CEREAL BETA-AMYLASES - DIVERSITY OF THE BETA-AMYLASE ISOZYME STATUS WITH IN CEREALS

beta-Amylase (EC 3.2.1.2.) activity was determined in the kernels of 29 cultivars and inbred lines of seven cereals (Triticum aestivum L., Triticum durum L,., Hordeum vulgare L,., Secale cereale L., Avena sativa L., Zea mays L., Sorghum vulgare L,) belonging to 4 tribes of the Gramineae. The ratio activity/mg kernels was found to be much higher for the Triticeae than for all other tribes. Attempts were made to identify in one representative of each of these tribes - the <<endosperm>> and the <<ubiquitous>> beta-amylase according to criteria previously established, namely comparison of antigenic specificities as well as in vivo and in vitro post-translational modifications (Daussant et al., 1991). All tribes investigated exhibit the <<ubiquitous>> type beta-amylase. The <<endosperm>> isoenzyme, however, appears to be restricted to the Triticeae tribe. The results are discussed in terms of the significance of beta-amylase for germination and with respect to current knowledge as to the genetics of cereal beta-amylases.