Strigolactone signalling inhibits trehalose 6-phosphate signalling independently of BRC1 to suppress shoot branching.

The phytohormone strigolactone (SL) inhibits shoot branching, whereas the signalling metabolite trehalose 6-phosphate (Tre6P) promotes branching. How Tre6P and SL signalling may interact and which molecular mechanisms might be involved remains largely unknown. Transcript profiling of Arabidopsis SL mutants revealed a cluster of differentially expressed genes highly enriched in the Tre6P pathway compared with wild-type (WT) plants or brc1 mutants. Tre6P-related genes were also differentially expressed in axillary buds of garden pea (Pisum sativum) SL mutants. Tre6P levels were elevated in the SL signalling mutant more axillary (max) growth 2 compared with other SL mutants or WT plants indicating a role of MAX2-dependent SL signalling in regulating Tre6P levels. A transgenic approach to increase Tre6P levels demonstrated that all SL mutant lines and brc1 flowered earlier, showing all of these mutants were responsive to Tre6P. Elevated Tre6P led to increased branching in WT plants but not in max2 and max4 mutants, indicating some dependency between the SL pathway and Tre6P regulation of shoot branching. By contrast, elevated Tre6P led to an enhanced branching phenotype in brc1 mutants indicating independence between BRC1 and Tre6P. A model is proposed whereby SL signalling represses branching via Tre6P and independently of the BRC1 pathway.

Cladosporium cladosporioides causes leaf blight on garden pea in Telangana, India.

Garden pea (Pisum sativum L.) is an important vegetable and pulse crop grown worldwide. Leaf blight symptoms with chlorotic lesions were observed on the pea genotypes, 2006-2008A and Arkel in field conditions at Asian Vegetable Research and Development Centre (AVRDC), Hyderabad (17°23' N; 78°29' E) and greenhouse conditions at University of Hyderabad, Hyderabad, India (17° 27' N; 78° 19' E) since 2010. The blight symptoms showed black lesions coated by a fine velvety layer of olive-grey conidia. The disease incidence on field and greenhouse pea plants ranged from 3-6%. The Cladosporium isolates, Gp01 and Gp02 were isolated from pea genotypes, Arkel and 2006-2008A in greenhouse and field conditions respectively. One fungus was predominantly isolated from infected leaf tissue plated onto potato dextrose agar (PDA), and it was identified as Cladosporium sp. based on colony morphology and conidial appearance. Single-spored cultures grown at 26±2 °C on PDA showed olive green mycelia on the obverse-side and dark green on reverse-side (Fig. 1 a,b). The conidia were limoniform with dimensions ranging from 5.91-7.33 x 3.19-4.58 µm (Table 1) and were produced on solitary conidiophores containing 1-2 septa, with no constriction whereas the aerial hyphae were septate and unbranched or rarely branched (Fig.1 c-d). To verify the pathogenicity of the fungus, detached leaf assay was carried on 30-day old Arkel leaves by point inoculation with 20 µL (106 spores/ml) spore suspension using a needle-less syringe to infiltrate the spores into the abaxial surface and the inoculated leaves were incubated at 26±2 °C for 3 days in petri plates containing moistened autoclaved absorbent cotton. Pea leaves inoculated with water served as controls. The experiment was repeated with a minimum of three times with five leaves per replication and three replications per experiment for each of the isolates. The appressorial germ tube formation was observed by scanning electron microscopy (SEM) at 12 hours post inoculation (hpi) (Fig.1 e-f). Thirty-day old pea plants were spray-inoculated with a spore suspension of 1-2 ml per plant with a concentration of 106 spores/ ml while the control plants were mock-inoculated (sprayed) with water. 5 plants per replicate per isolate with three replications per experiment and a minimum of three experiments were carried. The inoculated plants were covered with polythene zip-lock bags for two days post inoculation (dpi) and maintained in greenhouse at 26±2 °C with natural photoperiod of 14 hours. Wilting and necrosis symptoms accompanied by chlorotic lesions were observed on pea plants at 7 days post inoculation (dpi) (Fig. 2). Complying with Koch's postulates, the pathogen, which was re-isolated from the first appearance at 3 dpi from infected pea showed similar morphological characteristics as those used for inoculation. Sequencing analysis of the internal transcribed spacer (ITS) region using ITS1 and ITS4 primers (White et al. 1990), D1-D2 region sequencing (Kwiatkowski et al. 2012), Translation elongation factor 1-alpha (TEF) and Actin (ACT) gene sequencing (Nam et al. 2015) of Gp01 and Gp02 showed significant similarity with C. cladosporioides (Table S1). Further, concatenated phylogenetic trees constructed by maximum likelihood method using all the four (ITS, D1-D2, TEF and ACTIN) gene sequences of these isolates along with other reported Cladosporium species (Fig. S1a) and specific isolates of C. cladosporiodes which are reported as "sensu stricto" (Bensch et al. 2010) collected from different substrata (Fig. S1b) confirmed them as C. cladosporioides. Gp01 and Gp02 were also confirmed by Microbial Type Culture Collection (MTCC, India) as C. cladosporioides with Acc. No. MTCC 9994 and MTCC 9995. C. cladosporioides has been previously reported on Dalbergia sp. and Eucalyptus sp in India and on garden pea in other countries (Bensch et al. 2010). However, owing to the impact of this pathogen on growth and productivity of pea crop, further in-depth study needs to be carried. To our understanding this is the first report of Cladosporium cladosporioides infecting garden pea in India.

Integration of the SMXL/D53 strigolactone signalling repressors in the model of shoot branching regulation in Pisum sativum.

DWARF53 (D53) in rice (Oryza sativa) and its homologs in Arabidopsis (Arabidopsis thaliana), SUPPRESSOR OF MAX2-LIKE 6 (SMXL6), SMXL7 and SMXL8, are well established negative regulators of strigolactone (SL) signalling in shoot branching regulation. Little is known of pea (Pisum sativum) homologs and whether D53 and related SMXLs are specific to SL signalling pathways. Here, we identify two allelic pea mutants, dormant3 (dor3), and demonstrate through gene mapping and sequencing that DOR3 corresponds to a homolog of D53 and SMXL6/SMXL7, designated PsSMXL7. Phenotype analysis, gene expression, protein and hormone quantification assays were performed to determine the role of PsSMXL7 in regulation of bud outgrowth and the role of PsSMXL7 and D53 in integrating SL and cytokinin (CK) responses. Like D53 and related SMXLs, we show that PsSMXL7 can be degraded by SL and induces feedback upregulation of PsSMXL7 transcript. Here we reveal a system conserved in pea and rice, whereby CK also upregulates PsSMXL7/D53 transcripts, providing a clear mechanism for SL and CK cross-talk in the regulation of branching. To further deepen our understanding of the branching network in pea, we provide evidence that SL acts via PsSMXL7 to modulate auxin content via PsAFB5, which itself regulates expression of SL biosynthesis genes. We therefore show that PsSMXL7 is key to a triple hormone network involving an auxin-SL feedback mechanism and SL-CK cross-talk.

Prediction models for evaluating heavy metal uptake by Pisum sativum L. in soil amended with sewage sludge.

The present study aims to develop prediction models for estimating the potential uptake of 10 heavy metals (HMs) (cadmium, Cd; cobalt, Co; chromium, Cr; copper, Cu; iron, Fe; manganese, Mn; molybdenum, Mo; nickel, Ni; lead, Pb; zinc, Zn) by the tissues of Pisum sativum (root, shoot and pod) grown in soil amended with sewage sludge (SS) under greenhouse conditions. Soil organic matter (OM) was estimated by loss-on-ignition at 550 °C for 2 h. The pH was determined by shaking the soil and pure water at a 1:5 ratio. For HM quantifications, 0.5-1.0 g of each soil or plant sample was digested using a tri-acid mixture digestion method. The quantities of selected HMs were estimated by means of inductively coupled plasma optical emission spectrometry. Bio-concentration (BCF) and translocation (TF) factors were <1 for most of the HMs. In addition, simple linear correlations were significantly negative between the BCF of all studied HMs and soil pH, except for Pb, Mn and Ni, whereas significant positive correlations were observed between BCFs and soil OM, except for Mn, Ni and Zn. The accumulation of the 10 HMs in P. sativum tissues was predicted using regression models based on the values of the same HM in the soil as well as its pH and OM. The calculated prediction models performed well for most HMs in P. sativum tissues (except Ni in the pod, Cd in the shoot and Mn in the root). All measured soil factors (HM, pH and OM) consistently contributed to HM concentrations in the three tissues of the studied plants. These models may help to evaluate the safe cultivation of this species in soil amended with SS.

Detection of putative pathogenicity and virulence genes of Erysiphe pisi using genome-wide in-silico search and their suppression by er2 mediated resistance in garden pea.

The biotrophic fungus, Erysiphe pisi is the chief causal agent of powdery mildew disease of garden pea. A genome-wide search using in-silico approach was carried to detect putative pathogenicity and virulence genes of E. pisi, since information about these genes and their interaction with pea is limited. Nineteen putative pathogenicity gene sequences were detected through genome-wide pathogenicity gene-search and confirmed them to be conserved in E. pisi through genomic PCRs. Fifteen of these genes expressed through reverse transcriptase-polymerase chain reaction (RT-PCR) amplifying expected band size along with fungal and plant specific internal controls. Gene sequencing and annotation revealed them to be Erysiphe-specific. A time course study was carried to monitor expression of nine of these genes through real-time quantitative (qRT)-PCR in Erysiphe-challenged plants of powdery mildew resistant pea genotype, JI-2480 carrying er2 gene and susceptible pea cultivar, Arkel. Expression of these genes was differentially and temporally regulated. They were found mostly related to signaling; cAMP-PKA (cPKA, CRP and AC) and MAPK (MST7) pathways along with MFP, TRE and PEX which are reported pathogenicity factors in other ascomycete members indicating that similar conserved pathways function in E. pisi also. These genes expressed at higher level at initial hours post inoculation (hpi) as early as 6 hpi in Arkel compared to JI-2480 implying them as pathogenicity factors. The elevated level of expression of MFP, TRE, CRP and cPKA gene sequences in E. pisi-challenged JI-2480 genotype at 12 hpi alone suggests these genes to possess a role in avirulence in JI-2480, conferring er2 mediated resistance.

A novel lipid transfer protein from the pea Pisum sativum: isolation, recombinant expression, solution structure, antifungal activity, lipid binding, and allergenic properties.

BACKGROUND: Plant lipid transfer proteins (LTPs) assemble a family of small (7-9 kDa) ubiquitous cationic proteins with an ability to bind and transport lipids as well as participate in various physiological processes including defense against phytopathogens. They also form one of the most clinically relevant classes of plant allergens. Nothing is known to date about correlation between lipid-binding and IgE-binding properties of LTPs. The garden pea Pisum sativum is widely consumed crop and important allergenic specie of the legume family. This work is aimed at isolation of a novel LTP from pea seeds and characterization of its structural, functional, and allergenic properties. RESULTS: Three novel lipid transfer proteins, designated as Ps-LTP1-3, were found in the garden pea Pisum sativum, their cDNA sequences were determined, and mRNA expression levels of all the three proteins were measured at different pea organs. Ps-LTP1 was isolated for the first time from the pea seeds, and its complete amino acid sequence was determined. The protein exhibits antifungal activity and is a membrane-active compound that causes a leakage from artificial liposomes. The protein binds various lipids including bioactive jasmonic acid. Spatial structure of the recombinant uniformly (13)C,(15)N-labelled Ps-LTP1 was solved by heteronuclear NMR spectroscopy. In solution the unliganded protein represents the mixture of two conformers (relative populations ~ 85:15) which are interconnected by exchange process with characteristic time ~ 100 ms. Hydrophobic residues of major conformer form a relatively large internal tunnel-like lipid-binding cavity (van der Waals volume comes up to ~1000 Å(3)). The minor conformer probably corresponds to the protein with the partially collapsed internal cavity. CONCLUSIONS: For the first time conformational heterogeneity in solution was shown for an unliganded plant lipid transfer protein. Heat denaturation profile and simulated gastrointestinal digestion assay showed that Ps-LTP1 displayed a high thermal and digestive proteolytic resistance proper for food allergens. The reported structural and immunological findings seem to describe Ps-LTP1 as potential cross-reactive allergen in LTP-sensitized patients, mostly Pru p 3(+) ones. Similarly to allergenic LTPs the potential IgE-binding epitope of Ps-LTP1 is located near the proposed entrance into internal cavity and could be involved in lipid-binding.

Acrylamide formation in air-fryer roasted legumes as affected by legume species and roasting degree: the correlation of acrylamide with asparagine and free sugars.

Acrylamide is a well-recognized hazardous compound with known carcinogenic, genotoxic, neurotoxic, and reproductive toxic effects. This research aimed to investigate how different legume species and roasting durations influence acrylamide formation during air-fryer roasting. The study also examined the relationship between acrylamide formation and the levels of free asparagine and free sugars in different bean species. Asparagine content varies substantially across different bean species. Sucrose was the predominant sugar across all bean species, with smaller amounts of galactose and glucose. Air-fryer-roasted Wandu kong (garden pea) showed the highest acrylamide formation, followed by Ultari kong (kidney bean) and Heoktae (black soybean), in that order. Beans roasted for longer periods in an air fryer contained significantly higher levels of acrylamide. This study revealed a strong positive correlation between acrylamide formation and the level of free asparagine in the beans, highlighting the risks associated with certain legume species and air-fryer roasting durations.

Mendel-200: Pea as a model system to analyze hormone-mediated stem elongation.

In a recent Review Article on Gregor Mendel's (1822-1884) work with pea (Pisum sativum)-plants, it was proposed that this crop species should be re-vitalized as a model organism for the study of cell- and organ growth. Here, we describe the effect of exogenous gibberellic acid (GA3) on the growth of the second internode in 4-day-old light-grown pea seedlings (Pisum sativum, large var. "Senator"). lnjection of glucose into the internode caused a growth-promoting effect similar to that of the hormone GA3. Imbibition of dry pea seeds in GA3, or water as control, resulted in a drastic enhancement in organ development in this tall variety. Similar results were reported for dwarf peas. These "classical" experimental protocols are suitable to study the elusive effect of gibberellins (which act in coordination with auxin) on the regulation of plant development at the biochemical and molecular levels.

Functional Amyloids Germinate in Plants.

First identified in human disorders, amyloids serve biological functions in bacteria, archaea, fungi, and animals; however, their role in plants has remained unexplored. Recently, Antonets et al. identified a functional amyloid in plants, with a crucial role in seed longevity, confirming that amyloids are universally exploited for organisms' adaptation.

Trait Expression and Environmental Responses of Pea (Pisum sativum L.) Genetic Resources Targeting Cultivation in the Arctic.

In the Arctic part of the Nordic region, cultivated crops need to specifically adapt to adverse and extreme climate conditions, such as low temperatures, long days, and a short growing season. Under the projected climate change scenarios, higher temperatures and an earlier spring thaw will gradually allow the cultivation of plants that could not be previously cultivated there. For millennia, Pea (Pisum sativum L.) has been a major cultivated protein plant in Nordic countries but is currently limited to the southern parts of the region. However, response and adaptation to the Arctic day length/light spectrum and temperatures are essential for the productivity of the pea germplasm and need to be better understood. This study investigated these factors and identified suitable pea genetic resources for future cultivation and breeding in the Arctic region. Fifty gene bank accessions of peas with a Nordic landrace or cultivar origin were evaluated in 2-year field trials at four Nordic locations in Denmark, Finland, Sweden, and Norway (55° to 69° N). The contrasting environmental conditions of the trial sites revealed differences in expression of phenological, morphological, crop productivity, and quality traits in the accessions. The data showed that light conditions related to a very long photoperiod partly compensated for the lack of accumulated temperature in the far north. A critical factor for cultivation in the Arctic is the use of cultivars with rapid flowering and maturation times combined with early sowing. At the most extreme site (69°N), no accession reached full maturation. Nonetheless several accessions, predominantly landraces of a northern origin, reached a green harvest state. All the cultivars reached full maturation at the sub-Arctic latitude in northern Sweden (63°N) when plants were established early in the season. Seed yield correlated positively with seed number and aboveground biomass, but negatively with flowering time. A high yield potential and protein concentration of dry seed were found in many garden types of pea, confirming their breeding potential for yield. Overall, the results indicated that pea genetic resources are available for breeding or immediate cultivation, thus aiding in the northward expansion of pea cultivation. Predicted climate changes would support this expansion.

Comparative transcriptome of compatible and incompatible interaction of Erysiphe pisi and garden pea reveals putative defense and pathogenicity factors.

Comparative transcriptome analysis of Erysiphe pisi-infected pea (Pisum sativum) genotypes JI-2480 (resistant) and Arkel (susceptible) at 72 hours post-inoculation (hpi) was carried to detect molecular components involved in compatible and incompatible interactions. Differential gene expression was observed in Arkel and JI-2480 genotype at 72 hpi with E. pisi isolate (Ep01) using EdgeR software. Out of 32 217 transcripts, 2755 transcripts showed significantly altered gene expression in case of plants while 530 were related to E. pisi (P < 0.05). The higher transcript number of differentially expressed genes demonstrated peak activity of pathogenicity genes in plants at 72 hpi. Glycolysis was observed to be the major pathway for energy source during fungal growth. Differential gene expression of plant transcripts revealed significant expression of putative receptor and regulatory sequences involved in defense in the resistant, JI-2480 compared to susceptible, Arkel genotype. Expression of genes involved in defense and hormonal signaling, genes related to hypersensitive response, reactive oxygen species and phenylpropanoid pathway in JI-2480 indicated their crucial role in disease resistance against E. pisi. Down-regulation of transcription factors like-WRKY-28 and up-regulation of several putative pattern recognition receptors in JI-2480 compared to Arkel also suggested activation of host-mediated defense responses against E. pisi in pea.

Comparative proteomic analysis reveals molecular differences between incompatible and compatible interaction of Erysiphe pisi in garden pea.

Comparative proteome analysis of Erysiphe pisi-infected pea genotypes; JI-2480 carrying er2 resistant gene and Arkel, the susceptible genotype by liquid chromatography- mass spectrometry (LCMS/MS QTOF) at 72 h post inoculation (hpi) revealed several differentially abundant proteins (DAPs) of both the host and the pathogen. The functional annotation of proteins through gene enrichment and KEGG pathway analyses revealed strong up-regulation of pathogenesis related protein NPR1, proteins related to defense, transportation and signal transduction, hypersensitive response, cell wall modifications, phenylpropanoid and metabolic pathways in J-72. Significant abundance of membrane-related polypeptides, kinase domains and small GTPase signal transduction-related proteins suggested their major role in plant defense. The abundance of cellular antioxidant protein, catalase and its isozyme along with calreticulin-1 and 2 in J-72 confirmed their intervention in maintaining a redox balance in powdery mildew defense. High abundance levels of Glycolysis-related proteins indicated it as a major pathway for energy source during fungal growth. The majority of pathogenicity and virulence genes were downregulated in J-72 compared to A-72, while four EKA (Effectors homologues to Avk1 and Avra10) like avirulence proteins were significantly upregulated in incompatible interaction suggesting their role in eliciting hypersensitive response in pea against E. pisi.

Effects of Salinity and Abscisic Acid on Lipid Transfer Protein Accumulation, Suberin Deposition and Hydraulic Conductance in Pea Roots.

Lipid transfer proteins (LTPs) participate in many important physiological processes in plants, including adaptation to stressors, e.g., salinity. Here we address the mechanism of this protective action of LTPs by studying the interaction between LTPs and abscisic acid (ABA, a "stress" hormone) and their mutual participation in suberin deposition in root endodermis of salt-stressed pea plants. Using immunohistochemistry we show for the first time NaCl induced accumulation of LTPs and ABA in the cell walls of phloem paralleled by suberin deposition in the endoderm region of pea roots. Unlike LTPs which were found localized around phloem cells, ABA was also present within phloem cells. In addition, ABA treatment resulted in both LTP and ABA accumulation in phloem cells and promoted root suberization. These results suggested the importance of NaCl-induced accumulation of ABA in increasing the abundance of LTPs and of suberin. Using molecular modeling and fluorescence spectroscopy we confirmed the ability of different plant LTPs, including pea Ps-LTP1, to bind ABA. We therefore hypothesize an involvement of plant LTPs in ABA transport (unloading from phloem) as part of the salinity adaptation mechanism.

A high coverage reference transcriptome assembly of pea (Pisum sativum L.) mycorrhizal roots.

Arbuscular mycorrhiza (AM) is an ancient mutualistic symbiosis formed by 80-90 % of land plant species with the obligatorily biotrophic fungi that belong to the phylum Glomeromycota. This symbiosis is mutually beneficial, as AM fungi feed on plant photosynthesis products, in turn improving the efficiency of nutrient uptake from the environment. The garden pea (Pisum sativum L.), a widely cultivated crop and an important model for genetics, is capable of forming triple symbiotic systems consisting of the plant, AM fungi and nodule bacteria. As transcriptomic and proteomic approaches are being implemented for studying the mutualistic symbioses of pea, a need for a reference transcriptome of genes expressed under these specific conditions for increasing the resolution and the accuracy of other methods arose. Numerous transcriptome assemblies constructed for pea did not include mycorrhizal roots, hence the aim of the study to construct a reference transcriptome assembly of pea mycorrhizal roots. The combined transcriptome of mycorrhizal roots of Pisum sativum cv. Frisson inoculated with Rhizophagus irregularis BEG144 was investigated, and for both the organisms independent transcriptomes were assembled (coverage 177x for pea and 45x for fungus). Genes specific to mycorrhizal roots were found in the assembly, their expression patterns were examined with qPCR on two pea cultivars, Frisson and Finale. The gene expression depended on the inoculation stage and on the pea cultivar. The investigated genes may serve as markers for early stages of inoculation in genetically diverse pea cultivars.

Compared digestibility of plant protein isolates by using the INFOGEST digestion protocol.

The use of ingredients based on plant protein isolates is being promoted due to sustainability and health reasons. However, it is necessary to explore the behaviour of plant protein isolates during gastrointestinal digestion including the profile of released free amino acids and the characterization of resistant domains to gastrointestinal digestion. The aim of the present study was to monitor protein degradation of four legume protein isolates: garden pea, grass pea, soybean and lentil, using the harmonized Infogest in vitro digestion protocol. In vitro digests were characterized regarding protein, peptide and free amino acid content. Soybean was the protein isolate with the highest percentage of insoluble nitrogen at the end of the digestion (12%), being this fraction rich in hydrophobic amino acids. Free amino acids were mainly released during the intestinal digestion, comprising 21-24% of the total nitrogen content, while the percentage of nitrogen corresponding to peptides ranged from 66 to 76%. Legume globulins were resistant to gastric digestion whereas they were hydrolysed into peptides and amino acids during the intestinal phase. However, the molecular weight (MW) distribution demonstrated that all intestinal digests, except those from soybean, contained peptides with MW > 4 kDa at the end of gastrointestinal digestion. The profile of free amino acids released during digestion supports legume protein isolates as an excellent source of essential amino acids to be used in protein-rich food products. Peptides released during digestion matched with previously reported epitopes from the same plant species or others, explaining the ability to induce allergic reactions and cross-linked reactivity.

Transcriptomic Insights into Mechanisms of Early Seed Maturation in the Garden Pea (Pisum sativum L.).

The garden pea (Pisum sativum L.) is a legume crop of immense economic value. Extensive breeding has led to the emergence of numerous pea varieties, of which some are distinguished by accelerated development in various stages of ontogenesis. One such trait is rapid seed maturation, which, despite novel insights into the genetic control of seed development in legumes, remains poorly studied. This article presents an attempt to dissect mechanisms of early maturation in the pea line Sprint-2 by means of whole transcriptome RNA sequencing in two developmental stages. By using a de novo assembly approach, we have obtained a reference transcriptome of 25,756 non-redundant entries expressed in pea seeds at either 10 or 20 days after pollination. Differential expression in Sprint-2 seeds has affected 13,056 transcripts. A comparison of the two pea lines with a common maturation rate demonstrates that while at 10 days after pollination, Sprint-2 seeds show development retardation linked to intensive photosynthesis, morphogenesis, and cell division, and those at 20 days show a rapid onset of desiccation marked by the cessation of translation and cell anabolism and accumulation of dehydration-protective and -storage moieties. Further inspection of certain transcript functional categories, including the chromatin constituent, transcription regulation, protein turnover, and hormonal regulation, has revealed transcriptomic trends unique to specific stages and cultivars. Among other remarkable features, Sprint-2 demonstrated an enhanced expression of transposable element-associated open reading frames and an altered expression of major maturation regulators and DNA methyltransferase genes. To the best of our knowledge, this is the first comparative transcriptomic study in which the issue of the seed maturation rate is addressed.

Facile green biosynthesis of silver nanoparticles using Pisum sativum L. outer peel aqueous extract and its antidiabetic, cytotoxicity, antioxidant, and antibacterial activity.

BACKGROUND: The synthesis of silver nanoparticles (AgNPs) using food waste materials and their biomedical applications have garnered considerable attention recently. METHODS: Here, we investigated the synthesis of AgNPs using an aqueous extract of outer peel of Pisum sativum under different lighting conditions using standard procedures and explored their antidiabetic, cytotoxicity, antioxidant, and antibacterial potential. RESULTS: Characterization of AgNPs was done by Ultra Violet (UV-VIS) spectroscopy that showed absorption maxima at 456 nm for the samples exposed to laboratory lighting and at 464 nm for the samples exposed to direct sunlight, by scanning electron microscopy and energy-dispersive X-ray analysis that showed the surface nature and their elemental composition with a strong peak at 3 keV that corresponded to Ag (61.85 wt%), by Fourier-transform infrared spectroscopy that predicted the functional groups involved, and by X-ray powder diffraction that showed the structural properties. The average diameter of the synthesized AgNPs was calculated to be in the range of 10-25 nm. AgNPs exhibited promising antidiabetic activity as determined by inhibition of α-glucosidase (95.29% inhibition at 10 µg/mL and IC50 value of 2.10 µg/mL) and cytotoxicity (IC50 value 4.0 µg/mL as calculated from the slope equation) against HepG2 cells. Furthermore, they also exhibited moderate antioxidant activity (50.17% reduction of 1,1-diphenyl-2-picrylhydrazyl at 100 µg/mL) and antibacterial activity against four human pathogenic bacteria (as indicated by 8.70-11.10 mm inhibition zones on agar plates). CONCLUSION: In conclusion, the results confirm that food waste can be used in the synthesis of AgNPs and that the latter have the potential for applications in various fields including diabetic and cancer treatments as well as in biomedicine for the manufacture of antibacterial coatings in medical devices and instruments.

Shotgun proteomics provides an insight into pathogenesis-related proteins using anamorphic stage of the biotroph, Erysiphe pisi pathogen of garden pea.

E. pisi is an ascomycete member causing powdery mildew disease of garden pea. It is a biotrophic pathogen, requiring a living host for its survival. Our understanding of molecular mechanisms underlying its pathogenesis is limited. The identification of proteins expressed in the pathogen is required to gain an insight into the functional mechanisms of an obligate biotrophic fungal pathogen. In this study, the proteome of the anamorphic stage of E. pisi pathogen has been elucidated through the nano LC-MS/MS approach. A total of 328 distinct proteins were detected from Erysiphe isolates infecting the susceptible pea cultivar, Arkel. The proteome is available via ProteomeXchange with identifier PXD010238. The functional classification of protein accessions based on Gene Ontology revealed proteins related to signal transduction, secondary metabolite formation and stress which might be involved in virulence and pathogenesis. The functional validation carried through differential expression of genes encoding G-protein beta subunit, a Cyclophilin (Peptidyl prolyl cis-transisomerase) and ABC transporter in a time course study confirmed their putative role in pathogenesis between resistant and susceptible genotypes, JI2480 and Arkel. The garden pea-powdery mildew pathosystem is largely unexplored, therefore, the identified proteome provides a first-hand information and will form a basis to analyze mechanisms involving pathogen survival, pathogenesis and virulence.

Virus-Induced Gene Silencing (VIGS) and Foreign Gene Expression in Pisum sativum L. Using the "One-Step" Bean pod mottle virus (BPMV) Viral Vector.

Plant viral vectors have been developed to facilitate gene function studies especially in plant species not amenable to traditional mutational or transgenic modifications. In the Fabaceae plant family, the most widely used viral vector is derived from Bean pod mottle virus (BPMV). Originally developed for overexpression of foreign proteins and VIGS studies in soybean, we adapted the BPMV-derived vector for use in other legume species such as Phaseolus vulgaris and Pisum sativum. Here, we describe a protocol for efficient protein expression and virus-induced gene silencing (VIGS) in Pisum sativum leaves and roots using the "one-step" Bean pod mottle virus (BPMV) viral vector.