Genome-wide Association Study of Root Hair Length in Maize

Root hairs are a special type of tubular-shaped cell that is important for water and nutrient absorption in plants. Although a few genes and quantitative trait loci (QTL) have been identified and proven to contribute to root hair development in maize, the genetic basis remains unclear. In this study, we performed a genome-wide association study (GWAS) on root hair length in a maize association panel including 200 temperate inbred lines. A total of 399 significant single nucleotide polymorphism loci (SNPs) were identified for root hair length, and 88 QTLs were obtained after combining SNPs within a 50 kb interval, including 15 QTLs for multiple traits. We also demonstrate that the genetic basis of root hair length at different root regions was not entirely consistent. We further predicted a series of candidate genes, some of whose homologous genes have been proven to play roles in root hair development. These findings provide available resources for further gene cloning and functional characterization of root hair development in maize.