Interplay between phytohormone signalling pathways in plant defence – other than salicylic acid and jasmonic acid

Abstract

Phytohormones are essential for all aspects of plant growth, development, and immunity; however, it is the interplay between phytohormones, as they dynamically change during these processes, that is key to this regulation. Hormones have traditionally been split into two groups: growth-promoting and stress-related. Here, we will discuss and show that all hormones play a role in plant defence, regardless of current designation. We highlight recent advances in our understanding of the complex phytohormone networks with less focus on archetypal immunity-related pathways and discuss protein and transcription factor signalling hubs that mediate hormone interplay.

Entomopathogenic Fungus-Related Priming Defense Mechanisms in Cucurbits Impact Spodoptera littoralis (Boisduval) Fitness

“…JA can promote the activation of MYC2 transcription factor to induce the JA response signal through the interaction between JAZ, a repressor of JA signaling, and the SCFCOI1 ubiquitin ligase, which results in the ubiquitination of the JAZ protein and its degradation by the 26S proteasome ( 54 ). JAZ1 can also interact with DELLA proteins, which result in increased JA signaling and decreased SA ( 66 ). The DELLA family proteins are key regulators of GA signaling that repress transcription of GA-responsive genes ( 67 ).…”

Comparative transcriptome profiling reveals the role of phytohormones and phenylpropanoid pathway in early-stage resistance against powdery mildew in watermelon (Citrullus lanatus L.)

“…Auxins, cytokinins, gibberellins, jasmonic acid, salicylic, acid ethylene, abscisic acid, and brassinosteroid are phytohormones that respond to stress by acting synergistically and antagonistically in a process known as signaling cross talk ( Bostock, 2005 ; Sood et al., 2021 ; Gilroy and Breen, 2022 ). These phytohormones respond to environmental stimuli and developmental cues by harmoniously coordinating with one another ( Dopp et al., 2021 ; Fidler et al., 2022 ).…”

Tuning the Wavelength: Manipulation of Light Signaling to Control Plant Defense

“…JA biosynthesis begins at the inner chloroplast membrane and is known to be affected by light [ 27 , 28 ]. Furthermore, there are many environmental and developmental cues that induce various spatially and temporally regulated phytohormone pathways which are known to intersect in different ways with plant immunity [ 7 ].…”

“…Chloroplasts were historically considered to be responsible for the production of sugars from water, CO 2 , and sunlight during photosynthesis, and mitochondria produce energy from the breakdown of sugar during respiration. The role of chloroplasts in plant immunity has been of recent interest [ 7 , 29 , 30 , 31 ]. Chloroplasts are mobilized during pathogen infection to cellular regions sensitive to invader attack and to the nucleus, presumably to optimize the rapid exchange of signals, nucleic acids, and proteins [ 29 , 32 ].…”

“…Advances over the past two decades have developed an overview of defense regulation in plants and the interactions of a number of essential hormonal players [ 7 , 8 ]. This provides a framework by which to interpret the molecular relationships induced under environmental variables (such as light) and how these may influence the major regulatory hubs that orchestrate plant immunity [ 9 ].…”