Authors: Bozena Chrost Annekatrin Daniel Karin Krupinska
Publish Date: 2003/12/03
Volume: 218, Issue: 5, Pages: 886-889
Abstract
αGalactosidase activity αdgalactoside galactohydrolase EC 32122 increased during darkinduced senescence in primary foliage leaves of barley Hordeum vulgare L cv Steffi The changes in activity were accompanied by parallel changes in expression of the HvSF11 gene encoding a putative αgalactosidase The transcript level of HvSF23 encoding a second putative αgalactosidase stayed constant during leaf senescence Both αgalactosidase activity and the level of the HvSF11 transcript decreased after exogenous application of sucrose and glucose to detached darkincubated leaves In contrast the HvSF23 transcript level was not influenced by sugars Application of glucose analogs to detached and darkincubated leaves revealed that phosphorylation of hexose by hexokinase modulates both the αgalactosidase activity and the expression of HvSF11 These results indicate that the expression of the genes coding for two αgalactosidase isoenzymes is regulated by different signalling pathways suggesting different functions for the two gene products
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