Plant Reaction: Touch and Injury Trigger Calcium Signal and Leaflet Movement in Mimosa pudica

Original video: https://youtu.be/YaRAkRtatLw

Animals possess specialized systems, e.g., neuromuscular systems, to sense the environment and then move their bodies quickly in response. Mimosa pudica, the sensitive plant, moves its leaves within seconds in response to external stimuli; e.g., touch or wounding. However, neither the plant-wide signaling network that triggers these rapid movements nor the physiological roles of the movements themselves have been determined. Here by simultaneous recording of cytosolic Ca²⁺ and electrical signals, we show that rapid changes in Ca²⁺ coupled with action and variation potentials trigger rapid movements in wounded M. pudica. Furthermore, pharmacological manipulation of cytosolic Ca2+ dynamics and CRISPR-Cas9 genome editing technology revealed that an immotile M. pudica is more vulnerable to attacks by herbivorous insects. Our findings provide evidence that rapid movements based on propagating Ca²⁺ and electrical signals protect this plant from insect attacks.

This video showcases the role of calcium signalling in rapid plant movements. It demonstrates that while localised mechanical touch with forceps can cause a rapid increase in cytosolic calcium ([Ca²⁺]cyt) in various organs without affecting leaf movement, touch and wounding a leaflet with scissors induces [Ca²⁺]cyt increases specifically at the base of leaflets (tertiary pulvinus). This calcium increase occurs in parallel with leaflet movement, which is sequentially triggered along a rachilla. This aligns with previous findings that both electrical signals and leaf movement attenuate when extracellular Ca2+ concentration is reduced, implying a crucial role for Ca2+ signalling in regulating these rapid plant responses.

Keywords: Plant Movement, Touch Response, Wound Response, Calcium Signaling, [Ca²⁺cyt, Leaflet Movement, Tertiary Pulvinus, Mimosa Pudica, Plant Physiology, Plant Biology, Nastic movement

Citation:

Hagihara, T., Mano, H., Miura, T. et al. Calcium-mediated rapid movements defend against herbivorous insects in Mimosa pudica. Nat Commun 13, 6412 (2022). https://doi.org/10.1038/s41467-022-34106-x

Published on: 14 November 2022

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