EQTL mapping of the 12S globulin cruciferin gene PGCRURSE5 as a novel candidate associated with starch content in potato tubers

Dorota Sołtys-Kalina,Waldemar Marczewski,Emil Stefańczyk,Katarzyna Szajko,Paulina Smyda-Dajmund,Jadwiga Śliwka

doi:10.1038/s41598-020-74285-5

Dorota Sołtys-Kalina, Waldemar Marczewski + Show 4 more

Open Access

https://doi.org/10.1038/s41598-020-74285-5

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Abstract

Tuber starch content (TSC) is a very important trait in potato (Solanum tuberosum L.). This study is the first to use expression quantitative trait loci (eQTL) mapping of transcript-derived markers for TSC in potato. Thirty-four differentially expressed genes were selected by comparing the RNA-seq data of contrasting bulked segregants. For the 11 candidate genes, we determined their relative expression levels across the segregating diploid potato population using RT-qPCR. We detected 36 eQTL as candidate genes distributed on all twelve potato chromosomes, and nine of them overlapped with QTL for TSC. Peaks for two eQTL, eAGPaseS-a and ePGRCRURSE5, were close to the corresponding loci of the large subunit of ADP-glucose pyrophosphorylase (AGPaseS-a) and the 12S globulin cruciferin gene (PGCRURSE5), respectively. The eQTL peaks for AGPaseS-a and PGRCRURSE5 explained 41.0 and 28.3% of the phenotypic variation at the transcript level. We showed the association of the DNA markers for AGPaseS-a and PGRCRURSE5 with QTL for TSC, and significant correlation between the expression level of PGRCRURSE5 and TSC. We did not observe a significant correlation between the expression level of AGPaseS-a and TSC. We concluded that the cruciferin gene PGRCRURSE5 is a novel candidate involved in the regulation of starch content in potato tubers.

Highlights

Tuber starch content (TSC) is a very important trait in potato (Solanum tuberosum L.)
The AGPaseS loci, in particular, the locus AGPaseS-a on chromosome I, colocalized with Quantitative trait loci (QTL) for TSC, and the data indicated a small effect on this trait in the mapping p opulations[18,31]
The amplicons AGPsS-9a and AGPsS-10a, both derived from the AGPaseS-a locus, were correlated either positively or negatively with TSC32

Summary

Introduction

Tuber starch content (TSC) is a very important trait in potato (Solanum tuberosum L.). This study is the first to use expression quantitative trait loci (eQTL) mapping of transcript-derived markers for TSC in potato. We concluded that the cruciferin gene PGRCRURSE5 is a novel candidate involved in the regulation of starch content in potato tubers. In potato (Solanum tuberosum L.), RNA pools that consist of genotypes based on contrasting phenotypic or marker data were used to select candidate genes for tuber flesh colour and cooking type[6]. Among numerous characteristics that are subject to selection in potato breeding, tuber starch content (TSC) is one of the most agronomically important. The gene encoding AGPaseS-a was localized within the most important QTL on chromosome I that accounted for 15.2% of the variance in tuber starch content[12]

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