RNA–directed DNA methylation (RdDM) is an epigenetic control mechanism driven by small interfering RNAs (siRNAs) that influence gene function. In plants, little known of the involvement RdDM pathway in regulating traits related to immune responses. a genetic screen designed reveal factors immunity Arabidopsis thaliana, we identified NRPD2 as OVEREXPRESSOR OF CATIONIC PEROXIDASE 1 (OCP1). encodes second largest subunit plant-specific RNA Polymerases IV and V (Pol Pol V), which are crucial for...

In higher eukaryotes, induced resistance associates with acquisition of a priming state the cells for more effective activation innate immunity; however, nature components mounting this type immunological memory is not well known. We identified an extracellular subtilase from Arabidopsis, SBT3.3, overexpression which enhances immune responses while loss function compromises them. SBT3.3 expression initiates durable autoinduction mechanism that promotes chromatin remodeling and activates...

Summary In the present study, we evaluated role of defense‐related gene OCP3 in callose deposition as a response to two necrotrophic fungal pathogens, Botrytis cinerea and Plectosphaerella cucumerina. ocp3 plants exhibited accelerated intensified infection associated with enhanced disease resistance pathogens. A series double mutant analyses showed potentiation heightened phenotype required plant hormone abscisic acid (ABA) PMR4 encoding synthase. This finding was congruent an observation...

Abstract In this study, we show that the Arabidopsis (Arabidopsis thaliana) transcription factor MYB46, previously described to regulate secondary cell wall biosynthesis in vascular tissue of stem, is pivotal for mediating disease susceptibility fungal pathogen Botrytis cinerea. We identified MYB46 by its ability bind a new cis-element located 5′ promoter region pathogen-induced Ep5C gene, which encodes type III wall-bound peroxidase. present genetic and molecular evidence indicating...

Organogenesis occurs through cell division, expansion, and differentiation. How these cellular processes are coordinated remains elusive. The maize (Zea mays) leaf provides a robust system to study differentiation due its distinct tissues types. narrow odd dwarf (nod) mutant displays defects at both the tissue level that increase in severity throughout growth. nod leaves have reduced size fewer smaller cells compared with wild type. juvenile-to-adult transition is delayed, proximal...

The mechanisms controlling plant resistance to necrotrophic fungal pathogens are poorly understood. We previously reported on Ep5C, a gene shown be induced by the H2O2 generated during plant–pathogen interaction. To identify novel components operating in pathogen-induced signaling cascades, we initiated large-scale screen using Arabidopsis thaliana plants carrying β-glucuronidase reporter under control of H2O2-responsive Ep5C promoter. Here, report identification and characterization mutant,...

Water scarcity and corresponding abiotic drought stress is one of the most important factors limiting plant performance yield. In addition, productivity severely compromised worldwide by infection with microbial pathogens. Two prominent pathways responsible for tolerance disease resistance to fungal pathogens in Arabidopsis are those controlled phytohormones abscisic acid (ABA) oxylipin methyl jasmonate (MeJA), respectively. Here, we report on functional characterization OCP3, a...

Plant regulatory circuits coordinating nuclear and plastid gene expression have evolved in response to external stimuli. RNA editing is one of such control mechanisms. We determined the Arabidopsis nuclear-encoded homeodomain-containing protein OCP3 incorporated into chloroplast, contributes over extent ndhB transcript editing. encodes B subunit chloroplast NADH dehydrogenase-like complex (NDH) involved cyclic electron flow (CEF) around photosystem I. In ocp3 mutant strains, efficiency...

Abstract Background Upon appropriate stimulation, plants increase their level of resistance against future pathogen attack. This phenomenon, known as induced resistance, presents an adaptive advantage due to its reduced fitness costs and systemic broad-spectrum nature. In Arabidopsis , different types have been defined based on the signaling pathways involved, particularly those dependent salicylic acid (SA) and/or jasmonic (JA). Results Here, we assessed implication transcriptional...

Abstract Plant cell walls contain the hemicellulose xyloglucan, whose fine structure may vary depending on type, tissue, and/or plant species. Most but not all of glycosyltransferases involved in biosynthesis xyloglucan sidechains have been identified. Here, we report identification several functional from blueberry ( Vaccinium corymbosum bluecrop). Among those transferases is a hitherto elusive X yloglucan: B eta‐xylosyl T ransferase (XBT). Heterologous expression VcXBT Arabidopsis thaliana...

Bacterial speck caused by the pathogen Pseudomonas syringae pv. tomato (P. s. tomato) is a devastating disease of plants. Here we show that inhibition Ep5C gene expression, which encodes secreted cationic peroxidase, sufficient to confer resistance against P. tomato. The protein accumulation in antisense plants established was not accompanied pre-activation known defense pathways. Therefore, represents novel form based on loss-of-gene function plant required for successful infection...

The cell wall is a protective barrier of paramount importance for the survival plant cells. Monitoring integrity allows plants to quickly activate defence pathways minimize pathogen entry and reduce spread disease. Counterintuitively, however, pharmacological effects as well genetic lesions that affect cellulose biosynthesis content confer with enhanced resistance against necrotrophic fungi. This kind pathogens target degradation facilitate penetration generate glucose units food source. Our...

Mutants affected in the Arabidopsis TBL29/ESK1 xylan O-acetyltransferase display a strong reduction total wall O-acetylation accompanied by dwarfed plant stature, collapsed xylem morphology, and enhanced freezing tolerance. A newly identified tbl29/esk1 suppressor mutation reduces expression of MAX4 gene, affecting biosynthesis methyl carlactonoate (MeCLA), an active strigolactone (SL). Genetic biochemical evidence suggests that blocking this SL is sufficient to recover all developmental...

The presence of mixed-linkage (1,3;1,4)-β-d-glucan (MLG) in plant cell walls is a key feature grass species such as cereals, the main source calorie intake for humans and cattle. Accumulation this polysaccharide involves coordinated regulation biosynthetic metabolic machineries. While several components MLG biosynthesis machinery have been identified diverse species, degradation poorly understood. In study, we performed large-scale forward genetic screen maize (Zea mays) mutants with altered...

The development of efficient pipelines for the bioconversion grass lignocellulosic feedstocks is challenging due to limited understanding molecular mechanisms controlling synthesis, deposition, and degradation varying polymers unique cell walls. Here, we describe a large-scale forward genetic approach resulting in identification collection chemically mutagenized maize mutants with diverse alterations their wall attributes such as crystalline cellulose content or hemicellulose composition....

Defects in the biosynthesis and/or deposition of secondary plant cell wall polymers result collapse xylem vessels causing a dwarfed stature and an altered architecture termed irregular (irx) syndrome. For example, reduced xylan O-acetylation causes strong developmental defects increased freezing tolerance. Recently, we demonstrated that irx syndrome trichome birefringence-like 29/eskimo1 (tbl29/esk1) mutant is dependent on MORE AXILLARY GROWTH 4 (MAX4), key enzyme phytohormone strigolactone...

Transfer RNA (tRNA) is the most highly modified class of species in all living organisms. Recent discoveries have revealed unprecedented complexity tRNA chemical structures, modification patterns, regulation, and function, suggesting that each nucleoside may its own specific function. However, plants, our knowledge role individual modifications how they are regulated very limited. In a genetic screen designed to identify factors regulating disease resistance Arabidopsis, we identified...

tRNA is the most highly modified class of RNA species, and modifications are found in tRNAs from all organisms that have been examined. Despite their vastly different chemical structures presence tRNAs, occurring locations tRNA, biosynthetic pathways majority include a methylation step(s). Recent discoveries revealed unprecedented complexity modification patterns regulation function, suggesting each nucleoside may its own specific function. However, plants, our knowledge on role individual...