Elevated H(2)O (2) production via overexpression of a chloroplastic Cu/ZnSOD gene of lily (Lilium oriental hybrid 'Marco Polo') triggers ethylene synthesis in transgenic potato.
Transgenic potato plants (SS2 and SS4) that overexpressed a chloroplastic copper/zinc superoxide dismutase lily gene were utilized as an H(2)O(2)-inducible system in order to study the role of H(2)O(2) as a signaling molecule in the biosynthesis of ethylene. SS2 and SS4 plants grown in vitro under sealed microenvironment (SME) conditions displayed anomalous phenotypes including reduction of stem elongation, radial stem growth, and promotion of root hair formation in the generated root, which were similar to ethylene-induced responses. In addition, SS4 plants showed severe vitrification in developing leaves and elevated ethylene production under SME conditions. After the ethylene action inhibitor AgNO(3), 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) inhibitor CoCl(2), and ACC synthase inhibitor L -aminoethoxyvinylglycine were added to the growth media, the anomalous phenotypes in SS4 plants reverted to their normal phenotype with a concurrent decrease in ethylene production. Northern blot analysis showed that ACO transcripts in SS4 plants were constantly at high levels under normal and SME conditions, indicating that a high level of H(2)O(2) in SS4 plants up-regulates ACO transcripts. Moreover, the direct treatment of H(2)O(2) in potato plants confirmed the elevated expression of the ACO gene. Taken together, these data suggest that the high concentration of H(2)O(2) in transgenic potato plants stimulates ethylene biosynthesis by activating ACO gene expression.
Kim
Yoon-Sik
YS
Plant Genome Research Center, KRIBB, Yuseong, Daejeon 305-806, South Korea.
Kim
Hyun-Soon
HS
Lee
Yong-Hwa
YH
Kim
Mi-Sun
MS
Oh
Hyun-Woo
HW
Hahn
Kyu-Woong
KW
Joung
Hyouk
H
Jeon
Jae-Heung
JH
D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D003035:Cobalt / Q000494:pharmacology; D005030:Ethylenes / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism*; D027762:Lilium / Q000235:genetics*; D008855:Microscopy, Electron, Scanning; D009943:Organophosphorus Compounds / Q000494:pharmacology; D010641:Phenotype; D010940:Plant Proteins / Q000378:metabolism*; D018547:Plant Stems / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012835:Silver Nitrate / Q000494:pharmacology; D011198:Solanum tuberosum / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*
D005030:Ethylenes; D009943:Organophosphorus Compounds; D010940:Plant Proteins; D003035:Cobalt; C036216:ethylene; D012835:Silver Nitrate; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; C018021:cobaltous chloride; C088137:aminoethoxyvinylglycine; D005998:Glycine; C005073:ethephon