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Systemic cytosolic Ca 2+ elevation is activated upon wounding and herbivory in Arabidopsis
Author(s) -
Kiep Victoria,
Vadassery Jyothilakshmi,
Lattke Justus,
Maaß JanPeter,
Boland Wilhelm,
Peiter Edgar,
Mithöfer Axel
Publication year - 2015
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13493
Subject(s) - arabidopsis , cytosol , herbivore , botany , biology , chemistry , microbiology and biotechnology , gene , biochemistry , enzyme , mutant
Summary Calcium ion (Ca 2+ ) signalling triggered by insect herbivory is an intricate network with multiple components, involving positive and negative regulators. Real‐time, noninvasive imaging of entire Arabidopsis thaliana rosettes was employed to monitor cytosolic free calcium ([Ca 2+ ] cyt ) elevations in local and systemic leaves in response to wounding and Spodoptera littoralis feeding. Luminescence emitted by the cytosol‐localized Ca 2+ reporter aequorin was imaged using a high‐resolution photon‐counting camera system. Spodoptera littoralis feeding on Arabidopsis induced both local and systemic [Ca 2+ ] cyt elevations. Systemic [Ca 2+ ] cyt signals were found predominantly in adjacent leaves with direct vascular connections to the treated leaf and appeared with a delay of 1 to 2 min. Simulated herbivory by wounding always induced a local [Ca 2+ ] cyt response, but a systemic one only when the midrib was wounded. This systemic [Ca 2+ ] cyt response was suppressed by the presence of insect‐derived oral secretions as well as in a mutant of the vacuolar cation channel, Two Pore Channel 1 ( TPC 1). Our results provide evidence that in Arabidopsis insect herbivory induces both local and systemic [Ca 2+ ] cyt signals that distribute within the vascular system. The systemic [Ca 2+ ] cyt signal could play an important signalling role in systemic plant defence.