Hussain Ahmad Kakar, Ph.D. Research Scholar
Abstract
PLANT GROWTH PROMOTING ENDOPHYTIC FUNGI AND METHIONINE BASED HYDROXYAPATITE NANOSTRUCTURE IMPART POLYETHYLENE GLYCOL BASED OSMOTIC STRESS TOLERANCE IN ZEA MAYS L.
Hussain Ahmad Kakar
This study investigates the role of plant growth-romoting endophytic fungi and methionine-based hydroxyapatite nanostructures (Meth-HANPS) in improving osmotic Pistress tolerance in maize (Zea mays L.). Endophytic fungi were isolated from maize, followed by molecular characterization to identify their potential as bio-enhancers. These fungi were applied to one group of maize plants, while another group remained untreated. To assess stress tolerance, both groups were subjected to different levels of polyethylene glycol (PEG)-induced osmotic stress (0 MPa, -0.2 MPa, -0.4 MPa, and -0.6 MPa), simulating drought conditions. In addition, the plants were treated with four different plant growth regulators (PGRs): a control (without treatment), methionine, hydroxyapatite, and Meth-HANPs. Significant differences were observed between the fungal-treated and non-treated groups. Under non-stress conditions (0 MPa), methionine treatment provided the best results, improving growth and physiological parameters such as biomass and chlorophyll content. As osmotic stress increased, the performance of the treatments varied. Under moderate to severe stress conditions (-0.4 MPa and -0.6 MPa), Meth-HANPS emerged as the most effective treatment, enhancing stress tolerance by improving root length, shoot biomass, and water retention. Hydroxyapatite followed Meth-HANPS in effectiveness under high-stress levels. Moreover, the combined treatment of endophytic fungi with Meth-HANPS showed a synergistic effect, offering the best overall performance in terms of stress resilience. The fungal-treated plants showed enhanced growth, biochemical responses, and improved water-use efficiency under stress conditions, demonstrating the fungi's potential to boost the efficacy of Meth- HANPS in mitigating the effects of osmotic stress. This study highlights the potential of combining endophytic fungi and nanotechnology-based solutions, such as Meth-HANPS, to enhance osmotic stress tolerance in maize, offering promising strategies for improving crop resilience in water-limited environments.
