ABSTRACT

Biological methods for nanoparticle synthesis using microorganisms, enzymes, and plants or plant extracts have been suggested as possible ecofriendly alternatives to chemical and physical methods. In this study, we report on the synthesis of nanostructured zinc oxide particles by biological method using plant leaves extract. Highly stable and spherical zinc oxide nanoparticles are produced by using zinc nitrate and Coleus forskohlii leaf extract. Greater than 95% conversion to nanoparticles has been achieved with Coleus forskohlii broth concentration 20%. Structural, morphological and optical properties of the synthesized nanoparticles have been characterized by using UV–Vis spectrophotometer, FTIR spectrometer, transmission electron microscopy TEM and X-ray diffraction (XRD) analysis. TEM analysis shows that the zinc oxide nanoparticles prepared were poly dispersed and the average size ranged from 46 to 91nm. The particles obtained have been found to be predominantly spherical. This study explored the effectiveness of green zinc oxide nanoparticles (ZnO-NPs) foliar spray on tomato growth under drought stress. Tomato plant subjected to four water regimes (100%, 75%, 50% and 25% FC), and in the same while seedlings were sprayed with 25, 50 and 100 µg/l green ZnO-NPs. The results showed that tomato growth parameters reduced gradually by increasing drought stress level, while ZnONPs enhanced plant growth under all studied drought levels. 25 and 50 µg/l ZnO-NPs proved to be the optimum treatments for alleviating drought stress. They increased shoot and root length, chlorophyll a and b, proteins, carbohydrates and free amino acid concentrations at higher levels comparable to well-irrigated seedlings. Also, application of green 25 and 50 µg/l ZnO-NPs reduces proline level in tomato plants grown under drought conditions compared green ZnO-NPs untreated controls. Therefore, the application of green ZnO-NPs should be considered as a promising agricultural practice treatment in locations prone to suffering from water shortage. Keywords: Green nanoparticles, characterization, drought stress, growth factors, stress indicator
Publication date: 01/03/2022

https://ijbpas.com/pdf/2022/March/MS_IJBPAS_2022_5974.pdf

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https://doi.org/10.31032/IJBPAS/2022/11.3.5974