Genetic Loci Associated with Early Salt Stress Responses of Roots

Ayodeji O Deolu-Ajayi; A Jessica Meyer; Michel A Haring; Magdalena M Julkowska; Christa Testerink

doi:10.1016/j.isci.2019.10.043

Genetic Loci Associated with Early Salt Stress Responses of Roots

iScience. 2019 Nov 22:21:458-473. doi: 10.1016/j.isci.2019.10.043. Epub 2019 Oct 25.

Authors

Ayodeji O Deolu-Ajayi¹, A Jessica Meyer², Michel A Haring³, Magdalena M Julkowska⁴, Christa Testerink⁵

Affiliations

¹ Laboratory of Plant Physiology, Plant Sciences Group, Wageningen University and Research, 6708PB Wageningen, the Netherlands; Plant Physiology, Swammerdam Institute of Life Sciences, University of Amsterdam, 1098XH Amsterdam, the Netherlands.
² Laboratory of Plant Physiology, Plant Sciences Group, Wageningen University and Research, 6708PB Wageningen, the Netherlands.
³ Plant Physiology, Swammerdam Institute of Life Sciences, University of Amsterdam, 1098XH Amsterdam, the Netherlands.
⁴ Department of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, 23955-6900 Thuwal-Jeddah, Kingdom of Saudi Arabia.
⁵ Laboratory of Plant Physiology, Plant Sciences Group, Wageningen University and Research, 6708PB Wageningen, the Netherlands. Electronic address: christa.testerink@wur.nl.

Abstract

Salinity is a devastating abiotic stress accounting for major crop losses yearly. Plant roots can strikingly grow away from high-salt patches. This response is termed halotropism and occurs through auxin redistribution in roots in response to a salt gradient. Here, a natural variation screen for the early and NaCl-specific halotropic response of 333 Arabidopsis accessions revealed quantitative differences in the first 24 h. These data were successfully used to identify genetic components associated with the response through Genome-Wide Association Study (GWAS). Follow-up characterization of knockout mutants in Col-0 background confirmed the role of transcription factor WRKY25, cation-proton exchanger CHX13, and a gene of unknown function DOB1 (Double Bending 1) in halotropism. In chx13 and dob1 mutants, ion accumulation and shoot biomass under salt stress were also affected. Thus, our GWAS has identified genetic components contributing to main root halotropism that provide insight into the genetic architecture underlying plant salt responses.

Keywords: Biological Sciences; Plant Biology; Plant Genetics; Plant Physiology.