Plant growth-promoting bacteria (PGPRs) have the potential to act as biofertilizers and biopesticides. This study was planned to explore indigenously isolated PGPRs as a potential candidate to control charcoal rot that affects various crops including soybean. Among the four different tested species of PGPRs, Bradyrhizobium japonicum (FCBP-SB-406) showed significant potential to enhance growth and control soil borne pathogens such as Macrophomina phaseolina. Bacillus subtilis (FCBP-SB-324) followed next. Bradyrhizobium japonicum (FCBP-SB-406) reduced disease severity up to 81.25% in comparison to the control. The strain showed a strong fertilizing effect as a highly significant increase in biomass and other agronomic parameters was recorded in plants grown in its presence. The same was supported by the Pearson’s correlation and principal component analysis. A decrease in disease incidence and severity may be due to the induced resistance imparted by the bacterium. This resulted in significant increments in quantities of defense enzymes, including catalase, peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL) and superoxide dismutase (SOD). A significant production of proteases, catalases and hydrogen cyanide by B. japonicum (FCBP-SB-406) can also be associated to mycoparasitism. The establishment of PGPRs in treated soils also showed positive effects on soil health. Total metabolite profiling of treated plants in comparison to the control showed the upregulation of many flavonoids, isoflavonoids and amino acids. Many of these compounds have been well reported with antimicrobial activities. Bradyrhizobium japonicum (FCBP-SB-406) can be employed for the production of a potential formulation to support sustainable agriculture by reducing the input of synthetic pesticides and fertilizers.
Turmeric has attracted a significant amount of interest in recent years due to its strong antimicrobial properties. The tissue culture of turmeric is preferred to obtain disease-free, highest number of plantlets with good uniform chemistry. However, there is a need to increase the speed of the whole process to meet the growing demand for planting materials and to save time and resources. Iron oxide nanoparticles (Fe3O4 NPs) showed positive effects on callus initiation time, proliferation rate, percent root response, shoot length, percent rooting, and number of roots per explant. Highest callus induction, i.e., 80%, was recorded in cultures that were grown in the presence of 15 mg/L of Fe3O4 NPs. Callus initiated earlier in culture tubes that received green synthesized iron nanoparticles in a concentration between 10–15 mg/L. Biofabricated nanoparticles were characterized for their size, physiochemical, and optical properties through UV–Vis spectroscopy, FTIR, XRD, and SEM. Curcuminoids profiling was performed by implementing LC-Ms that revealed increased quantities in plantlets grown in nano-supplemented media when compared to the control.
Agricultural growers worldwide face significant challenges in promoting plant growth. This research introduces a green strategy utilizing nanomaterials to enhance crop production. While high concentrations of nanomaterials are known to be hazardous to plants, this study demonstrates that low doses of biologically synthesized zinc oxide nanoparticles (ZnO NPs) can serve as an effective regulatory tool to boost plant growth. These nanoparticles were produced using Nigella sativa seed extract and characterized through UV-Vis spectroscopy, FT-IR, X-ray diffraction, and scanning electron microscopy (SEM). The antifungal properties of ZnO NPs were evaluated against Cercospora canescens, the causative agent of Cercospora leaf spot in mung bean. Application of ZnO NPs significantly improved plant metrics, including shoot, root, pod, leaf, and root nodule counts, as well as plant length, fresh weight, and dry weight—all indicators of healthy growth. Moreover, low-dose ZnO NPs positively influenced enzymatic activity, physicochemical properties, and photosynthetic parameters. These findings suggest that biologically synthesized ZnO NPs offer a promising approach for enhancing crop yield and accelerating plant growth.
Salinity stress poses a severe risk to food security and crop productivity. Stress reduction techniques are not necessarily sustainable or environmentally friendly. With the increasing adverse impact of salinity and area, it is necessary to restore and ameliorate salinity stress using environmentally friendly approaches. In this context, beneficial rhizospheric microbes may offer a sustainable approach to managing salinity stress. We used Bacillus subtilis strain Z-12 and B. aryabhattai strain Z-48 to improve the growth of turnip (Brassica rapa subsp. rapa) plants under salinity stress conditions and elucidated the beneficial impact of these bacterial strains on different physiological and biochemical aspects of plants. The application of both strains had a significant (p < 0.05) positive influence on analyzed parameters under salt stress. Here, B. aryabhattai strain Z-48 superiorly increased shoot length (33.2-, 25.8%), root length (38.6-, 31.5%), fresh biomass (23.9-, 17.8%), and dry biomass (38.60-, 48.6%) in normal and saline stress (200 mM NaCl) conditions, respectively. Physiological studies showed that antioxidant enzyme activities were significantly increased by B. subtilis Z-12 and B. aryabhattai Z-48 under salinity stress, with a few exceptions. Moreover, the inoculation of both strains effectively increased total chlorophyll, soluble sugar, phenolic, flavonoid, and glucosinolate contents under simulated salinity stress and normal conditions. Hence, these findings support the framework that inoculating turnip plants with these strains can enhance their tolerance against salinity stress.
Long ago, the human population profoundly relied on agri-farming, which was principally directed toward speedy, protected, and enhanced yields. These systems have undoubtedly fostered exploding populations with high food and fiber demands. To meet all these demands, the soil microbial ecosystem has been overlooked because of its long-term effects on the health and sustainability of the planet. Sustainable agricultural practices can not only highlight the microbial health of the soil and environment but also increase yields with minimal input. These sustainable practices benefit from the following advantages: (1) soil health preservation; (2) promotion of microbial diversity; (3) future food supply security; (4) support of farmer livelihoods; and (5) combating climate change. Biological pest control is an important and environmentally friendly strategy for sustainable agriculture in which natural microbial predators, including pathogens, nematodes, insects, and weeds, are applied to control pests, thus reducing pesticide dependency. Through a cautious and comprehensive understanding of the ecological niche and complex associations among living organisms, biological control can act as an encouraging approach to increase and stabilize crop yield while promoting congruent coexistence between agriculture and the ecological biosphere.