title: Asparagine slows down the breakdown of storage lipid and degradation of autophagic bodies in sugar-starved embryo axes of germinating lupin seeds.
abstract: The research was conducted on embryo axes of yellow lupin (Lupinus luteus L.), white lupin (Lupinus albus L.) and Andean lupin (Lupinus mutabilis Sweet), which were isolated from imbibed seeds and cultured for 96h in vitro under different conditions of carbon and nitrogen nutrition. Isolated embryo axes were fed with 60mM sucrose or were sugar-starved. The effect of 35mM asparagine (a central amino acid in the metabolism of germinating lupin seeds) and 35mM nitrate (used as an inorganic kind of nitrogen) on growth, storage lipid breakdown and autophagy was investigated. The sugar-starved isolated embryo axes contained more total lipid than axes fed with sucrose, and the content of this storage compound was even higher in sugar-starved isolated embryo axes fed with asparagine. Ultrastructural observations showed that asparagine significantly slowed down decomposition of autophagic bodies, and this allowed detailed analysis of their content. We found peroxisomes inside autophagic bodies in cells of sugar-starved Andean lupin embryo axes fed with asparagine, which led us to conclude that peroxisomes may be degraded during autophagy in sugar-starved isolated lupin embryo axes. One reason for the slower degradation of autophagic bodies was the markedly lower lipolytic activity in axes fed with asparagine.
authors.affiliation: Department of Plant Physiology, Adam Mickiewicz University, ul. Umultowska 89, 61-614 Poznań, Poland. Electronic address: borek@amu.edu.pl.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Borek
authors.affiliation: Department of Plant Physiology, Adam Mickiewicz University, ul. Umultowska 89, 61-614 Poznań, Poland. Electronic address: e.paluch@amu.edu.pl.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Paluch-Lubawa
authors.affiliation: Institute of Dendrology, Polish Academy of Sciences, ul. Parkowa 5, 62-035 Kórnik, Poland. Electronic address: spukacka@man.poznan.pl.
authors.forename: Stanisława
authors.initials: S
authors.lastname: Pukacka
authors.affiliation: Department of Biochemistry and Biotechnology, Poznan University of Life Sciences, ul. Dojazd 11, 60-632 Poznań, Poland. Electronic address: gospi@up.poznan.pl.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Pietrowska-Borek
authors.affiliation: Department of Plant Physiology, Adam Mickiewicz University, ul. Umultowska 89, 61-614 Poznań, Poland. Electronic address: wiktoria@amu.edu.pl.
authors.forename: Lech
authors.initials: L
authors.lastname: Ratajczak
mesh_terms: D001216:Asparagine / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects*; D018533:Biomass; D002241:Carbohydrates / Q000737:chemistry*; D018525:Germination / Q000187:drug effects*; D066292:Lipid Droplets / Q000187:drug effects / Q000378:metabolism*; D008055:Lipids / Q000737:chemistry*; D031297:Lupinus / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism; D018519:Meristem / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure; D012639:Seeds / Q000187:drug effects / Q000196:embryology* / Q000648:ultrastructure; D012995:Solubility
chemical_list: D002241:Carbohydrates; D008055:Lipids; D001216:Asparagine
keywords: Autophagy; Nitrate; Peroxisome; Sucrose; Ultrastructure