Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Engineering Technology Research Center for Drug and Food Biological Resources Processing and Comprehensive Utilization, College of Life Sciences, South China Normal University, Guangzhou 510631, PR China.
Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Engineering Technology Research Center for Drug and Food Biological Resources Processing and Comprehensive Utilization, College of Life Sciences, South China Normal University, Guangzhou 510631, PR China.
Ecotoxicol Environ Saf. 2019 Apr 30;171:352-360. doi: 10.1016/j.ecoenv.2018.12.097. Epub 2019 Jan 4.
Arbuscular mycorrhizal fungus (AMF) can relieve Cd phytotoxicity and improve plant growth, but the mechanisms involved in this process have still been not completely known. In the present work, a pot experiment was conducted to examine productions of glutathione (GSH) and phytochelatins (PCs), and absorption, chemical forms and subcellular distribution of Cd in maize (Zea mays) inoculated with or without AMF (Rhizophagus intraradices (Ri) and Glomus versiforme (Gv)) in Cd-amended soils (0, 1 and 5 mg Cd kg soil). In general, both Ri and Gv inoculation dramatically enhanced biomass production and reduced Cd concentrations in shoots and roots of maize when compared to the non-mycorrhizal treatment. Moreover, both Ri and Gv symbiosis obviously increased contents of GSH and PCs, both in shoots and roots. Subcellular distribution of Cd in maize indicated that most of Cd (more than 90%) was accumulated in cell wall and soluble fraction. In addition, Cd proportions in soluble fractions in shoots of maize inoculated with Gv or Ri were considerably increased, but reduced in cell wall fractions compared to non-mycorrhizal maize, indicating that mycorrhizal symbiosis promoted Cd transfer to vacuoles. Furthermore, proportions of Cd in inorganic and water-soluble forms were declined, but elevated in pectates and proteins-integrated forms in mycorrhizal maize, which suggested that Gv and Ri could convert Cd into inactive forms. These observations could provide a further understanding of potential Cd detoxification mechanism in maize inoculated with AMF.
丛枝菌根真菌 (AMF) 可以缓解 Cd 的植物毒性并促进植物生长，但这一过程涉及的机制尚不完全清楚。本研究采用盆栽试验，研究了接种丛枝菌根真菌（Rhizophagus intraradices (Ri) 和 Glomus versiforme (Gv)）对 Cd 胁迫下玉米（Zea mays）体内谷胱甘肽 (GSH) 和植物螯合肽 (PCs) 的产生、Cd 的吸收、化学形态和亚细胞分布的影响。一般来说，与非菌根处理相比，Ri 和 Gv 接种显著提高了玉米的生物量，降低了地上部和根系中 Cd 的浓度。此外，Ri 和 Gv 共生明显增加了地上部和根系中 GSH 和 PCs 的含量。玉米体内 Cd 的亚细胞分布表明，大部分 Cd（超过 90%）积累在细胞壁和可溶部分。此外，与非菌根玉米相比，接种 Gv 或 Ri 的玉米地上部可溶部分中 Cd 的比例显著增加，而细胞壁部分则减少，这表明菌根共生促进了 Cd 向液泡的转移。此外，Cd 在无机和水溶性形态中的比例下降，而在果胶和蛋白质整合形态中的比例上升，这表明 Gv 和 Ri 可以将 Cd 转化为非活性形式。这些观察结果可以进一步了解 AMF 接种玉米潜在的 Cd 解毒机制。
