"St\u00E1rnouc\u00ED listy jsou v\u00FDznamn\u00FDm zdrojem metabolit\u016F translokovan\u00FDch do vyv\u00EDjej\u00EDc\u00EDch se semen. Na tomto principu je zalo\u017Eena v\u00FDvojov\u00E1 strategie monokarpick\u00FDch rostlin, v\u010Detn\u011B obilnin, kter\u00E9 se vyzna\u010Duj\u00ED v\u00FDraznou postupnou (sekven\u010Dn\u00ED) senescenc\u00ED. Dynamika senescence je v\u00FDrazn\u011B ovliv\u0148ov\u00E1na fytohormony a \u017Eivinami, zejm\u00E9na cytokininy a dus\u00EDkem, kter\u00E9 p\u016Fsob\u00ED na odd\u00E1len\u00ED senescence a prodlou\u017Een\u00ED fotosyntetick\u00E9 aktivity list\u016F. Pokusy uveden\u00E9 v projektu maj\u00ED p\u0159in\u00E9st nov\u00E9 informace o (1) zp\u016Fsobech kooperace a interakce p\u016Fsoben\u00ED cytokinin\u016F a nitr\u00E1tu na zpomalen\u00ED senescence, (2) regula\u010Dn\u00EDm p\u016Fsoben\u00ED nitr\u00E1tu na hladinu cytokinin\u016F a naopak a to zejm\u00E9na prost\u0159ednictv\u00EDm glukosylace cytokinin\u016F a indukce cytokininoxid\u00E1zy a nitr\u00E1tredukt\u00E1zy a (3) r\u016Fzn\u00E9 \u00FAloze isoprenoidn\u00EDch a aromatick\u00FDch cytokinin\u016F p\u0159i regulaci senescence list\u016F p\u0161enice a ovsa, tj. druh\u016F odli\u0161n\u011B reaguj\u00EDc\u00EDch na tyto dv\u011B skupiny fytohormon\u016F. D\u00E1le s pomoc\u00ED transgenn\u00EDch rostlin p\u0161enice exprimuj\u00EDc\u00EDch gen pro biosynt\u00E9zu cytokinin\u016F (IPT) pod"@cs . . "1"^^ . . . "Hormon\u00E1ln\u00ED regulace senescence list\u016F a jej\u00ED vztah k vyu\u017Eit\u00ED dus\u00EDku u obilnin"@cs . "4695"^^ . . "1"^^ . "Hormonal regulation of leaf senescence and its relation to utilization of nitrogen in cereals"@en . . "2831"^^ . . . . . "Senescing leaves represent an important source of metabolites which are re-translocated into developing leaves. Developmental strategy of monocarpic plants including cereals, which exhibit conspicious sequential senescence, is based on this principle. Progress of senescence is significantly affected by phytohormones and nutrients, especially by cytokinins and nitrogen, which are capable to delay senescence and prolong photosynthetic activity of leaves. The experiments described in this proposal shouldprovide new information (1) how cytokinins and nitrate co-operate/interact in dealaying senescence, (2) how nitrate regulates cytokinin levels and vice versa with respect to cytokinin glucosylation and induction of cytokinin oxidase and nitrate reductaseand (3) what is the role of aromatic-side chain cytokinins as compared to isoprenoid ones in control of leaf senescence in wheat and oat plants, which differ in their response to these two groups of phytohormones. Moreover, using transgenic wheat plants"@en . "9"^^ . . . "0"^^ . "9"^^ . "Neuvedeno."@en .