Antioxidant activity and ROS tolerance in triticale (×Triticosecale Wittm.) anthers affect the efficiency of microspore embryogenesis

• Published in: Plant cell, tissue and organ culture tissue and organ culture, 2014-10, Vol.119 (1), p.79-94
• Main Authors: Żur, Iwona, Dubas, Ewa, Krzewska, Monika, Janowiak, Franciszek, Hura, Katarzyna, Pociecha, Ewa, Bączek-Kwinta, Renata, Płażek, Agnieszka
• Format: Article
• Language: English
• Subjects: Anthers; antioxidant activity; Antioxidants; Biomedical and Life Sciences; Catalase; Cell viability; cold stress; doubled haploids; Embryogenesis; Embryonic growth stage; Enzymatic activity; Enzyme activity; Enzymes; Hydrogen peroxide; Life Sciences; Low temperature; Original Paper; Oxidative stress; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Pretreatment; Reactive oxygen species; Signal generation; Superoxide dismutase; temperature; tillers; toxicity; Triticale
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-014-0515-3

To verify the hypothesis that cell redox status regulates the process of microspore embryogenesis (ME), reactive oxygen species (ROS) generation and the activity of enzymatic and non-enzymatic antioxidants were analyzed in eight doubled haploid lines of triticale with significant differences in embryogenic potential. The analyses were performed in anthers excised from freshly cut tillers (control) and from low temperature (LT) pre-treated tillers (3 weeks at 4 °C) in which ME has been initiated. Significant associations between ME effectiveness and the variables studied were found. In control cultures, high superoxide dismutase (SOD) activity appeared crucial for microspore viability. On the other hand, positive though non-linear correlation between ME effectiveness and H₂O₂ generation, and negative correlation with catalase (CAT) activity suggest that some threshold level of H₂O₂ is important for successful ME initiation. LT tillers pre-treatment significantly increased H₂O₂ accumulation, which had a negative effect on ME effectiveness. However, even high level of H₂O₂ did not endanger cell viability as long as the cells exhibited high activity of ROS-decomposing enzymes (SOD, CAT and POX). The ability to sustain antioxidative enzyme activity under cold stress in the dark was another important requirement for high effectiveness of ME, allowing for the generation of the signal initiating microspore reprogramming and simultaneously protecting the cells from the toxic effects of ROS production. The role of antioxidative enzymes cannot be replaced even by high activity of non-enzymatic antioxidants. In conclusion, genetically controlled but environmentally modified cell tolerance to oxidative stress seems to play an important role in triticale ME.