Glutathione transferase activity and expression patterns during grain filling in flag leaves of wheat genotypes differing in drought tolerance: Response to water deficit

• Published in: Journal of plant physiology 2009-11, Vol.166 (17), p.1878-1891
• Main Authors: Gallé, Ágnes, Csiszár, Jolán, Secenji, Maria, Guóth, Adrienn, Cseuz, László, Tari, Irma, Györgyey, János, Erdei, László
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; carotenoids; Carotenoids - metabolism; Cellular Senescence - genetics; chlorophyll; Chlorophyll - metabolism; Cluster Analysis; drought; Drought stress; drought tolerance; Droughts; enzyme activity; filling period; Fundamental and applied biological sciences. Psychology; Gene Expression; gene expression regulation; genetic variation; Genotype; glutathione peroxidase; Glutathione Peroxidase - metabolism; Glutathione transferase; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; Grain filling; Phylogeny; Plant Leaves - enzymology; Plant Leaves - genetics; Plant physiology and development; plant stress; plant-water relations; RNA, Messenger - metabolism; soil water content; Stress, Physiological; Triticum - enzymology; Triticum - genetics; Triticum aestivum; Water - metabolism; water stress; Wheat
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2009.05.016

Total glutathione S-transferase (GST, EC 2.5.1.18) and glutathione peroxidase (GPOX) activity were measured spectrophotometrically in Triticum aestivum cv. MV Emese and cv. Plainsman (drought tolerant) and cv. GK Élet and Cappelle Desprez (drought-sensitive) flag leaves under control and drought stress conditions during the grain-filling period, in order to reveal possible roles of different GST classes in the senescence of flag leaves. Six wheat GSTs, members of 3 GST classes, were selected and their regulation by drought and senescence was investigated. High GPOX activity (EC 1.11.1.9) was observed in well-watered controls of the drought-tolerant Plainsman cultivar. At the same time, TaGSTU1B and TaGSTF6 sequences, investigated by real-time PCR, showed high-expression levels that increased with time, indicating that the gene products of these genes may play important roles in monocarpic senescence of wheat. Expression of these genes was also induced by drought stress in all of the four investigated cultivars, but extremely high transcript amounts were detected in cv. Plainsman. Our data indicate genotypic variations of wheat GSTs. Expression levels and early induction of two senescence-associated GSTs under drought during grain filling in flag leaves correlated with high yield stability.