For over 60 years, salicylic acid (SA) has been known as a plant immune signal required for basal and systemic acquired resistance (SAR). SA activates these immune responses by reprogramming ∼20% of the transcriptome through the function of NPR1. However, components in the NPR1-signaling hub, which appears as nuclear condensates, and the NPR1-signaling cascade remained elusive due to difficulties in studying this transcriptional cofactor whose chromatin association is indirect and likely transient. To overcome this challenge, we applied TurboID to divulge the NPR1-proxiome, which detected almost all known NPR1-interactors as well as new components of transcription-related complexes. Testing of new components showed that chromatin remodeling and histone demethylation contribute to SA-induced resistance. Globally, NPR1-proxiome shares a striking similarity to GBPL3-proxiome involved in SA synthesis, except associated transcription factors (TFs), suggesting that common regulatory modules are recruited to reprogram specific transcriptomes by transcriptional cofactors, like NPR1, through binding to unique TFs. Stepwise greenCUT&RUN analyses showed that, upon SA-induction, NPR1 initiates the transcriptional cascade primarily through association with TGA TFs to induce expression of secondary TFs, predominantly WRKYs. WRKY54 and WRKY70 then play a major role in inducing immune-output genes without interacting with NPR1 at the chromatin. Moreover, loss of NPR1 condensate formation decreases the protein\'s chromatin-association and transcriptional activity, indicating the importance of condensates in organizing the NPR1-signaling hub and initiating the transcriptional cascade. This study demonstrates how combinatorial applications of TurboID and stepwise greenCUT&RUN transcend traditional genetic methods to globally map signaling hubs and transcriptional cascades for in-depth explorations.

Chili pepper cultivation in the Indian subcontinent is severely affected by viral diseases, prompting the need for environmentally friendly disease control methods. To achieve this, it is essential to understand the molecular mechanisms of viral resistance in chili pepper. The NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1) genes are known to provide broad-spectrum resistance to various phytopathogens by activating systemic acquired resistance (SAR). An in-depth understanding of NPR1 gene expression during begomovirus infection and its correlation with different biochemical and physiological parameters is crucial for enhancing resistance against begomoviruses in chili pepper. Nevertheless, limited information on chili CaNPR genes and their role in biotic stress constrains their potential in breeding for biotic stress resistance. By employing bioinformatics for genome mining, we identify 5 CaNPR genes in chili. The promoter regions of 1,500 bp of CaNPR genes contained cis-elements associated with biotic stress responses, signifying their involvement in biotic stress responses. Furthermore, these gene promoters harbored components linked to light, development, and hormone responsiveness, suggesting their roles in plant hormone responses and development. MicroRNAs played a vital role in regulating these five CaNPR genes, highlighting their significance in the regulation of chili genes. Inoculation with the begomovirus \"cotton leaf curl Khokhran virus (CLCuKV)\" had a detrimental effect on chili plant growth, resulting in stunted development, fibrous roots, and evident virus symptoms. The qRT-PCR analysis of two local chili varieties inoculated with CLCuKV, one resistant (V1) and the other susceptible (V2) to begomoviruses, indicated that CaNPR1 likely provides extended resistance and plays a role in chili plant defense mechanisms, while the remaining genes are activated during the early stages of infection. These findings shed light on the function of chili\'s CaNPR in biotic stress responses and identify potential genes for biotic stress-resistant breeding. However, further research, including gene cloning and functional analysis, is needed to confirm the role of these genes in various physiological and biological processes. This in-silico analysis enhances our genome-wide understanding of how chili CaNPR genes respond during begomovirus infection.

Isochorismate-derived metabolism enables biosynthesis of the plant defence hormone salicylic acid (SA) and its derivatives. In Arabidopsis thaliana, the stress-induced accumulation of SA depends on ISOCHORISMATE SYNTHASE1 (ICS1), and also requires the presumed isochorismate transporter ENHANCED DISEASE SUSCEPTIBILITY5 (EDS5) and the GH3 enzyme avrPphB SUSCEPTIBLE3 (PBS3). By comparative metabolite and structural analyses, we identified several hitherto unreported ICS1- and EDS5-dependent, biotic stress-inducible Arabidopsis metabolites. These involve meta-substituted SA derivatives (5-formyl-SA, 5-carboxy-SA, 5-carboxymethyl-SA), their benzoic acid (BA) analogues (3-formyl-BA, 3-carboxy-BA, 3-carboxymethyl-BA) and, besides the previously detected salicyloyl-aspartate (SA-Asp), the ester conjugate salicyloyl-malate (SA-Mal). SA functions as a biosynthetic precursor for SA-Mal and SA-Asp, but not for the meta-substituted SA- and BA-derivatives, which accumulate to moderate levels at later stages of bacterial infection. Interestingly, Arabidopsis leaves possess oxidising activity to effectively convert meta-formyl- into meta-carboxy-SA/BAs. In contrast to SA, exogenously applied meta-substituted SA/BA-derivatives and SA-Mal exert moderate impact on plant immunity and defence-related gene expression. While the isochorismate-derived metabolites are negatively regulated by the SA receptor NON-EXPRESSOR OF PR GENES1, SA conjugates (SA-Mal, SA-Asp, SA-glucose conjugates) and meta-substituted SA/BA-derivatives are oppositely affected by PBS3. Notably, our data indicate a PBS3-independent path to isochorismate-derived SA at later stages of bacterial infection, which does not considerably impact immune-related characteristics. Moreover, our results argue against a previously proposed role of EDS5 in the biosynthesis of the immune signal N-hydroxypipecolic acid and associated transport processes. We propose a significantly extended biochemical scheme of plant isochorismate metabolism that involves an alternative generation mode for benzoate- and salicylate-derivatives.

Receptor guanylyl cyclases (GCs) are single membrane spanning, multidomain enzymes, that synthesize cGMP in response to natriuretic peptides or other ligands. They are evolutionarily conserved from sea urchins to humans and regulate diverse physiologies. Most family members are phosphorylated on four to seven conserved serines or threonines at the beginning of their kinase homology domains. This review describes studies that demonstrate that phosphorylation and dephosphorylation are required for activation and inactivation of these enzymes, respectively. Phosphorylation sites in GC-A, GC-B, GC-E and sea urchin receptors are discussed as are mutant receptors that mimic the dephosphorylated, inactive or phosphorylated, active forms of GC-A and GC-B, respectively. A salt bridge model is described that explains why phosphorylation is required for enzyme activation. Potential kinases, phosphatases and ATP regulation of GC receptors are also discussed. Critically, knock-in mice with glutamate substitutions for receptor phosphorylation sites are described. The inability of opposing signaling pathways to inhibit cGMP synthesis in mice where GC-A or GC-B cannot be dephosphorylated demonstrates the necessity of receptor dephosphorylation in vivo. Cardiac hypertrophy, oocyte meiosis, long bone growth/achondroplasia, and bone density are regulated by GC phosphorylation, but additional processes are likely to be identified in the future.

Natriuretic peptides (NP) have multiple actions benefitting cardiovascular and metabolic health. Although many of these are mediated by Guanylyl Cyclase (GC) receptors NPR1 and NPR2, their role and relative importance in vivo is unclear. The intracellular mediator of NPR1 and NPR2, cGMP, circulates in plasma and can be used to examine relationships between receptor activity and tissue responses targeted by NPs. Plasma cGMP was measured in 348 participants previously recruited in a multidisciplinary community study (CHALICE) at age 50 years at a single centre. Associations between bio-active NPs and bio-inactive aminoterminal products with cGMP, and of cGMP with tissue response, were analysed using linear regression. Mediation of associations by NPs was assessed by Causal Mediation Analysis (CMA). ANP\'s contribution to cGMP far exceed those of other NPs. Modelling across three components (demographics, NPs and cardiovascular function) shows that ANP and CNP are independent and positive predictors of cGMP. Counter intuitively, findings from CMA imply that in specific tissues, NPR1 responds more to BNP stimulation than ANP. Collectively these findings align with longer tissue half-life of BNP, and direct further therapeutic interventions towards extending tissue activity of ANP and CNP.

Systemic acquired resistance (SAR) is an inducible disease resistance phenomenon in plant species, providing plants with broad-spectrum resistance to secondary pathogen infections beyond the initial infection site. In Arabidopsis, SAR can be triggered by direct pathogen infection or treatment with the phytohormone salicylic acid (SA), as well as its analogues 2,6-dichloroisonicotinic acid (INA) and benzothiadiazole (BTH). The SA receptor non-expressor of pathogenesis-related protein gene 1 (NPR1) protein serves as a key regulator in controlling SAR signaling transduction. Similarly, in common wheat (Triticum aestivum), pathogen infection or treatment with the SA analogue BTH can induce broad-spectrum resistance to powdery mildew, leaf rust, Fusarium head blight, and other diseases. However, unlike SAR in the model plant Arabidopsis or rice, SAR-like responses in wheat exhibit unique features and regulatory pathways. The acquired resistance (AR) induced by the model pathogen Pseudomonas syringae pv. tomato strain DC3000 is regulated by NPR1, but its effects are limited to the adjacent region of the same leaf and not systemic. On the other hand, the systemic immunity (SI) triggered by Xanthomonas translucens pv. cerealis (Xtc) or Pseudomonas syringae pv. japonica (Psj) is not controlled by NPR1 or SA, but rather closely associated with jasmonate (JA), abscisic acid (ABA), and several transcription factors. Furthermore, the BTH-induced resistance (BIR) partially depends on NPR1 activation, leading to a broader and stronger plant defense response. This paper provides a systematic review of the research progress on SAR in wheat, emphasizes the key regulatory role of NPR1 in wheat SAR, and summarizes the potential of pathogenesis-related protein (PR) genes in genetically modifying wheat to enhance broad-spectrum disease resistance. This review lays an important foundation for further analyzing the molecular mechanism of SAR and genetically improving broad-spectrum disease resistance in wheat.

Resistance to infection by plant viruses involves proteins encoded by plant resistance (R) genes, viz., nucleotide-binding leucine-rich repeats (NLRs), immune receptors. These sensor NLRs are activated either directly or indirectly by viral protein effectors, in effector-triggered immunity, leading to induction of defense signaling pathways, resulting in the synthesis of numerous downstream plant effector molecules that inhibit different stages of the infection cycle, as well as the induction of cell death responses mediated by helper NLRs. Early events in this process involve recognition of the activation of the R gene response by various chaperones and the transport of these complexes to the sites of subsequent events. These events include activation of several kinase cascade pathways, and the syntheses of two master transcriptional regulators, EDS1 and NPR1, as well as the phytohormones salicylic acid, jasmonic acid, and ethylene. The phytohormones, which transit from a primed, resting states to active states, regulate the remainder of the defense signaling pathways, both directly and by crosstalk with each other. This regulation results in the turnover of various suppressors of downstream events and the synthesis of various transcription factors that cooperate and/or compete to induce or suppress transcription of either other regulatory proteins, or plant effector molecules. This network of interactions results in the production of defense effectors acting alone or together with cell death in the infected region, with or without the further activation of non-specific, long-distance resistance. Here, we review the current state of knowledge regarding these processes and the components of the local responses, their interactions, regulation, and crosstalk.

UNASSIGNED: Genetic variants causing diseases with hypertension as a secondary feature have previously been identified. Studies focussing on primary hypertension have utilised common and latterly rare genetic variants in attempts to elucidate the genetic contribution to the risk of primary hypertension.
UNASSIGNED: Using genome-wide association studies (GWASs), associations of hypertension with hundreds of common genetic variants have been reported, implicating thousands of genes. Individual variants have small effect sizes and cumulatively account for around 6% of genetic risk. The common variant signal is enriched for relevant tissues and physiological processes, while some variants are associated with traits expected to have secondary impacts on hypertension risk, such as fruit intake, BMI, or time watching television. Studies using rare variants obtained from exome sequence data have implicated a small number of genes for which impaired function has moderate effects on blood pressure and/or hypertension risk. Notably, genetic variants which impair elements of guanylate cyclase activation, stimulated by either natriuretic hormones or nitric oxide, increase hypertension risk. Conversely, variants impairing dopamine beta-hydroxylase or renin production are associated with lower blood pressure. Variants for which a definite effect can be designated remain cumulatively extremely rare and again make only a small contribution to overall genetic risk. Although these results are of interest, it is not clear that they provide radical new insights or identify drug targets which were not previously known. Nor does it seem that genetic testing could be useful in terms of quantifying disease risk or guiding treatment.
UNASSIGNED: Research has increased our knowledge about the relationship between naturally occurring genetic variation and risk of hypertension. Although some results serve to confirm our understanding of underlying physiology, their value in terms of potentially leading to practical advances in the management of hypertension appears questionable.

Plants have evolved sophisticated mechanisms to regulate gene expression to activate immune responses against pathogen infections. However, how the translation system contributes to plant immunity is largely unknown. The evolutionarily conserved thiolation modification of transfer RNA (tRNA) ensures efficient decoding during translation. Here, we show that tRNA thiolation is required for plant immunity in Arabidopsis. We identify a cgb mutant that is hyper-susceptible to the pathogen Pseudomonas syringae. CGB encodes ROL5, a homolog of yeast NCS6 required for tRNA thiolation. ROL5 physically interacts with CTU2, a homolog of yeast NCS2. Mutations in either ROL5 or CTU2 result in loss of tRNA thiolation. Further analyses reveal that both transcriptome and proteome reprogramming during immune responses are compromised in cgb. Notably, the translation of salicylic acid receptor NPR1 is reduced in cgb, resulting in compromised salicylic acid signaling. Our study not only reveals a regulatory mechanism for plant immunity but also uncovers an additional biological function of tRNA thiolation.

Nonexpressor of pathogenesis-related genes 1 (NPR1) was discovered in Arabidopsis as an activator of salicylic acid (SA)-mediated immune responses nearly 30 years ago. How NPR1 confers resistance against a variety of pathogens and stresses has been extensively studied; however, only in recent years have the underlying molecular mechanisms been uncovered, particularly NPR1\'s role in SA-mediated transcriptional reprogramming, stress protein homeostasis, and cell survival. Structural analyses ultimately defined NPR1 and its paralogs as SA receptors. The SA-bound NPR1 dimer induces transcription by bridging two TGA transcription factor dimers, forming an enhanceosome. Moreover, NPR1 orchestrates its multiple functions through the formation of distinct nuclear and cytoplasmic biomolecular condensates. Furthermore, NPR1 plays a central role in plant health by regulating the crosstalk between SA and other defense and growth hormones. In this review, we focus on these recent advances and discuss how NPR1 can be utilized to engineer resistance against biotic and abiotic stresses.