Visualization of autophagy in Arabidopsis using the fluorescent dye monodansylcadaverine and a GFP-AtATG8e fusion protein

Authors

  • Anthony L. Contento,

    1. Department of Genetics, Development and Cell Biology,
    2. Plant Sciences Institute, and
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    • These authors contributed equally to this work.

  • Yan Xiong,

    1. Department of Genetics, Development and Cell Biology,
    2. Interdepartmental Plant Physiology Program, 253 Bessey Hall, Iowa State University, Ames, IA 50011, USA
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    • These authors contributed equally to this work.

  • Diane C. Bassham

    Corresponding author
    1. Department of Genetics, Development and Cell Biology,
    2. Plant Sciences Institute, and
    3. Interdepartmental Plant Physiology Program, 253 Bessey Hall, Iowa State University, Ames, IA 50011, USA
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(fax 515 294 1337; e-mail bassham@iastate.edu).

Summary

Autophagy is a process that is thought to occur in all eukaryotes in which cells recycle cytoplasmic contents when subjected to environmental stress conditions or during certain stages of development. Upon induction of autophagy, double membrane-bound structures called autophagosomes engulf portions of the cytoplasm and transfer them to the vacuole or lysosome for degradation. In this study, we have characterized two potential markers for autophagy in plants, the fluorescent dye monodansylcadaverine (MDC) and a green fluorescent protein (GFP)-AtATG8e fusion protein, and propose that they both label autophagosomes in Arabidopsis. Both markers label the same small, apparently membrane-bound structures found in cells under conditions that are known to induce autophagy such as starvation and senescence. They are usually seen in the cytoplasm, but occasionally can be observed within the vacuole, consistent with a function in the transfer of cytoplasmic material into the vacuole for degradation. MDC-staining and the GFP-AtATG8e fusion protein can now be used as very effective tools to complement biochemical and genetic approaches to the study of autophagy in plant systems.

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