Hydrogen peroxide in inducible plant stress responses

Academic dissertation To be presented for public criticism, with permission of the Abbreviations ABA abscisic acid HRGP hydroxyproline-rich glycopro-tein AOX alternative oxidase JA jasmonic acid APX ascorbate peroxidase MJ methyl jasmonate ARE antioxidant responsive element MPT1 mitochondrial phosphate translocator1 CAT catalase MRE metal responsive element Cat1AS CAT1 antisense mRNA messenger RNA cDNA complementary DNA MTF-1 metal response element binding transcription factor 1 CHS chalcone synthase NahG bacterial gene encoding salicy-late hydroxylase CHX cycloheximide PAL phenylalanine ammonia-lyase DAB 3'3-diaminobezidine PAO polyamine oxidase DAO diamine oxidase PCD programmed cell death DDRT-PCR differential display reverse transcriptase-PCR PCR polymerase chain reaction DPI diphenylene iodonium PiC phosphate carrier ECM extracellular matrix POX peroxidase EC-SOD extracellular superoxide dis-mutase PR10 pathogenesis related protein 10 ERELEE4 ethylene responsive element, Lycopersicon esculentum E4 PR-protein pathogenesis related protein ERF ethylene responsive element binding factor Q quinacrine EST expressed sequence tag RbcS Rubisco small subunit G glucose rbohA respiratory burst oxidase ho-molog A GO glucose oxidase rcd1 radical induced cell death 1 GPX glutathione peroxidase ROS reactive oxygen species GR glutathione reductase SA salicylic acid GSH glutathione SAR systemic acquired resistance GSSG glutathione disulphide SOD superoxide dismutase GST glutathione-S-transferase TEM transmission electron micros-copy HL high light TMV tobacco mosaic virus HPLC high performance liquid chromatography UV ultraviolet HR hypersensitive response VOC volatile organic compound WRKY protein DNA-binding protein containing WRKYGQC-amino acid sequence in the N-terminus Original publications This thesis is based on the following publications, which will be referred to in the text with their Roman numerals. Additional unpublished data will also be presented in the text. Kangasjärvi J. 1996. Ozone affects birch (Betula pendula Roth) phenylpropanoid, polyamine and active oxygen detoxifying pathways at biochemical and gene-expression level. activates cell death and defense gene-expression in birch (Betula pendula) (Manuscript). H2O2 primes an active cell death process in tobacco (Manuscript).Summary Plant inducible defence responses during stress were studied in the commercially important forest tree species Silver birch (Betula pendula Roth). A model system, catalase1 antisense tobacco (Nicotiana tabacum)(Cat1AS, deficient in catalase activity), was used to reveal further mechanisms underlying oxidative stress-induced cell death process. Numerous environmental factors affect the productivity of plants during their life span. Some of these are stress inducing and they may be biotic (such as pathogens) or abiotic (such as air pollutants or irradiation). Many biotic and abiotic stresses have in common the ability to induce the accumulation of apoplastic and intracellular reactive oxygen species (ROS) in plant …