Tea Research Institute of the Chinese Academy of Agricultural Sciences and the Key Laboratory for Plant Biology and Resource Application of Tea, the Ministry of Agriculture, Hangzhou, 310008, China.
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
J Integr Plant Biol. 2015 Oct;57(10):830-7. doi: 10.1111/jipb.12312. Epub 2015 Jan 31.
Glucose (Glu) is involved in not only plant physiological and developmental events but also plant responses to abiotic stresses. Here, we found that the exogenous Glu improved root and shoot growth, reduced shoot cadmium (Cd) concentration, and rescued Cd-induced chlorosis in Arabidopsis thaliana (Columbia ecotype, Col-0) under Cd stressed conditions. Glucose increased Cd retained in the roots, thus reducing its translocation from root to shoot significantly. The most Cd retained in the roots was found in the hemicellulose 1. Glucose combined with Cd (Glu + Cd) treatment did not affect the content of pectin and its binding capacity of Cd while it increased the content of hemicelluloses 1 and the amount of Cd retained in it significantly. Furthermore, Leadmium Green staining indicated that more Cd was compartmented into vacuoles in Glu + Cd treatment compared with Cd treatment alone, which was in accordance with the significant upregulation of the expression of tonoplast-localized metal transporter genes, suggesting that compartmentation of Cd into vacuoles also contributes to the Glu-alleviated Cd toxicity. Taken together, we demonstrated that Glu-alleviated Cd toxicity is mediated through increasing Cd fixation in the root cell wall and sequestration into the vacuoles.
葡萄糖（Glu）不仅参与植物的生理和发育事件，还参与植物对非生物胁迫的响应。在这里，我们发现，在镉胁迫条件下，外源 Glu 可促进拟南芥（哥伦比亚生态型，Col-0）的根和地上部生长，降低地上部镉浓度，并挽救镉诱导的黄化。葡萄糖增加了根中镉的保留量，从而显著减少了镉从根向地上部的转运。在根中保留的最多的镉位于半纤维素 1 中。葡萄糖与镉（Glu + Cd）处理不会影响果胶的含量及其对镉的结合能力，而会显著增加半纤维素 1 的含量及其对镉的保留量。此外，Leadmium Green 染色表明，与单独镉处理相比，在 Glu + Cd 处理中更多的镉被区室化为液泡，这与液泡定位金属转运蛋白基因的表达显著上调一致，表明将镉区室化为液泡也有助于减轻 Glu 缓解的镉毒性。总之，我们证明了 Glu 缓解镉毒性是通过增加根细胞壁中镉的固定和将镉螯合到液泡中来实现的。
