title: The Arabidopsis ceramidase AtACER functions in disease resistance and salt tolerance.
abstract: Ceramidases hydrolyze ceramide into sphingosine and fatty acids. In mammals, ceramidases function as key regulators of sphingolipid homeostasis, but little is known about their roles in plants. Here we characterize the Arabidopsis ceramidase AtACER, a homolog of human alkaline ceramidases. The acer-1 T-DNA insertion mutant has pleiotropic phenotypes, including reduction of leaf size, dwarfing and an irregular wax layer, compared with wild-type plants. Quantitative sphingolipid profiling showed that acer-1 mutants and the artificial microRNA-mediated silenced line amiR-ACER-1 have high ceramide levels and decreased long chain bases. AtACER localizes predominantly to the endoplasmic reticulum, and partially to the Golgi complex. Furthermore, we found that acer-1 mutants and AtACER RNAi lines showed increased sensitivity to salt stress, and lines overexpressing AtACER showed increased tolerance to salt stress. Reduction of AtACER also increased plant susceptibility to Pseudomonas syringae. Our data highlight the key biological functions of ceramidases in biotic and abiotic stresses in plants.
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Plant Resource, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Wu
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Zhe
authors.initials: Z
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Yin
authors.forename: Zhen-Yi
authors.initials: ZY
authors.lastname: Chang
authors.forename: Chan
authors.initials: C
authors.lastname: Rong
authors.forename: Jia-Li
authors.initials: JL
authors.lastname: Wu
authors.forename: Fang-Cheng
authors.initials: FC
authors.lastname: Bi
authors.forename: Nan
authors.initials: N
authors.lastname: Yao
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D055572:Ceramidases / Q000235:genetics / Q000378:metabolism*; D002518:Ceramides / Q000378:metabolism; D060467:Disease Resistance; D004721:Endoplasmic Reticulum / Q000201:enzymology; D006056:Golgi Apparatus / Q000201:enzymology; D009154:Mutation; D010641:Phenotype; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology; D054046:Plant Stomata / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology; D030821:Plants, Genetically Modified; D044224:Pseudomonas syringae / Q000502:physiology*; D055049:Salt Tolerance; D036226:Seedlings / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology; D013107:Sphingolipids / Q000378:metabolism; D013110:Sphingosine / Q000378:metabolism; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D002518:Ceramides; D013107:Sphingolipids; D055572:Ceramidases; D013110:Sphingosine
keywords: Arabidopsis thaliana; ceramidase; ceramide; defense; salt tolerance; sphingolipids