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KT/HAK/KUP High-affinity Transporters in Plants
Šustr, Marek ; Tylová, Edita (advisor) ; Vaňková, Radomíra (referee) ; Gloser, Vít (referee)
Due to its essential role in plant metabolism and often low availability in the soil, sufficient potassium uptake and management are among the challenges plants face to survive in different environments. Since all potassium functions are related to the transport of the monovalent cation K+ , research focuses on the transporters responsible for K+ uptake and allocation. In addition to playing an essential role in potassium nutrition, K+ transporters also mediate the uptake of pollutants such as Cs. Radioisotopes 134 Cs and 137 Cs released from nuclear bomb tests and nuclear power plant accidents remain in the environment and their accumulation in plants is being studied to reveal the risks of crop production in contaminated soils as well as the possibility of remediating contaminated soil through plants. Ion transport also seems to be a major driver of plant adaptation to unfavourable environments. Several ion transporters appear to be involved in the adaptation of Arabidopsis arenosa populations to serpentine soils, including the potassium transporter AaKUP9. This thesis summarises my effort to characterise two transporters from KT/HAK/KUP family, AtKUP7 and AtKUP9, in Arabidopsis thaliana, and related projects. For AtKUP9, I have significantly expanded the knowledge of its involvement in...
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Uptake and Utilization of Different Nitrogen Forms by Wheat Plants
Raimanová, Ivana ; Haberle, Jan (advisor) ; Vaněk, Václav (referee) ; Gloser, Vít (referee)
4" Concllsions The aiill trt ihi. tilc'i: \\as the evaIuationoť physioIoeicaIand agronoriiicaspet'i.,rl i,1'1;,1r.-iul,.irltilizaticinof main fclnnsof'N in rvlreat. \\'hcri bcltiligs tc Íhe species sensitive to toxic effect of ammoniuntir-.nsuch;isitl Ílttspeciesrr.ithnegatil'ereactionto low pH too. In pIantsrrith\ij' a\ ÍheonIi sourceof nitrogentoxicitysymptoms- limited root grorr-tiric'tl:i R.! ratio.deíiciencyof essentia|cations(K', C-a2*,Mg'*) or aceulnulaticrr.of ainrncnrurnions in the oldest leaves- were cbserved. T.heseS\,l1]ptol1-lsuere iargely'suppressedby increasingpÍ{ of cultivation soiution. Lori pH also had negative effects on plants frorn the nitrate treailÍlent'T.hetcxrc effeet of. ammoniurnions is deereaseelby the higher availabilitl'of both forms of nitrogen.lt seemsthata strongacidificationof' rhizospherecausetlby the ammonium ion uptake is the main reason of' negativegrowin_qreaetionof wheatplants. Kinetie parametersof uptake(V."* and K,) characterizinghigh- affinity uptake system,can be used for assessmentof intra and inter specieselifferencesin effectivenessof nitrate and ammonium uptake.ln both studiedspeeies of wheaÍ(T.aestivutnand T"durum)a higher eapacity (V*,*) for the uptake of ammonium ions when comparedto nitrates,but simultaneouslya beťteraÍfinit1'for nitrate(|owerK,n)was...
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