cGMP and abscisic acid are required for seed germination in soybean plants

SANTA CRUZ DM; YANNARELLI GG; TOMARO, M; BALESTRASSE KB

Potrero de los Funes. San Luis.

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2011

Cyclic guanosine 3,5 monophosphate (cGMP) is an important second messenger in animals, and is emerging as a player in regulatory functions in plants. In this study, we investigated the role of cGMP in seed germination in soybean. The seeds were pretreated with different concentrations of a membrane-permeant analogue of cGMP (100µM) (8-Br-cGMP), hemin (20µM) (an inducer of heme oxygenase), Zn-protoporphyrin (20µM) (ZnPPIX) (specific inhibitor of heme oxygenase) and abscisic acid (ABA) for 48 h. We demonstrated that both 8-Br-cGMP and hemine promoted seed germination. Experiments performed in seeds treated with ZnPPIX demonstrated that heme oxygenase (HO) activity is required for seed germination. When different concentrations of ABA (0.5, 1 and 2µM) were assessed, the highest concentration induced plant growth.  These findings highlight that cGMP is a positive regulator and plays a crucial role in soybean seed germination. Furthermore, both ABA and cGMP are required for seed germination. These results infer that cGMP is involved in the HO signaling pathway.