Aluminum-induced cell death in root-tip cells of barley

• Published in: Environmental and experimental botany 2001-08, Vol.46 (1), p.71-79
• Main Authors: Pan, Jian-wei, Zhu, Mu-yuan, Chen, Hong
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Apoptosis; Applied ecology; Biological and medical sciences; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Fundamental and applied biological sciences. Psychology; Hordeum vulgare; Necrosis; Physiological diseases. Varia; Phytopathology. Animal pests. Plant and forest protection; Programmed cell death; Reactive oxygen species
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/S0098-8472(01)00083-1

Aluminum-induced cell death was investigated in root-tip cells of barley ( Hordeum vulgare). The growth of roots in 0.1–50 mM Al treatments was inhibited after 8 h treatments, and could not be recovered after 24 h recovery culture without Al. Viable detection with fluorescein diacetate–propidium iodide (FDA–PI) staining shows that most of the root-tip cells have lost viability. These results suggest that the irreversible inhibition of root growth after 8 h Al treatments or 24 h recovery culture is mainly caused by cell death. DNA ladders occurred in root tips only after 8 h Al treatments (0.1–1.0 mM), but no apoptotic bodies in root tips were observed. Thus, the cell death caused by Al stress is likely to be Al-induced programmed cell death (PCD). The reactive oxygen species (ROS) in root-tip cells measured by ultraweak luminescence indicated that the oxidation status in root-tip cells basically ceased after exposure to 10–50 mM Al for 24 h, but was very violent in the root-tip cells treated with 0.1–1.0 mM for 24 h. Exposure to 0.1–1.0 mM Al for 3–12 h led to ROS burst. Therefore, our results suggest that 0.1–1.0 mM Al treatments for 8 h induce cell death (Al-induced PCD) possibly via a ROS-activated signal transduction pathway, whereas 10–50 mM Al treatments may cause necrosis in the root-tip cells. These results have an important role for further studies on the mechanism of Al toxicity in plants.