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

• Published in: Journal of the Serbian Chemical Society Vol. 75; no. 3; pp. 323 - 331
• Main Authors: Dragicevic, Vesna, Sredojevic, Slobodanka, Spasic, Mihajlo
• Format: Journal Article
• Language: English
• Published: Serbian Chemical Society 01.01.2010
• Subjects: aging; free thiols; glutathione; maize seeds; seed germination ability; thermodynamics
• ISSN: 0352-5139; 1820-7421
• DOI: 10.2298/JSC090630017D

Two maize hybrids with a different ability to maintain seed germination were examined during the course of accelerated aging (AA). Initially, the similar seed reduction potential of the GSSG/2GSH half-cell increased in H1 (dent hybrid) without influencing the seed germination ability up to the 6th day of AA, while in H2 (sweet corn hybrid), it was not changed up to the 6th day of AA but with a significant later loss of seed germination ability. During the AA course, the amount of free thiol decreased in H1 and increased in H2. Irrespective of the continual increase of the differential Gibbs energy during AA, the characteristics of the examined hybrids are possibly connected to the different metabolic pathways of the seeds: H1 is characterized by higher entropy and positive enthalpy values, while H2 had negative entropy values and a decreasing trend of enthalpy, indicating a shift of the system from a relatively ordered to a disordered state. The different types of nanomolecular switches, resulting in a faster decrease of GSH in the H2 than in the H1 hybrids, indicate that a combination of the GSSG/2GSH half-cell potential and thermodynamics could be a useful tool to quantify plant stress. Proucavano je ubrzano starenje semena dva hibrida kukuruza koja imaju drugaciju sposobnost ocuvanja klijavosti. Slican pocetni redukcioni potencijal GSSG/2GSH para je kod H1(zuban) rastao bez uticaja na sposobnost klijanja do sestog dana ubrzanog starenja, dok se kod H2 (secerac) nije menjao do sestog dana starenja, uz kasniji znacajan pad klijavosti. Kolicina PSH se smanjivala kod H1, dok je rasla kod H2 tokom tretmana starenja. Bez obzira na kontinuiran pad slobodne energije tokom ubrzanog starenja, osobine semena ispitivanih hibrida su mozda bile vezane za drugacije metabolicke puteve: H1 karakterise visoka entropija i pozitivne vrednosti entalpije, dok je za H2 karakteristicna relativno niska entropija, uz negativne vrednosti entalpije, ukazujuci na pomeranje sistema iz relativno uredjenog u neuredjeno stanje. Drugaciji tipovi nanomolekulskih prekidaca, uticuci na brzi pad GSH kod H2 u odnosu na H1, isticu da se kombinacija GSSG/2GSH celijskog potencijala i termodinamike mogu koristiti pri kvantifikaciji biljnog stresa.