甘肽 (GSH) 都参与过多的植物细胞过程。因此，我们假设外源单独或共同施用 PUT 和 GSH 可以减轻遗传多样性油菜品种的 Cr ⁶⁺胁迫。用 GSH (0.1 mM) 启动种子减轻了 Cr ⁶⁺对根生长的抑制作用，因此用 GSH 处理的种子培育的植物具有更高的叶叶绿素a含量（分别在 Shiralee、Rainbow 和 Dunkled 品种中为 78%、69% 和 82%）、类胡萝卜素含量、茎酚类物质、根 GSH、叶和根 NO 浓度。PUT 叶面处理导致 Shiralee 和 Dunkled 枝条中 Cr 的积累分别减少 37% 和 11.9%。总体而言，结果表明，在生长早期，用 GSH 激发种子可调节叶片光合色素以应对 Cr ⁶⁺冲击，而用 PUT 进行叶面处理会减少 Cr 向地上部的转运，从而提高生长后期的耐受性，而与品种无关。