The LRX-RALF-FER cell wall integrity sensing module controls plant growth and salt stress responses by modulating multiple plant hormones
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ABSTRACT: Plants have evolved cell wall integrity signaling pathways to maintain cell wall homeostasis during rapid growth and in response to environmental stress. The cell wall leucine-rich repeat extensins LRX3/4/5, the RAPID ALKALINIZATION FACTOR (RALF) peptides RALF22/23, and FERONIA (FER) function as a module to regulate plant growth and salt stress responses via the sense of cell wall integrity. However, the intracellular signaling pathways that mediate the effects of the LRX3/4/5-RALF22/23-FER module are still largely unknown. Here, we report that jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA) accumulate constitutively in lrx345 and fer mutants. Blocking JA pathway rescues the retarded growth phenotype of the lrx345 and fer-4 mutants, while disruption of ABA biosynthesis suppresses the salt-hypersensitivity of these mutants. Many salt stress-responsive genes display abnormal expression patterns in the lrx345 and fer-4 mutants, as well as in wild type plants treated with epigallocatechin gallate (EGCG), an inhibitor of pectin methylesterases, suggesting that the cell wall integrity is a critical factor that determines the expression of stress-responsive genes. Production of reactive oxygen species (ROS) is constitutively increased in the lrx345 and fer-4 mutants, and inhibition of ROS accumulation suppresses the salt-hypersensitivity of these mutants. Together, our results suggest that the LRX3/4/5-RALF22/23-FER module controls plant growth and salt stress responses by regulating hormonal homeostasis and ROS accumulation.
Project description:Perception and relay of cell wall signals is critical for plants to regulate growth and stress responses, but the mechanism underlying this biological process remains largely unknown. Here we report that RAPID ALKALINIZATION FACTOR (RALFs) peptides, Leucine-rich repeat extensins (LRXs) and FERONIA (FER) are physically associated in extracellular region. lrx345, fer-4, and transgenic plants overexpressing RALF22 or RALF23 all showed retarded growth, increased sensitivity to salt stress, and constitutively increased levels of ABA, JA, and SA. Salt treatment or chemical disruption of cell wall promotes the release of mature RALF peptides, which negatively regulate the function of FER by inducing its internalization. JA mutants coi1 and aos restore the retarded growth, and mutation of ABA2 suppresses the salt-sensitive phenotype of lrx345. Together, we propose that LRXs, RALFs, and FER function as a module to sense and transduce cell wall signals, thereby regulating growth and stress responses via hormones-mediated pathways.
Project description:Cell wall remodeling is important for plants to adapt to environmental stress, and therefore needs to be efficiently modulated during stress conditions. Under salt stress, cortical microtubules undergo a depolymerization-reassembly process to promote the biosynthesis of stress-adaptive cellulose, but the regulatory mechanisms underlying this process are still largely unknown. In this study, we reveal that FERONIA, a potential cell wall sensor, interacts with CC1 and its closest homolog, CC2; two proteins that are required for cortical microtubule reassembly under salt stress. Biochemical data indicate that FER phosphorylates CC1 on multiple residues in the second and third hydrophobic microtubule-binding regions in vitro and in vivo, and that these phosphorylations impact the ability of CC1 to engage with microtubules. Furthermore, FER kinase activity and the CC1 phosphorylation level were temporally coordinated upon exposure to salt stress, which coincided with dynamic microtubule reorganization. Both fer-4 and cc1 cc2 mutants displayed similar salt-sensitive phenotypes, which were related to compromised microtubule reassembly, corroborating that FER and CC1/CC2 function in the same pathway to regulate microtubule organization. Taken together, our study outlines an important intracellular mechanism that maintains microtubule dynamics during salt exposure in plant cells.
Project description:Here we report that FERONIA (FER) integrates phyB-mediated light signaling pathway to control salt stress response. Mutation in phytochrome B (phyB) largely suppresses the dwarfism and leaf bleaching phenotype of fer-4 mutant under salt stress. FER interacts with and phosphorylates the N-terminal domain of phyB. Mutation in fer-4 or disruption of the FER-mediated phosphorylation sites of phyB at Ser106 and Ser227 leads to a retention of phyB in the photobodies under dark conditions, suggesting that FER-mediated phosphorylation accelerates the dark reversion of phyB. Interestingly, salt stress slows down the dark reversion of phyB via the inhibition of the kinase activity of FER, and mutation of phyB or overexpression of PIF5 attenuates the salt-induced growth inhibition. Together, our study indicates that the plasma membrane-localized FER determines the dark reversion rate of phyB in the nucleus via a signature of phosphorylation and thus coordinates the extracellular stress signals and nuclear outputs to dynamically control plant growth and survival under stress conditions.
Project description:Expression Data of Barley Crown and Growing Point Tissue Under Salt Stress abd JA treatment Keywords: treatments (control, salt stressed, JA and JA plus salt stress)
Project description:FERONIA (FER) is a plasma membrane-localized receptor-like kinase (RLK) that belongs to the Catharantus roseus RLK1-like (CrRLK1L) subfamily. FER serves as a potential cell wall sensor that regulates multiple phytohormones, including ABA, JA, SA, BR, auxin, and ethyl, but the underlying regulatory mechanisms are still largely unknown. To further understand how FER regulates downstream signaling pathway, we performed FER-interacting proteins via immunoprecipitation-mass spectrometry (IP-MS) assay generated from FER-GFP transgenic plants.
Project description:As sessile organism, plants evolved a highly complicated signaling system to cope with unfavorable and fluctuating environmental conditions. Rapid and transient Reactive Oxygen Species (ROS) burst is a common response to both biotic and abiotic stresses. Plants exposed with O3 could trigger extracellular similar ROS production through cell wall peroxidases and NPADPH oxidases, resulting in changes in the gene expression and cell death. Whereas ROS induced cell death is not simply due to its toxicity, rather due to interplay with several other signaling pathways, such as salicylic acid (SA), jasmonic acid (JA) and ethylene signaling pathways. Furthermore, the three hormones have both synergistic and antagonistic interactions, where the suppression of JA signaling by SA is the mostly studied. In addition, ethylene promotes cell death while JA has a protective role upon O3 exposure. The role of SA is more complicated; depending on the genetic background it can have either cell death promoting or protecting roles. Hence, a clean system to deliver apoplastic ROS is required to study the role of ROS apart from con-current activation of other signaling pathways. Arabidopsis thaliana offer a convenient system to study apoplastic ROS signaling due to the availability of hormone signaling or biosynthesis mutants including the JA receptor mutant coi1-16 (CORONATINE INSENSITIVE1), the essential ethylene signaling mutant ein2 (ETHYLENE INSENSITIVE2), the SA biosynthesis mutant sid2 (SALICYLIC ACID INDUCTION DEFICIENT2 also known as ISOCHORISMATE SYNTHASE1), and essential regulators in SA/JA/ethylene-induced defense response triple mutant tga2 tga5 tga6 (Clade II TGA transcription factors). Here we used a combination of transcriptome analysis, cell death assays and mutant analysis to systematically quantified the contribution of hormone signaling in relation to apoplastic ROS signaling, identified transcription factors (TFs) involved in ROS regulation and dissected the components involved in defense hormones associated cell death. Transcriptome profiling of ozone response using two arabidopsis triple mutants coi1-16 ein2 sid2 and tga2 tga5 tga6 related to Jasmonic acid, salicylic acid and ethylene signaling to identify hormone-independant apoplastic ROS signaling
Project description:The JA deficient mutant (aoc) showed weaker symptoms than WT when both are exposed to salt. JAs signaling in WT, appeared then to impair salt tolerance and we were interested, through this transcriptomic approach, to highlight the JA-dependent component of the salt stress response that could explain the differential phenotype We report, for root and 2nd leaf, the compared transcriptomes of WT and aoc, before and at 3 different times (1 h, 6 h and 72 h) after salt exposure. The study reveals some key JA-regulated negative and positive effectors of salt stress tolerance in rice
Project description:Expression Data of Barley Crown and Growing Point Tissue Under Salt Stress abd JA treatment Experiment Overall Design: Barley genotype Golden Promise was used for expression anlaysis using the tissue from crown and growing point under control, salt stressed, JA treatment and JA pretreatment followed by salt stress
Project description:Salinity is a major abiotic stress at critical stages of seed germination and seedling establishment. Germination rate (GR) and field emergence rate (FER) are the key traits that determine the basic number of plants stand under field conditions. To explore molecular mechanisms in upland cotton under salt stress, a population of 177 recombinant inbred lines (RILs) and their parents were evaluated for seed germination traits (GP, germination potential; GR; FW, fresh weight; DW, dry weight; GL, germinal length) and seedling traits (FER; SH, seedling height; NL, Number of main stem leaves) in 2016-2018. Based on the linkage map contained 2,859 single nucleotide polymorphism (SNP) and simple sequence repeats (SSR) markers, traits under salt stress (E1) and normal condition, (E2) and the converted relative index (R-value) of three years’ trials were used to map quantitative trait loci (QTL). A total of three QTL and two clusters were detected as salt-tolerant QTL. Three QTL (qGR-Chr4-3, qFER-Chr12-3, qFER-Chr15-1) were detected under salt stress and R-value, which explained phenotypic variance of 9.62%-13.67%, and 4.2%-4.72%, 4.75%-8.96%, respectively. Two clusters (Loci-Chr4-2 and Loci-Chr5-4) harboring the QTL for four germination traits (GR, FER, GL, NL) and six seedling traits (GR, FER, DW, FW, SH, NL) were detected related under salt stress. A total of 691 genes were found in the candidate QTL or clusters. Among them, four genes (Gh_A04G1106, Gh_A05G3246, Gh_A05G3177, Gh_A05G3266) showed expression changes between sensitive and tolerant lines under salt stress, and were assigned as candidate genes in response to salt stress. The consistent salt-tolerance QTL identified in both germination and seedling stages will facilitate new information for cotton breeding.