scholarly journals Antibacterial activity of tannins towards Pseudomonas syringae pv. tomato, and their potential as biostimulants on tomato plants

2021 ◽  
Vol 60 (1) ◽  
pp. 23-36
Author(s):  
Paolo CANZONIERE ◽  
Sara FRANCESCONI ◽  
Samuele GIOVANDO ◽  
Giorgio BALESTRA
Keyword(s):  
Antibacterial Activity ◽  
Water Treatment ◽  
Pseudomonas Syringae ◽  
Crop Protection ◽  
Dry Weight ◽  
Economic Losses ◽  
Copper Hydroxide ◽  
Copper Treatment

Pseudomonas syringae pv. tomato (Pst), the causal agent of bacterial speck of tomato, is a significant cause of economic losses in tomato crops. This disease is mainly controlled with preventive use of cupric salt formulations. Antibacterial activity of the tannins U1, U2, U3 and U4, applied alone at 1% w/v concentration or in combination with half (0.045% w/v) of standard of copper hydroxide treatments, was assayed for effects on Pst. In vitro, the four tannins completely inhibited Pst colony formation after 24 h, but U2 (quebracho tannins) + ½ Cu(OH)2 allowed Pst growth after 48 h of incubation, indicating that, since U2 is composed of high molecular condensed tannins it is likely that their structures have chelated the copper hydroxide much more then hydrolysable ones, thus inactivating copper hydroxide and tannins. In fact, this activity of the tannins was equivalent to that for 0.045% w/v of copper hydroxide. Effects of tannins on tomato plant growth were also assessed. On seedlings, long-term U1 treatments increased dry weight of shoots compared to copper hydroxide, but not to water treatment. The U4 treatment increased the NBI values compared to copper treatment but did not show significant differences compared to the water treatment. Inhibitory activity of tannin treatments reduced disease by 37–62%, and 60% after copper treatment, while disease severity was reduced by 33–54% after treating plants with tannins and 36% after copper treatment. On mature plants treated once, the disease reduction was 27–39% after tannin treatments and 44% after copper treatment, while severity was reduced by 50–60% from tannin treatments, and 47% by copper. In seedlings and mature plants, these reductions were similar (P > 0.05) for the tannins and copper treatments. This study indicates a novel crop protection strategy using natural products as alternatives to xenobiotic compounds.

scholarly journals Effectiveness of Dunaliella salina Extracts against Bacillus subtilis and Bacterial Plant Pathogens

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 613
Author(s):  
Alfredo Ambrico ◽  
Mario Trupo ◽  
Rosaria Magarelli ◽  
Roberto Balducchi ◽  
Angelo Ferraro ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pseudomonas Syringae ◽  
Dunaliella Salina ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Economic Losses ◽  
Tomato Plants ◽  
Hexane Extracts

Several bacteria pathogens are responsible for plant diseases causing significant economic losses. The antibacterial activity of Dunaliella salina microalgae extracts were investigated in vitro and in vivo. First, biomass composition was chemically characterized and subjected to extraction using polar/non-polar solvents. The highest extraction yield was obtained using chloroform:methanol (1:1 v/v) equal to 170 mg g−1 followed by ethanol (88 mg g−1) and hexane (61 mg g−1). In vitro examination of hexane extracts of Dunaliella salina demonstrated antibacterial activity against all tested bacteria. The hexane extract showed the highest amount of β-carotene with respect to the others, so it was selected for subsequent analyses. In vivo studies were also carried out using hexane extracts of D. salina against Pseudomonas syringae pv. tomato and Pectobacterium carotovorum subsp. carotovorum on young tomato plants and fruits of tomato and zucchini, respectively. The treated young tomato plants exhibited a reduction of 65.7% incidence and 77.0% severity of bacterial speck spot disease. Similarly, a reduction of soft rot symptoms was observed in treated tomato and zucchini fruits with a disease incidence of 5.3% and 12.6% with respect to 90.6% and 100%, respectively, for the positive control.

scholarly journals Growth of Transplants and in Vitro-cultured Clones of Asparagus in Response to CO2 Enrichment and Supplemental Lighting

1990 ◽  
Vol 115 (3) ◽  
pp. 364-368 ◽  
Author(s):  
Yves Desjardins ◽  
André Gosselin ◽  
Michel Lamarre
Keyword(s):  
Co2 Enrichment ◽  
Dry Weight ◽  
Plant Size ◽  
Asparagus Officinalis ◽  
Photon Flux ◽  
Long Term Effects ◽  
Shoot Dry Weight ◽  
Supplemental Lighting

Asparagus (Asparagus officinalis L.) transplants and in vitro-cultured clones were grown and acclimatized under two photosynthetic photon flux (PPF) conditions (ambient and ambient + 80 μmol·s-1·m-2) and three atmospheric CO2 concentrations (330, 900, and 1500 ppm). Short- and long-term effects were measured in the greenhouse and after two seasons of growth in the field, respectively. In the greenhouse, CO2 enrichment (CE) and supplemental lighting (SL) increased root and fern dry weight by 196% and 336%, respectively, for transplants and by 335% and 229%, respectively, for clones. For these characteristics, a significant interaction was observed between SL and CE with tissue-cultured plantlets. In the absence of SL, CE did not significantly increase root or shoot dry weight. No interaction was observed between CE and SL for transplants, although these factors significantly improved growth. It was possible to reduce the nursery period by as much as 3 weeks with CE and SL and still obtain a plant size comparable to that of the control at the end of the experiment. Long-term effects of SL were observed after two seasons of growth in the field. Supplemental lighting improved survival of transplants and was particularly beneficial to in vitro plants. Clones grown under SL were of similar size as transplants after 2 years in the field.

scholarly journals Growth of `Cunningham's White' Rhododendron in Plastic and Fiber Pots Treated With Copper Hydroxide

2002 ◽  
Vol 12 (1) ◽  
pp. 134-137 ◽  
Author(s):  
Sven E. Svenson
Keyword(s):  
Root Growth ◽  
Dry Weight ◽  
Growth Responses ◽  
Copper Hydroxide ◽  
Shoot Height ◽  
Copper Treatment ◽  
Average Maximum ◽  
Growing Block ◽  
Black Plastic ◽  
Maximum Temperatures

Shoot and root growth responses of `Cunningham's White' rhododendron (Rhododendron x) was studied when grown in black plastic or molded fiber pots treated with copper hydroxide, or not treated. Containers of two sizes were studied, and the influence of pot type on substrate temperature was recorded. Rhododendron shoot height and dry weight was not influenced by pot volume, pot type, or copper treatment at 49, 131, or 362 d after potting. Rhododendron shoots were larger when grown in 3.8-L (trade 2-gal) pots compared to 2.8-L (trade 1-gal) pots, or when grown in 3.8-L fiber pots compared to 3.8-L plastic pots, both 131 and 362 d after potting. Copper treatment did not influence shoot size. Copper treatment reduced the amount of circling or matted roots at the container-substrate interface for both plastic and fiber pots, but there was better control of root growth in 3.8-L pots compared to 2.8-L pots. Substrate average minimum temperatures were warmer, and average maximum temperatures were cooler when pots were located near the center of the growing block compared to the southwest corner ofthe growing block. Substrate average maximum temperatures were cooler in fiber pots compared to plastic pots, but only when pots were located on the southwest corner of the growing block.

scholarly journals Greenhouse Cucumber Growth and Yield Response to Copper Application

HortScience ◽  
2010 ◽  
Vol 45 (5) ◽  
pp. 771-774 ◽  
Author(s):  
Youbin Zheng ◽  
Linping Wang ◽  
Diane Feliciano Cayanan ◽  
Mike Dixon
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Nutrient Solution ◽  
Dry Weight ◽  
Leaf Number ◽  
Leaf Injury ◽  
Copper Treatment ◽  
Cucumber Fruit ◽  
Leaf Dry Weight

To determine the nutrient solution copper (Cu2+) level above which Cucumis sativus L. (cucumber, cv. LOGICA F1) plant growth and fruit yield will be negatively affected, plants were grown on rockwool and irrigated with nutrient solutions containing Cu2+ at 0.05, 0.55, 1.05, 1.55, and 2.05 mg·L−1. Copper treatment began when plants were 4 weeks old and lasted for 10 weeks. During this 10-week period, plants were harvested at 3 weeks (short-term) and 10 weeks (long-term) after the start of Cu2+ treatment. Neither visible leaf injury nor negative Cu2+ effect was observed on plant growth (leaf number, leaf area, leaf dry weight, and stem dry weight) after 3 weeks of continuous Cu2+ treatment. However, after 10 weeks of continuous Cu2+ application, cucumber leaf dry weight was significantly reduced by Cu2+ levels 1.05 mg·L−1 or greater; leaf number, leaf area, and stem dry weight were significantly reduced by Cu2+ levels 1.55 mg·L−1 or greater. Copper (Cu2+ levels 1.05 mg·L−1 or greater) also caused root browning. Some plants under the 2.05 mg·L−1 Cu2+ treatment started to wilt after 6 weeks of continuous Cu2+ treatment. Copper treatment did not result in any change in leaf greenness until after Week 9 from the start of the treatments. There was no sign of a negative Cu2+ effect on cucumber fruit numbers after the first 2 weeks of production, but plants under the highest Cu2+ concentration treatment (2.05 mg·L−1) gradually produced fewer cucumber fruit than the control (0.05 mg·L−1) and eventually resulted in lower cucumber yield. Nutrient solution can be treated with 1.05 mg·L−1 of Cu2+ in cucumber production greenhouses; however, it is not recommended to use Cu2+ concentrations 1.05 mg·L−1 or greater continuously long-term (more than 3 weeks). When applying Cu2+, it is suggested that cucumber roots be examined regularly because roots are a better indicator for Cu2+ toxicity than leaf injury.

scholarly journals Innate Immune Responses to Wildtype and Attenuated Sheeppox Virus Mediated Through RIG-1 Sensing in PBMC In-Vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Tesfaye Rufael Chibssa ◽  
Richard Thiga Kangethe ◽  
Francisco J. Berguido ◽  
Tirumala Bharani K. Settypalli ◽  
Yang Liu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Small Ruminants ◽  
Significant Negative Correlation ◽  
Individual Variability ◽  
Innate Immune ◽  
Economic Losses ◽  
Viral Dsrna ◽  
Sheeppox Virus

Sheeppox (SPP) is a highly contagious disease of small ruminants caused by sheeppox virus (SPPV) and predominantly occurs in Asia and Africa with significant economic losses. SPPV is genetically and immunologically closely related to goatpox virus (GTPV) and lumpy skin disease virus (LSDV), which infect goats and cattle respectively. SPPV live attenuated vaccines (LAVs) are used for vaccination against SPP and goatpox (GTP). Mechanisms related to innate immunity elicited by SPPV are unknown. Although adaptive immunity is responsible for long-term immunity, it is the innate responses that prevent viral invasion and replication before LAVs generate specific long-term protection. We analyzed the relative expression of thirteen selected genes that included pattern recognition receptors (PRRs), Nuclear factor-κβ p65 (NF-κβ), and cytokines to understand better the interaction between SPPV and its host. The transcripts of targeted genes in sheep PBMC incubated with either wild type (WT) or LAV SPPV were analyzed using quantitative PCR. Among PRRs, we observed a significantly higher expression of RIG-1 in PBMC incubated with both WT and LAV, with the former producing the highest expression level. However, there was high inter-individual variability in cytokine transcripts levels among different donors, with the expression of TNFα, IL-15, and IL-10 all significantly higher in both PBMC infected with either WT or LAV compared to control PBMC. Correlation studies revealed a strong significant correlation between RIG-1 and IL-10, between TLR4, TNFα, and NF-κβ, between IL-18 and IL-15, and between NF-κβ and IL-10. There was also a significant negative correlation between RIG-1 and IFNγ, between TLR3 and IL-1 β, and between TLR4 and IL-15 (P< 0.05). This study identified RIG-1 as an important PRR in the signaling pathway of innate immune activation during SPPV infection, possibly through intermediate viral dsRNA. The role of immunomodulatory molecules produced by SPPV capable of inhibiting downstream signaling activation following RIG-1 upregulation is discussed. These findings advance our knowledge of the induction of immune responses by SPPV and will help develop safer and more potent vaccines against SPP and GTP.

scholarly journals A Siderophore Analog of Fimsbactin from Acinetobacter Hinders Growth of the Phytopathogen Pseudomonas syringae and Induces Systemic Priming of Immunity in Arabidopsis thaliana

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 806
Author(s):  
Fabrice Betoudji ◽  
Taha Abd El Rahman ◽  
Marvin J. Miller ◽  
Manuka Ghosh ◽  
Mario Jacques ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Antibacterial Activity ◽  
Pseudomonas Syringae ◽  
Quantitative Polymerase Chain Reaction ◽  
Plant Growth Promoting Rhizobacteria ◽  
Infection Model ◽  
Plant Infection ◽  
Plant Growth Promoting ◽  
Acinetobacter Spp

Siderophores produced in soil by plant growth-promoting rhizobacteria (PGPRs) play several roles, including nutrient mobilizers and can be useful as plants defense elicitors. We investigated the role of a synthetic mixed ligand bis-catechol-mono-hydroxamate siderophore (SID) that mimics the chemical structure of a natural siderophore, fimsbactin, produced by Acinetobacter spp. in the resistance against the phytopathogen Pseudomonas syringaepv tomato DC3000 (Pst DC3000), in Arabidopsis thaliana. We first tested the antibacterial activity of SID against Pst DC3000 in vitro. After confirming that SID had antibacterial activity against Pst DC3000, we tested whether the observed in vitro activity could translate into resistance of Arabidopsis to Pst DC3000, using bacterial loads as endpoints in a plant infection model. Furthermore, using quantitative polymerase chain reaction, we explored the molecular actors involved in the resistance of Arabidopsis induced by SID. Finally, to assure that SID would not interfere with PGPRs, we tested in vitro the influence of SID on the growth of a reference PGPR, Bacillus subtilis. We report here that SID is an antibacterial agent as well as an inducer of systemic priming of resistance in A. thaliana against Pst DC3000, and that SID can, at the same time, promote growth of a PGPR.

scholarly journals In vitro inhibition of Pseudomonas syringae pv actinidiae by wound protectants

2015 ◽  
Vol 68 ◽  
pp. 332-339
Author(s):  
D.A. Cornish ◽  
J. Yu ◽  
J.M. Oldham ◽  
J. Benge ◽  
W. Max ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Antibacterial Activity ◽  
Pseudomonas Syringae ◽  
Disease Incidence ◽  
Bacterial Canker ◽  
Streptomycin Sulphate ◽  
Chain Reaction ◽  
Commercial Formulation ◽  
Polymerase Chain

Preventing Pseudomonas syringae pv actinidiae (Psa) the causal agent of bacterial canker of kiwifruit from entering pruning wounds would reduce disease incidence and facilitate canopy management Antibacterial activity against Psa has been determined in the laboratory for active ingredients commercially available in New Zealand Only tebuconazole tebuconazole with octhilinone and a formulation of cyproconazole and iodocarb killed Psa on agar plates or in liquid medium However only tebuconazole with octhilinone killed Psa within 5 min Psa was detected by polymerase chain reaction following plating on instruments used for applying wound protectants in an infected orchard This suggests that under some conditions the pathogen could be transferred from vine to vine when applying some wound protectants Addition of streptomycin sulphate to tebuconazole or a formulation of cyproconazole and iodocarb did not result in a rapid and complete kill of Psa similar to that with a commercial formulation of streptomycin applied alone

scholarly journals Antibacterial Activity of Coptis chinensis Extract Against Pectobacterium carotovorum subsp. carotovorum

2016 ◽  
Vol 5 (2) ◽  
pp. 61-66
Author(s):  
Stephen Kironji Githeng'u ◽  
Samuel Nyalala ◽  
Liu Gaoqiong
Keyword(s):  
Antibacterial Activity ◽  
Crop Protection ◽  
In Vitro Study ◽  
Soft Rot ◽  
Pectobacterium Carotovorum ◽  
Streptomycin Sulphate ◽  
Coptis Chinensis ◽  
Calla Lily ◽  
Carotovorum Subsp

Soft rot of Zantedeschia, caused by Pectobacterium carotovorum subsp. carotovorum (Pcc), has caused a significant worldwide threat to calla lily production. Hence, in order to effectively manage the disease, an intensive management programme aimed at adequte suppression of the pathogen is paramount. In order to investigate the antibacterial effect of a Coptis chinensis extract product against the soft rot- causing bacterium, an in vitro study was set up. Bacterial isolate were obtained from rotting calla lily tubers and maintained in Nutrient Broth under refrigeration. Sterile petri plates containing 15 ml of Nutrient agar were prepared and aseptically inoculated with 0.1 ml an overnight grown culture of a standardized Pectobacterium carotovorum subsp. carotovorum inoculum containing about 1x 108 cfu/ml. The inoculum was spread evenly over the whole surface of the plates. After solidification, 1 ml of the different concentrations of C. chinensis (1, 10, 25, 50 and 100%) were placed individually at the centre of the inoculated petri plates. Positive check was maintained using Streptomycin sulphate (100ppm) and a negative check using sterile distilled water. Eight replicates were maintained for each treatment and the experiment was repeated twice. Results indicated that the lower concentrations of C. chinensis did not cause any inhibition against Pcc. On the other hand, 100% C. chinensis made an inhibition zone comparable to that streptomycin sulphate. Our results demonstrated that C. chinensis has antibacterial activity and therefore feasible for use in crop protection against soft rots caused by Pectobacterium carotovorum subsp. carotovorum.

scholarly journals Cryopreservation of Pistacia vera embryonic axes

2016 ◽  
Vol 61 (No. 4) ◽  
pp. 182-187 ◽  
Author(s):  
B. Benmahioul ◽  
F. Daguin ◽  
M. Kaïd-Harche
Keyword(s):  
Germination Rate ◽  
Dry Weight ◽  
Pistacia Vera ◽  
Ambient Conditions ◽  
Embryo Viability ◽  
Embryonic Axes ◽  
Simple Protocol ◽  
Set Up

This preliminary study investigated the conservation of Pistacia vera genetic resources using seeds and isolated embryonic axes. First, the effect of storing seeds in ambient conditions on embryo viability was evaluated by in vitro culture. The germination rate of P. vera embryonic axes gradually decreased from 100% to 31% after 30-month storage of seeds. Cryopreservation may thus be necessary for the long-term conservation of embryos. A simple protocol was set up using embryonic axes. It included a single dehydration step with silica gel prior to direct freezing in liquid nitrogen (&ndash;196&deg;C). The optimal germination rate was obtained after 60 min dehydration (water content of 0.2 grams of water per gram of dry weight [g&middot;g<sup>&ndash;1</sup> DW]). However, 90 minutes of dehydration (0.14 g&middot;g<sup>&ndash;1</sup> DW) were necessary to obtain seedlings whose qualitative development was equivalent to that of the control embryonic axes.

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