Enzyme changes during seed storage in groundnut (Arachis hypogaea L.)

Abstract

A change in enzyme activity in seeds due to ageing is a topic of scientific importance. Vigour is essentially a physiological phenomenon influenced by the reserved metabolites, enzyme activities and growth regulators. The exact cause of loss of seed vigour and viability is still unknown as deterioration of seed is a complex process. In the presence of oxygen, ageing of seed can lead to peroxidative changes in polyunsaturated fatty acids. The free radical -induced non-enzymatic peroxidation, which has the potential to damage membrane, is likely to be a primary cause of deterioration of stored seeds. Certain anabolic enzymes help in maintaining viability while some catabolic enzymes decrease viability. The seed catalase and peroxidase activity seem to be decreased during storage. The results revealed that the peroxidase enzyme activity decreased from 0.236 to 0.444 OD 10 min-1 when storage period increased. A decrease in catalase activity from 0.454 to 0.444 ?g H2O2 mg-1 min-1 followed by a small increase from 0.434 to 0.452 ?g H2O2 mg-1 min-1 was observed during storage. But the activity of lipase enzyme increased from 0.236 to 0.231 meq min-1g-1 of sample when the storage period was increased. The study would help to know the deterioration pattern of stored groundnut seeds.