Revisiting plant stress memory: mechanisms and contribution to stress adaptation

Abstract

Highly repetitive adverse environmental conditions are encountered by plants multiple times during their lifecycle. These repetitive encounters with stresses provide plants an opportunity to remember and recall the experiences of past stress-associated responses, resulting in better adaptation towards those stresses. In general, this phenomenon is known as plant stress memory. According to our current understanding, epigenetic mechanisms play a major role in plants stress memory through DNA methylation, histone, and chromatin remodeling, and modulating non-coding RNAs. In addition, transcriptional, hormonal, and metabolic-based regulations of stress memory establishment also exist for various biotic and abiotic stresses. Plant memory can also be generated by priming the plants using various stressors that improve plants' tolerance towards unfavorable conditions. Additionally, the application of priming agents has been demonstrated to successfully establish stress memory. However, the interconnection of all aspects of the underlying mechanisms of plant stress memory is not yet fully understood, which limits their proper utilization to improve the stress adaptations in plants. This review summarizes the recent understanding of plant stress memory and its potential applications in improving plant tolerance towards biotic and abiotic stresses.

Keywords: Abiotic and biotic stress; Climate change; Epigenetics; Plant adaptation; Stress memory.

Fig. 1

Number of publications found in the Web of Science database in a query of “Plant stress Memory” for the period of 2000–2023. The number of publications related to PSM increased more than twice in recent years in comparison to previous years

Fig. 2

Schematic diagram showing the regulatory mechanisms involved in PSM establishment, maintenance, and transfer to the later phase A Plant faces diverse biotic and abiotic stresses which are perceived by plants through specific features such as ROS, Ca²⁺, and MAPK (details in Fig. 3). Plant implies a diverse set of molecular, physiological, metabolic, and epigenetics mechanisms to minimize the negative impact. B Several mechanisms establish the stress memory and C maintain it during the favorable or recovery phases. D Upon exposure to stresses at the later phases and recurrent stresses, plants reactivate the defense mechanisms which are faster and more precise, resulting in enhanced stress tolerance

Fig. 3

Regulatory network involved in stress signal perception, transduction, and activation of defense systems. Stress stimulus is perceived through the receptors in cell wall which are received by both primary and secondary messengers. Signaling cascades transduce the signal and activate the transcriptional events resulting in gene expression which shape the plant responses