title: Exploring the neutral invertase-oxidative stress defence connection in Arabidopsis thaliana.
abstract: Over the past decades, considerable advances have been made in understanding the crucial role and the regulation of sucrose metabolism in plants. Among the various sucrose-catabolizing enzymes, alkaline/neutral invertases (A/N-Invs) have long remained poorly studied. However, recent findings have demonstrated the presence of A/N-Invs in various organelles in addition to the cytosol, and their importance for plant development and stress tolerance. A cytosolic (At-A/N-InvG, At1g35580) and a mitochondrial (At-A/N-InvA, At1g56560) member of the A/N-Invs have been analysed in more detail in Arabidopsis and it was found that At-A/N-InvA knockout plants show an even more severe growth phenotype than At-A/N-InvG knockout plants. The absence of either A/N-Inv was associated with higher oxidative stress defence gene expression, while transient overexpression of At-A/N-InvA and At-A/N-InvG in leaf mesophyll protoplasts down-regulated the oxidative stress-responsive ascorbate peroxidase 2 (APX2) promoter. Moreover, up-regulation of the APX2 promoter by hydrogen peroxide or abscisic acid could be blocked by adding metabolizable sugars or ascorbate. A hypothetical model is proposed in which both mitochondrial and cytosolic A/N-Invs can generate glucose as a substrate for mitochondria-associated hexokinase, contributing to mitochondrial reactive oxygen species homeostasis.
authors: KULeuven, Laboratory of Molecular Plant Physiology, Kasteelpark Arenberg 31, B-3001 Leuven, Belgium.
authors: Li
authors: L
authors: Xiang
authors: Katrien
authors: K
authors: Le Roy
authors: Mohammad-Reza
authors: MR
authors: Bolouri-Moghaddam
authors: Mieke
authors: M
authors: Vanhaecke
authors: Willem
authors: W
authors: Lammens
authors: Filip
authors: F
authors: Rolland
authors: Wim
authors: W
authors: Van den Ende
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D060387:Ascorbate Peroxidases; D003600:Cytosol / Q000201:enzymology; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology / Q000235:genetics; D018384:Oxidative Stress; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D011523:Protoplasts / Q000201:enzymology / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D043324:beta-Fructofuranosidase / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D017382:Reactive Oxygen Species; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D010544:Peroxidases; C555293:APX2 protein, Arabidopsis; D060387:Ascorbate Peroxidases; D043324:beta-Fructofuranosidase