Early signalling mechanisms underlying receptor kinase-mediated immunity in plants

Abstract

Pattern-recognition receptors (PRRs), which are single transmembrane proteins belonging to the receptor-like kinase (RLK) and receptor-like protein (RLP) super families, sense microbe- and host-derived molecular patterns to activate immune responses in plants. PRRs associate with co-receptors, scaffold proteins and receptor-like cytoplasmic kinases (RLCKs) to form immune receptor complexes at the cell surface, allowing activation of cellular responses upon perception of extracellular ligands. Recent advances have uncovered new mechanisms by which these immune receptor complexes are regulated at the levels of composition, stability and activity. It has become clear that RLCKs are central components directly linking PRRs to multiple downstream signalling modules. Furthermore, new studies have provided important insights into the regulation of reactive oxygen species, mitogen-activated protein (MAP) kinase cascades and heterotrimeric G proteins, which has not only deepened our understanding of immunity, but also expanded our view of transmembrane signalling in general. This article is part of the theme issue ‘Biotic signalling sheds light on smart pest management’.

QTL Mapping for Resistance to Cankers Induced by Pseudomonas syringae pv. actinidiae (Psa) in a Tetraploid Actinidia chinensis Kiwifruit Population

“…There seems to be functional commonality in the genes that underlie the QTLs identified for Psa resistance in the field in both diploid [ 38 ] and tetraploid A. chinensis ; for example, the gene family that encodes RL kinases. RL kinases are known to play a significant role in plant immunity, especially early pathogen recognition and activation of plant defense [ 55 , 56 , 57 , 58 ]. The mechanistic basis of resistance for the two sub-species may rely on combinatorial action of defense proteins providing strong surveillance for pathogen-associated molecular patterns (PAMPs) and activation of signaling cascade for PAMPS-triggered immunity [ 59 ].…”

Herbivore-induced activation of viral phosphatase disarms plant antiviral immunities for pathogen transmission

“…By perceiving exogenous stresses, e.g. herbivore or pathogen attacks, plant activates a variety of early defense responses including kinase activation such as mitogen-activated protein kinase (MAPK) and sucrose non-fermenting 1 related protein kinase (SnRK), calcium (Ca 2+ ) influxes, and defense hormones signaling (Schuman and Baldwin, 2016; Zhou et al, 2019). Plants reprogram their downstream transcriptional network composing with AP2/ERF, MYB, bHLH and WRKY families to regulate biosynthesis of specialized metabolites such as terpenoids, phytoalexins, reactive oxygen species (ROS) burst including hydrogen peroxide (H 2 O 2 ) and callose deposition (Tsuda and Somssich, 2015).…”

Overview: biotic signalling for smart pest management

“…PRRs trigger immune responses upon perception of microbial or endogenous molecular patterns released during infection, and pattern-triggered immunity has been a centre piece of plant innate immunity studies. Zhou et al highlighted recent advances in early signalling mechanisms, particularly the tight regulation of major components of receptor complexes and signalling relay from receptor kinases to downstream cellular responses [13]. How pathogenic bacteria sense host plant and plant-associated stimuli remains unknown.…”