TaABF1, ABA response element binding factor 1, is related to seed dormancy and ABA sensitivity in wheat (Triticum aestivum L.) seeds

A seed-specific bZIP type transcription factor involved in abscisic acid (ABA) signal transduction of developing wheat (Triticum aestivum L.) seeds is TaABF1, ABA response element binding factor 1. The expression of TaABF1 was examined in wheat cultivars possessing different levels of seed dormancy and ABA sensitivity at 40-50 days after pollination. Zenkoujikomugi, Norin61, and OW104 were dormant cultivars showing high sensitivity to ABA. Chihokukomugi, RL4137, and Chinese Spring, all non-dormant cultivars, show low sensitivity to ABA. Tamaizumi, AUS1408, and Kitakei-1354 represent intermediate levels of seed dormancy and sensitivity to ABA. The relation between seed dormancy and ABA sensitivity is high (r = 0.89) in these cultivars. Relative amounts of transcripts of TaABF1 in embryos revealed high coefficients of correlation to seed dormancy (r = 0.78) and ABA sensitivity (r = 0.86). These results suggest that TaABF1 plays a role in the regulation of seed dormancy and ABA sensitivity in wheat.