3rd Edition Of Plant Science and Molecular Biology World Conference 2026

Abstract

The health of soil plays an essential role in the ability of plants to produce food, fuel, and fiber for a growing world population. To keep pace, the total area of cultivated land worldwide has increased by over 500% in the last five decades, with a 700% increase in fertilizer use and a several-fold increase in pesticide use (Banerjee et al., 2019). However, it resulted in a remarkable increase in crop yield. Still, it drastically reduced soil fertility, increased production costs, food prices, and carbon footprints, and depleted fossil reserves and soil health with huge penalties to the environment and ecological sustainability.  Moreover, the continuous release of these chemical inputs causes toxic compounds such as metals to accumulate in the soil and move to the plants with prolonged exposure, ultimately impacting human health. Besides, Pakistan is the world's third-largest edible oil importer, imposing an enormous burden on the country's economy. Sunflower (Helianthus annuus L.) has great potential to bridge the gap between production and consumption of edible oil. Using plant growth-promoting rhizobacteria is a promising strategy for sustainable agriculture production and is a potential alternative to chemical fertilizers and pesticides. Despite its economic importance, little is known about the response of sunflowers towards inoculation with PGPR. This study was envisaged for (a) the isolation, characterization, and identification of a potent plant root-associated beneficial bacteria from the soil samples collected from different sites of sub-division Dhirkot, AJK using biochemical and molecular techniques, (b) analysis of bacterial diversity using polyphasic techniques, (c) documenting exo and endo-rhizospheric bacterial interaction in sunflower using different microscopy techniques, i.e., Transmission Electron microscopy and Confocal Laser Scanning Microscopy and (d) sunflower plant inoculation and evaluation of potential plant growth promoting rhizobacteria under controlled conditions and field environment to select the candidate bacteria for inoculum production of sunflower.  A potential Azospirillum brasilense AF-22 was isolated from Bandi, Himalayan Mountain region of Dhirkot (subdivision), Azad Jammu and Kashmir. The bacterium produced 24.67µgmL-1 indole-3-acetic acid, showed 137.84nmoles mg-1 protein h-1 nitrogenase activity, and solubilized 40.11μgmL−1 insoluble phosphorus and showed a significant decrease in pH (from 7 to 4.74) due to the production of oxalic acid, malic acid, and gluconic acid. The Azospirillum brasilense AF-22 was metabolically diverse (utilized 68 out of 96 carbon sources), resistant to many antibiotics, and showed antagonistic activity against Fusarium oxysporum. Inoculation with this bacterium to sunflower grown in soil-free (hydroponic) medium, sterilized soil, and under natural field conditions at two locations, i.e., Rawalakot, Azad Jammu and Kashmir, and Faisalabad, Pakistan, showed a significant increase in sunflower growth, yield and oil contents and achene NP uptake compared with non-inoculated control treatments. Azospirillum brasilense AF-22 could colonize on sunflower roots, forming a biofilm-like structure, documented through yfp-labeling by confocal laser scanning microscopy and immunogold labeling coupled with transmission electron microscope.  This study concludes that the Azospirillum brasilense AF-22, containing multiple plant growth-promoting traits, can be a potential candidate for the production of biofertilizers for sunflower crops to enhance yield with reduced application of chemical (NP) fertilizers, hence reducing the chemical fertilizer pollution crises.