Salinity is one of the most devastating abiotic stresses accounting for major crop losses yearly. Seedlings display a directed root growth response away from increasing salt levels in soil or agar plates, which has been named halotropism. GWAS on root growth of 333 Arabidopsis accessions identified WRKY25, CHX13 and a gene of unknown function DOB1, as new components contributing to early main root halotropic responses. We showed that halotropism required MIZ1 and MIZ2, genes previously shown to be involved in hydrotropism, and these responses are also dependent on components of both ethylene and ABA signalling pathways. In addition, we physiologically characterised KAB1 a putative K+ regulator, which does not play a direct role in halotropism. KAB1 contributes to root architecture, germination, stomata closure and shoot growth under both control and stress conditions in plants. Majority of the components were transcriptionally upregulated during salt stress and these proteins also function in maintaining Na+/K+ homeostasis during increased salinity. Deciphering the underlying mechanism of root halotropism and acclimation to abiotic stresses is a stepping stone in further elucidation of salt stress responses in planta. Phytohormones and Na+/K+ transporters are key players and are required for plant acclimation and adaptation to various stresses.
|Qualification||Doctor of Philosophy|
|Award date||8 Oct 2019|
|Place of Publication||Wageningen|
|Publication status||Published - 8 Oct 2019|