Stress priming, memory, and signalling in plants

Abstract

Plants need to cope with changing environmental conditions, be it variable light or temperature, different availability of water or nutrients, or attack by pathogens or insects. Some of these changing conditions can become stressful and require strong countermeasures to ensure plant survival. Plants have evolved numerous distinct sensing and signalling mechanisms to perceive and respond appropriately to a variety of stresses.Because of the unpredictable nature of numerous stresses, resource-saving stress response mechanisms are inducible and become activated only upon a stress experience. Furthermore, plants have evolved mechanisms by which they can remember past stress events and prime their responses in order to react more rapidly or more strongly to recurrent stress. Research over the last decade has revealed mechanisms of this information storage and retrieval, which include epigenetic regulation, transcriptional priming, primed conformation of proteins, or specific hormonal or metabolic signatures. There is also increasing understanding of the ecological constraints and relevance of stress priming and memory. This special issue presents research articles and reviews addressing various aspects of this exciting and growing field of research. Here, we introduce the topic by referring to the articles published in this issue, and we outline open questions and future directions of research.

Autophagy: An Intracellular Degradation Pathway Regulating Plant Survival and Stress Response

“…As immovable organisms, plants need to cope with various environmental changes, including nutrient starvation, salt, drought, and heat stresses Shen et al, 2014;Qi et al, 2018;Hilker and Schmülling, 2019). To respond appropriately to these stresses, plants have evolved various distinct signaling and regulatory mechanisms (Hilker and Schmülling, 2019). It has been shown that autophagy is involved in removing damaged proteins and cellular components produced in response to environmental stresses (Wang et al, 2018b).…”

Global Gene Responses of Resistant and Susceptible Sugarcane Cultivars to Acidovorax avenae subsp. avenae Identified Using Comparative Transcriptome Analysis

“…In Ca 2+ signaling, Ca 2+ flux across membranes is promoted through the activity of several families of Ca 2+ -permeable channels, such as CNGCs. Plant cytoplasmic Ca 2+ is sensed by different Ca 2+ sensor proteins (e.g., CaMs, CMLs, CBLs, CDPKs), which further induce expression of downstream genes (e.g., transcription factors, NADPH oxidases genes) and mediate responses to abiotic and biotic stresses through reactive oxygen species (ROS) and/or nitrogen monoxide (NO) production [67,68]. CDPKs are involved not only in Ca 2+ -and ROS-mediated initiation of stress signaling, but also in hormone-regulated systemic signal propagation during pathogen infection [68,69].…”

“…Plant cytoplasmic Ca 2+ is sensed by different Ca 2+ sensor proteins (e.g., CaMs, CMLs, CBLs, CDPKs), which further induce expression of downstream genes (e.g., transcription factors, NADPH oxidases genes) and mediate responses to abiotic and biotic stresses through reactive oxygen species (ROS) and/or nitrogen monoxide (NO) production [67,68]. CDPKs are involved not only in Ca 2+ -and ROS-mediated initiation of stress signaling, but also in hormone-regulated systemic signal propagation during pathogen infection [68,69]. On the other hand, the MAPK cascade generally has three components, a MAPK, a MAPKK (MAPK kinase) and a MAPKKK (MAPKK kinase), which play essential roles in plant growth and development as well as responses to abiotic and biotic stresses [67,68].…”

“…CDPKs are involved not only in Ca 2+ -and ROS-mediated initiation of stress signaling, but also in hormone-regulated systemic signal propagation during pathogen infection [68,69]. On the other hand, the MAPK cascade generally has three components, a MAPK, a MAPKK (MAPK kinase) and a MAPKKK (MAPKK kinase), which play essential roles in plant growth and development as well as responses to abiotic and biotic stresses [67,68].…”

O3-Induced Priming Defense Associated With the Abscisic Acid Signaling Pathway Enhances Plant Resistance to Bemisia tabaci

“…Upon pre-exposure to abiotic stress, plants are able to establish a defense priming with a fast and/or strong activation of defense responses, including phytohormones, against subsequent challenges from microbes, insects, or other biotic stresses (Mauch-Mani et al, 2017;Hilker and Schmülling, 2019). Previous studies have shown that because of strong oxidative stress, pre-exposure to O 3 can prime tomato leaves for an enhanced defense against subsequent herbivorous insect infestation by upregulating the expression of salicylic acid (SA)-dependent defensive gene pathogenesis-related protein and increasing the emission of jasmonic acid (JA)-mediated monoterpene volatiles by tomato plants to decrease the population abundance and feeding fitness of B. tabaci (Cui et al, 2012;Cui et al, 2014).…”