Introduction of the interdependence between the glutathione half-cell reduction potential and thermodynamic parameters during accelerated aging of maize seeds

Two maize hy brids with a different ability to maintain seed ger mi- nation were ex amined during the course of a ccelerated agin g (AA). Initially, the si milar se ed reduction p otential of the GSSG/2GSH half-cell increased in H1 (dent hy brid) without influ encing the seed germination ability up to the 6 th day of AA, wh ile in H2 ( sweet corn hy brid), it was not changed up to t he 6 th day of AA but with a significa nt later loss of seed ger mination ability. During the AA course, the amount of free thiol d ecreased in H1 and increased in H2. Irrespective of the continual increase of the differential Gibbs energy during AA, the chara cteristics of the examined hybrids are po ssibly connected to t he different metabolic pathw ays of the seed s: H1 is ch aracterised by highe r entropy and po sitive enthalpy values, while H2 ha d ne gative entropy valu es and a de creasing trend of ent halpy, indicating a shift of th e sy stem fro m a relatively ordered to a di sordered st ate. The different ty pes of nano molecular switches, result ing in a faster decrease of GSH in the H2 than in the H1 hybrids, indicate that a c ombination of the G SSG/2GSH half-cell potential and thermodynamics could be a useful tool to quantify plant stress.