Long-Distance Lipid Signaling and its Role in Plant Development and Stress Response.

Lipids are important signaling compounds in plants. They can range from small lipophilic molecules like the dicarboxylic acid Azelaic acid to complex phosphoglycerolipids and regulate plant development as well as the response to biotic and abiotic stress. While their intracellular function is well described, several lipophilic signals are known to be found in the plant phloem and can, thus, also play a role in long-distance signaling. Mostly, they play a role in the pathogen response and systemic acquired resistance. This is particularly true for oxylipins, dehydroabietinal, and azelaic acid. However, several phospholipids have now been described in phloem exudates. Their intracellular function as well as implications and a model for long-distance signaling are discussed in this chapter.