scholarly journals Inducing Systemic Resistance against Cucumber Mosaic Cucumovirus using Streptomyces spp.

2016 ◽  
Vol 44 (1) ◽  
pp. 127-142 ◽  
Author(s):  
Radwa Shafie ◽  
Aly Hamed ◽  
Hany El-Sharkawy
Keyword(s):  
Systemic Resistance ◽  
Streptomyces Spp ◽  
Cucumber Mosaic Cucumovirus

scholarly journals Improving Regulation of Enzymatic and Non-Enzymatic Antioxidants and Stress-Related Gene Stimulation in Cucumber mosaic cucumovirus-Infected Cucumber Plants Treated with Glycine Betaine, Chitosan and Combination

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2341 ◽  
Author(s):  
Ahmed R. Sofy ◽  
Rehab A. Dawoud ◽  
Mahmoud R. Sofy ◽  
Heba I. Mohamed ◽  
Ahmed A. Hmed ◽  
...  
Keyword(s):  
Glycine Betaine ◽  
Indole Acetic Acid ◽  
Soluble Sugars ◽  
Economic Consequences ◽  
Systemic Resistance ◽  
Enzymatic Antioxidants ◽  
Challenge Control ◽  
Induce Resistance ◽  
Cucumber Mosaic Cucumovirus ◽  
Chemical Pesticides

Cucumber mosaic cucumovirus (CMV) is a deadly plant virus that results in crop-yield losses with serious economic consequences. In recent years, environmentally friendly components have been developed to manage crop diseases as alternatives to chemical pesticides, including the use of natural compounds such as glycine betaine (GB) and chitosan (CHT), either alone or in combination. In the present study, the leaves of the cucumber plants were foliar-sprayed with GB and CHT—either alone or in combination—to evaluate their ability to induce resistance against CMV. The results showed a significant reduction in disease severity and CMV accumulation in plants treated with GB and CHT, either alone or in combination, compared to untreated plants (challenge control). In every treatment, growth indices, leaf chlorophylls content, phytohormones (i.e., indole acetic acid, gibberellic acid, salicylic acid and jasmonic acid), endogenous osmoprotectants (i.e., proline, soluble sugars and glycine betaine), non-enzymatic antioxidants (i.e., ascorbic acid, glutathione and phenols) and enzymatic antioxidants (i.e., superoxide dismutase, peroxidase, polyphenol oxidase, catalase, lipoxygenase, ascorbate peroxidase, glutathione reductase, chitinase and β-1,3 glucanase) of virus-infected plants were significantly increased. On the other hand, malondialdehyde and abscisic acid contents have been significantly reduced. Based on a gene expression study, all treated plants exhibited increased expression levels of some regulatory defense genes such as PR1 and PAL1. In conclusion, the combination of GB and CHT is the most effective treatment in alleviated virus infection. To our knowledge, this is the first report to demonstrate the induction of systemic resistance against CMV by using GB.

scholarly journals Pseudomonas fluorescens LBUM223 Increases Potato Yield and Reduces Common Scab Symptoms in the Field

2015 ◽  
Vol 105 (10) ◽  
pp. 1311-1317 ◽  
Author(s):  
Tanya Arseneault ◽  
Claudia Goyer ◽  
Martin Filion
Keyword(s):  
Gene Expression ◽  
Pseudomonas Fluorescens ◽  
Common Scab ◽  
Potato Yield ◽  
Field Conditions ◽  
Systemic Resistance ◽  
Thaxtomin A ◽  
Streptomyces Spp ◽  
Defense Related Gene ◽  
And Control

Common scab of potato, caused by pathogenic Streptomyces spp., is an important disease not efficiently controlled by current methods. We previously demonstrated that Pseudomonas fluorescens LBUM223 reduces common scab development under controlled conditions through phenazine-1-carboxylic (PCA) production, leading to reduced thaxtomin A production by the pathogen, a key pathogenicity and virulence factor. Here, we aimed at determining if LBUM223 is able to increase potato yield and control common scab under field conditions, while characterizing the biocontrol mechanisms involved. We investigated if a reduction in pathogen soil populations, activation of induced systemic resistance in potato, and/or changes in txtA gene expression, involved in thaxtomin A biosynthesis in pathogenic Streptomyces spp. were involved in common scab control by LBUM223. Common scab symptoms were significantly reduced and total tuber weight increased by 46% using biweekly applications of LBUM223. LBUM223 did not reduce pathogen soil populations, nor was potato systemic defense-related gene expression significantly altered between treatments. However, a significant down-regulation of txtA expression occurred in the geocaulosphere. This is the first demonstration that a Pseudomonas strain can directly alter the transcriptional activity of a key pathogenesis gene in a plant pathogen under field conditions, contributing to disease control.

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