Functional characterization of the IGT gene family in wheat reveals conservation and variation in root architecture under drought condition

Abstract

Plant architecture traits are a pivotal component in crop improvement and one of the key aspects of breeding programs for centuries. Among architecture traits, leaves and roots angle are most important whereas roots angle is considered to play a vital role in plant response to drought avoidance. Several genes regulating drought response reported in plants, such as LAZY1, Deeper Rooting 1 (DRO1), and Tiller angle control 1 (TAC1), belong to the IGT family. The wheat (Triticum aestivum L.) genome is complex because it consists of three subgenomes A, B, and D. A genome-wide (A, B, and D) identification and characterization of IGT family genes in wheat was reported in this study. A total of 12 IGT genes were identified and categorized based on phylogenetic reconstruction and gene structure analysis. These genes were distributed on chromosomes 2, 5, and 6 corresponding to the A, B, and D genomes of wheat. Most of the genes showed similar structures. Cis-regulatory elements in the promoter regions interpreted the presence of light, stress, development, and hormone-related elements. Five miRNAs (tae-miR9773, tae-miR531, tae-miR9678–3p, tae-miR9781, and tae-miR5049–3p) were predicted which target these TaIGT. Both the RNA-seq-based transcriptomic and real-time gene expression analysis suggested that all the genes are strongly expressed in roots, thus showing function conservation. 3D models and molecular docking of TaIGT were also carried out systematically, and binding patterns and the orientation of ligands in the active site of proteins were predicted. This study delves further into TaIGT genes and their expression patterns. The findings of this work are important for understanding the molecular control of root development and for future functional characterization of wheat root architecture genes. Key messageIGT gene family has not been identified and characterized and we identified 12 genes strongly expressing in roots. Furthermore, five miRNAs were predicted and could have a role in root conservation.