The nomenclature of autophagy-related genes was recently changed to the novel gene name ATG (for autophagy) (Klionsky et al., 2003). Consequently, autophagy genes from Arabidopsis thaliana are derivatively named AtATG. In the present study, the new ATG nomenclature has been adopted.
Starvation-induced expression of autophagy-related genes in Arabidopsis
Article first published online: 9 JAN 2012
2006 Société Française des Microscopies and Société Biologie Cellulaire de France
Biology of the Cell
Volume 98, Issue 1, pages 53–67, January 2006
How to Cite
Rose, T. L., Bonneau, L., Der, C., Marty-Mazars, D. and Marty, F. (2006), Starvation-induced expression of autophagy-related genes in Arabidopsis. Biology of the Cell, 98: 53–67. doi: 10.1042/BC20040516
- Issue published online: 9 JAN 2012
- Article first published online: 9 JAN 2012
- Received 26 November 2004/ 1 April 2005; Accepted 6 April 2005
Background information. Autophagy is a catabolic process for degradation of cytoplasmic components in the vacuolar apparatus. A genome-wide survey recently showed evolutionary conservation among autophagy genes in yeast, mammals and plants. To elucidate the molecular and subcellular machinery responsible for the sequestration and subsequent digestion of intracellular material in plants, we utilized a combination of morphological and molecular methods (confocal laser-scanning microscopy, transmission electron microscopy and real-time PCR respectively).
Results. Autophagy in Arabidopsis thaliana suspension-cultured cells was induced by carbon starvation, which triggered an immediate arrest of cell growth together with a rapid degradation of cellular proteins. We followed the onset of these responses and, in this report, provide a clear functional classification for the highly polymorphic autophagosomes by which the cell sequesters and degrades a portion of its own cytoplasm. Quantification of autophagy-related structures shows that cells respond to the stress signal by a rapid and massive, but transient burst of autophagic activity, which adapts to the stress signal. We also monitored the real-time expressions of AtATG3, AtATG4a, AtATG4b, AtATG7 and AtATG8a–AtATG8i genes, which are orthologues of yeast genes involved in the Atg8 ubiquitination-like conjugation pathway and are linked to autophagosome formation. We show that these autophagy-related genes are transiently up-regulated in a co-ordinated manner at the onset of starvation.
Conclusions. Sucrose starvation induces autophagy and up-regulates orthologues of the yeast Atg8 conjugation pathway genes in Arabidopsis cultured cells. The AtATG3, AtATG4a, AtATG4b, AtATG7 and AtATG8a–AtATG8i genes are expressed in successive waves that parallel the biochemical and cytological remodelling that takes place. These genes thus serve as early markers for autophagy in plants.