Plants employ numerous cell-surface and intracellular immune receptors to perceive a variety of immunogenic signals associated with pathogen infection and subsequently activate defenses. Immune ...signaling is potentiated by the major defense hormone salicylic acid (SA), which reprograms the transcriptome for defense. Here we highlight recent advances in understanding the mechanisms underlying activation of the main classes of immune receptors, summarize the current understanding of their signaling mechanisms, and discuss an updated model for SA perception and signaling. In addition, we discuss how different receptors are organized into networks and the implications of such networks in the integration of complex danger signals for appropriate defense outputs.
Plants possess a sophisticated and complex immune signaling system, many components or which are either conserved or have analogous counterparts in animals. Jian-Min Zhou and Yuelin Zhang review plant immune signaling mechanisms, from sensing mechanisms to transcriptional responses, noting key parallels to animal immunity.
Plant immune signaling: Advancing on two frontiers Wang, Wei; Feng, Baomin; Zhou, Jian‐Min ...
Journal of integrative plant biology,
January 2020, 2020-Jan, 2020-01-00, 20200101, 2020, Letnik:
62, Številka:
1
Journal Article
Recenzirano
Plants have evolved multiple defense strategies to cope with pathogens, among which plant immune signaling that relies on cell‐surface localized and intracellular receptors takes fundamental roles. ...Exciting breakthroughs were made recently on the signaling mechanisms of pattern recognition receptors (PRRs) and intracellular nucleotide‐binding site (NBS) and leucine‐rich repeat (LRR) domain receptors (NLRs). This review summarizes the current view of PRRs activation, emphasizing the most recent discoveries about PRRs’ dynamic regulation and signaling mechanisms directly leading to downstream molecular events including mitogen‐activated protein kinase (MAPK) activation and calcium (Ca2+) burst. Plants also have evolved intracellular NLRs to perceive the presence of specific pathogen effectors and trigger more robust immune responses. We also discuss the current understanding of the mechanisms of NLR activation, which has been greatly advanced by recent breakthroughs including structures of the first full‐length plant NLR complex, findings of NLR sensor‐helper pairs and novel biochemical activity of Toll/interleukin‐1 receptor (TIR) domain.
In nature, plants are constantly exposed to pathogens thus have evolved multiple defense strategies to cope with pathogens, including plant immune signaling that relies on cell‐surface localized pattern recognition receptors (PRRs) and intracellular NLR immune receptors. This review mainly summarized the current views of PRRsactivated immunity and the mechanisms of NLRs activation.
Receptor kinases (RKs) are of paramount importance in transmembrane signaling that governs plant reproduction, growth, development, and adaptation to diverse environmental conditions. Receptor-like ...cytoplasmic kinases (RLCKs), which lack extracellular ligand-binding domains, have emerged as a major class of signaling proteins that regulate plant cellular activities in response to biotic abiotic stresses and endogenous extracellular signaling molecules. By associating with immune RKs, RLCKs regulate multiple downstream signaling nodes to orchestrate a complex array of defense responses against microbial pathogens. RLCKs also associate with RKs that perceive brassinosteroids and signaling peptides to coordinate growth, pollen tube guidance, embryonic and stomatal patterning, floral organ abscission, and abiotic stress responses. The activity and stability of RLCKs are dynamically regulated not only by RKs but also by other RLCK-associated proteins. Analyses of RLCK-associated components and substrates have suggested phosphorylation relays as a major mechanism underlying RK-mediated signaling.
The ever‐increasing demand for clean and renewable power sources has sparked intensive research on water splitting to produce hydrogen, in which the exploration of electrocatalysts is the central ...issue. Herein, a new strategy, metal–organic framework template‐directed fabrication of hierarchically structured Co3O4@X (X = Co3O4, CoS, C, and CoP) electrocatalysts for efficient oxygen evolution reaction (OER) is developed, where Co3O4@X are derived from cobalt carbonatehydroxide@zeolitic‐imidazolate‐framework‐67 (CCH@ZIF‐67). Unique hierarchical structure and synergistic effect of resulting catalysts endow abundant exposed active sites, facile ion diffusion path, and improved conductivity, being favorable for improving catalytic activity of them. Consequently, these derivatives Co3O4@X reveal highly efficient electrocatalytic performance with long‐term durability for the OER, much superior to previously reported cobalt‐based catalysts as well as the Ir/C catalyst. Particularly, Co3O4@CoP exhibits the highest electrocatalytic capability with the lower overpotential of 238 mV at the current density of 10 mA cm−2. Furthermore, Co3O4@X can also efficiently catalyze other small molecules through electro‐oxidation reaction (e.g., glycerol, methanol, or ethanol). It is expected that the strategy presented here can be extended to the fabrication of other composite electrode materials with hierarchical structures for more efficient water splitting.
A new strategy for the fabrication of hierarchically structured composites as highly effective and stable electrocatalysts is proposed. The oxidation, sulfurization, carbonization, and phosphorization of premade cobalt carbonate hydroxide@zeolitic‐imidazolate‐framework‐67 (CCH@ZIF‐67) produced Co3O4@X (X = Co3O4, CoS, C, and CoP) derivatives, respectively, which as electrocatalysts exhibit excellent performance in the oxygen evolution reaction with low overpotential and high stability.
Receptor-like kinases (RLKs) and Receptor-like proteins (RLPs) play crucial roles in plant immunity, growth, and development. Plants deploy a large number of RLKs and RLPs as pattern recognition ...receptors (PRRs) that detect microbe- and host-derived molecular patterns as the first layer of inducible defense. Recent advances have uncovered novel PRRs, their corresponding ligands, and mechanisms underlying PRR activation and signaling. In general, PRRs associate with other RLKs and function as part of multiprotein immune complexes at the cell surface. Innovative strategies have emerged for the rapid identification of microbial patterns and their cognate PRRs. Successful pathogens can evade or block host recognition by secreting effector proteins to “hide” microbial patterns or inhibit PRR-mediated signaling. Furthermore, newly identified pathogen effectors have been shown to manipulate RLKs controlling growth and development by mimicking peptide hormones of host plants. The ongoing studies illustrate the importance of diverse plant RLKs in plant disease
Phytopathogenic bacteria, fungi, and oomycetes invade and colonize their host plants through distinct routes. These pathogens secrete diverse groups of effector proteins that aid infection and ...establishment of different parasitic lifestyles. Despite this diversity, a comparison of different plant-pathogen systems has revealed remarkable similarities in the host immune pathways targeted by effectors from distinct pathogen groups. Immune signaling pathways mediated by pattern recognition receptors, phytohormone homeostasis or signaling, defenses associated with host secretory pathways and pathogen penetrations, and plant cell death represent some of the key processes controlling disease resistance against diverse pathogens. These immune pathways are targeted by effectors that carry a wide range of biochemical functions and are secreted by completely different pathogen groups, suggesting that these pathways are a common battleground encountered by many plant pathogens.
Plants employ a highly effective surveillance system to detect potential pathogens, which is critical for the success of land plants in an environment surrounded by numerous microbes. Recent efforts ...have led to the identification of a number of immune receptors and components of immune receptor complexes. It is now clear that receptor-like kinases （RLKs） and receptor-like proteins （RLPs） are key pattern-recognition receptors （PRRs） for microbe- and plant-derived molecular patterns that are associated with pathogen invasion. RLKs and RLPs involved in immune signaling belong to large gene families in plants and have undergone lineage specific expansion. Molecular evolution and population studies on phytopathogenic molecular signatures and their receptors have provided crucial insight into the co-evolution between plants and pathogens.
Heteroatom‐doping is a promising strategy to tuning the microstructure of carbon material toward improved electrochemical storage performance. However, it is a big challenge to control the doping ...sites for heteroatom‐doping and the rational design of doping is urgently needed. Herein, S doping sites and the influence of interlayer spacing for two kinds of hard carbon, perfect structure and vacancy defect structure, are explored by the first‐principles method. S prefers doping in the interlayer for the former with interlayer distance of 3.997 Å, while S is doped on the carbon layer for the latter with interlayer distance of 3.695 Å. More importantly, one step molten salts method is developed as a universal synthetic strategy to fabricate hard carbon with tunable microstructure. It is demonstrated by the experimental results that S‐doping hard carbon with fewer pores exhibits a larger interlayer spacing than that of porous carbon, agreeing well with the theoretical prediction. Furthermore, the S‐doping carbon with larger interlayer distance and fewer pores exhibits remarkably large reversible capacity, excellent rate performance, and long‐term cycling stability for Na‐ion storage. A stable and reversible capacity of ≈200 mAh g−1 is steadily kept even after 4000 cycles at 1 A g−1.
Two kinds of S‐doped hard carbon with different microsctructures are synthesized by a universal synthetic strategy. It is demonstrated that S‐doping hard carbon with fewer pores exhibits a larger interlayer spacing than that of porous carbon, and an excellent Na‐ion storage performance with a stable capacity of ≈200 mAh g−1 after 4000 cycles at 1 A g−1 is displayed.
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