Volume: 3, 2024
3rd International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: P015
DOI: https://doi.org/10.24326/ICDSUPL3.P015
Published online: 24 April 2024
ICDSUPL, 3, P015 (2024)
Effect of meIAA on development processes and auxin response in seedlings of Arabidopsis thaliana
Aleksandra Sobiech1*, Alicja Banasiak1
1 Department of Plant Development Biology, Faculty of Biological Sciences, University of Wroclaw, Kanonia 6/8, 50-328 Wroclaw, Poland
* Corresponding author: 334182@uwr.edu.pl
Abstract
Indole-3-acetic acid methyl ester (meIAA) is one of the especially important metabolites (conjugates) of auxin (IAA), the function of which is not fully understood yet. It is believed to be biologically inactive and does not bind to nuclear-localized auxin receptors. Nevertheless, studies conducted so far indicate that it plays a key role in a lot of developmental processes in plants such as root initiation and elongation, cotyledon and leaf growth, and adventitious root formation. This is explained by facilitated transport of meIAA and its hydrolysis to IAA at the site of action. Currently it is assumed that meIAA may be a storage form of auxin. However, its hydrolysis does not increase the level of available, biologically active IAA. Thus, the role of meIAA in plant development remains a matter of debate, and its mechanisms of action have not been fully described. To better understand the role of this conjugate in regulation of developmental processes, comparative analyses of the effects of meIAA and free IAA on seedling development and auxin response in Arabidopsis thaliana were conducted. Studies were conducted on wild type (WT) plants and transgenic lines with auxin response markers: DR5::GUS and DR5rev::GFP. Two different methods of treatment with exogenous meIAA and IAA were used: incubation in solutions and in vitro cultivation on media containing auxin or conjugate, respectively. The results showed that meIAA induces the expression of auxin response reporters DR5::GUS and DR5rev::GFP seedlings stronger and with a broader expression domain than IAA. Interestingly, longer treatment of seedlings with free auxin resulted in a return to an auxin homeostasis like in WT, while in case of meIAA such effect was not observed. A stronger effect of meIAA than free IAA was also found during the analyses of seedling development. The conjugate induced more adventitious roots, stronger inhibited the growth of seedlings and caused greater changes in the vascular pattern of cotyledons and leaves. These studies show that meIAA is important for plant development, but its effect cannot be explained solely by hydrolysis to free auxin. Thus, it is possible that this conjugate has biological activity, but related, for example, to the recently described non-canonical auxin signaling pathways.
Keywords: methyl ester (meIAA), auxin (IAA), vascular system, DR5::GUS, DR5rev::GFP
How to cite
A. Sobiech, A. Banasiak, 2024. Effect of meIAA on development processes and auxin response in seedlings of Arabidopsis thaliana. In: 3rd International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL3.P015