Biogenic AgNPs—A Nano Weapon against Bacterial Canker of Tomato (BCT)

Abstract

Bacterial canker of tomato caused by the bacterial pathogen Clavibacter michiganensis subsp. michiganensis (Cmm) is a major limiting factor for tomato production worldwide. Currently there exists no resistant variety of tomato to bacterial canker; only cultural and chemical controls are available. This study synthesized AgNPs (silver nanoparticles) via a green chemistry route and investigated their bactericidal potential against bacterial canker of tomato (BCT). AgNPs were prepared using mycellial aqueous extract of agriculturally beneficial fungi Pythium oligandrum. The formation of AgNPs was confirmed by using UV–Vis spectroscopy for the absorbance pattern while their morphology was investigated by the transmission electron microscopy (TEM). The X-ray diffraction profile for the biogenic AgNPs confirmed a crystalline structure with an average particle size of 12 nm. AgNPs treated seeds showed a normal germination rate with normal seedling growth. An in-vitro study found that the prepared AgNPs caused the maximum inhibition of the bacterial pathogen. In the greenhouse the introduction of AgNPs significantly prevents and inhibits the bacterial pathogen Cmm on tomato plants. These results suggest that this process is a strong candidate for industrial scale production of AgNPs. These particles act as an inhibitor and broad spectrum antibacterial agent against cmm, and hence offer a new and eco-friendly alternative in BCT control.

Efficacy of biosynthesized silver nanoparticles from Larrea tridentata against Clavibacter michiganensis

“…However, the plants treated with AgNPs50 showed only 20% incidence 42 days after infection (DAI), and this is considered the best treatment to decrease the incidence of the disease in infected plants (Figure 2a). Similar results were reported by Noshad et al (2020), who reached only a 20% of disease incidence on tomato plants infected with Cmm by treating with 0.444 mg L −1 of biogenic AgNPs, without significant differences in the streptomycin antibiotic used as a control.…”

“…However, few investigations have been carried out regarding the in vivo growth-inhibitory effects of silver nanoparticles (AgNPs) against phytopathogenic microorganisms by reducing the incidence and severity of bacterial diseases. Noshad et al (2020) synthesized AgNPs using mycelial aqueous extract of Pythium oligandrum. The AgNPs inhibited the growth of Cmm and enhanced plant growth without significant differences compared with the standard antibiotic application.…”

Smart nanomaterial and nanocomposite with advanced agrochemical activities

“… Spot blotch pathogen of wheat Inhibit conidial germination [ 191 ] Clavibacter michiganensis CuNPs and K 2 SiO 3 NPs Bacterial ring rot in potato Decrease bacterial cell viability [ 192 ] X. perforans Photochemically active TiO 2 NPs Spot disease in tomato Due to high photocatalytic activity, reduction in bacterial spot [ 193 ] Ralstonia solanacearum MgONPs Vascular wilt disease Inhibit bacterial activity [ 185 ] Xanthomonas campestris pv. campestris Silver (Ag) NPs Bacterial blight Enhance antioxidant enzyme activity [ 194 ] Colletotrichum gloeosporioides Chitosan NP Disease in Chile Inhibition growth of mycelia [ 195 ] A. alternata Chitosan NP Leaf spot Inhibit spore germination [ 83 ] Xanthomonas alfalfae Synthesized Mg(OH) 2 NPs Bacterial leaf spot Significantly decrease the activity of X. alfalfae [ 11 ] Target species Nanoparticles used Mechanism of action References Insects ...…”

Biosynthesis of metal nanoparticles using microorganisms and its medicinal applications

“…Interestingly, no aggregation or precipitation happened after two to three weeks of AgNPs incubation. According to Noshad et al, (2020), AgNPs was produced by mix 1:1 fungal extracts of Trichoderma harzianum and Aspergillus fumigatus separately with AgNO 3 and then heated to 29 °C for 24 h. The change of mixture color from yellowish to dark brown confirmed the formation of AgNPs. Similarly, the study of Khaddam et al, (2019) used Aspergillus sp.…”