Influence of exogenous abscisic acid on alterations in protein expression in the proteome of Triticosecale seedlings

The aim of this study was to investigate molecular basis of germination inhibition of Triticosecale under the influence of exogenous ABA. Seedlings were isolated from seeds after 48 h of germination in water (control sample) and 100 mu M ABA solution. It was observed that the applied concentration of phytohormone caused a significant inhibition of germination and a suppressed contribution of polysomes in the total ribosomal fraction. To identify proteins whose expression was affected by ABA, a proteomic approach employing 2D electrophoresis was used. Proteome maps for both control and ABA-treated samples displayed over 2,200 Coomassie Brilliant Blue-stained spots each. Protein spots showing either increase or decrease in spot intensity under the ABA influence were identified by mass spectrometry. Many of the identified proteins whose expression was stimulated by ABA proved to be stress-related, involved in nucleotide metabolism or playing a regulatory and signal transduction role, whereas proteins whose expression decreased are known to be involved in numerous metabolic pathways (including energy, carbohydrate or nucleotide metabolism) as well as related to genetic information processing and protein synthesis. Our results show that the germination inhibition caused by ABA is a result of multigene, diversified actions leading together to triticale growth suppression.