Advisory Committee Chair
Peggy Biga
Advisory Committee Members
Shahid Mukhtar
Karolina Pajerowska-Mukhtar
Raju Bheemanahalli Rangappa
Vinoy Thomas
Document Type
Thesis
Date of Award
1-1-2025
Degree Name by School
Master of Science (MS) College of Arts and Sciences
Abstract
The master's thesis presents research on enhancing plant resilience and growth through the study of the microbiome of submerged aquatic plants and the application of plasma technology in agriculture. We isolated 177 endophytic microbial strains from submerged plants collected from various locations. Screening revealed 50 strains producing ACC deaminase, an enzyme that mitigates plant stress by reducing ethylene levels. Predominant genera included Pseudomonas, Bacillus, and Acinetobacter. Metagenomic analysis characterized the diverse bacterial communities associated with these plants. Different plasma treatments were tested to optimize their effects on plant growth. Atmospheric jet and globe plasma treatments significantly improved root length and chlorophyll content. These treatments also maintained or enhanced the growth of beneficial microbes, including those with ACC deaminase activity. This study contributes to understanding plant-microbe interactions and demonstrates the potential of plasma technology for sustainable, climate-resilient agriculture. Findings suggest that ACC deaminase-producing microbes and optimized plasma treatments can promote plant health and resilience. Chapter 1 focused on understanding the microbiome of submerged plants like Hydrilla and Pondweed. We aimed to identify microbes producing ACC deaminase to mitigate plant stress by degrading ACC, a precursor to ethylene, and explored microbial diversity through metagenomic analysis. Sample collection from various sites yielded 177 endophytic microbial strains from 162 samples across 15 locations. Techniques included microbial isolation, DNA extraction, amplicon sequencing, and screening for ACC deaminase activity using Dworkin and Foster minimal medium with ACC as the sole nitrogen source. Results showed 50 strains with ACC deaminase activity, indicating potential as bioinoculants for sustainable agriculture, particularly for aquatic crops like rice and watercress. Key genera included Pseudomonas, Bacillus, and Acinetobacter, with metagenomic analysis revealing diverse communities dominated by Proteobacteria and Actinobacteria. Future directions included functional metagenomics to confirm gene expression, screening for indole-3-acetic acid production, and phenotypic screening of treated plants. Chapter 2 optimized plasma treatment for enhancing plant growth and exploring its effects on plant-microbe interactions, with applications in climate-smart agriculture. Different plasma types like glow discharge, atmospheric jet, and globe plasma were tested under varying conditions from 10 seconds to 5 minutes. Measurements included chlorophyll estimation, root length calculation, and microbial quantification assays focusing on ACC deaminase-positive strains like Pseudomonas fluorescens. Results showed significant effects on chlorophyll content and root length, particularly at 1-minute exposures with atmospheric jet and globe plasma, maintaining or enhancing beneficial microbial growth without promoting pathogens. Future directions included further exploration under stress conditions, understanding molecular mechanisms, and investigating plasma-induced nodule formation in non-leguminous plants.
Recommended Citation
Mohan, Binoop, "Understanding Submerged Plant Microbiome And Exploring Plant Microbe Interaction Through Plasma Optimization Studies" (2025). All ETDs from UAB. 6873.
https://digitalcommons.library.uab.edu/etd-collection/6873
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