Latex Proteins Research Articles

HEALING RATE IN DIABETIC FOOT ULCERS TREATED WITH BIOMEMBRANE AND HYDROCOLLOID POWDER: RANDOMIZED CLINICAL TRIAL

Objective: to evaluate the rate of healing in diabetic foot ulcers treated with a biomembrane of latex proteins from Calotropis procera (BioMem CpLP) when compared to powdered hydrocolloid. Method: randomized controlled clinical trial, registered by the Brazilian Clinical Trial Registry (REBEC), according to protocol RBR-98f3j9, carried out with eight people with diabetic foot, in a diabetic foot clinic, from March to July 2019. In the experimental group (n = 04), biomembrane was applied; in the control group (n = 04), hydrocolloid powder was used. The healing rate was assessed at 30 and 60 days after starting treatment. Results: no statistical differences were found between the healing rates of the control group and the experimental group in the temporal analysis of the initial 30 days (p = 0.726) and in the 60 days following the start of treatment (p = 0.562). Conclusion: BioMem CpLP presented healing rates similar to the conventional product, being an effective and low cost alternative for the treatment of diabetic feet.

Unraveling Interactions of the Necrotrophic Fungal Species Botrytis cinerea With 1-Methylcyclopropene or Ozone-Treated Apple Fruit Using Proteomic Analysis.

Gray mold caused by the necrotrophic fungus Botrytis cinerea is one of the major postharvest diseases of apple fruit. The exogenous application of 1-methylcyclopropene (1-MCP) and gaseous ozone (O 3) is commonly used to ensure postharvest fruit quality. However, the effect of these treatments on the susceptibility of apple fruit to postharvest pathogens remains largely unknown. Herein, the effect of O 3 and 1-MCP treatments on the development of gray mold on apple fruit (cv. “Granny Smith”) was investigated. Artificially inoculated apple fruits, treated or not with 1-MCP, were subjected for 2 months to cold storage [0°C, relative humidity (RH) 95%] either in an O3-enriched atmosphere or in a conventional cold chamber. Minor differences between 1-MCP-treated and control fruits were found in terms of disease expression; however, exposure to ozone resulted in a decrease of disease severity by more than 50% compared with 1-MCP-treated and untreated fruits. Proteomic analysis was conducted to determine proteome changes in the mesocarp tissue of control and 1-MCP- or O3-treated fruits in the absence or in the presence of inoculation with B. cinerea. In the non-inoculated fruits, 26 proteins were affected by 1-MCP, while 51 proteins were altered by ozone. Dynamic changes in fruit proteome were also observed in response to B. cinerea. In O3-treated fruits, a significant number of disease/defense-related proteins were increased in comparison with control fruit. Among these proteins, higher accumulation levels were observed for allergen, major allergen, ACC oxidase, putative NBS-LRR disease resistance protein, major latex protein (MLP)-like protein, or 2-Cys peroxiredoxin. In contrast, most of these proteins were down-accumulated in 1-MCP-treated fruits that were challenged with B. cinerea. These results suggest that ozone exposure may contribute to the reduction of gray mold in apple fruits, while 1-MCP was not effective in affecting this disease. This is the first study deciphering differential regulations of apple fruit proteome upon B. cinerea infection and postharvest storage treatments, underlying aspects of host response related to the gray mold disease.

Exogenous cysteine alleviates chromium stress via reducing its uptake and regulating proteome in roots of Brassica napus L. seedlings

Sulfur compounds are known to play crucial roles in plants facilitating tolerance to heavy metal stress. Previous studies have shown the protective role of exogenous cysteine (Cys) to improve chromium (Cr) tolerance. In the present study, we aimed to evaluate the capability of Cys (0.5 mM) to reduce chromium toxicity (100 μM) in rapeseed by physiological and proteomic analyses. Seedlings treated with Cr showed reduced growth and activities of antioxidant enzymes, and increased malondialdehyde (MDA) content. Exogenous application of Cys reduced Cr accumulation and MDA content, restored catalase (CAT) and peroxidase (POD) activities, and caused significant enhancements in seedling growth. 2-DE gel electrophoresis and mass spectrometry were performed to investigate changes in the root proteome in response to Cys and Cr. The Cr-induced down-regulations of glycine-rich RNA-binding protein, lactoylglutathione lyase, fructose-bisphosphate aldolase, and glutamine synthetase were restored with Cys. Additionally, Cys removed the Cr-induced up-regulation of some proteins including pathogenesis-related protein, major latex protein (MLP) like proteins, 22.0 kDa HSP, triosephosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase, glutamine amidotransferase, cysteine synthase, and L-lactate dehydrogenase. Taken together, proteomic analysis revealed that exogenous Cys helps plants to overcome Cr stress by modulating energy metabolism, amino acid metabolism, and defense mechanism.

Latex proteins from Plumeria pudica reduce ligature-induced periodontitis in rats.

Previous studies have shown that latex proteins from Plumeria pudica (LPPp) have anti-inflammatory and antioxidant activity. Therefore, the aim of this study was to evaluate the effects in rats of LPPp on ligature-induced periodontitis, an inflammatory disease. The animals were divided into groups: saline (animals without induction of periodontitis), periodontitis (induced periodontitis and untreated) and LPPp (induced periodontitis and treated with 40mg/kg). The following parameters were evaluated after 20 consecutive days of treatment: gingival bleeding index (GBI), probing pocket depth (PPD), alveolar bone height (ABH) and gingival myeloperoxidase (MPO) activity. In the hepatic tissue, malondialdehyde (MDA), glutathione (GSH) and histopathological alterations were evaluated. Blood levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. Significant reduction in GBI, PPD and gingival MPO activity and ABH was seen in animals treated with LPPp compared with periodontitis. Values of GSH, MDA, ALT and histopathological evaluation were preserved in animals treated with LPPp. Treatment with LPPp improved clinical aspects of periodontitis, reduced the blood and hepatic alterations and prevented alveolar bone loss. Data suggest that LPPp have potential for treatment of periodontitis.

Perspectives for the use of latex peptidases from Calotropis procera for control of inflammation derived from Salmonella infections

BackgroundAnti-inflammatory properties have been attributed to latex proteins of the medicinal plant Calotropis procera. PurposeA mixture of cysteine peptidases (LPp2) from C. procera latex was investigated for control of inflammatory mediators and inflammation in a mouse model of Salmonella infection. MethodsLPp2 peptidase activity was confirmed by the BANA assay. Cytotoxicity assays were conducted with immortalized macrophages. Peritoneal macrophages (pMØ) from Swiss mice were stimulated with lipopolysaccharide (LPS) in 96-well plates and then cultured with nontoxic concentrations of LPp2. Swiss mice intravenously received LPp2 (10 mg/kg) and then were challenged intraperitoneally with virulent Salmonella enterica Ser. Typhimurium. ResultsLPp2 was not toxic at dosages lower than 62.2 μg/mL. LPp2 treatments of pMØ stimulated with LPS impaired mRNA expression of pro-inflammatory cytokines IL-1β, TNF-α, IL-6 and IL-10. LPp2 increased the intracellular bacterial killing in infected pMØ. Mice given LPp2 had a lower number of leukocytes in the peritoneal cavity in comparison to control groups 6 h after infection. The bacterial burden and histological damage were widespread in target organs of mice receiving LPp2. ConclusionWe conclude that LPp2 contains peptidases with strong anti-inflammatory properties, which may render mice more susceptible to early disseminated infection caused by Salmonella.

Cheese-making Ability of <i>Plumeria alba</i> and <i>Plumeria rubra</i> Latex: Milk Clotting and Proteolytic Activities

In cheese making industry, plant enzymes are used to produce cheese. In Ouest Africa, they produced the cheese “waragashi” with the mix milk and the plant <i>Calotropis procera</i>. The objective of our study is to assess ability to coagulate milk of the latex from news plants <i>Plumeria alba </i>and<i> Plumeria rubra. </i>If the two plants can supplied<i> Calotropis procera in cheese making.</i> For the results, we observed that the latex of <i>Plumeria alba</i> and <i>Plumeria rubra</i> are richer in proteins and mineral elements than the latex of <i>Calotropis procera</i>. It appears that the milk clotting and proteolytic activities of the latex of <i>Plumeria alba</i> and <i>Plumeria rubra</i> reached their optimum at 75°C while those <i>of Calotropis procera</i> reached the optimum at 55°C but remained active above 60 and 70°C. The Proteolytic Activity of the latex of <i>C. procera</i> and the two species of <i>Plumeria</i> was maximal at concentrations of 10% and 20% in the reaction medium, respectively. Polyacrylamide gel electrophoresis revealed that <i>Plumeria alba</i> latex had proteins with molecular weights of 10 and 25 kDa while the molecular weights <i>Plumeria rubra</i> latex proteins were 10, 25, 45kDa. The MCA/ PA ratio of <i>Calotropis procera</i>, <i>Plumeria alba</i> and <i>Plumeria rubra</i> was 1142.86; 810.81 and 576.92 respectively. These two <i>Plumeria</i> latex could validly replace <i>C. procera</i> latex in the production of cheese.

Protein Removal from Natural Rubber Latex with Fe3O4@Al2O3 Nanoparticle

The presence of protein in the natural rubber latex for the medical device manufacture seems to be the most considered compound due to its allergic effect. Magnetic coated alumina (Fe3O4@Al2O3) has been known as an adsorbent for organic substrates due to its performance through physical and/or chemical interaction. In the current study, we tried to figure out the potential of Fe3O4@Al2O3 to prepare low protein’s natural rubber latex with and without the presence of surfactant through a continuous batch system. The dry rubber content, surfactant amount, and time during the incubation were investigated to determine the effective protein removal natural rubber. The highly deproteinized natural rubber was confirmed using Kjeldahl method, proven that the utilization of Fe3O4@Al2O3 could reduce the protein content from 0.38 to 0.016% in an optimum condition (dry rubber content of 10.00%; surfactant of 0.25%; Fe3O4@Al2O3 of 1.00 wt.%; and 15 min of incubation time). These results showed that Fe3O4@Al2O3 is a very good material to remove protein from natural rubber latex and this method can be performed using a continuous batch system.

Considering the switch to a latex-free glove policy to safeguard staff and patients.

While it is difficult to imagine that before the late 1800s, surgeons in the theatre environment operated on patients without gloves, gloves are now a clinical necessity. Their use has risen exponentially over the last 30 years, along with concerns over staff and patient allergy and sensitivity to the natural rubber latex proteins used in their manufacture. Having used latex gloves for the better part of 35 years, the author recently evaluated a latex-free alternative. In this article, which presents a rationale for the introduction of a latex-free glove policy across NHS departments and trusts, particularly in theatre settings, the author presents his experience, together with cases from four other surgeons, as well as evidence from the literature regarding potential clinical outcomes, quality of life and cost-effectiveness associated with latex-free gloves.

Latex particles by emulsion and dispersion polymerizations: sensitization with specific antigens of leptospirosis and application to immunoagglutination

The controlled synthesis of polymer nanoparticles is of great interest in the production of latexes with well defined characteristics. These products can be applied in biomedicine as carriers of biomolecules (e.g. proteins and enzymes), and in particular as latexes for immunoassays used for example in immunoagglutination test, which allow amplify the antigen–antibody reaction, being simple, quick and inexpensive diagnostic tools. The synthesis of polystyrene (PS) latex particles and of core–shell particles, with controlled size distribution, functional groups and surface charge densities is considered here. PS latexes were synthesized in the 100–1100 nm diameter range, by either emulsion or dispersion polymerization. Such latexes were then used as seeds in emulsion copolymerizations of styrene and a functional monomer (methacrylic acid or glycidyl methacrylate), thus producing particles with carboxyl or epoxy functionalities, respectively. Changes in the polymerization recipes employed under batch operation were analyzed. Latex characterization involved measurements of mean particle diameters, the polydispersity index, functional group densities and zeta potential. Finally, latexes were sensitized (by either physical adsorption or covalent coupling) with specific antigens to obtain latex–protein complexes, and one of them was tested as agglutination assay for detecting leptospirosis disease in bovine samples, as an example of the potential application of the latexes produced.

Major latex protein-like encoding genes contribute to Rhizoctonia solani defense responses in sugar beet

Sugar beets are attacked by several pathogens that cause root damages. Rhizoctonia (Greek for “root killer”) is one of them. Rhizoctonia root rot has become an increasing problem for sugar beet production and to decrease yield losses agronomical measures are adopted. Here, two partially resistant and two susceptible sugar beet genotypes were used for transcriptome analysis to discover new defense genes to this fungal disease, information to be implemented in molecular resistance breeding. Among 217 transcripts with increased expression at 2 days post-infection (dpi), three resistance-like genes were found. These genes were not significantly elevated at 5 dpi, a time point when increased expression of three Bet v I/Major latex protein (MLP) homologous genes BvMLP1, BvMLP2 and BvML3 was observed in the partially resistant genotypes. Quantitative RT-PCR analysis on diseased sugar beet seedlings validated the activity of BvMLP1 and BvMLP3 observed in the transcriptome during challenge by R. solani. The three BvMLP genes were cloned and overexpressed in Arabidopsis thaliana to further dissect their individual contribution. Transgenic plants were also compared to T-DNA mutants of orthologous MLP genes. Plants overexpressing BvMLP1 and BvMLP3 showed significantly less infection whereas additive effects were seen on Atmlp1/Atmlp3 double mutants. The data suggest that BvMLP1 and BvMLP3 may contribute to the reduction of the Rhizoctonia root rot disease in sugar beet. Impact on the defense reaction from other differential expressed genes observed in the study is discussed.

Hevea brasiliensis latex proteomics: a review of analytical methods and the way forward.

Natural rubber or latex from the Hevea brasiliensis is an important commodity in various economic sectors in today's modern society. Proteins have been detected in latex since the early twentieth century, and they are known to regulate various biological pathways within the H. brasiliensis trees such as the natural rubber biosynthesis, defence against pathogens, wound healing, and stress tolerance. However, the exact mechanisms of the pathways are still not clear. Proteomic analyses on latex have found various proteins and revealed how they fit into the mechanisms of the biological pathways. In the past three decades, there has been rapid latex protein identification due to the improvement of latex protein extraction methods, as well as the emergence of two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). In this manuscript, we reviewed the methods of latex protein extraction that keeps on improving over the past three decades as well as the results of numerous latex protein identification and quantitation.

Latex Proteins from Plumeria pudica with Therapeutic Potential on Acetaminophen-Induced Liver Injury.

Liver disease is global health problem. Paracetamol (APAP) is used as an analgesic drug and is considered safe at therapeutic doses, but at higher doses, it causes acute liver injury. N-acetyl-p- Benzoquinone Imine (NAPQI) is a reactive toxic metabolite produced by biotransformation of APAP. NAPQI damages the liver by oxidative stress and the formation of protein adducts. The glutathione precursor N-acetylcysteine (NAC) is the only approved antidote against APAP hepatotoxicity, but it has limited hepatoprotective effects. The search for new drugs and novel therapeutic intervention strategies increasingly includes testing plant extracts and other natural products. Plumeria pudica (Jacq., 1760) is a plant that produces latex containing molecules with therapeutic potential. Proteins obtained from this latex (LPPp), a well-defined mixture of chitinases, proteinases proteinase inhibitors have shown anti-inflammatory, antinociceptive, antidiarrheal effects as well as a protective effect against ulcerative colitis. These studies have demonstrated that LPPp acts on parameters such as Glutathione (GSH) and Malondialdehyde (MDA) concentration, Superoxide Dismutase (SOD) activity, Myeloperoxidase (MPO) activity, and TNF- α IL1-β levels. Since oxidative stress and inflammation have been reported to affect the initiation and progression of liver injury caused by APAP, it is suggested that LPPp can act on aspects related to paracetamol hepatoxicity. This article brings new insights into the potential of the laticifer proteins extracted from the latex of P. pudica and opens new perspectives for the treatment of this type of liver disease with LPPp.

Identification and Characterization of Glycoproteins and Their Responsive Patterns upon Ethylene Stimulation in the Rubber Latex.

Natural rubber is an important industrial material, which is obtained from the only commercially cultivated rubber tree, Hevea brasiliensis. In rubber latex production, ethylene has been extensively used as a stimulant. Recent research showed that post-translational modifications (PTMs) of latex proteins, such as phosphorylation, glycosylation and ubiquitination, are crucial in natural rubber biosynthesis. In this study, comparative proteomics was performed to identify the glycosylated proteins in rubber latex treated with ethylene for different days. Combined with Pro-Q Glycoprotein gel staining and mass spectrometry techniques, we provided the first visual profiling of glycoproteomics of rubber latex and finally identified 144 glycosylated protein species, including 65 differentially accumulated proteins (DAPs) after treating with ethylene for three and/or five days. Gene Ontology (GO) functional annotation showed that these ethylene-responsive glycoproteins are mainly involved in cell parts, membrane components and metabolism. Pathway analysis demonstrated that these glycosylated rubber latex proteins are mainly involved in carbohydrate metabolism, energy metabolism, degradation function and cellular processes in rubber latex metabolism. Protein–protein interaction analysis revealed that these DAPs are mainly centered on acetyl-CoA acetyltransferase and hydroxymethylglutaryl-CoA synthase (HMGS) in the mevalonate pathway for natural rubber biosynthesis. In our glycoproteomics, three protein isoforms of HMGS2 were identified from rubber latex, and only one HMGS2 isoform was sharply increased in rubber latex by ethylene treatment for five days. Furthermore, the HbHMGS2 gene was over-expressed in a model rubber-producing grass Taraxacum Kok-saghyz and rubber content in the roots of transgenic rubber grass was significantly increased over that in the wild type plant, indicating HMGS2 is the key component for natural rubber production.

Anti-inflammatory latex proteins of the medicinal plant Calotropis procera: a promising alternative for oral mucositis treatment.

Oral mucositis (OM) is an intense inflammatory reaction progressing to tissue damage and ulceration. The medicinal uses of Calotropis procera are supported by anti-inflammatory capacity. PII-IAA, a highly homogenous cocktail of laticifer proteins (LP) prepared from the latex of C. procera, with recognized pharmacological properties was tested to treat OM. Male Golden Sirius hamsters were used in all treatments. The latex protein samples were injected i.p. (5 mg/Kg) 24 h before mucositis induction (mechanical trauma) and 24 h later. Histology, cytokine measurements [ELISA], and macroscopic evaluation [scores] were performed. PII-IAA eliminated OM, accompanied by total disappearance of myeloperoxidase activity and release of IL-1b, as well as reduced TNF-a. Oxidative stress was relieved by PII-IAA treatment, as revealed by MDA and GSH measurements. PII-IAA also reduced the expression of adhesion molecules (ICAM-1) and Iba-1, two important markers of inflammation, indicating modulatory effects. Histological analyses of the cheek epithelium revealed greater deposition of type I collagen fibers in animals given PII-IAA compared with the control group. This performance was only reached when LPPII was treated with iodoacetamide (IAA), an irreversible inhibitor of proteolytic activity of cysteine proteases. The endogenous proteolytic activity of LPPII induced adverse effects in animals. Candidate proteins involved in the phytomodulatory activity are proposed. Therapy was successful in treating OM with the laticifer protein fraction, containing peptidases and osmotin, from Calotropis procera. The effective candidate from the latex proteins for therapeutic use is PII-IAA.

Antifungal Proteins from Plant Latex.

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants' defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.

Current state of occupational latex allergy.

During the 1980s, natural rubber latex (NRL) emerged as a major cause of occupational allergy and asthma, especially in healthcare workers using powdered NRL gloves. Increased recognition of NRL allergies and transfer of research findings into prevention strategies resulted into an almost elimination of this health problem. Here, the current knowledge on allergens, their use in diagnostics, prevalence data of occupational NRL allergy and the status of prevention strategy are summarized. While the current studies conducted in high-income countries show that prevention measures have reduced NRL allergy, this does not yet apply worldwide. For latex allergy diagnosis, it is important that recombinant allergens as reliable tools are available, because in several European countries and the United States, NRL skin prick test extracts and powdered latex gloves for bronchial challenge test are no longer commercially available, leading to a deficit in diagnostic tools. Due to the fact that latex is suitable with good properties as a raw material for gloves, alternatives with significantly lower protein content and without cross-reactive structures to latex proteins are sought. Awareness of the sensitization risk associated with the use of latex gloves should still be present in all occupational settings.

Chitin nanocrystals reticulated self‐assembled architecture reinforces deproteinized natural rubber latex film

AbstractNatural rubber (NR) latex was initially deproteinized, then, the interactions between chitin nanocrystals (ChNCs) and deproteinized natural rubber (DNR) latex particles in an aqueous system and the properties of DNR/ChNCs composites were investigated. Composite films were obtained by casting and evaporating off the prevulcanized DNR/ChNCs complexation rather than simply mixing of DNR latex and ChNCs suspension. The results of DLS and TEM confirmed that this kind of complexation was formed between negative charged DNR and positively charged ChNCs by self‐assembly. The tensile strength of composite films containing 4 wt% ChNCs was 25.00 ± 1.42 MPa, which was 3.11 multiples of the pure pre‐vulcanized DNR. DNR/ChNCs composite films could provide excellent mechanical properties and avoid allergies caused by proteins in NR latex.

Major Latex Protein MdMLP423 Negatively Regulates Defense against Fungal Infections in Apple.

Major latex proteins (MLPs) play critical roles in plants defense and stress responses. However, the roles of MLPs from apple (Malus × domestica) have not been clearly identified. In this study, we focused on the biological role of MdMLP423, which had been previously characterized as a potential pathogenesis-related gene. Phylogenetic analysis and conserved domain analysis indicated that MdMLP423 is a protein with a ‘Gly-rich loop’ (GXGGXG) domain belonging to the Bet v_1 subfamily. Gene expression profiles showed that MdMLP423 is mainly expressed in flowers. In addition, the expression of MdMLP423 was significantly inhibited by Botryosphaeria berengeriana f. sp. piricola (BB) and Alternaria alternata apple pathotype (AAAP) infections. Apple calli overexpressing MdMLP423 had lower expression of resistance-related genes, and were more sensitive to infection with BB and AAAP compared with non-transgenic calli. RNA-seq analysis of MdMLP423-overexpressing calli and non-transgenic calli indicated that MdMLP423 regulated the expression of a number of differentially expressed genes (DEGs) and transcription factors, including genes involved in phytohormone signaling pathways, cell wall reinforcement, and genes encoding the defense-related proteins, AP2-EREBP, WRKY, MYB, NAC, Zinc finger protein, and ABI3. Taken together, our results demonstrate that MdMLP423 negatively regulates apple resistance to BB and AAAP infections by inhibiting the expression of defense- and stress-related genes and transcription factors.

Identification and functional characterization of NbMLP28, a novel MLP-like protein 28 enhancing Potato virus Y resistance in Nicotiana benthamiana

BackgroundMajor latex proteins (MLPs) belong to the MLP subfamily in Bet v 1 protein family and respond to both biotic and abiotic stresses, which play critical roles in plant disease resistance. As the type species of widely distributed and economically devastating Potyvirus, Potato virus Y (PVY) is one of the major constraints to important crop plants including tobacco (Nicotiana benthamiana) worldwide. Despite the great losses owing to PVY infection in tobacco, there is no previous study investigating the potential role of MLPs in developing resistance to viral infection.ResultsIn this study, for the first time we have identified and functionally analyzed the MLP-like protein 28 from N. benthamiana, denoted as NbMLP28 and investigated its role in conferring resistance to N. benthamiana against PVY infection. NbMLP28 was localized to the plasmalemma and nucleus, with the highest level in the root. NbMLP28 gene was hypothesized to be triggered by PVY infection and was highly expressed in jasmonic acid (JA) signaling pathway. Further validation was achieved through silencing of NbMLP28 through virus-induced gene silencing (VIGS) that rendered N. benthamiana plants more vulnerable to PVY infection, contrary to overexpression that enhanced resistance.ConclusionsTaken together, this is the first study describing the role of NbMLP28 in tobacco against PVY infection and provide a pivotal point towards obtaining pathogen-resistant tobacco varieties through constructing new candidate genes of MLP subfamily.

Genome-wide identification and expression analysis of the phosphatase 2A family in rubber tree (Hevea brasiliensis).

The protein phosphatase 2As (PP2As) play a key role in manipulating protein phosphorylation. Although a number of proteins in the latex of laticifers are phosphorylated during latex regeneration in rubber tree, information about the PP2A family is limited. In the present study, 36 members of the HbPP2A family were genome-wide identified. They were clustered into five subgroups: the subgroup HbPP2AA (4), HbPP2AB' (14), HbPP2AB'' (6), HbPP2AB55 (4), and HbPP2AC (8). The members within the same subgroup shared highly conserved gene structures and protein motifs. Most of HbPP2As possessed ethylene- and wounding-responsive cis-acting elements. The transcripts of 29 genes could be detected in latex by using published high-throughput sequencing data. Of the 29 genes, seventeen genes were significantly down-regulated while HbPP2AA1-1 and HbPP2AB55α/Bα-1were up-regulated by tapping. Of the 17 genes, 14 genes were further significantly down-regulated by ethrel application. The down-regulated expression of a large number of HbPP2As may attribute to the enhanced phosphorylation of the proteins in latex from the tapped trees and the trees treated with ethrel application.