title: Wounding of potato tubers induces increases in ABA biosynthesis and catabolism and alters expression of ABA metabolic genes.
abstract: The effects of physical wounding on ABA biosynthesis and catabolism and expression of genes encoding key ABA metabolic enzymes were determined in potato tubers. An increase in ABA and ABA metabolite content was observed 48h after wounding and remained elevated through 96h. Wounding induced dramatic increases in the expression of the ABA metabolic genes encoding zeaxanthin epoxidase (ZEP), 9-cis-epoxycarotenoid dioxygenase (NCED), and ABA-8'-hydroxylase. Although the patterns of wound-induced expression of individual genes varied, increased gene expression was observed within 3h of wounding and remained elevated through 96h. An apparent correlation between expression of the gene encoding ZEP and the increase in ABA content suggested that the wound-induced increase in ABA biosynthesis was regulated by both substrate availability and increased NCED activity. Suppression of wound-induced jasmonic acid accumulation by rinsing the wounded tissue with water did not inhibit the subsequent increase in ABA content. Exogenous ethylene completely suppressed the wound-induced increase in ABA content and dramatically reduced wound-induced up-regulation of ABA metabolic genes. This study is the first to identify the molecular bases for increased ABA accumulation following physical trauma in potato tubers and highlights the complex physiological interactions between various wound-induced hormones.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, 1605 Albrecht Blvd. N, Fargo, ND 58102-2765, USA. jeff.suttle@ars.usda.gov
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Suttle
authors.forename: Edward C
authors.initials: EC
authors.lastname: Lulai
authors.forename: Linda L
authors.initials: LL
authors.lastname: Huckle
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Neubauer
mesh_terms: D000040:Abscisic Acid / Q000235:genetics / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008660:Metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D010937:Plant Growth Regulators / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D035281:Plant Tubers / Q000235:genetics / Q000502:physiology*; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism
chemical_list: D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; C011006:jasmonic acid; D000040:Abscisic Acid; D003577:Cytochrome P-450 Enzyme System; C036216:ethylene; D010088:Oxidoreductases; C097153:zeaxanthin epoxidase; D049308:Dioxygenases; C109043:9-cis-epoxy-carotenoid dioxygenase; C107203:abscisic acid 8'-hydroxylase