Plant Immunity: From Signaling to Epigenetic Control of Defense

Abstract

Pathogen recognition by plants results in the activation of signaling pathways that induce defense reactions. There is growing evidence indicating that epigenetic mechanisms directly participate in plant immune memory. Here, we discuss current knowledge of diverse epigenomic processes and elements, such as noncoding RNAs, DNA and RNA methylation, histone post-translational modifications, and chromatin remodeling, that have been associated with the regulation of immune responses in plants. Furthermore, we discuss the currently limited evidence of transgenerational inheritance of pathogen-induced defense priming, together with its potentials, challenges, and limitations for crop improvement and biotechnological applications.

The Polycomb protein LHP1 regulates Arabidopsis thaliana stress responses through the repression of the MYC2‐dependent branch of immunity

“…However, it is also known that the excessive and unnecessary activation of immune responses can have detrimental effects on physiology, as evidenced by the existence of several autoimmune mutants, many of which display compromised development and growth (van Wersch et al ., ). Plants must therefore fine tune the expression of stress‐responsive genes, and there is increasing evidence indicating that chromatin dynamics plays a crucial role in this process (Smale et al ., ; Mehta et al ., ; Probst and Mittelsten Scheid, ; Espinas et al ., ; Lämke and Bäurle, ; Ramirez‐Prado et al ., ,b). The characterization of mutants for various chromatin modifiers has elucidated the role of several of these proteins in the regulation of both developmental and stress‐responsive pathways.…”

“…The characterization of mutants for various chromatin modifiers has elucidated the role of several of these proteins in the regulation of both developmental and stress‐responsive pathways. Several epigenomic regulators with diverse functions, including histone mark writers, readers and erasers, were identified as positive and negative regulators of immunity, or shown to play an important role in the regulation of the interplay between the diverse hormonal pathways that constitute the plant immune system (Bu et al ., , Ding and Wang, ; Espinas et al ., ; Ramirez‐Prado et al ., ,b).…”

Phytohormonal cross-talk modulate Bipolaris sorokiniana (Scc.)interaction with Zea mays

“…Upon the plant microbe interaction, several hypersensitive reactions, including hormonal biosyntheses and the subsequent signal transduction mechanism are triggered (Kim et al, 2018). Such signal transduction in host later develops the expression of genes which decide the fate of microbe interaction with host (Ramirez-Prado et al, 2018). Recently, gibberellins hypersensitivity accompanied by their signal transduction processes have emerged as a critical component of plant-microbe interactions (Binenbaum et al, 2018).…”

The role of plant epigenetics in biotic interactions

“…Because it would exceed the scope of the present article, we cannot discuss the plethora of plant–pathogen interactions involving noncoding RNAs, even though small RNAs have been associated with immunity in various plant species and have even recently been shown to modulate pathogen virulence in cross‐kingdom interference (Cai et al ., ). Instead, we will here focus on chromatin configuration changes related to biotic interactions, and point readers interested in the role of noncoding RNAs to recent reviews on the topic (Wang et al ., ; Ramirez‐Prado et al ., ).…”