Defence‐related priming and responses to recurring drought: Two manifestations of plant transcriptional memory mediated by the ABA and JA signalling pathways

Abstract

Collective evidence from agricultural practices and from scientific research has demonstrated that plants can alter their phenotypic responses to repeated biotic and abiotic stresses or their elicitors. A coordinated reaction at the organismal, cellular, and genome levels has suggested that plants can "remember" an earlier stress and modify their future responses, accordingly. Stress memory may increase a plant's survival chances by improving its tolerance/avoidance abilities and may provide a mechanism for acclimation and adaptation. Understanding the mechanisms that regulate plant stress memory is not only an intellectually challenging topic but has important implications for agricultural practices as well. Here, I focus exclusively on specific aspects of the transcription memory in response to recurring dehydration stresses and the memory-type responses to insect damage in a process known as "priming." The questions discussed are (a) whether/how the two memory phenomena are connected at the level of transcriptional regulation; (b) how differential transcription is achieved mechanistically under a repeated stress; and (c) whether similar molecular and/or epigenetic mechanisms are involved. Possible biological relevance of transcriptional stress memory and its preservation in plant evolution are also discussed.

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

“…Furthermore, the negative effects of elevated O 3 on the phloem-feeding behavior of B. tabaci was also absent in the 2-DDG-treated AC plants, which suggested that callose deposition contributed to O 3induced priming defense against B. tabaci. This is consistent with previous studies showing that preliminary reagent (e.g., indole-3-carboxylic acid and b-amino-butyric acid) treatmentinduced or abiotic stress (e.g., high silicon concentration)induced defense priming against subsequent insects or pathogen challenge is dependent on callose accumulation (Baccelli and Mauch-Mani, 2016;Yang et al, 2018;Avramova, 2019). In Arabidopsis, indole-3-carboxylic acid-and b-aminobutyric acid-induced callose priming against P. cucumerina infection is blocked in ABA-deficient mutants such as npq2, aba1-5, and aba2.3 (Ton and Mauch-Mani, 2004;Gamir et al, 2018).…”

Stress priming, memory, and signalling in plants

“…The interaction of JA with ABA has intensively been studied, particularly in response to recurring dehydration stress (Avramova, ). The plant's response to a first dehydration stress is mediated by both ABA and JA and induces transcriptional memory of drought‐inducible genes.…”

Abscisic acid mediation of drought priming‐enhanced heat tolerance in tall fescue (Festuca arundinacea) and Arabidopsis

“…Heat tolerance of plants can be induced or improved by stress or chemical priming (Savvides et al , Hossain et al ). Plants can ‘remember’ an earlier stress and modify their future responses to later stresses accordingly (Avramova ). Exposure of plants to mild or moderate drought, or drought priming of plants, can enhance plant tolerance to subsequent stresses, including drought, heat and cold (Li et al , Wang et al , Fleta‐Soriano and Munne‐Bosch ).…”