Evidence of stress proteins and a potential maturity marker in peanuts

Stress proteins are induced in plants in response to environmental changes in temperature, oxygen, or water levels. It was hypothesized that stress proteins occur in peanut seeds during maturation and curing because these processes are known to be associated with water deficit and anaerobic metabolism in peanut seeds. To test this hypothesis, a polyclonal antibody against dehydrin, a plant stress protein, was used. Immunoblot analyses showed that a number of dehydrin-related stress proteins were detected in peanut seeds of different maturity and curing stages. Of these, only two were induced during seed curing and maturation. One (protein a) is potentially a peanut maturity marker because it was shown to occur only in uncured fully mature seeds. Immunoblot analyses of alcohol dehydrogenase (ADH), an enzyme known to be induced in mature peanut seeds, showed that ADH was not recognized by the antibody. This suggests that ADH is probably not related to protein a or dehydrin.