scholarly journals Chitosan Nanoparticles Inactivate Alfalfa Mosaic Virus Replication and Boost Innate Immunity in Nicotiana glutinosa Plants

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2701
Author(s):  
Ahmed Abdelkhalek ◽  
Sameer H. Qari ◽  
Mohamed Abd Al-Raheem Abu-Saied ◽  
Abdallah Mohamed Khalil ◽  
Hosny A. Younes ◽  
...  

Plant viral infection is one of the most severe issues in food security globally, resulting in considerable crop production losses. Chitosan is a well-known biocontrol agent against a variety of plant infections. However, research on combatting viral infections is still in its early stages. The current study investigated the antiviral activities (protective, curative, and inactivation) of the prepared chitosan/dextran nanoparticles (CDNPs, 100 µg mL−1) on Nicotiana glutinosa plants. Scanning electron microscope (SEM) and dynamic light scattering analysis revealed that the synthesized CDNPs had a uniform, regular sphere shapes ranging from 20 to 160 nm in diameter, with an average diameter of 91.68 nm. The inactivation treatment was the most effective treatment, which resulted in a 100% reduction in the alfalfa mosaic virus (AMV, Acc# OK413670) accumulation level. On the other hand, the foliar application of CDNPs decreased disease severity and significantly reduced viral accumulation levels by 70.43% and 61.65% in protective and curative treatments, respectively, under greenhouse conditions. Additionally, the induction of systemic acquired resistance, increasing total carbohydrates and total phenolic contents, as well as triggering the transcriptional levels of peroxidase, pathogen-related protein-1, and phenylalanine ammonia-lyase were observed. In light of the results, we propose that the potential application of CDNPs could be an eco-friendly approach to enhance yield and a more effective therapeutic elicitor for disease management in plants upon induction of defense systems.

Plant Disease ◽  
2021 ◽  
Author(s):  
Binoy Babu ◽  
Mathews L Paret ◽  
Xavier Martini ◽  
Gary Knox ◽  
Barron Riddle ◽  
...  

Rose rosette disease (RRD) caused by rose rosette emaravirus (RRV) is a major issue in the U.S. rose industry with no effective method for its management. This study evaluated the effect of foliar application of Acibenzolar S-methyl (ASM), a plant systemic acquired resistance inducer in reducing RRD disease severity on Rosa species cv. Radtkopink (Pink Double Knock Out®) under greenhouse condition, and the effect of ASM on plant growth under commercial nursery production conditions. ASM at 50 or 100 mg/L at weekly intervals significantly reduced RRD severity compared to the untreated control in two of the three greenhouse trials (P < 0.05). The plants in these trials were subsequently pruned and observed for symptoms, which further indicated that application of ASM at 50 or 100 mg/L lowered disease severity compared to the untreated control (P < 0.05) in these two trials. Plants treated with ASM at 50 or 100 mg/L had delayed incidence of RRD compared to the non-treated controls. Plants treated with ASM at 50 or 100 mg/L rate in all three trials either did not have RRV present or the virus was present in fewer leaf samples than untreated controls as indicated by RT-qPCR analysis. Overall, plants treated with ASM at 50 mg/L had 36-43% reduced RRD incidence compared to the water control. The treatment of two cultivars of rose, ‘Radtkopink’ and ‘Meijocos’ (Pink Drift®), with weekly foliar applications of ASM at three rates (0.5, 0.75 and 1.0 oz/A) indicated that ASM had no negative effect on flowering or plant growth at even the highest rate.


Author(s):  
Xing Luo ◽  
Xuesong Cao ◽  
Chuanxi Wang ◽  
Le Yue ◽  
Xiaofei Chen ◽  
...  

Plant disease seriously threatens the global food security. However, an effective and sustainable control strategy is lacking. In this study, foliar application with 10 mg/L nitrogen doped carbon dots (N-CDs)...


2007 ◽  
Vol 20 (6) ◽  
pp. 659-670 ◽  
Author(s):  
Andrew J. Love ◽  
Valérie Laval ◽  
Chiara Geri ◽  
Janet Laird ◽  
A. Deri Tomos ◽  
...  

We analyzed the susceptibility of Arabidopsis mutants with defects in salicylic acid (SA) and jasmonic acid (JA)/ethylene (ET) signaling to infection by Cauliflower mosaic virus (CaMV). Mutants cpr1-1 and cpr5-2, in which SA-dependent defense signaling is activated constitutively, were substantially more resistant than the wild type to systemic infection, implicating SA signaling in defense against CaMV. However, SA-deficient NahG, sid2-2, eds5-1, and pad4-1 did not show enhanced susceptibility. A cpr5 eds5 double mutant also was resistant, suggesting that resistance in cpr5 may function partially independently of SA. Treatment of cpr5 and cpr5 eds5, but not cpr1, with salicyl-hydroxamic acid, an inhibitor of alternative oxidase, partially restored susceptibility to wild-type levels. Mutants etr1-1, etr1-3, and ein2-1, and two mutants with lesions in ET/JA-mediated defense, eds4 and eds8, also showed reduced virus susceptibility, demonstrating that ET-dependent responses also play a role in susceptibility. We used a green fluorescent protein (GFP)-expressing CaMV recombinant to monitor virus movement. In mutants with reduced susceptibility, cpr1-1, cpr5-2, and etr1-1, CaMV-GFP formed local lesions similar to the wild type, but systemic spread was almost completely absent in cpr1 and cpr5 and was substantially reduced in etr1-1. Thus, mutations with enhanced systemic acquired resistance or compromised ET signaling show diminished long-distance virus movement.


2003 ◽  
Vol 16 (2) ◽  
pp. 115-122 ◽  
Author(s):  
Olivier Klarzynski ◽  
Valérie Descamps ◽  
Bertrand Plesse ◽  
Jean-Claude Yvin ◽  
Bernard Kloareg ◽  
...  

Sulfated fucans are common structural components of the cell walls of marine brown algae. Using a fucan-degrading hydrolase isolated from a marine bacterium, we prepared sulfated fucan oligosaccharides made of mono- and disulfated fucose units alternatively bound by α-1,4 and α-1,3 glycosidic linkages, respectively. Here, we report on the elicitor activity of such fucan oligosaccharide preparations in tobacco. In suspension cell cultures, oligofucans at the dose of 200 μg ml−1 rapidly induced a marked alkalinization of the extracellular medium and the release of hydrogen peroxide. This was followed within a few hours by a strong stimulation of phenylalanine ammonia-lyase and lipoxygenase activities. Tobacco leaves treated with oligofucans locally accumulated salicylic acid (SA) and the phytoalexin scopoletin and expressed several pathogenesis-related (PR) proteins, but they displayed no symptoms of cell death. Fucan oligosaccharides also induced the systemic accumulation of SA and the acidic PR protein PR-1, two markers of systemic acquired resistance (SAR). Consistently, fucan oligosaccharides strongly stimulated both local and systemic resistance to tobacco mosaic virus (TMV). The use of transgenic plants unable to accumulate SA indicated that, as in the SAR primed by TMV, SA is required for the establishment of oligofucan-induced resistance.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ahmed Abdelkhalek ◽  
Abdulaziz A. Al-Askar ◽  
Said I. Behiry

Abstract Alfalfa mosaic virus (AMV) is a worldwide distributed virus that has a very wide host range and causes significant crop losses of many economically important crops, including potato (Solanum tuberosum L.). In this study, the antiviral activity of Bacillus licheniformis strain POT1 against AMV on potato plants was evaluated. The dual foliar application of culture filtrate (CF), 24 h before and after AMV-inoculation, was the most effective treatment that showed 86.79% reduction of the viral accumulation level and improvement of different growth parameters. Moreover, HPLC analysis showed that a 20 polyphenolic compound was accumulated with a total amount of 7,218.86 and 1606.49 mg/kg in POT1-treated and non-treated plants, respectively. Additionally, the transcriptional analysis of thirteen genes controlling the phenylpropanoid, chlorogenic acid and flavonoid biosynthetic pathways revealed that most of the studied genes were induced after POT1 treatments. The stronger expression level of F3H, the key enzyme in flavonoid biosynthesis in plants, (588.133-fold) and AN2, anthocyanin 2 transcription factor, (97.005-fold) suggested that the accumulation flavonoid, especially anthocyanin, might play significant roles in plant defense against viral infection. Gas chromatography-mass spectrometry (GC-MS) analysis showed that pyrrolo[1,2-a]pyrazine-1,4-dione is the major compound in CF ethyl acetate extract, that is suggesting it acts as elicitor molecules for induction of systemic acquired resistance in potato plants. To our knowledge, this is the first study of biological control of AMV mediated by PGPR in potato plants.


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