ABSTRACT
ß-1,3-glucanases are found in organisms as diverse as plants, animals, bacteria and fungi. In plants, such enzymes are not only associated with defense mechanisms against pathogens, but also play critical roles in physiological and developmental processes. Here we identified a new ß-1,3-glucanase in maize seeds, and named it ZmGlucA. Sequence analysis revealed that ZmGlucA belongs to the class A of ß-1,3-glucanase, a class related to defense and physiological processes in plants. mRNA and protein assays showed that zmGlucA is expressed exclusively in seeds, and it is differentially regulated during seed development. Additionally, zmGlucA expression is strongly induced in seeds of the mutant dek 827Kpro1, which is defective for embryo and endosperm development. Our data support the idea that ZmGlucA protein is relevant to seed development.
Subject(s)
Glycoside Hydrolases/metabolism , Plants, Genetically Modified/growth & development , Seeds/enzymology , Seeds/growth & development , Zea mays/enzymology , Zea mays/growth & development , Blotting, Northern , Gene Expression Regulation, Enzymologic/genetics , Gene Expression Regulation, Enzymologic/physiology , Gene Expression Regulation, Plant/genetics , Gene Expression Regulation, Plant/physiology , Glycoside Hydrolases/genetics , Plants, Genetically Modified/genetics , Seeds/genetics , Zea mays/geneticsABSTRACT
Jasmonates are signaling molecules that play a key role in the regulation of metabolic processes, reproduction and defense against insects and pathogens. This study investigated the effects of methyl jasmonate on the protein pattern of Ricinus communis plants and the activity of guaiacol peroxidase, an antioxidant enzyme. Methyl jasmonate treatment caused a transient reduction in guaiacol peroxidase activity. A similar response was observed for the levels of 2-Cys peroxiredoxin protein. Moreover, the levels of the small and large chains of Rubisco were also reduced. The transient reduction of the levels and activity of antioxidant enzymes could account for the increase in the levels of H2O2, an important signaling molecule in plant defense.
