Disruption of the ceramide synthase LOH1 causes spontaneous cell death in Arabidopsis thaliana
Article first published online: 22 AUG 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 192, Issue 4, pages 841–854, December 2011
How to Cite
Ternes, P., Feussner, K., Werner, S., Lerche, J., Iven, T., Heilmann, I., Riezman, H. and Feussner, I. (2011), Disruption of the ceramide synthase LOH1 causes spontaneous cell death in Arabidopsis thaliana. New Phytologist, 192: 841–854. doi: 10.1111/j.1469-8137.2011.03852.x
- Issue published online: 11 NOV 2011
- Article first published online: 22 AUG 2011
- Received: 11 June 2011, Accepted: 11 July 2011
- Arabidopsis thaliana;
- cell death;
- ceramide synthase;
- pathogenesis-related gene;
- sphingoid base;
- •The bioactive lipid ceramide is produced by the enzyme ceramide synthase, which exists in several isoforms in most eukaryotic organisms. Here, we investigated functional differences between the three ceramide synthase isoforms in Arabidopsis thaliana.
- •The biochemical properties of the three ceramide synthases were investigated by comparing lipid profiles of yeast strains expressing LOH1, LOH2 or LOH3 with those of wild-type and loh1, loh2 and loh3 knockout plants. Expression profiles of the ceramide synthases and of the pathogenesis-related gene PR-1 were investigated by real-time PCR.
- •Each ceramide synthase isoform showed a characteristic preference regarding acyl-CoA chain length as well as sphingoid base hydroxylation, which matches the pattern of ceramide and glucosylceramide species found in leaves. After extended culture under short-day conditions, loh1 plants showed spontaneous cell death accompanied by enhanced expression of PR-1. The levels of free trihydroxy sphingoid bases as well as ceramide and glucosylceramide species with C16 fatty acid were significantly elevated while species with C20–C28 fatty acids were reduced.
- •These data suggest that spontaneous cell death in the loh1 line is triggered either by the accumulation of free trihydroxy sphingoid bases or ceramide species with C16 fatty acid.