"GA522/00/1346" . . "0"^^ . "2008-05-19+02:00"^^ . . "Levels of phytohormones including cytokinins in plant cells are regulated by changes in their biosynthesis, degradation and/or metabolic interconversions connected with modification or removal of their biological activities. With respect to the absence oknowledge of biosynthetic pathway(s) of cytokinins in non-transformed plant cells investigation of their metabolic degradation and modification of biological activity is experimentally accessible. This proposal is focused on elucidation of (a) the physiological role of cytokinin degradation by cytokinin oxidase and (b) their protection against this enzyme via cytokinin side chain saturation by zeatin reductase in crop plants. This will be achieved by (1) determination of the presence and activity of cytokinin oxidase and zeatin reductase in selected crop plants, tissues, organs and in transport systems (xylem and phloem), (2) specification of the role(s) of different isozymes of both enzymes differing in their biochemical properties, (3)"@en . . "Funkce a fyziologick\u00FD v\u00FDznam cytokininoxid\u00E1zy a zeatinredukt\u00E1zy p\u0159i \u0159\u00EDzen\u00ED hladin aktivn\u00EDch cytokinin\u016F a jejich vztah k produktivit\u011B hospod\u00E1\u0159sky v\u00FDzn.plodin" . . "Function and physiol.significance of cytokinin oxidase& zeatin reductase in control of active cytokinin levels and their relation to productivity of crop plants"@en . . . . . "http://www.isvav.cz/projectDetail.do?rowId=GA522/00/1346"^^ . . "Neuvedeno."@en . "Pl\u00E1novan\u00E9 c\u00EDle byly spln\u011Bny. Byly vypracov\u00E1ny a optimalizov\u00E1ny metodiky stanoven\u00ED cytokininoxidasy (CKX) a zeatinreduktasy (Zr).Kompetice enzymov\u00FDch aktivit CKX a Zr udr\u017Euje rovnov\u00E1hu endogenn\u00EDch cytokinin\u016F v listech. Glykosylovan\u00E1 forma enzymu CKX je p\u0159"@cs . . . . "1"^^ . . . "Hladiny fytohormon\u016F v\u010Detn\u011B cytokinin\u016F jsou v rostlinn\u00FDch bu\u0148k\u00E1ch regulov\u00E1ny na \u00FArovni jejich biosynt\u00E9zy, degradace nebo metabolick\u00FDch p\u0159em\u011Bn souvisej\u00EDc\u00EDch s modifikac\u00ED nebo ztr\u00E1tou biologick\u00E9 aktivity. V p\u0159\u00EDpad\u011B cytokinin\u016F jsou dosud velmi omezen\u00E9 znalosti jejich biosynt\u00E9zy v netransformovan\u00FDch rostlinn\u00FDch bu\u0148k\u00E1ch. Z toho d\u016Fvodu se experiment\u00E1ln\u00ED studium cytokinin\u016F zam\u011B\u0159uje p\u0159edev\u0161\u00EDm na problematiku jejich odbour\u00E1v\u00E1n\u00ED spole\u010Dn\u011B s modifikacemi jejich biologick\u00FDch aktivit. P\u0159edm\u011Btem p\u0159edkl\u00E1dan\u00E9ho projektu bude objasnit ve vybran\u00FDch hospod\u00E1\u0159sky v\u00FDznamn\u00FDch plodin\u00E1ch fyziologick\u00FD v\u00FDznam (a) degradace cytokinin\u016F katalyzovan\u00E9 cytokininoxid\u00E1zou a (b) %22ochrany%22 p\u0159ed t\u00EDmto enzymem saturac\u00ED postrann\u00EDho \u0159et\u011Bzce v molekule cytokininu, cytokininoxid\u00E1zy a zeatinredukt\u00E1zy ve vybran\u00FDch plodin\u00E1ch, pletivech, org\u00E1nech a v transportn\u00EDch syst\u00E9mech (xyl\u00E9m, flo\u00E9m), (2) specifikace \u00FAlohy r\u016Fzn\u00FDch isozym\u016F obou enzym\u016F, (3) lokalizace obou enzym\u016F v bu\u0148ce s ohledem na dostupnost jejich substr\u00E1t\u016F, (4) zji\u0161t\u011Bn\u00ED \u00FA\u010Dink\u016F" . . "0"^^ . . "4"^^ . . . "4"^^ .