Proteinaceous and oligosaccharidic elicitors induce different calcium signatures in the nucleus of tobacco cells

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• 作者：David Lecourieux ; Olivier Lamotte ; Sté ; phane Bourque ; David Wendehenne ; Christian Mazars ; Raoul Ranjeva ; Alain Pugin
• 关键词：Calcium ; Elicitor ; Cryptogein ; Signal transduction ; Nucleus ; Protein kinases ; Tobacco
• 刊名：Cell Calcium
• 出版年：2005
• 出版时间：December 2005
• 年：2005
• 卷：38
• 期：6
• 页码：527-538
• 全文大小：611 K

文摘

We previously reported elevated cytosolic calcium levels in tobacco cells in response to elicitors [D. Lecourieux, C. Mazars, N. Pauly, R. Ranjeva, A. Pugin, Analysis and effects of cytosolic free calcium elevations in response to elicitors in Nicotiana plumbaginifolia cells, Plant Cell 14 (2002) 2627–2641]. These data suggested that in response to elicitors, Ca²⁺, as a second messenger, was involved in both systemic acquired resistance (RSA) and/or hypersensitive response (HR) depending on calcium signature. Here, we used transformed tobacco cells with apoaequorin expressed in the nucleus to monitor changes in free nuclear calcium concentrations ([Ca²⁺]_nuc) in response to elicitors. Two types of elicitors are compared: proteins leading to necrosis including four elicitins and harpin, and non-necrotic elicitors including flagellin (flg22) and two oligosaccharidic elicitors, namely the oligogalacturonides (OGs) and the β-1,3-glucan laminarin. Our data indicate that the proteinaceous elicitors induced a pronounced and sustainable [Ca²⁺]_nuc elevation, relative to the small effects of oligosaccharidic elicitors. This [Ca²⁺]_nuc elevation, which seems insufficient to induce cell death, is unlikely to result directly from the diffusion of calcium from the cytosol. The [Ca²⁺]_nuc rise depends on free cytosolic calcium, IP₃, and active oxygen species (AOS) but is independent of nitric oxide.