engleski

Auxin homeostasis as a mechanism of abiotic stress adaptation

Drought and increased salinity are considered as main abiotic stresses causing the most serious problem for global agriculture effecting plant growth, development and crop yield. Plant responses to osmotic and salinity stress are represented by a number of cellular and molecular processes which are regulated by a complex network of phytohormones. Among them, phytohormone auxin (indole-3-acetic acid, IAA) is the key one mediating plant responses to stress conditions. In order to clarify mechanisms regulating auxin homeostasis in response to osmotic and salinity stress, we have focused on the reversible auxin conjugation as a mechanism of stress adaptation. The role of specific genes of auxin homeostasis in abiotic stress response was addressed, namely functional research was performed on the Arabidopsis thaliana lines that carry mutations in the genes for auxin amidohydrolases (ILR, IAR3 and ILL). Furthermore, the potential to invoke salt and osmotic stress tolerance by over-expression of selected auxin amidohydrolases was evaluated. To screen auxin activity and distribution under stress conditions auxin reporter line (DR5::GFP) was used. Local changes in the auxin levels in the root are connected to the re- adjustment of the auxin homeostasis on the whole plant level in response to salt and osmotic stress.

Auxin ; Homeostasis ; Abiotic stress ; Auxin-amidohydrolase

This work has been supported by the Croatian Science Foundation (Grant no. IP-2014-09-4359).