Seeds as a Source of Plant Inhibitory Fungi: Potential for Discovering New Antibiotics

Affiliation

1Oklahoma University Health Sciences Center, Oklahoma City, OK, 73104

²Deer Creek School District, Edmond, Oklahoma

^#Middle School student, Performed as part of a summer project

^##High School student, Performed as part of a summer project

Abstract

Background: Many antibiotics have been discovered in soil, however many more have remained undetected. In the present study we used Mung bean seeds to grow plants hydroponically. Fungal infestation in some showed consistent growth inhibition.
Methods: Store bought Mung bean seeds imported from Thailand grew into mature plants in tap water (pH 7.3 - 7.5) in six beakers on top of stainless steel strainers (20 seeds per beaker).
Results: Of the 6 beakers containing the Mung bean plants, we compared one, showing no noticeable fungal growth (beaker 1) with two which had either moderate fungal growth (beaker 2) and one which had severe fungal infestation (beaker 3). From a quantitative perspective the wet weight/dry weight ratio of the roots cut from beaker 1 was 2.06/0.12 grams (ratio = 17.17) compared to those pooled from Beakers 2 and 3, 1.22/0.73 grams (ratio = 1.70, p < 0.05, Chi-square analysis). The number of grown plants in the beaker 1, 39, was significantly greater than in the fungal groups, 22, p < 0.002 (2 × 2 contingency table, Fisher exact test). Comparing the number of seeds that germinated in the Petri dishes containing tap water versus those immersed in liquid from around the roots of the fungal group found, 9/15 in the former; whereas 0/15 germinated in the fungal water group after a week placed in the dark, p = 7 x 10^-4 (Chi-square analysis, 2 × 2 contingency table, Fisher exact test).
Conclusion: We found significant inhibition of plant growth and seed germination from fungi on seeds grown hydroponically.