School of Agronomy , Anhui Agricultural University , Hefei 230036 , People's Republic of China.
J Agric Food Chem. 2019 Jan 9;67(1):433-440. doi: 10.1021/acs.jafc.8b04622. Epub 2018 Dec 20.
The association between hydrogen sulfide (HS) and cell wall composition with regard to the mitigation of cadmium (Cd) toxicity in Brassica napus L. was investigated. Cd caused growth retardation, leaf chlorosis, and decreased endogenous HS content in Brassica napus roots. Stimulating l-cysteine desulfhydrase (LCD)-mediated HS production with HS releaser (NaHS) markedly improved plant growth, reduced Cd content in stems and leaves, and rescued Cd-induced chlorosis. Furthermore, increased Cd retention was observed in root cell walls, indicating that NaHS reduced Cd movement from the roots to upper-plant parts. Exogenous NaHS also significantly increased the content of pectin and the activity of pectin methylesterase in cell walls of roots, thereby increasing Cd retention in pectin fractions. However, intensification of HS barely affected hemicellulose content under Cd stress. Intensified HS signal, therefore, alleviates Cd toxicity in Brassica napus by increasing pectin content and its demethylation, increasing Cd fixation in cell walls, and reducing root-to-shoot Cd translocation.
研究了硫化氢（HS）与细胞壁组成与油菜（Brassica napus L.）减轻镉（Cd）毒性之间的关系。Cd 导致油菜根生长迟缓、叶片失绿和内源性 HS 含量降低。用 HS 释放剂（NaHS）刺激 l-半胱氨酸脱硫酶（LCD）介导的 HS 产生，显著促进了植物生长，降低了茎和叶中的 Cd 含量，并挽救了 Cd 诱导的失绿。此外，在根细胞壁中观察到 Cd 保留量增加，表明 NaHS 减少了 Cd 从根部向地上部分的迁移。外源 NaHS 还显著增加了细胞壁中果胶的含量和果胶甲酯酶的活性，从而增加了果胶部分的 Cd 保留量。然而，在 Cd 胁迫下，HS 信号的增强对半纤维素含量影响不大。因此，增强的 HS 信号通过增加果胶含量及其去甲基化、增加细胞壁中 Cd 的固定以及减少根到茎的 Cd 转运，缓解了油菜中的 Cd 毒性。
