Transformation of flg22 perception into electrical signals decoded in vasculature leads to sieve tube blockage and pathogen resistance.

This study focuses on the question how and where information acquired by FLS2 perception of flg22 is transformed into electrical signals crucial for generation of local and systemic defense responses. In and leaves, FLS2 density was high in the epidermis and vascular parenchyma, low in mesophyll, and absent in sieve elements (SEs). Aequorin-based examinations disclosed dual cytosolic Ca peaks shortly after flg22 application, which corresponded with two voltage shifts from the epidermis to SEs.

Systemic cytosolic Ca(2+) elevation is activated upon wounding and herbivory in Arabidopsis.

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.