Identification of molecular mechanisms and candidate genes for salt stress tolerance of potato genotypes through genome-wide association studies

• Applicant: Dr. Christin Bündig
• Subject Area: Plant Breeding and Plant Pathology
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 570362438

The objectives of the project are divided into 5 work packages: WP1: The aim of this work package is to analyse the salt stress tolerance of 96 potato genotypes in vitro by adding NaCl. The data obtained will be used for GWAS analyses to identify QTLs that can be associated with the salt stress response. Parameters to be analyzed include growth parameters and osmotic adjustment. The aim is to generate phenotyping data that can be used in a GWAS study to detect QTLs and related genes for salt stress tolerance responses in tetraploid potato. WP2: In this work package it will be investigated whether different potato genotypes that respond divergently to salt stress also show differences in the uptake of selected nutrients. The nutrients Na, Cl, K, B, Ca, Cu, Fe, Mg, Mn, Mo, P, Zn, S and C will be analysed by ICP-OES for the 30 most divergent responding genotypes of the 96-genotype test set from WP1. The aim is to clarify whether divergent genotypes show different nutrient uptake patterns under salt stress. WP3: This work package is based on a GWAS and combines phenotypic data from WP1 with genomic sequence data from the 96-genotype test set to identify QTLs for salt stress tolerance. Subsequently, specific genes will be identified, which will be further analyzed in the course of the project. Osmotic stress data from a previous study will be integrated to analyze overlaps between the two stressors. The aim is to detect QTLs, map them and identify specific genes for salt stress responses in potatoes. Furthermore, segregating populations of the genotypes are available. WP4: The aim of this work package is to analyze the gene expression of INH1 and 19 other genes based on WP1-3. INH1, which showed increased gene expression under drought stress and osmotic stress in potato, will be analyzed to determine whether it also plays a role under salt stress in potato. The aim is to further elucidate molecular processes based on the QTLs found. WP5: This work package aims to decipher the function and effect of three genes that are specifically more strongly expressed under salt stress. Three genes from WP4 will be analysed by precise genome editing using CRISPR/Cas9. Genotypes with high salt stress tolerance and transformation efficiency will be used. Transformed lines will be tested under salt stress and compared with wild types. The aim is to perform functional studies of the detected genes to analyze whether their function is essential for the salt stress response in potatoes.

• DFG Programme: Research Grants