Search

Organic cathode materials (OCMs) have been widely applied in aqueous rechargeable zinc batteries (ARZBs), but there are still many novel structures to be explored for better electrochemical performance and clearer mechanism. Herein, we have studied an organic biological dye, namely thionin (Thn‐CH3COO), as a bipolar‐type OCM for ARZBs based on its electroactive phenothiazine unit. In the optimal electrolyte of 2 M Zn(CF3SO3)2, Thn‐CH3COO exhibited the lowest solubility and thus the highest cycling stability (94 % capacity retention after 100 cycles), with a reversible capacity of 162 mAh g−1 (the theoretical value is 186 mAh g−1) and a discharge plateau at ∼0.8 V vs. Zn2+/Zn. Various characterization and DFT calculations have revealed that both CH3COO− and CF3SO3− anions and H+ cations participated the p‐type and n‐type reactions, respectively. In brief, the novel structure, competitive performance, and exhaustive mechanism investigation will facilitate the further development of ARZBs based on OCMs. [ABSTRACT FROM AUTHOR]

The article presents a study on the use of natural anthraquinone derivative, Physcion, in controlling powdery mildew in Blumeria graminis. Based on bioassay and microarray methods, Physcion does not show effectiveness on the conidial germination of Blumeria graminis but shows significant results in conidial germination in vivo. In conclusion, Physcion controls powdery mildew by enhancing the expression of defence related genes in barley leaves.

Multicellular organisms produce small cysteine-rich antimicrobial peptides as an innate defense against pathogens. While defensins, a well-known class of such peptides, are common among eukaryotes, there are other classes restricted to the plant kingdom. These include thionins, lipid transfer proteins and snakins. In earlier work, we identified several divergent classes of small putatively secreted cysteine-rich peptides (CRPs) in legumes [ Graham et al. (2004) Plant Physiol. 135, 1179–97]. Here, we built sequence motif models for each of these classes of peptides, and iteratively searched for related sequences within the comprehensive UniProt protein dataset, the Institute for Genomic Research’s 33 plant gene indices, and the entire genomes of the model dicot, Arabidopsis thaliana, and the model monocot and crop species, Oryza sativa (rice). Using this search strategy, we identified ∼13 000 plant genes encoding peptides with common features: (i) an N-terminal signal peptide, (ii) a small divergent charged or polar mature peptide with conserved cysteines, (iii) a similar intron/exon structure, (iv) spatial clustering in the genomes studied, and (v) overrepresentation in expressed sequences from reproductive structures of specific taxa. The identified genes include classes of defensins, thionins, lipid transfer proteins, and snakins, plus other protease inhibitors, pollen allergens, and uncharacterized gene families. We estimate that these classes of genes account for ∼2–3% of the gene repertoire of each model species. Although 24% of the genes identified were not annotated in the latest Arabidopsis genome releases (TIGR5, TAIR6), we confirmed expression via RT-PCR for 59% of the sequences attempted. These findings highlight limitations in current annotation procedures for small divergent peptide classes. [ABSTRACT FROM AUTHOR]

Abstract: Crystal structure of ubiquitous toxin from barley α-hordothionin (α-HT) has been determined at 1.9Å resolution by X-ray crystallography. The primary sequence as well as the NMR solution structure of α-HT firmly established that α-HT belongs to a family of membrane active plant toxins–thionins. Since α-HT crystallized in a space group (P41212) that is different from the space group (I422) of previously determined α1- and β-purothionins, and visocotoxin A3, therefore, it provided independent information on protein–protein interactions that may be relevant to the toxin mechanism. The structure of α-HT not only confirms overall architectural features (crambin fold) but also provides an additional confirmation of the role for crucial solute molecules, that were postulated to be directly involved in the mechanism of toxicity for thionins. [Copyright &y& Elsevier]

Abstract In the present study, a rabbit polyclonal antiserum against cell wall-bound thionins from barley leaf and a mouse monoclonal antibody against hydroxyproline-rich glycoproteins (HRGP) from maize were used to investigate the subcellular localization of thionins and HRGP or extensins in Fusarium culmorum -infected wheat spikes by means of the immunogold labelling technique. The proteins were localized in cell walls of different tissues including the lemma, ovary and rachis, while the cytoplasm and organelles in these tissues showed almost no labelling. However, accumulation of thionins and HRGP in infected wheat spikes of resistant wheat cultivars differed distinctly from those of susceptible cultivars. Compared with the healthy tissues, labelling densities for the two types of proteins in cell walls of the infected lemma, ovary and rachis increased only slightly in the susceptible cultivar Agent, while in cell walls of infected tissues of the resistant cultivar Arina labelling densities of thionins and HRGP increased markedly. These findings indicated that accumulation of thionins and HRGP in cell walls of infected resistant wheat spikes may be involved in defence responses to infection and in spreading of F. culmorum . [ABSTRACT FROM AUTHOR]

Studies the processing of thionin precursors in barley leaves by a vacuolar proteinase. Antibodies used to recognize domains in the precursors; Accumulation of thionins in the vacuolar content.