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

Abstract

Agriculture needs to decrease the use of agrochemicals due to their high toxicity and adopt new strategies to achieve sustainable food production. Therefore, nanoparticles (NPs) and plant growth-promoting bacteria (PGPB) have been proposed as viable strategies to obtain better crop yields with less environmental impact. Here, we describe the effect of silica nanoparticles (SiO2-NPs) on survival, antioxidant enzymatic activity, phosphate solubilization capacity, and gibberellin production of Bacillus cereus-Amazcala (B.c-A). Moreover, the effect of the co-application of SiO2-NPs and B.c-A on seed germination, physiological characteristics, and antioxidant enzymatic activity of chili pepper plants was investigated under greenhouse conditions. The results indicated that SiO2-NPs at 100 ppm enhanced the role of B.c-A as PGPB by increasing its phosphate solubilization capacity and the production of GA7. Moreover, B.c-A catalase (CAT) and superoxide dismutase (SOD) activities were increased with SiO2-NPs 100 ppm treatment, indicating that SiO2-NPs act as a eustressor, inducing defense-related responses. The co-application of SiO2-NPs 100 ppm and B.c-A improved chili pepper growth. There was an increase in seed germination percentage, plant height, number of leaves, and number and yield of fruits. There was also an increase in CAT and PAL activities in chili pepper plants, indicating that bacteria–NP treatment induces plant immunity.

Microbial seed coating: An attractive tool for sustainable agriculture

“…One of the reasons for the enhancement of mineral compounds solubilization in soil may be due to the production of siderophores through metabolites of bacterial [ 34 ]. In addition, a study showed that Bacillus cereus -Amazcala (B.c-A) increased the phosphate solubilization capacity [ 35 ]. Production of phytohormones …”

“…It has been reported that Bacillus subtilis can produce cytokinin and induce an enhancement in root and shoot weight [ 38 ]. In addition, Bacillus amyloliquefaciens produced a high concentration of gibberellic acid [ 35 ]. Inoculation of plants with PGPR increased plant growth.…”

Biostimulant and Elicitor Responses to Cricket Frass (Acheta domesticus) in Tomato (Solanum lycopersicum L.) under Protected Conditions

“…Both biostimulation and elicitation are positive plant responses that, based on the hormesis phenomenon, can be defined as part of the eustress zone in the biphasic hormetic curve [ 1 , 17 ]. The case of elicitation is interesting to highlight because if it is excessive, the plant will be in distress, thus showing symptoms of toxicity as suggested above [ 1 , 18 ].…”

Sustainable cultivation of red chili plants (Capsicum annuum L.) through a composition of NPK and biological organics fertilizers

“…can synthesize auxin phytohormones (Indole 3-Acetic Acid/IAA) which functions to increase growth, because the dichotomy of chili plants can grow optimally [13]. [14] added plant height can increase thanks to the application of biofertilizer made from Bacillus. 1 shows that the composition of 75% NPK fertilizer + sludge compost is able to provide harvest age relatively the same as the provision of 100% NPK fertilizer.…”