Nanoinhibitory Impacts of Salicylic Acid, Glycyrrhizic Acid Ammonium Salt, and Boric Acid Nanoparticles against Phytoplasma Associated with Faba Bean

Abstract

Phytoplasmas are economically important plant pathogenic bacterial diseases, causing severe yield losses worldwide. In this study, we tested nanoformulations such as glycyrrhizic acid ammonium salt (GAS), salicylic acid (SA), and boric acid (BA) as novel antimicrobial agents inducing the resistance against the phytoplasma disease in faba bean. The nanoparticles (NP) were foliar-applied to naturally phytoplasma-infected faba bean with three concentrations from each of SA, GAS, and BA, under field conditions. Nested PCR (using universal primer pairs P1/P7 and R16F2n/R16R2) were reacted positively with all symptomatic samples and gave a product size of approximately 1200 bp, while the healthy plant gave no results. Transmission electron microscopy examinations of phytoplasma-infected faba bean plants treated with different nanoparticles revealed that severe damage occurred in phytoplasma particle’s structure, degradation, malformation, lysis in the cell membrane, and the cytoplasmic leakage followed by complete lysis of phytoplasma cells. Exogenous application of GAS-NP (1.68 µM), SA-NP (0.28 µM), and BA-NP (0.124 µM) suppressed the infection percentage of phytoplasma by 75%, 50%, and 20%, and the disease severity by 84%, 64%, and 54%, respectively. Foliar application of nanoparticles improved Fv/Fm (maximum quantum efficiency of PSII Photochemistry), PI (the performance index), SPAD chlorophyll (the relative chlorophyll content), shoots height, and leaves number, thus inducing recovery of the plant biomass and green pods yield. The most effective treatment was GAS-NP at 1.68 µM that mediated substantial increases in the shoots’ fresh weight, shoots’ dry weight, number of pods per plant, and green pods yield by 230%, 244%, 202% and 178%, respectively, compared to those of infected plants not sprayed with nanoparticles. This study demonstrated the utility of using nanoparticles, particularly GAS-NP at 1.68 µM to suppress the phytoplasma infection.

Enhancing sweet potato (Ipomoea batatas) resilience grown in cadmium-contaminated saline soil: a synergistic approach using Moringa leaf extract and effective microorganisms application

“…Moreover, plants treated with EMs can produce exopolysaccharides (EPSs), enabling plants to have a more substantial accumulation of sugars, free proline, TFA, and soluble protein content (Khan and Bano 2019 ). As a result, these beneficial bacteria cause the manufacture of these osmolytes in plant cells, which protects cells from oxidative damage and increases tolerance to Cd 2+ or/and salt stress (Rady et al 2021 ; Ahmed et al 2022 ).…”

Soil application of effective microorganisms and nitrogen alleviates salt stress in hot pepper (Capsicum annum L.) plants

“…(2017) . Furthermore, increasing the photosynthetic machinery and relative chlorophyll content under salt stress after the application of EMs + and/or high N gives biochemical insights into salt stress tolerance ( Ashraf and Harris, 2013 ; Ahmed et al., 2022 ). Similar results have been obtained when EMs ( Abd El-Mageed et al., 2022 ) and N ( Ahanger et al., 2019 ) elevated the compatible solutes accumulation, antioxidant capacity, and nutrients acquisition in sweet potato and wheat, to prevent oxidative damage, preserve cell water status and membrane stability, protecting the photosynthetic transport electron, increasing chlorophyll contents, and the efficiency of photosynthesis.…”

Tackling banded leaf and sheath blight disease of maize through activation of host defense

“…Exogenously applied SA has been observed to induce both local and systemic acquired resistance in diverse plant species against a range of pathogens, such as Fusarium oxysporum (Jendoubi et al, 2015), Penicillium digitatum/Alternaria alternata (Allahverdi Beyk et al, 2021), Magnaporthe grisea (Yang et al, 2019a), Colletotrichum gloeosporioides (He et al, 2017), Xanthomonas spp. (Le Thanh et al, 2017), viruses (Ong and Cruz, 2016;Zhao et al, 2019), and phytoplasma (Ahmed et al, 2022). For instance, in China, foliar application of different concentrations of SA ranging from 0.1 to 5.0 mM resulted in direct and systemic effects on chemical defense responses with an increase in content of total phenol, DIMBOA (2,4-dihydroxy-7methoxy-2H,1,4-benzoxazin-3(4H)-one), and a significant increase in activity of superoxide dismutase (SOD), polyphenol oxidase, peroxidase, and catalase (Feng et al, 2022).…”