Silica nanoparticles as novel sustainable approach for plant growth and crop protection

Elicitation of Bacillus cereus-Amazcala (B.c-A) with SiO2 Nanoparticles Improves Its Role as a Plant Growth-Promoting Bacteria (PGPB) in Chili Pepper Plants

“…One possible explanation for this is that both the nanoparticles and the bacteria alone exert positive effects on the crop, but their combination also enhances the activity of the bacteria, so it is possible to find better results for growth, development, and crop yield. SiO 2 -NPs have a direct effect on plant cells since they are capable of modulating biochemical and physiological responses through the activation of genes related to the induction of growth regulators, the activation of the antioxidant system, and the generation of a mechanical barrier in the plant cell walls, which allows a better development, resistance, and vigor of the plants [16,39]. Moreover, similar responses have been observed with the combined use of PGPB and NPs.…”

“…This phenomenon is similar to that observed in plants since some NPs, including SiO 2 -NPs, can have negative impacts at specific doses and forms of application. Thus, hormetic studies in the evaluation of nanoparticles are essential [16]. Some studies have analyzed the effects of NPs on the growth and survival of PGPB.…”

“…NPs can improve the beneficial attributes of PGPB such as nitrogen fixation, siderophore production, phosphorous solubilization, and phytohormone production [29] by stimulating their growth and activity; moreover, some authors report that NPs could function as platforms to stabilize bacteria attachment to roots [41], which in turn enhance plant growth and development. Furthermore, NPs alone have demonstrated their potential as plant growth-promoting factors, depending on their physicochemical characteristics such as nature (metallic, oxides, carbon-based, or composite), morphology, size, concentration, and crystallinity, by men-tioning the main ones [16,45]. The double action (NPs-PGPB) allows this technology to acquire an important role in microbial formulation development.…”

“…It was observed that plants uptake SiO 2 -NPs through their roots and leaves by diffusion to later be polymerized or translocated into other tissues, producing different physiological and cellular functions [14,15]. SiO 2 -NP accumulation provides mechanical strength to the cell wall, functioning as a physical barrier against pathogens and abiotic stress factors [16]. Moreover, SiO 2 -NPs function as modulators of gene expression, controlling different signaling pathways that involve growth regulators such as salicylic acid (SA), jasmonic acid (JA), and ethylene.…”

“…Therefore, they may promote the induction of different biochemical and physiological processes, enhancing plant growth and yield. Different studies have shown that SiO 2 -NPs, when applied to plants, increase lignification, biomass, height, flowering, nutrient acquisition, water absorption, germination rate, and chlorophyll and antioxidant enzyme content, improving photosynthetic efficiency, global yield, and disease management; moreover, they are viable for use in agriculture since they are nontoxic in nature [16]. For example, SiO 2 -NP application has shown improvements in germination and shoot and root growth in barley and maize [17].…”