Popis: |
The polyamines (PAs) putrescine (Put), spermidine (Spd) and spermine (Spm) exist as free (soluble; S-), or as conjugated to small (SH-) or to large (PH-) molecules. Increasing evidence supports that PAs represent important in-trinsic developmental signals, which may affect developmental processes that range from cell division and morphogenesis to stress responses (Perez-Amador et al. 2002, Fos et al. 2003, Arias et al. 2005, Paschalidis et al. 2001, Paschalidis and Roubelakis-Angelakis 2005a, b, Cona et al. 2006, Vuosku et al. 2006, Ku-sano et al. 2007, Agalou et al. 2008, Moschou et al. 2008a, b, c). The first step in PA biosynthesis is the formation of Put from Orn and Arg |