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  • Open access
  • 79 Reads
The Acclimation Mechanisms of Chlamydomonas reinhardtii against Nitrosative Stress: A Role of NADPH Oxidase (RBOL2) in the Regulation of Nitric Oxide-Mediated ER Stress and Glutathione Redox State

Nitric oxide (NO) is a signal in the modulation of acclamatory responses to stress in plants. This study has investigated the metabolic shift in the acclimation of a green alga Chlamydomonas reinahrdii to NO stress. On exposure to 0.1 mM SNAP, a NO donor, causes a transient inhibition in photosysnthesis after 1 h, followed by a fast recovery. The RNA-seq results discover that NO enhances the catabolism of cysteine, threonine, aromatic amino acids, and branched-chain amino acids to other metabolites for the synthesis of functional compounds. NO also induces the endosomal protein trafficking system in association with the ubiquitinylation machinery (ubiquition, SNARE, and autophagy) for the degradation of sequestered damaged proteins to generate small molecules for re-synthesis of macromolecules, and triggers the protein modification system (heat proteins). The antioxidant defense system (VTC2, APX, MDAR, DHAR, GR, GPXH/GPX5, GSTS1, and GSTS2) and redox state (AsA/DHA and GSHH/GSSG) are activated by NO. Two PsbP-like proteins and LHCBM9 are induced for the acclimayion to NO stress. Besides, THB, FLVb, and CYP55B1 are induced to reduce NO level for NO detoxification, allowing the acclimation to NO stress. NO significantly induced NADPH oxidase, RBOL2, but slightly decreased RBOL1 expression. Unfolded protein response (UPR) in response to ER stress was inhibited by NO stress. Using RBOL2 mutant, the UPR was induced and the glutathione synthesis and redox state was inhibited. This finding demonstrates that NADPH oxidase (RBOL2)-mediated signaling pathway is involved in the NO-induced inhibition of ER stress and the induction of glutathione availability while other NO-induced metabolisms are under control by other signaling pathway. Our analyses provide a valuable tool for selecting genetic modification targets to understand acclamatory mechanisms to NO stress in Chlamydomonas.

  • Open access
  • 70 Reads
Nutrient and Water Use Efficiency at Leaf Level of Cucumber Plants under Contrasting Soil Nutrient and Lignosulfonate Level

To reduce the use of commercial conventional inorganic fertilizers the possibility of using pulp and paper industry wastes in agriculture as an alternative source of nutrients is recently under study and discussion. This work aimed to evaluate the effect of sodium lignosulfonate application to soil on photosynthetic leaf nutrient- (N, P, K, Ca, Mg, Fe, and Mn) and water- use efficiency. A pot culture experiment was conducted with cucumber seedlings, using five lignosulfonate concentrations (0, 1, 2.5, 5, and 10 vol. %) in sandy soil under sufficient or low nutrient availability for plants. The impact of nutrient availability on plant physiological traits was stronger than the lignosulfonate impact. Under the condition of sufficient nutrient availability, the lignosulfonate application decreased N-, P-, K-, Ca-, Mg-, and Fe- use efficiency, increased Mn- use efficiency and did not change water- use efficiency. The decrease of nutrient- use efficiency was connected with both photosynthetic rate decrease and leaf nutrient content increase. The decline in soil nutrient availability caused a decrease in nutrient and water use efficiency. Under low nutrient availability, soil lignosulfonate tended to increase nutrient- and water- use efficiency, but it was not successful to eliminate the negative effects of soil nutrient deficiency on plant growth, photosynthetic processes, and efficiency of nutrient use.

  • Open access
  • 98 Reads
The Essential Oils of Thyme, Sage and Peppermint against Strawberry Anthracnose

Strawberry Colletotrichum spp. is a significant strawberry pathogen with yield losses of up to 50 %, due to agrometeorological conditions change its spread in a temperate climate is growing. The most convenient way for controlling diseases is use of chemical fungicides. The demand for alternative measures for biological protection is growing because of the increasing pathogens resistance and pesticides harm for human and environment. Thyme, sage and peppermint are a source of natural antioxidants and biologically active compounds. The findings of antimicrobial and antifungal activities of these plants, low toxicity and biodegradability of essential oils (EO) make them suitable for biological protection against pathogens. This study aims to evaluate the inhibition of Colletotrichum spp. by thyme, sage and peppermint EO in vitro and in vivo, to determine chemical composition of EO. The results revealed that the dominant compound of thyme was thymol 41.35%, peppermint – menthone 44.56%, sage - α-thujone 20% and camphor 25%. Thyme EO inhibited Colletotrichum spp. completely above 200 μL L−1 concentration in vitro. Peppermint and sage EO slightly reduced mycelial growth of Colletotrichum spp. However, in vitro, results are very promising for biological control. The in vivo experiments showed that Colletotrichum spp. disease severity 4 days after inoculation were suppressed by 1000 μL L−1 peppermint EO (12.5%) and 800 μL L−1 thyme (4.2%) compared with control. Our findings could potentially help to manage Colletotrichum spp.; however, the in vivo assay showed that EO efficacy was relatively low on tested concentrations and should be increased.

  • Open access
  • 100 Reads
Participation of glutathione in the formation of the associative symbiosis of trancsgenic tomato plants with R. leguminosarum

Rhizobia, known as legume endosymbionts, can serve as beneficial associative bacteria for many non-legume crops, including tomato. There are a number of studies to improve this associative interaction by transforming plants with various genes, in particular, the genes of plant lectins and bacterial agglutinins. It is known that glutathione (GSH) plays an important role in the formation of associative symbiosis between plants and bacteria. The aim of this work was to study the redox state of glutathione in various artificial symbiotic systems on the roots of tomato plants, transformed with the lectin genepsl and the bacterial agglutinin gene rapA1after treatment of R. leguminosarum strain. It was found that in the roots of wild-type tomato, treatment with the bacteria caused the accumulation of GSH, without affecting its oxidized form-GSSG and the indicator of the GSH/GSSG ratio was 3.2. Evaluation of the glutathione content in the roots of transgenic plants withpsl gene showed a significant increase in the GSH content and the GSH/GSSG ratio was 4.6, while the adsorption of bacteria on the roots of these plants increased 9 times. In the transgenic roots with the rapA1 gene bacteria were sorbed three times more in comparison with the control plants, and the GSH/GSSG ratio was 4.1. It should be noted that in both variants of the studied transgenic plants, bacteria did not affect the GSSG content and its value remained at the level of untreated plants, which indicates the absence of a negative effect of rhizobia on tomatoes. The results obtained demonstrate the promise of studying the redox state of glutathione for assessing the effectiveness of artificial symbiotic systems.

  • Open access
  • 130 Reads
Phylogenetic Placement and Taxonomic Reinvestigation of Endemic and Endangered Plant Species: Silene Leucophylla Boiss. and Silene schimperiana Boiss. (Caryophyllaceae)

The two endemic plant species Silene leucophylla and Silene schimperiana (Caryophyllaceae) are native to the Sinai Peninsula which considered as one of the floristically richest phytogeographical hot spot regions of the Mediterranean basin. The acquaintance of Sinai’s biodiversity is crucial for conservation and sustainable development. Endemic plant species of Sinai are vulnerable to anthropogenic threats due to their relatively low population size. The current study reinvestigated the taxonomic status of two medicinally important and vulnerable species. The integrated approach of macro and micro-morphological traits using a scanning electron microscope (SEM) as well as phylogenetic analysis were conducted. Phylogenetic reconstruction using Bayesian Inference based on DNA sequences of nuclear (ITS) and chloroplast (rbcl and matk) markers retrieved the species phylogeny successfully. Silene leucphylla and Silene schimperiana was placed phylogenetically within the whole genus. The sectional classification of the two species was confirmed. Silene leucophylla was placed in section Siphonomorpha while Silene schimperiana allied to section Sclerocalycinae. The current study reassured that the integration between the various morphological and molecular approaches is substantial to identify, determine the taxonomic status, and reveal the phylogenetic position of those two endangered plant taxa.

  • Open access
  • 154 Reads
DNA Barcoding, and Phylogenetic Placement of the Genus Euphorbia L. (Euphorbiaceae) in Egypt

The genus Euphorbia L. in Egypt is represented by 40 species, a subspecies, and 3 varieties. Those species are distributed in almost all phytogeographical regions in the study area. The genus is well known for its medicinal importance. Moreover, it is characterized by various and sometimes anomalous plant habits that make them interesting for taxonomists. In this study, six DNA markers: matK, rbcL, ETS, trnL intron, trnL spacer, and the entire ITS region (ITS1+5.8S+ITS2), as well as subunits ITS1 and ITS2 were evaluated singly and in combination to investigate their usage as potential DNA barcodes. The Maximum Likelihood (ML) and BLASTn analyses were conducted for 37 individuals representing 26 species of Egyptian Euphorbia. The BLASTn comparison of the newly generated DNA sequences of the Egyptian Euphorbia species showed that ITS, ITS1 and ITS2 subunits displayed high levels of species discrimination. On the other hand, the ML analysis of the DNA sequences of trnL intron yielded a better resolved phylogenetic tree, compared to the other regions. We also presented the phylogeny of Egyptian Euphorbia based on DNA sequences of other markers: matK, rbcL, trnL, and the entire ITS region, with additional sequences from GenBank. Our results have shown that E. dracunculoides, E. hyssopifolia, E. lasiocarpa and E. granulata are probably not monophyletic. This study along with the widest taxon coverage in Egypt, emphasizes the importance of using DNA markers for precise identification and phylogenetic placement of the genus Euphorbia in Egypt within the whole genus.

  • Open access
  • 71 Reads
Foliar Application of Gibberellic Acid and Methyl Jasmonate Improves Leaf Greenness in Hesperantha coccinea (syn. Schizostylis coccinea), a Rare Ornamental Plant

Hesperantha coccinea (Iridaceaea) is a little-known ornamental plant recommended for cultivation in pots, gardens and for cut flowers. The species produces narrow, decorative green leaves that sometimes turn yellow as the plants begin to bloom. Solution to the problem may be the application of growth regulators, and so far none has been studied in Hesperantha cultivation.

The study assessed the effect of foliar application of gibberellic acid solutions (GA3; 50,100 and 200 mg dm-3) and methyl jasmonate (MeJA; 100, 500 and 1000 umol dm-3) on the leaf greenness index (SPAD index), leaf number, leaf length and leaf width of H. coccinea. It was found that both GA3 and MeJA applied at all tested concentrations significantly increased the greenness index of H. coccinea leaves. In addition, GA3 increased the number of leaves without affecting the length and width of the leaves. In the case of MeJA, it was shown that this regulator had a growth inhibitory effect. Compared to control, plants sprayed with MeJA solutions produced fewer leaves that also had reduced length and width. Summarizing, both regulators positively affected plant quality by improving leaf greenness.

  • Open access
  • 77 Reads
JetGene—Online Database and Toolkit for an Analysis of Regulatory Regions or Nucleotide Contexts at Differently Translated Plants Transcripts

The discrepancy between mRNAs levels and translation effectivity in eukaryotic cells, in particular in plant cells, encountered by researchers at any step of organism development and under influence of different stress factors at an entire organism. Thus, nowadays researchers direct close attention to study fine translation mechanisms.

As we know mRNA has regulatory codes which define the individual mRNA fate during translation. In silico analysis of different mRNA regions is applied by scientists for detection such regulatory codes and motives. For the purpose of such regulatory codes discovery in mRNA and their correlation with translational efficiency we have created online database JetGene (https://jetgene.bioset.org/) that contains cDNA, CDS, 5’-/3’-UTR sequences of six groups of living organisms. This should be noted all information about CDS and cDNA is downloaded and updated from Ensembl regularly. JetGene has wide toolkit and very friendly user interface. JetGene allows make a comparative analysis of sequences, namely: (i) to estimate the variation of length, nucleotide composition, codon usage frequency, to analyze GC-content, CpG-islands, to study nucleotides surrounding of the start codon and much more; (ii) to identify and define statistically significant representation of potential regulatory contexts at mRNA with different translation efficiency. It should be mentioned that the analysis could be performed both by full-length transcript, by interval of transcript and by coding/non-coding regions. It’s important to note that sequences selected by for the analysis by a user can be extracted in fasta-format from JetGene at any step of the work. The graphical interpretation of analysis accompanies every phase of the study. Such pleasant details are greatly facilitated the work of any researcher. Moreover, beta-version of JetGene (https://beta.bioset.org) allows user to compare two mRNA samples and apply omics data for searching and prediction regulatory determinants of translation.

Supported by the Russian Science Foundation (project no. 18-14-00026; IVG-P).

  • Open access
  • 211 Reads
Assessment of Phytochemicals and Antioxidant Properties of Root Extracts of Rubia cordifolia L. in Different Solvent Systems

Rubia cordifolia L. is an important plant used in Ayurvedic and Siddha medicinal systems of India for treatment of blood disorders. Of all the plant parts, roots of R. cordifolia are the most suitable source of effective secondary metabolites. The present work investigated phytochemical content and antioxidant potential of R. cordifolia root powder extracted in different solvents. Total polyphenols and flavonoids content were estimated. High antioxidant activity was corroborated with DPPH, hydrogen peroxide, nitric oxide, reducing power and total antioxidant assays. Obtained results showed that ethanol extracts were most potent over methanol, aqueous and PBS extracts for DPPH, hydrogen peroxide and reducing power assays. In contrast, methanol and aqueous extracts had higher potency in nitric oxide and total antioxidant assays. Encouraging results were obtained for antioxidant activity even upon PVPP treatment that removed the polyphenols from the extracts. The results suggest a potential of ethanol / methanol extracts for anti-cancer cellular activities as many reports earlier have shown that antioxidant activities are closely correlated with anticancer activities.

  • Open access
  • 148 Reads
Anmicrobial Activity and Composition of Different Cultivars of Honeysuckle Berry Lonicera caerulea L.

The edible blue honeysuckle berries comes from Russia and in recent years has been considerably planted in some European countries, Lithuania is among them. Honeysuckle berries do not require special care during cultivation: they have high resistance to cold, different soil acidities, pests and various diseases. The berries are rich in ascorbic acid and phenolic contents, which have nutritional and health promoting properties for humans. Using spectrophotometric methods we compare the content of total phenolic compounds (TPC) and anthocyanis, chromatic characteristics of eleven Lonicera caerulea L. cultivars. Berries were grown in collection of Vytautas Magnus University Botanical Garden and collected at maturation stage. Also content of ascorbic acid and saccharides were evaluated by HPLC using diode ray detector. Antimicrobial activity of ethanol and water extracts of honeysuckle berry was evaluated by the agar well diffusion method. Bacterial tests have identified antimicrobial properties of ethanol extract of honeysuckle berries, being particularly efficient against Bacillus subtilis and Listeria monocytogenes but without affecting Salmonella typhimurium. Water extracts showed inhibition effect on Escherichia coli, Enterococcus faecalis, Bacillus subtilis, Salmonella typhimurium and Pseudomonas aeruginosa, but without affecting Candida and Saccharomyces cerevisiae yeasts. The cultivar 'Morena' had the highest anthocyanins (781 mg/100 g) and total phenolic compounds (799 mg/100 g), the lowest anthocyanins (282 mg/100 g) and TPC (300 mg/100 g) content was detected in 'Vostorg' cultivar. Cultivars 'Pavlovskaja' and 'Pereselenka' had high content of ascorbic acid. The maximum glucose and fructose content was detected in 'Leningradskaja' cultivar.

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