Integration of electric, calcium, reactive oxygen species and hydraulic signals during rapid systemic signaling in plants. (25th June 2021)

• Record Type: Journal Article
• Authors: Fichman, Yosef; Mittler, Ron
• Is Part Of: Plant journal. Volume 107:Number 1(2021)
• Page Start: 7
• Page End: 20
• Publication Date: 2021-06-25
• Subjects: abiotic stress -- aquaporins -- light stress -- glutamate receptor‐like -- plasmodesmata -- reactive oxygen species -- respiratory burst oxidase homolog -- systemic signaling -- whole‐plant live imaging -- wounding -- technical advance; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.15360
• Languages: English
• ISSNs: 0960-7412

Abstract

SUMMARY: The sensing of abiotic stress, mechanical injury or pathogen attack by a single plant tissue results in the activation of systemic signals that travel from the affected tissue to the entire plant. This process is essential for plant survival during stress and is termed systemic signaling. Among the different signals triggered during this process are calcium, electric, reactive oxygen species and hydraulic signals. These are thought to propagate at rapid rates through the plant vascular bundles and to regulate many of the systemic processes essential for plant survival. Although the different signals activated during systemic signaling are thought to be interlinked, their coordination and hierarchy still need to be determined. Here, using a combination of advanced whole‐plant imaging and hydraulic pressure measurements, we studied the activation of all four systemic signals in wild‐type and different Arabidopsis thaliana mutants subjected to a local treatment of high‐light (HL) stress or wounding. Our findings reveal that activation of systemic membrane potential, calcium, reactive oxygen species and hydraulic pressure signals, in response to wounding, is dependent on glutamate receptor‐like proteins 3.3 and 3.6. In contrast, in response to HL stress, systemic changes in calcium and membrane potential depended on glutamate receptor‐like 3.3 and 3.6, while systemic hydraulic signals did not. We further show that plasmodesmata functions are required for systemic changes in membrane potential and calcium during responses to HL stress or wounding. Our findings shed new light on the different mechanisms that integrate different systemic signals in plants during stress. Significance Statement: At least four different signals are thought to mediate rapid systemic signaling in plants: electric, calcium, reactive oxygen species and hydraulic. Using newly developed whole‐plant imaging methods and hydraulic pressure probes, we studied the activation of all four signals in different Arabidopsis mutants subjected to local treatment of high light stress or wounding, revealing a key role for glutamate receptor‐like proteins in regulating hydraulic signals during systemic responses to wounding.