Effects of high temperature stress on enzymatic and nonenzymatic antioxidants and proteins in strawberry plants

Authors : Sergül ERGİN, Hatice GÜLEN, Müge KESİCİ, Ece TURHAN, Ahmet İPEK, Nezihe KÖKSAL

Pages : 908-917

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Publication Date : 2016-12-01

Article Type : Research Paper

Abstract :The mechanism of tolerance to high temperatures was investigated in two strawberry insert ignore into journalissuearticles values(Fragaria x ananassa Duch); cultivars, `Redlands Hope` insert ignore into journalissuearticles values(`R. Hope`, heat tolerant); and `Cal. Giant 3` insert ignore into journalissuearticles values(`CG3`, heat sensitive);. Leaves were collected from plants that were exposed to gradual heat stress and heat-shock stress separately. The contents of nonenzymatic antioxidants such as ascorbic acid insert ignore into journalissuearticles values(AsA); and glutathione insert ignore into journalissuearticles values(GSH); and the activities of enzymatic antioxidants such as ascorbate peroxidase insert ignore into journalissuearticles values(APX); insert ignore into journalissuearticles values(EC 1.11.1.11);, catalase insert ignore into journalissuearticles values(CAT); insert ignore into journalissuearticles values(EC 1.11.1.6);, and glutathione reductase insert ignore into journalissuearticles values(GR); insert ignore into journalissuearticles values(EC. 1.6.4.2); were measured followed by heat treatments. Additionally, proline content was determined, and heat shock proteins insert ignore into journalissuearticles values(HSPs); were analyzed with an immunoblotting method to investigate protein markers involved in the heat-stress tolerance of strawberry plants. The contents of AsA and GSH did not change depending on heat stress type, temperatures, or cultivars. While APX and CAT activities increased with high temperatures, GR activity was almost unchanged. The proline content of the cultivars increased in both treatments. Anti-HSP60 immunoblots revealed that a 23 kDa polypeptide was detected during the heat acclimation of strawberry cultivars. The intensity of the heat shock protein in `R. Hope` plants was more than in `CG3` plants. Thus, the accumulation of 23 kDa heat shock protein was correlated with the heat tolerance of the cultivars. In conclusion, strawberry leaf tissues of `R. Hope` were found to enhance the structural stability of cellular membranes under high temperature by increasing both the activity of such enzymes as CAT and APX to activate the antioxidative systems and the expression of 23 kDa HSP.
Keywords : Antioxidative enzyme, Fragaria x ananassa, heat stress, HSP60