Plant immune memory in systemic tissue does not involve changes in rapid calcium signaling

• Verfasst von: Eichstädt, Bernadette [VerfasserIn]
• Verfasst von: Lederer, Sarah Consuela [VerfasserIn]
• Verfasst von: Trempel, Fabian [VerfasserIn]
• Verfasst von: Jiang, Xiyuan [VerfasserIn]
• Verfasst von: Guerra, Tiziana [VerfasserIn]
• Verfasst von: Waadt, Rainer [VerfasserIn]
• Verfasst von: Lee, Justin Eng Eng [VerfasserIn]
• Verfasst von: Liese, Anja Katarina Claire [VerfasserIn]
• Verfasst von: Romeis, Tina [VerfasserIn]
• Titel: Plant immune memory in systemic tissue does not involve changes in rapid calcium signaling
• Verf.angabe: Bernadette Eichstädt, Sarah Lederer, Fabian Trempel, Xiyuan Jiang, Tiziana Guerra, Rainer Waadt, Justin Lee, Anja Liese, Tina Romeis
• E-Jahr: 2021
• Jahr: 14 December 2021
• Umfang: 14 S.
• Fussnoten: Gesehen am 06.05.2022
• Titel Quelle: Enthalten in: Frontiers in plant science
• Ort Quelle: Lausanne : Frontiers Media, 2010
• Jahr Quelle: 2021
• Band/Heft Quelle: 12(2021), Artikel-ID 798230, Seite 1-14
• ISSN Quelle: 1664-462X
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1801098506

Abstract

Upon pathogen recognition, a transient rise in cytoplasmic calcium levels is one of the earliest events in plants and a prerequisite for defense initiation and signal propagation from a local site to systemic plant tissues. However, it is unclear if calcium signaling differs in the context of priming: Do plants exposed to a first pathogen stimulus and have consequently established systemic acquired resistance (SAR) display altered calcium responses to a second pathogen stimulus? Several calcium indicator systems including aequorin, YC3.6 or R-GECO1 have been used to document local calcium responses to the bacterial flg22 peptide but systemic calcium imaging within a single plant remains a technical challenge. Here, we report on an experimental approach to monitor flg22-induced calcium responses in systemic leaves of primed plants. The calcium-dependent protein kinase CPK5 is a key calcium sensor and regulator of the NADPH oxidase RBOHD and plays a role in the systemic calcium-ROS signal propagation. We therefore compared flg22-induced cytoplasmic calcium changes in Arabidopsis wild-type, cpk5 mutant and CPK5-overexpressing plants (exhibiting constitutive priming) by introgressing the calcium indicator R-GECO1-mTurquoise that allows internal normalization through mTurquoise fluorescence. Aequorin-based analyses were included for comparison. Based on the R-GECO1-mTurquoise data, CPK5-OE appears to reinforce an “oscillatory-like” Ca2+ signature in flg22-treated local tissues. However, no change was observed in the flg22-induced calcium response in the systemic tissues of plants that had been pre-challenged by a priming stimulus - neither in wild-type nor in cpk5 or CPK5-OE-lines. These data indicate that the mechanistic manifestation of a plant immune memory in distal plant parts required for enhanced pathogen resistance does not include changes in rapid calcium signaling upstream of CPK5 but rather relies on downstream defense responses.