Metabolic changes and associated cytokinin signals in response to nitrate assimilation in roots and shoots of Lolium perenne

0460033 - ÚEB 2017 RIV US eng J - Článek v odborném periodiku
Roche, J. - Love, J. - Guo, Q. - Song, J.C. - Cao, M. - Fraser, K. - Huege, J. - Jones, C. - Novák, Ondřej - Turnbull, M. - Jameson, P. E.
Metabolic changes and associated cytokinin signals in response to nitrate assimilation in roots and shoots of Lolium perenne.
Physiologia Plantarum. Roč. 156, č. 4 (2016), s. 497-511. ISSN 0031-9317. E-ISSN 1399-3054
Grant CEP: GA MŠMT(CZ) LO1204; GA MŠMT LK21306
Institucionální podpora: RVO:61389030
Klíčová slova: ZEATIN-TYPE CYTOKININS * FRUCTAN METABOLISM * USE EFFICIENCY
Kód oboru RIV: EB - Genetika a molekulární biologie
Impakt faktor: 3.330, rok: 2016

The efficiency of inorganic nitrogen (N) assimilation is a critical component of fertilizer use by plants and of forage production in Lolium perenne, an important pasture species worldwide. We present a spatiotemporal description of nitrate use efficiency in terms of metabolic responses and carbohydrate remobilization, together with components of cytokinin signal transduction following nitrate addition to N-impoverished plants. Perennial ryegrass (L. perenne cv. Grasslands Nui) plants were grown for 10weeks in unfertilized soil and then treated with nitrate (5mM) hydroponically. Metabolomic analysis by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry revealed a dynamic interaction between N and carbon metabolism over a week-long time course represented by the relative abundance of amino acids, tricarboxylic acid intermediates and stored water-soluble carbohydrates (WSCs). The initial response to N addition was characterized by a rapid remobilization of carbon stores from the low-molecular weight WSC, along with an increase in N content and assimilation into free amino acids. Subsequently, the shoot became the main source of carbon through remobilization of a large pool of high-molecular weight WSC. Associated quantification of cytokinin levels and expression profiling of putative cytokinin response regulator genes by quantitative reverse transcription polymerase chain reaction support a role for cytokinin in the mediation of the response to N addition in perennial ryegrass. The presence of high levels of cis-zeatin-type cytokinins is discussed in the context of hormonal homeostasis under the stress of steady-state N deficiency.
Trvalý link: http://hdl.handle.net/11104/0260174