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Summary: Plant intracellular nucleotide‐binding leucine‐rich repeat immune receptors (NLRs) perceive the activity of pathogen‐secreted effector molecules that, when undetected, promote colonisation of hosts. Signalling from activated NLRs converges with and potentiates downstream responses from activated pattern recognition receptors (PRRs) that sense microbial signatures at the cell surface. Efficient signalling of both receptor branches relies on the host cell nucleus as an integration point for transcriptional reprogramming, and on the macromolecular transport processes that mediate the communication between cytoplasm and nucleoplasm. Studies on nuclear pore complexes (NPCs), the nucleoporin proteins (NUPs) that compose NPCs, and nuclear transport machinery constituents that control nucleocytoplasmic transport, have revealed that they play important roles in regulating plant immune responses. Here, we discuss the contributions of nucleoporins and nuclear transport receptor (NTR)‐mediated signal transduction in plant immunity with an emphasis on NLR immune signalling across the nuclear compartment boundary and within the nucleus. We also highlight and discuss cytoplasmic and nuclear functions of NLRs and their signalling partners and further consider the potential implications of NLR activation and resistosome formation in both cellular compartments for mediating plant pathogen resistance and programmed host cell death. [ABSTRACT FROM AUTHOR]

Summary: Calcium serves as a second messenger in a variety of developmental and physiological processes and has long been identified as important for plant immune responses. We discuss recent discoveries regarding plant immune‐related calcium‐permeable channels and how the two intertwined branches of the plant immune system are intricately linked to one another through calcium signalling. Cell surface immune receptors carefully tap the immense calcium gradient that exists between apoplast and cytoplasm in a short burst via tightly regulated plasma membrane (PM)‐resident cation channels. Intracellular immune receptors form atypical calcium‐permeable cation channels at the PM and mediate a prolonged calcium influx, overcoming the deleterious influence of pathogen effectors and enhancing plant immune responses. See also the Commentary on this article by Lee & Romeis, 234: 769–772. [ABSTRACT FROM AUTHOR]

Summary: Intracellular nucleotide binding (NB) and leucine‐rich repeat (NLR) proteins function as immune receptors to recognize effectors from pathogens. They often guard host proteins that are the direct targets of those effectors. Recent findings have revealed that a typical NLR sometimes cooperates with another atypical NLR for effector recognition.Here, by using the CRISPR/Cas9 gene editing method, knockout analysis and biochemical assays, we uncovered differential pairings of typical Toll Interleukin1 receptor (TIR) type NLR (TNL) receptor SOC3 with atypical truncated TIR‐NB (TN) proteins CHS1 or TN2 to guard the homeostasis of the E3 ligase SAUL1.Overaccumulation of SAUL1 is monitored by the SOC3−TN2 pair, while SAUL1's disappearance is guarded by the SOC3−CHS1 pair. SOC3 forms a head‐to‐head genomic arrangement with CHS1 and TN2, indicative of transcriptional co‐regulation.Such intricate cooperative interactions can probably enlarge the recognition spectrum and increase the functional flexibility of NLRs, which can partly explain the overwhelming occurrence of NLR gene clustering in higher plants. [ABSTRACT FROM AUTHOR]