title: Galactolipase and chilling sensitivity of plants.
abstract: Galactolipase is a lipid acyl hydrolase (EC 3.1.1.26) acting predominantly on galactolipids which constitute up to 80% of total acyl lipids in chloroplast membrane. Evidence is presented on the involvement of this enzyme in plant response to chilling via degradation of membrane lipids and the increase of free fatty acids, associated with reduced oxygen evolution in the Hill reaction. The occurrence of two pools of fatty acids has been hypothesized. Analysis of numerous plant species showed higher galactolipase activity in the chilling-sensitive than in the chilling-resistant plants. Differences in the pH-dependence curve and in the response to detergents of galactolipases from these two groups of plants suggest heterogeneity of the enzyme. Referring to the hypothesis concerning the role of high melting-point fatty acids of phosphatidylglicerol molecular species in chilling sensitivity the data are presented against generalization of this hypothesis.
authors.affiliation: Institute of Biochemistry, University of Warsaw, Poland.
authors.forename: Z
authors.initials: Z
authors.lastname: Kaniuga
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000502:physiology*; D018521:Plant Physiological Phenomena; D013696:Temperature
chemical_list: D002265:Carboxylic Ester Hydrolases; C019262:galactolipase