Profiles of Trinexapac-ethyl- and ABA-induced heat-stable proteins in embryonic axes of wheat seeds

Treatment of plants with abscisic acid (ABA) can enhance resistance to environmental stresses in general and to preharvest sprouting in particular. Inhibitors of gibberellin (GA) synthesis have been reported to enhance the metabolic activity or effectiveness of ABA. Wheat seeds ( Triticum aestivum L., cv. Bet Hashita) were soaked for 2 h in 100 mum ABA, in 1250 ppm trinexapac-ethyl (TE, an acylcyclohexanedione-based GA synthesis inhibitor), or in a combination of the two. After drying, seeds were imbibed 24 h in water and the protein in heat-stable extracts from embryos was examined. Treatment with ABA alone increased expression of dehydrin and of a 37 kDa protein. Treatment with TE more than doubled protein concentration in the embryo and enhanced expression of dehydrin and of proteins weighing 37, 20, and 15 kDa. Combined treatments of TE and ABA led to enhanced expression of dehydrin and of a 15 kDa protein.