A QTL located on chromosome 3D enhances the selenium concentration of wheat grain by improving phytoavailability and root structure

Abstract

Background and aims As an essential mineral element, selenium (Se) plays a critical role in human health. Given the low concentrations (<100 mg Se kg-1) of Se in staple crops, the identification of genetic resources with enriched Se, as well as the genes controlling Se concentration, is valuable for the marker-assisted selection of Se-rich varieties. Methods We determined the chromosomal quantitative trait (QTL) for Se concentration over two consecutive plant growth cycles using recombinant inbred lines (RILs) treated with two different concentrations of Se under both field-grown and hydroponic conditions. Results Several QTL for Se concentration were detected across the different treatments. Significant genotypic variation in the tissues of the RIL was found at Sedeficicencycondition. Notably, a QTL located on 3D (interval 214.00-218.00, Qse.sau-3D) affected root length and Se concentration in the leaves and grains, suggesting the existence of the same allele with distinctly different functions. However, the QTL for the agronomic traits measured (plant height, flowering time, and tillering number) and Se concentration were not found to be located on the same chromosomal regions, suggesting that marker-assisted selection for both traits is feasible. Se concentrations in the grains were primarily determined by the mineral transport efficiency of the lines, and the line with the highest Se concentration in the grains always possessed larger, more fibrous root systems. The concentrations of Se in the plant tissues were in the order of: root > stem > grain. Conclusions This is the first study to document a Serich synthetic wheat line, and root structure and Se grain concentration was strongly affected by QTL located on 3D.

Advances in Genomic Interventions for Wheat Biofortification: A Review

“…These seleno-proteins are necessary antioxidant enzymes that prevent cellular damage from free radicals, resulting in the prevention of chronic diseases, such as cancer and heart disease [147]. In staple crops, Se is present at a low concentration (<100 mg of Se kg −1 ), so the genetic resources with a high amount of Se, as well as the genes/QTLs controlling the Se concentration, need to be identified to breed the Se-rich varieties, either using the conventional or molecular breeding approach, such as MAS [139].…”

“…Knowledge of the underlying genetic mechanism of the Se content is a necessary step for the Se biofortification of wheat. QTL mapping aids in the understanding of the genetic basis, but unfortunately, only a small number of QTL mapping studies, in which the QTLs for the Se concentration in wheat grain are mapped, have been conducted [132,[138][139][140]. In 2014, Pu et al [132] identified a total of 39 QTLs for five micronutrient (Se, Fe, Zn, Cu and Mn) concentrations using two RIL populations derived from the crosses between SHW-L1 (synthetic hexaploid wheat) and Chuanmai 32 and, Chuanmai 42 and Chuannong 16.…”

QTLs identified for Biofortification Traits in Wheat: A Review

“…These seleno-proteins are necessary antioxidant enzymes that prevent cellular damage from free radicals resulting in the prevention of chronic diseases, such as cancer and heart disease [123]. In staple crops, Se present at low concentration (<100 mg Se kg-1), so the genetic resources having high amount of Se, as well as the genes/QTLs controlling Se concentration are need to be identified to bred the Se-rich varieties either using conventional or molecular breeding approach such as MAS [118].…”

“…Knowledge of the underlying genetic mechanism of Se content is the necessary step for Se biofortification of wheat to enhance grain Se content. QTL mapping helps in understanding the genetic basis but, unfortunately, only a small number of QTL mapping studies have been conducted for mapping the QTLs for Se concentration in wheat grain [107,117,118,119]. In 2014, Pu et al [107] identified a total of 39 QTLs for five micronutrients (Se, Fe, Zn, Cu and Mn) concentrations using two RIL population derived from the crosses between SHW-L1 (synthetic hexaploid wheat) and Chuanmai 32 and, Chuanmai 42 and Chuannong 16 respectively.…”

“…Each mapped QTL explained from 7.37 to 20.22% of the total phenotypic variance of Se content. Recently in 2018, for the first time, Pu et al [118] documented a Se rich synthetic wheat line and mapped a total of 24 QTLs for Se component traits on chromosomes 1B, 3D, 5A, 6A, 6B, 6D and 7D. Notably, a QTL located on chromosome 3D (marker interval 214.00-218.00, Qse.sau-3D), was explaining the maximum amount (up to 28.38%) of genetic variation.…”