Development of (1 leads to 3, 1 leads to 4)-beta-D-glucan endohydrolase isoenzymes in isolated scutella and aleurone layers of barley (Hordeum vulgare)

• Published in: Plant physiology (Bethesda) 1986-02, Vol.80 (2), p.310-314
• Main Authors: Stuart, I.M, Loi, L, Fincher, G.B
• Format: Article
• Language: English
• Subjects: Aleurone cells; Aleurone layer; Barley; Biological and medical sciences; COTILEDONES; COTYLEDON; COTYLEDONS; Endosperm; Enzyme activity; Enzymes; Fundamental and applied biological sciences. Psychology; GLUCANE; GLUCANO; GLUCANS; Grains; HIDROLASAS; HORDEUM VULGARE; HYDROLASE; HYDROLASES; Immunology; Metabolism; Plant physiology and development; Plants; Secretion
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.80.2.310

An immunological assay has been used to investigate the synthesis of (1→3,1→4)-β-glucanase (EC 3.2.1.73) isoenzymes from isolated barley aleurone layers and scutella. Enzyme release from both tissues is enhanced by 1 micromolar gibberellic acid and 10 millimolar Ca2+, although increases induced by gibberellic acid are observed only in the presence of Ca2+. Isoenzyme I is synthesized predominantly in the scutellum, while isoenzyme II is synthesized exclusively in the aleurone. A third, putative isoenzyme III has been detected in significant proportions in scutellar secretions and may also be secreted from aleurone layers. Both gibberellic acid and Ca2+ appear to preferentially enhance isoenzyme II secretion from the aleurone and isoenzyme III secretion from scutella. The patterns of isoenzyme secretion are suggestive of tissue-specific differences in expression of the genes which code for (1→3,1→4)-β-glucanase isoenzymes. Qualitatively similar results were obtained with barley cultivars harvested in Australia and North America.