Genome-wide association study reveals the genetic basis controlling mineral accumulation in wheat grains under potassium deficiency

Abstract

Potassium deficit might affect the accumulation of macronutrients in wheat grains that are crucial to plant health, growth, yield, and quality. Understanding the genetic basis underlying the accumulation of macronutrients in wheat grains is important for improved nutritional wheat quality and human health under potassium deficiency. In this study, a core collection of 111 wheat accessions was evaluated under potassium deficiency, including moderate potassium treatment (K1) and low potassium treatment (K2). The four macronutrients of magnesium (Mg), calcium (Ca), potassium (K), and phosphorus (P) were measured in wheat grains under both treatments. Significant reductions were detected for macronutrient accumulation under the low K2 treatment as compared with the moderate K1 treatment. All wheat accessions treated with low K2 showed a significant decrement when compared to those treated with moderate K1. Upon GWAS analysis and linkage disequilibrium (LD), 31 significant SNP markers were revealed associated with all of the measured macronutrients (Mg, Ca, K, and P) under both potassium treatments. Interestingly, seven genomic regions were detected for chromosomes 1A, 1B, 2A, 2B, 3A, 3B, 4B, 5A, 5B, 5D, 6A, and 6D that showed multi-trait associations (MTAs) with all of the measured macronutrients under both treatments. A pleiotropic gene TraesCS1B02G346700 is encoded as magnesium ion (Mg2+) transmembrane transporter activity and has a crucial role in nutrient accumulation in wheat grain, particularly under potassium deprivation. This study advances genetic knowledge of nutrient utilization in plants and provides practical strategies to improve crop yield and sustainability amid resource constraints and shifting climatic patterns. By integrating these genetic factors into breeding programs, it is feasible to develop wheat cultivars that exhibit enhanced nutrient efficiency, stress tolerance, and increased yield potential.