EFFECTS OF GLUTATHIONE ON CHLOROPLAST MEMBRANE FLUIDITY AND THE GLUTATHIONE CIRCULATION SYSTEM IN YOUNG LOQUAT FRUITS UNDER LOW TEMPERATURE STRESS

The effects and mechanisms of exogenous glutathione (GSH) on cold stress in young loquat (Eriobotrya japonica Lindl.) fruits were investigated in this study.
Three-year-old ‘Zaozhong No. 6’ loquat seedlings were foliar-sprayed with 50, 100 and 300 mg•L^-1 GSH, subjected to -3°C stress for 6 h, and cultured at 25°C for 10 h.
Low temperature stress inhibited glutathione peroxidase (GPX), glutathione-S-trasferase (GST) and glutathione reductase (GR) activity, and decreased GSH and membrane fluidity activity in young loquat fruit chloroplasts.
Low temperature stress exacerbated damage to membrane lipid peroxidation, and destroyed anti-oxidation system function.
The study found that treatment with certain concentrations of GSH decreased malondialdehyde (MDA) and H₂O₂ levels in young loquat fruit chloroplasts under low temperature stress.
In addition, membrane fluidity and GPX, GST, GR activity, and GSH concentration were elevated.
The study demonstrated that treatment with exogenous GSH increased GPX, GST, and GR activities, promoted GSH circulation and regeneration, reduced the degree of chloroplast membrane lipid peroxidation, and increased chloroplast membrane fluidity in young loquat fruit chloroplasts.
Consequently, cold temperature resistance was increased in young loquat fruits with an optimal GSH dosage of 100 mg•L^-1.

III International Symposium on Loquat

J.C. Wu, S.H. Sun, Y.T. Ke, C.P. Xie, F.X. Chen

Eriobotrya japonica, low temperature stress, glutathione, chloroplast, membrane fluidity

https://doi.org/10.17660/ActaHortic.2011.887.36