Nanobiotechnology approach using plant rooting hormone synthesized silver nanoparticle as “nanobullets” for the dynamic applications in horticulture – An in vitro and ex vitro study

Abstract

Horticulture is the branch of agriculture that deals with science and technology and business of plant cultivation and it is considered to be the foremost part of the world economy. Even though, one of the major challenges which has seriously influenced the economic loss of horticulture is rooting of cuttings and root growth inhibiting plant pathogens. To address this issue through nanobiotechnology, we ingeniously build a concept of silver nanoparticles (AgNPs) as “nano-bullets” can act for a dual mode like root enhancer and pathogen destroyer on the target site. After that, we succeeded in AgNPs synthesis, using two auxin rooting hormones of Indole-3-acetic acid and Indole-3-butyric acid as a reducing cum stabilizing agent. Further, its efficacy of root promoting and pathogen inhibitory action was sufficiently validated through in vitro and ex vitro studies with model plants and plant pathogens. As a result, the action duality of hormone-stabilized AgNPs was manifested to threefold enhanced root growth compared to controls and it increased the rooting capabilities against root growth inhibiting phytopathogens. This feature was also proved by the direct antifungal assay. Moreover, hormone-AgNPs left no toxicity to treated plants which was revealed by RAPD molecular markers. Therefore, with a detailed study and analysis with instruments such as Spectroscopy, TEM, Zetasizer, FTIR, Cyclic Voltammetry, Fluorescence microscopy (nanoparticles uptake), SEM coupled with EDS (bioaccumulation), TGA (grafting density) and PCR (RAPD analysis), this study can unravel the relevance, scope and current challenges at horticulture plants root development and plant disease management for the sustainable agricultural crop production.