Zea mays Transcriptome or Gene expression

It is of great importance to decipher the genetic mechanisms of agronomic traits for crop improvement and global food security. The majority of these traits are quantitatively controlled by multiple quantitative trait loci (QTL), and the identification of the underlying genes by conventional QTL fine-mapping is usually time-consuming and labor-intensive. Here, a novel method named as QTG-Seq(Quantitative Trait Gene Sequencing) was devised to accelerate QTL fine-mapping. QTG-Seq combines QTL partitioning to convert quantitative trait into a near qualitative trait in just one generation selection, bulked segregant sequencing on a large segregating population with relative low coverage, and a dedicated new algorithm for identification of candidate genes. UsingQTG-Seq, a major plant height QTL-qPH7 was fine-mapped to a 300-Kb genomic interval, where a NF-YC transcription factor was verified to be the functional gene. Molecular evidences suggested that qPH7 influences plant height by interacting with core flowering time pathway genes CONSTANS and AP2. Selection analysis indicated that qPH7 was subject to strong selection during maize domestication and improvement. In summary, QTG-Seq contributes an efficient way to QTL fine-mapping in the era of “big data”.