Abscisic Acid and Cytokinins Are Not Involved in the Regulation of Stomatal Conductance of Scots Pine Saplings during Post-Drought Recovery

0571910 - ÚEB 2024 RIV CH eng J - Journal Article
Zlobin, I. E. - Vaňková, Radomíra - Dobrev, Petre - Gaudinová, Alena - Kartashov, A. V. - Ivanov, Y. V. - Ivanova, A. I. - Kuznetsov, V.G.
Abscisic Acid and Cytokinins Are Not Involved in the Regulation of Stomatal Conductance of Scots Pine Saplings during Post-Drought Recovery.
Biomolecules. Roč. 13, č. 3 (2023), č. článku 523. E-ISSN 2218-273X
Institutional support: RVO:61389030
Keywords : 6-benzylaminopurine * Pinus sylvestris * plant hormones * water balance * water deficit
OECD category: Biochemical research methods
Impact factor: 5.5, year: 2022
Method of publishing: Open access
https://doi.org/10.3390/biom13030523

Delayed or incomplete recovery of gas exchange after water stress relief limits assimilation in the post-drought period and can thus negatively affect the processes of post-drought recovery. Abscisic acid (ABA) accumulation and antagonistic action between ABA and cytokinins (CKs) play an important role in regulation of stomatal conductance under water deficit. Specifically, in pine species, sustained ABA accumulation is thought to be the main cause of delayed post-drought gas exchange recovery, although the role of CKs is not yet known. Therefore, we aimed to study the effects of ABA and CKs on recovery of stomatal conductance in greenhouse-grown 3-year-old Scots pine saplings recovering from water stress. We analysed both changes in endogenous ABA and CK contents and the effects of treatment with exogenous CK on stomatal conductance. Drought stress suppressed stomatal conductance, and post-drought stomatal conductance remained suppressed for 2 weeks after plant rewatering. ABA accumulated during water stress, but ABA levels decreased rapidly after rewatering. Additionally, trans-zeatin/ABA and isopentenyladenine/ABA ratios, which were decreased in water-stressed plants, recovered rapidly in rewatered plants. Spraying plants with 6-benzylaminopurine (0.1–100 µM) did not influence recovery of either stomatal conductance or needle water status. It can be concluded that the delayed recovery of stomatal conductance in Scots pine needles was not due to sustained ABA accumulation or a sustained decrease in the CK/ABA ratio, and CK supplementation was unable to overcome this delayed recovery.
Permanent Link: https://hdl.handle.net/11104/0342796