Cytokinin, auxin and physiological polarity in the aquatic carnivorous plants Aldrovanda vesiculosa and Utricularia australis

0461643 - ÚEB 2017 RIV GB eng J - Journal Article
Šimura, Jan - Spíchal, Lukáš - Adamec, Lubomír - Pěnčík, A. - Rolčík, Jakub - Novák, Ondřej - Strnad, Miroslav
Cytokinin, auxin and physiological polarity in the aquatic carnivorous plants Aldrovanda vesiculosa and Utricularia australis.
Annals of Botany. Roč. 117, č. 6 (2016), s. 1037-1044. ISSN 0305-7364. E-ISSN 1095-8290
R&D Projects: GA MŠMT(CZ) LO1204; GA MŠMT LK21306
Institutional support: RVO:61389030 ; RVO:67985939
Keywords : Auxin * Aldrovanda vesiculosa * cytokinin
OECD category: Plant sciences, botany; Plant sciences, botany (BU-J)
Impact factor: 4.041, year: 2016

Methods The main auxin and cytokinin metabolites in separated shoot segments and turions of two carnivorous plants, Aldrovanda vesiculosa and Utricularia australis, were analysed using ultra-high-performance liquid chromatography coupled with triple quad mass spectrometry.

Key Results In both species, only isoprenoid cytokinins were identified. Zeatin cytokinins predominated in the apical parts, with their concentrations decreasing basipetally, and the trans isomer predominated in A. vesiculosa whereas the cis form was more abundant in U australis. Isopentenyladenine-type cytokinins, in contrast, increased basipetally. Conjugated cytokinin metabolites, the O-glucosides, were present at high concentrations in A. vesiculosa but only in minute amounts in U. australis. N-9-glucoside forms were detected only in U. australis, with isopentenyladenine-9-glucoside (iP9G) being most abundant. In addition to free indole-3-acetic acid (IAA), indole-3-acetamide (IAM), IAA-aspartate (IAAsp), IAA-glutamate (IAGlu) and IAA-glycine (IAGly) conjugates were identified.

Conclusions Both species show common trends in auxin and cytokinin levels, the apical localization of the cytokinin biosynthesis and basipetal change in the ratio of active cytokinins to auxin, in favour of auxin. However, our detailed study of cytokinin metabolic profiles also revealed that both species developed different regulatory mechanisms of active cytokinin content; on the level of their degradation, in U. australis, or in the biosynthesis itself, in the case of A. vesiculosa. Results indicate that the rapid turnover of these signalling molecules along the shoots is essential for maintaining the dynamic balance between the rapid polar growth and development of the apical parts and senescence of the older, basal parts of the shoots.
Permanent Link: http://hdl.handle.net/11104/0261242