Identification of ε-Poly-L-lysine as an Antimicrobial Product from an Endophyte and Isolation of Fungal ε-PL Synthetase Gene.

The endophytic fungus is known to produce bioactive metabolites, which consequently protect the host plants from biotic and abiotic stresses. We previously found that the overexpression of (a gene for transcription factor) in strain E437 resulted in the secretion of an unknown fungicide. In the present study, the active substance was purified and chemically identified as ε-poly-L-lysine (ε-PL), which consisted of 28-34 lysine units.

RNAi of the sesquiterpene cyclase gene for phytoalexin production impairs pre- and post-invasive resistance to potato blight pathogens.

Potato antimicrobial sesquiterpenoid phytoalexins lubimin and rishitin have been implicated in resistance to the late blight pathogen, Phytophthora infestans and early blight pathogen, Alternaria solani. We generated transgenic potato plants in which sesquiterpene cyclase, a key enzyme for production of lubimin and rishitin, is compromised by RNAi to investigate the role of phytoalexins in potato defence. The transgenic tubers were deficient in phytoalexins and exhibited reduced post-invasive resistance to an avirulent isolate of P.

Nitrate analogs as attractants for soybean cyst nematode.

Soybean cyst nematode (SCN) Heterodera glycines Ichinohe, a plant parasite, is one of the most serious pests of soybean. In this paper, we report that SCN is attracted to nitrate and its analogs. We performed attraction assays to screen for novel attractants for SCN and found that nitrates were attractants for SCN and SCN recognized nitrate gradients.

1,10-Phenanthroline and its derivatives are novel hatching stimulants for soybean cyst nematodes.

Soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is a plant-parasitic nematode and one of the most serious soybean pests. Herein, we present the heterocyclic compound 1,10-phenanthroline (Phen) and its derivatives as novel hatching stimulants for SCN. Phen treatment promoted hatching of second-stage juveniles of SCNs in a concentration-dependent manner.

Identification of lactate dehydrogenase as a mammalian pyrroloquinoline quinone (PQQ)-binding protein.

Pyrroloquinoline quinone (PQQ), a redox-active o-quinone, is an important nutrient involved in numerous physiological and biochemical processes in mammals. Despite such beneficial functions, the underlying molecular mechanisms remain to be established. In the present study, using PQQ-immobilized Sepharose beads as a probe, we examined the presence of protein(s) that are capable of binding PQQ in mouse NIH/3T3 fibroblasts and identified five cellular proteins, including l-lactate dehydrogenase (LDH) A chain, as potential mammalian PQQ-binding proteins.

Oxidative Deamination of Serum Albumins by (-)-Epigallocatechin-3-O-Gallate: A Potential Mechanism for the Formation of Innate Antigens by Antioxidants.

(-)-Epigallocatechin-3-O-gallate (EGCG), the most abundant polyphenol in green tea, mediates the oxidative modification of proteins, generating protein carbonyls. However, the underlying molecular mechanism remains unclear. Here we analyzed the EGCG-derived intermediates generated upon incubation with the human serum albumin (HSA) and established that EGCG selectively oxidized the lysine residues via its oxidative deamination activity.

Toll-like receptors as a target of food-derived anti-inflammatory compounds.

Toll-like receptors (TLRs) play a key role in linking pathogen recognition with the induction of innate immunity. They have been implicated in the pathogenesis of chronic inflammatory diseases, representing potential targets for prevention/treatment. Vegetable-rich diets are associated with the reduced risk of several inflammatory disorders.

EPIDERMAL PATTERNING FACTOR LIKE5 peptide represses stomatal development by inhibiting meristemoid maintenance in Arabidopsis thaliana.

Stomatal development in Arabidopsis epidermis is both positively and negatively regulated by a family of Cys-rich peptides, EPIDERMAL PATTERNING FACTOR LIKEs (EPFLs). We synthesized biologically active synthetic EPFL5 (sEPFL5) peptide, which reduced the number of stoma in leaves and cotyledons. The sEPFL5 possesses three disulfide bonds at positions identical to those of a positive development factor, stomagen.

Differential effects of the peptides Stomagen, EPF1 and EPF2 on activation of MAP kinase MPK6 and the SPCH protein level.

The positioning and density of leaf stomata are regulated by three secretory peptides, EPIDERMAL PATTERNING FACTOR 1 (EPF1), EPF2 and stomagen. Several lines of published evidence have suggested a regulatory pathway as follows. EPF1 and EPF2 are perceived by receptor complexes consisting of a receptor-like protein, TOO MANY MOUTHS (TMM), and receptor kinases, ERECTA (ER), ERECTA-LIKE (ERL) 1 and ERL2.

Analogs of the CLV3 peptide: synthesis and structure-activity relationships focused on proline residues.

CLAVATA3 (CLV3) is a plant peptide hormone in which the proline residues are post-translationally hydroxylated and glycosylated. CLV3 plays a key role in controlling the stem cell mass in the shoot meristem of Arabidopsis thaliana. In a previous report, we identified a dodecapeptide (MCLV3) from CLV3-overexpressing Arabidopsis calli; MCLV3 was the smallest functional peptide derived from the CLV3 precursor.

Stomatal density is controlled by a mesophyll-derived signaling molecule.

Stomata are composed of a pair of guard cells and a pore between them, and their density and positions are regulated by developmental and environmental signals. In a screen in which we overexpressed many genes coding for putative secretory proteins one by one in Arabidopsis, we identified a gene named STOMAGEN, which increases stomatal density when overexpressed. The STOMAGEN gene encodes a small peptide with a putative secretory signal sequence at its N-terminus and is expressed preferentially in mesophyll cells.

O-linked N-acetylglucosamine is present on the extracellular domain of notch receptors.

Rare types of glycosylation often occur in a domain-specific manner and are involved in specific biological processes. In particular, O-fucose glycans are reported to regulate the functions of EGF domain-containing proteins such as Notch receptors. In the course of mass spectrometric analysis of O-glycans displayed on Drosophila Notch receptors expressed in S2 cells, we found an unusual O-linked N-acetylhexosamine (HexNAc) modification which occurs at a site distinct from those of O-fucose and O-glucose glycosylations.

Articulospora sp. produces Art1, an inhibitor of bacterial histidine kinase.

A two-component system (TCS) comprising a histidine kinase (HK) sensor and a response regulator (RR) plays important roles in regulating the virulence of many pathogenic bacteria. We used a new screening method to isolate novel inhibitor Art1 against bacterial sensory HK from an acetone extract of solid cultures of Articulospora sp., an aquatic hypomycete.

Dioctatin A is a strong inhibitor of aflatoxin production by Aspergillus parasiticus.

Dioctatin A (DotA), a metabolite of Streptomyces, is known to be an inhibitor of human dipeptidyl aminopeptidase II. Here, it was found that DotA strongly inhibited aflatoxin production by Aspergillus parasiticus, with an IC50 value of 4.0 microM.

A plant peptide encoded by CLV3 identified by in situ MALDI-TOF MS analysis.

The Arabidopsis CLAVATA3 (CLV3) gene encodes a stem cell-specific protein presumed to be a precursor of a secreted peptide hormone. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) applied to in situ Arabidopsis tissues determined the structure of a modified 12-amino acid peptide (MCLV3), which was derived from a conserved motif in the CLV3 sequence. Synthetic MCLV3 induced shoot and root meristem consumption as cells differentiated into other organs, displaying the typical phenotype of transgenic plants overexpressing CLV3.