title: Ectopic expression of VpALDH2B4, a novel aldehyde dehydrogenase gene from Chinese wild grapevine (Vitis pseudoreticulata), enhances resistance to mildew pathogens and salt stress in Arabidopsis.
abstract: Aldehyde dehydrogenases (ALDHs) catalyze the irreversible oxidation of a broad spectrum of reactive aldehydes to their corresponding carboxylic acids. Although the proteins have been studied from various organisms and at different growth stages in plants, their potential roles in pathogen infection have not been examined. Here we isolated and functionally characterized a pathogen-inducible ALDH gene (VpALDH2B4) from Chinese wild grapevine Vitis pseudoreticulata accession Baihe-35-1. When transiently expressed in Arabidopsis leaves, VpALDH2B4 was found to be localized in mitochondria. Escherichia coli expressed GST-VpALDH2B4 exhibited ALDH activity in vitro and was capable of utilizing malondialdehyde (MDA), acetaldehyde and glyceraldehydes as its substrate. Over-expression of VpALDH2B4 in Arabidopsis resulted in hypersensitive response-like cell death, enhanced resistance to downy mildew and powdery mildew presumably via the SA-signaling pathway. The same Arabidopsis transgenic plants also showed enhanced tolerance to salt stress, which is accompanied by less MDA accumulation and upregulation of the stress-responsive superoxide dismutase activity. Taken together, our results suggest that VpALDH2B4 and perhaps its orthologous genes may be involved in responses of plants to stresses imposed by both biotrophic pathogens and high salinity conditions.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China. wenyq@nwsuaf.edu.cn
authors.forename: Yingqiang
authors.initials: Y
authors.lastname: Wen
authors.forename: Xiping
authors.initials: X
authors.lastname: Wang
authors.forename: Shunyuan
authors.initials: S
authors.lastname: Xiao
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D001203:Ascomycota / Q000472:pathogenicity*; D060467:Disease Resistance / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008315:Malondialdehyde / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology; D009868:Oomycetes / Q000472:pathogenicity*; D010935:Plant Diseases / Q000276:immunology* / Q000469:parasitology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins; D054712:Salinity; D055049:Salt Tolerance; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D027843:Vitis / Q000201:enzymology* / Q000235:genetics
chemical_list: D011993:Recombinant Fusion Proteins; D008315:Malondialdehyde; D013482:Superoxide Dismutase; D000444:Aldehyde Dehydrogenase