Abstract
In recent years, it has been emerging that the defense systems based on the recognition of pathogen-associated molecular pattern (PAMPs) in plants and animals show various similarity. Flagella protein, flagellin, and fungal cell wall polysaccharides such as chitin and β-glucan can be seen as representative PAMPs and have been studied for their activity in both plant and animal defense systems.
Compared to these molecules, possible role of lipopolysaccharides (LPS), a typical PAMP recognized by animals, in plant defense has not been well characterized, especially in monocots. In this study, we analyzed the effect of 7 LPS preparations from various gram-negative bacteria on the defense responses in suspension-cultured rice cells. We found that the LPS preparations could induce defense responses including ROS generation, defense gene expression and also programmed cell death in the rice cells. We also found that these activities required the presence of intact glycan chains in LPS.
