Cytokinins: Their impact on molecular and growth responses to drought stress and recovery in arabidopsis

0490589 - ÚEB 2019 RIV CH eng J - Journal Article
Přerostová, Sylva - Dobrev, Petre - Gaudinová, Alena - Knirsch, Vojtěch - Körber, N. - Pieruschka, R. - Fiorani, F. - Brzobohatý, Břetislav - Černý, M. - Spíchal, Lukáš - Humplík, Jan - Vaněk, Tomáš - Schurr, U. - Vaňková, Radomíra
Cytokinins: Their impact on molecular and growth responses to drought stress and recovery in arabidopsis.
Frontiers in Plant Science. Roč. 9, MAY 22 (2018), č. článku 655. ISSN 1664-462X. E-ISSN 1664-462X
R&D Projects: GA MŠMT(CZ) LTAUSA17081; GA ČR GA17-04607S
Grant - others:EPPN(XE) 284443
Program: FP7
Institutional support: RVO:61389030 ; RVO:68081707
Keywords : Abscisic acid * Auxin * Cytokinin * Cytokinin oxidase/dehydrogenase * Drought stress * Isopentenyl transferase * Phytohormone
OECD category: Plant sciences, botany; Plant sciences, botany (BFU-R)
Impact factor: 4.106, year: 2018

Our phenotyping and hormonal study has characterized the role of cytokinins (CK) in the drought and recovery responses of Arabidopsis thaliana. CK down-regulation was achieved by overexpression of the gene for CK deactivating enzyme cytokinin oxidase/dehydrogenase (CKX): constitutive (35S:CKX) or at the stress onset using a dexamethasone-inducible pOp/LhGR promoter (DEX:CKX). The 35S:CKX plants exhibited slow ontogenesis and higher expression levels of stress-associated genes, e.g., AtP5CS1, already at well-watered conditions. CK down-regulation resulted during drought in higher stress tolerance (indicated by relatively low up-regulation of the expression of drought stress marker gene AtRD29B) accompanied with lower leaf water loss. Nevertheless, these plants exhibited slow and delayed recovery after re-watering. CK levels were increased at the stress onset by stimulation of the expression of CK biosynthetic gene isopentenyl transferase (ipt) (DEX:IPT) or by application of exogenous CK meta-topolin. After water withdrawal, long-termCK elevation resulted in higher water loss in comparison with CKX transformants as well as with plants overexpressing ipt driven by senescence-inducible SAG12 promoter (SAG:IPT), which gradually enhanced CKs during the stress progression. In all cases, CKup-regulation resultedin fast andmore vigorous recovery. All drought-stressed plants exhibited growth suppression associated with elevation of abscisic acid and decrease of auxins and active CKs (with the exception of SAG:IPT plants). Apart from the ipt overexpressers, also increase of jasmonic and salicylic acid was found.
Permanent Link: http://hdl.handle.net/11104/0284763