Ethanol and Acetaldehyde in Imbibing Soybean Seeds in Relation to Deterioration

Abstract

Deterioration as evidenced by decline in germination or seedlng growth of soybean (cv. Essex) seeds during accelerated aging treatments at 41 C and 100% relative humidity is accompanied by increased levels of acetaldehyde and ethanol in hbbing embryonic axes and seeds. These increases become more pronounced with duration of the aging treatment. A similar inverse relationship between leels of acetaldehyde and ethanol and deterioration was observed when seeds were "naturally" aged for several years. During imbibition of low-vigor, accelerated-aged seeds at 25 C, acetaldehyde and ethanol increased from near trace amounts in dry tissues to maximum levels at 4 hours. Increases in acetaldehyde and ethanol during imbibition were less in high-than in low-vigor seeds. Increases were also less pronounced in low-vigor seeds when water uptake injury was avoided by osmotically decreasing water uptake rate with 30% polyethylne glycol.Embryonic axes from deteriorated seeds were characterized by low rates of 02 uptake and high respiratory quotients relative to the unaged controls.

ARABIDOPSIS THALIANA HOMEOBOX25 Uncovers a Role for Gibberellins in Seed Longevity

“…Seeds are partially or completely rehydrated and exposed to high temperatures, leading to rapid loss of seed viability (e.g. days instead of years, as in natural aging; Woodstock and Taylorson, 1981;Tesnier et al, 2002;Prieto-Dapena et al, 2006;Tejedor-Cano et al, 2010). Accelerated aging mimics natural aging (Tesnier et al, 2002;, and similar results are obtained with controlled hydration or with seeds imbibed in water (Tejedor-Cano et al, 2010).…”

A fast ethanol assay to detect seed deterioration

“…Elevated levels of ethanol and its precursor, acetaldehyde, were detected in soybean seeds 30 min after the beginning of imbibition (Woodstock and Taylorson, 1981). The soybean seeds were thought unable to generate adequate energy (ATP) via aerobic respiration early in imbibition and employed anaerobic respiration, or fermentation, as an alternative mechanism of generating energy.…”

“…When mitochondria are non-functional due to the damage, initiation of anaerobic respiration is expected to deliver the energy for metabolic processes, at least for repair. Indeed, a relation between ethanol production and seed deterioration, as evidenced by a decline in germination or seedling growth, has been suggested (Perry, 1978;Woodstock and Taylorson, 1981;Taylor et al, 1999;Kataki and Taylor, 2001;Bicanic et al, 2003;Akimoto et al, 2004;Rutzke et al, 2008). In those studies seed deterioration was imposed by natural or conditional ageing of the seeds and ethanol production was measured using gas chromatography, immobilized enzyme technology or laser-based photo-acoustic spectroscopy.…”

Ethylene, Ethane, Acetaldehyde, and Ethanol Production By Plants under Stress

“…Under aerobic conditions, little or none ofthese glycolytic metabolites is normally produced (4). Ethanol and acetaldehyde are also produced by some fruits, such as strawberries, and by deteriorating seeds (11,15). In all of these cases, reduced 02 availability or reduced 02 transport is thought to inhibit TCA electron transport leading ultimately to formation of acetaldehyde and ethanol (4).…”