Effects of Applying Hydrogen Peroxide on Phosphorus Uptake and Adhase Activity of Flooded Snap Bean Roots

Flooding is one of the major abiotic stresses for vegetable production in Florida due to heavy rains and hurricanes, etc. There are few effective solutions to flooding or hypoxic stresses snap bean production has to face. We hypothesized that application of oxygen fertilizer/oxygen enrichment may increase nutrient uptake of snap bean and minimize economic loss caused by flooding. This study was hydroponically conducted in greenhouse to evaluate the effects of oxygen fertilization on biochemistry and physiology of flooded snap bean. Ten percent of Hoagland solution was used to grow the snap bean seedlings in 1500 ml containers. There were three treatments: (1) control without either aeration or oxygen fertilization; (2) aeration with an air pump; (3) oxygen fertilization by using 3% hydrogen peroxide. The measurements were completed at the first trifoliate growth stage. Phosphorus (P) uptake rates were determined by using an AQ2 Discrete Analyzer. Alcohol dehydrogenase (ADH, EC 1.1.1.1) of flooded snap bean root tips was calorimetrically analyzed at 340 nm. The P uptake rates were 0.47, 0.82, and 0.76 mg plant^-1 hr^-1 for Treatments 1, 2, and 3, respectively. Treatments 2 and 3 both had significantly greater P uptake rates than Treatment 1 but there was not any significant difference between the uptake rates of Treatments 2 and 3. The respective ADH activity was 12.24, 0.89, and 1.25 nmol NADH min^-1 mg^-1 protein for Treatments 1, 2, and 3. These results showed that oxygen fertilization significantly improved flooded snap bean’s biochemical and physiological status. Therefore, oxygen fertilization may provide a new solution to alleviate flooding or hypoxic stresses for snap bean production but more research is needed.