2-D DIGE analysis of UV-C radiation-responsive proteins in globe artichoke leaves

Plants respond to ultraviolet stress inducing a self-defence through the regulation of specific gene family members. The UV acclimation is the result of biochemical and physiological processes, such as enhancement of the antioxidant enzymatic system and accumulation of UV-absorbing phenolic compounds (e.g. flavonoids). Globe artichoke is an attractive species for studying the protein network involved in UV stress response, being characterized by remarkable levels of inducible antioxidants. Proteomic tools can assist the evaluation of the expression patterns of UV-responsive proteins and we applied the difference in-gel electrophoresis (DIGE) technology for monitoring the globe artichoke proteome variation at four time points following an acute UV-C exposure. A total of 145 UV-C-modulated proteins were observed and 119 were identified by LC-MS/MS using a ～144,000 customized Compositae protein database, which included about 19,000 globe artichoke unigenes. Proteins were Gene Ontology (GO) categorized, visualized on their pathways and their behaviour was discussed. A predicted protein interaction network was produced and highly connected hub-like proteins were highlighted. Most of the proteins differentially modulated were chloroplast located, involved in photosynthesis, sugar metabolisms, protein folding and abiotic stress. The identification of UV-C-responsive proteins may contribute to shed light on the molecular mechanisms underlying plant responses to UV stress.     

Immunity of the greater wax moth Galleria mellonella

Investigation of insect immune mechanisms provides important information concerning innate immunity, which in many aspects is conserved in animals. This is one of the reasons why insects serve as model organisms to study virulence mechanisms of human pathogens. From the evolutionary point of view, we also learn a lot about host–pathogen interaction and adaptation of organisms to conditions of life. Additionally, insect‐derived antibacterial and antifungal peptides and proteins are considered for their potential to be applied as alternatives to antibiotics. While Drosophila melanogaster is used to study the genetic aspect of insect immunity, Galleria mellonella serves as a good model for biochemical research. Given the size of the insect, it is possible to obtain easily hemolymph and other tissues as a source of many immune‐relevant polypeptides. This review article summarizes our knowledge concerning G. mellonella immunity. The best‐characterized immune‐related proteins and peptides are recalled and their short characteristic is given. Some other proteins identified at the mRNA level are also mentioned. The infectious routes used by Galleria natural pathogens such as Bacillus thuringiensis and Beauveria bassiana are also described in the context of host–pathogen interaction. Finally, the plasticity of G. mellonella immune response influenced by abiotic and biotic factors is described.     

A modified Coomassie Brilliant Blue staining method at nanogram sensitivity compatible with proteomic analysis

A more sensitive and convenient Coomassie Brilliant Blue (CBB) staining method for visualizing proteins was developed. Compared with the modifications include the supplement of 10% (v/v) methanol into the fixing solution, an increase of an additional sensitization step and CBB raised from 0.1 to 0.125%. The improved method can detect proteins at nanogram level. The improved method is more sensitive than Blue Silver and more convenient than the Silver protocol. Mass spectrometry results confirmed that it is suitable for subsequent proteomic research.     

Plant lectins as potent Anti-coronaviruses,Anti-inflammatory,antinociceptive and antiulcer agents

Lectins are defined as carbohydrate-binding proteins/glycoproteins of none immune origin, they are ubiquitous in nature, exist from bacteria to human cells. And due to their carbohydrate-binding recognition capacity, they have been a useful biological tool for the purification of glycoproteins and their subsequent characterization. Some plant lectins have also been revealed to own antinociceptive, antiulcer, and anti-inflammatory properties, where these features, in many instances, depending on the lectin carbohydrate-binding site. Coronavirus disease of 2019 (COVID-19) is a respiratory disease that struck the entire world leaving millions of people dead and more infected. Although COVID-19 vaccines have been made available, and quite a large number of world populations have already been immunized, the viral infection rates remained in acceleration, which continues to provoke major concern about the vaccines' efficacy. The belief in the ineffectiveness of the vaccine has been attributed in part to the recurrent mutations that occur in the epitope determinant fragments of the virus. Coronavirus envelope surface is extensively glycosylated being covered by more than sixty N-linked oligomannose, composite, and hybrid glycans with a core of Man3GlcNAc2Asn. In addition some O–linked glycans are also detected. Of these glyco-chains, many have also been exposed to several mutations, and a few remained conserved. Therefore, numerous plant lectins with a specificity directed towards these viral envelope sugars have been found to interact preferentially with them and are suggested to be scrutinized as a possible future tool to combat coronaviruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through blocking the viral attachment to the host cells. In this review, we will discuss the possible applications of plant lectins as anti-coronaviruses including SARS-CoV-2, antinociceptive, anti-inflammatory, and antiulcer agents with the proposed mechanism of their actions.     

The rumen anaerobic fungi

The anaerobic fungi represent a new group of organisms inhabiting the rumen ecosystem and possess a life cycle alternating between a motile flagellated form (zoospore) and a non-motile vegetative reproductive form (thallus). In vivo studies show extensive colonization of plant material suspended in the rumen indicating the fungi have a role in fiber digestion. Pure cultures of anaerobic fungi ferment cellulose to give lactate, acetate, CO₂ and H₂ as the major products. Ethanol and formate may also be produced. Fermentation of cellulose by the fungi in coculture with H₂-utilizing methanogens results in a shift in the fermentation pattern favouring the production of H₂ (utilized in the formation of CH₄) and acetate at the expense of the electron-sink products, lactate and ethanol. It is postulated that the methanogens in reducing the partial pressure of H₂, facilitate an increased passage of reducing equivalents towards the production of H₂ via a pyridine-nucleotide (PN)-linked hydrogenase reaction. H₂ is believed to be produced in microbodies of the fungi called hydrogenosomes which possess all of the enzymes necessary for this function including PN-linked hydrogenase. Absence of mitochondria and key electron transport components in these organisms indicate a dependence wholly on fermentative processes for growth. Anaerobic fungi also participate in hemicellulose and starch degredation but it is not yet clear whether they have a role in the degradation of lignin. Simple sugars (mono- and disaccharides) are readily utilized and their uptake is subject to similar regulatory constraints such as is found with other micro-organisms.Enzymological studies have revealed that anaerobic fungi release substantial amounts of endo-acting cellulase and protease, possibly giving them a competitive advantage over rumen bacteria in the degradation of plant structural material.     

The function of small RNAs in plant biotic stress response

Small RNAs(s RNAs) play essential roles in plants upon biotic stress. Plants utilize RNA silencing machinery to facilitate pathogen-associated molecular pattern-triggered immunity and effector-triggered immunity to defend against pathogen attack or to facilitate defense against insect herbivores. Pathogens, on the other hand, are also able to generate effectors and s RNAs to counter the host immune response. The arms race between plants and pathogens/insect herbivores has triggered the evolution of s RNAs,RNA silencing machinery and pathogen effectors. A great number of studies have been performed to investigate the roles of s RNAs in plant defense, bringing in the opportunity to utilize s RNAs in plant protection. Transgenic plants with pathogen-derived resistance ability or transgenerational defense have been generated, which show promising potential as solutions for pathogen/insect herbivore problems in the field. Here we summarize the recent progress on the function of s RNAs in response to biotic stress, mainly in plant-pathogen/insect herbivore interaction,and the application of s RNAs in disease and insect herbivore control.     

The Nicotiana attenuata LECTIN RECEPTOR KINASE 1 is involved in the perception of insect feeding

The Nicotiana attenuata LECTIN RECEPTOR KINASE 1 (LecRK1) has been recently identified as a component of the mechanism used by plants to suppress the Manduca sexta-triggered accumulation of salicylic acid (SA). The suppression of the SA burst by LecRK1 allows for the unfettered induction of jasmonic acid (JA)-mediated defense responses against M. sexta herbivory. LecRK1 contains a multi-domain extracellular region composed of a G-type Lectin domain and a PAN-AP domain separated by a variable sequence with low similarity to an EGF domain. The LecRK1 intracellular region is composed of a single domain structure with predicted Ser/Thr protein kinase activity. The multi-domain structure of the extracellular region of LecRK1 adds a level of complexity in terms of the potential ligands that this receptor protein could recognize.