ISHS Acta Horticulturae 711: V International Symposium on Artificial Lighting in Horticulture
AN EXTRACELLULAR MECHANISM OF LIGHT PROTECTION IN PLANTS IDENTIFIED USING A CHEMICAL GENETIC SCREEN |
| Author: | J. Einset |
| Keywords: | oxidative stress, photoprotection, cell wall, glycine betaine, gene expression |
| DOI: | 10.17660/ActaHortic.2006.711.46 |
| Abstract:
Glycine betaine can increase photoprotection in plants at low concentrations, either after application to plants or in transgenics engineered to produce glycine betaine. We hypothesized that at least part of GB’s effect could be ascribed to the activation of the expression of genes involved in photoprotection. Using a strategy based on high-throughput gene expression analysis with microarrays, we identified 24 genes activated by GB in leaves. Several of these GB-activated genes reinforce intracellular processes protecting cells from oxidative damage while others appear to be involved in setting up a functional ROS scavenging system in walls of leaf cells. Genes for the extracellular ROS scavenging system include two transcription factors, membrane trafficking proteins, cell wall peroxidases, ascorbate oxidase and the plasma membrane NADPH oxidases. Based on evidence from gene expression studies, knockout mutants and GUS transgenic plants, we propose that the extracellular ROS scavenging system represents an important oxidative stress protection mechanism in plants that complements other mechanisms already described. | |
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