Genome-Wide Association Mapping of Mixed Linkage (1,3;1,4)-β-Glucan and Starch Contents in Rice Whole Grain

Abstract

The glucan content of rice is a key factor defining its nutritional and economic value. Starch and its derivatives have many industrial applications such as in fuel and material production. Non-starch glucans such as (1,3;1,4)-β-D-glucan (mixed-linkage β-glucan, MLG) have many benefits in human health, including lowering cholesterol, boosting the immune system, and modulating the gut microbiome. In this study, the genetic variability of MLG and starch contents were analyzed in rice (Oryza sativa L.) whole grain, by performing a new quantitative analysis of the polysaccharide content of rice grains. The 197 rice accessions investigated had an average MLG content of 252 μg/mg, which was negatively correlated with the grain starch content. A new genome-wide association study revealed seven significant quantitative trait loci (QTLs) associated with the MLG content and two QTLs associated with the starch content in rice whole grain. Novel genes associated with the MLG content were a hexose transporter and anthocyanidin 5,3-O-glucosyltransferase. Also, the novel gene associated with the starch content was a nodulin-like domain. The data pave the way for a better understanding of the genes involved in determining both MLG and starch contents in rice grains and should facilitate future plant breeding programs.

Genetic dissection of monosaccharides contents in rice whole grain using genome‐wide association study

“…Comparison of the locations of the detected genomic regions in this study (QTLs) and the known reported QTLs for grain yield and other related traits are represented in Supplemental Table S2. Notably, a number of QTLs for arabinose, xylose, fucose, galactose, and rhamnose contents were mapped in the same genomic regions that were identified in our earlier report on starch and (1,3;1,4)-β-glucan contents in RWG (Panahabadi et al, 2021).…”

“…The studied plant panel consisted of 197 rice accessions collected from 70 countries (Supplemental Table S1). The grains from these accessions were previously analyzed in another GWAS project to understand the genetic control of starch and (1,3;1,4)‐β‐glucan content in grain (Panahabadi et al., 2021) and cellulose, lignin, and fermentable sugars in rice straw (Panahabadi et al., 2022). Our new analyses present major monosaccharides composition (including arabinose, xylose, mannose, galactose, fucose, and rhamnose) in whole grain of the same accessions.…”

“…The seeds were grown as described previously (Panahabadi et al., 2021), planted in plots of 2 by 2 m 2 with 25 cm within rows spacing at research farm of Sari Agricultural and Natural Resources University, Iran during the 2017–2019 cultivation season. The accessions consisted of a mixture of landraces, breeding lines, varieties, and cultivars.…”

An evaluation of isolation by distance and isolation by resistance on genetic structure of the Persian squirrel (Sciurus anomalus) in the Zagros forests of Iran

“…Micro‐checker software was used to check scoring errors, stutter, or null alleles (Van Oosterhout et al, 2004 ). Gametic disequilibrium between all pairs of microsatellite loci was tested using POPGENE (Version: 1.32; Panahabadi et al, 2021 , 2022 ; Yeh Francis et al, 1999 ). Null alleles and deviations from Hardy–Weinberg equilibrium for each locus were estimated using Genepop (Version 4.2.1; Panhabadi et al, 2022 ; Rousset, 2008 ).…”

Understanding Wheat Starch Metabolism in Properties, Environmental Stress Condition, and Molecular Approaches for Value-Added Utilization

“…A genome-wide association study (GWAS) is considered an attractive approach for assessing grain quality. Starch contents and starch-related parameters in rice were studies using GWAS analysis [162,163]. Recently, GWAS was performed to identify genetic factors of wheat grain quality including grain protein content, grain starch content, and grain hardness [164].…”