Abstract:

【Objective】 Phospholipase C (PLC) was investigated in response to ParA1, a protein elicitor from Phytophthora parasitica, and could trigger cell death and defense responses in tobacco suspension cells. 【Method】 Using a pharmacological approach, tobacco suspension cells pretreated with PLC inhibitors (neomycin and U73122) in ParA1-induced cells were used to compare cell death and a series of defense responses. 【Result】 Tobacco suspension cells treated with ParA1 resulted in defense responses, such as hypersensitive cell death, an oxidative burst, alkalization of the extracellular medium, expression of 5 defense-related genes and accumulation of scopoletin, defense-related genes hin1, hsr203J, PR-1a, PR-1b and PAL were expressed in ParA1-induced cells. Cell death induced by ParA1 was entirely inhibited by the addition of U73122, a PLC specific inhibitor. Oxidative burst, alkalization of the extracellular medium, expression of 5 defense-related genes and scopoletin accumulation was significantly suppressed by U73122, respectively. 【Conclusion】 PLC is required for ParA1-mediated cell death and defense response in tobacco suspension cells which may involve in signal transduction.

Key words: phospholipase C, ParA1, tobacco, cell death, defense response