Genome-wide identification and characterization of late embryogenesis abundant protein-encoding gene family in wheat: Evolution and expression profiles during development and stress

Late embryogenesis abundant (LEA) proteins are involved in plant stress responses and osmotic regulation, and they are accumulated in the late embryonic stage. There have been no previous genome-wide analyses of the LEA gene family members in wheat and its close relatives. In this study, 281, 53, 151, 89, 99, and 99 LEA genes were identified in wheat (Triticum aestivum), Triticum urartu, Triticum dicoccoides, Aegilops tauschii, barley, and Brachypodium distachyon, respectively. The wheat LEA gene family (TaLEA genes) was divided into eight subfamilies according to the conserved domains. All TaLEA genes contain very few introns (<3) and they are unevenly distributed on the 21 chromosomes. We identified 39 pairs of tandem duplication genes and 9 pairs of segmental duplication genes in the wheat LEA gene family. This proved that the tandem duplication and segmental duplication played an important role in the expansion of the TaLEA gene family. According to published transcriptome data and qRT-PCR analysis, the TaLEA genes exhibit different tissue expression patterns and they are regulated by various abiotic stresses, especially salt and cold stress. This study provides a comprehensive understanding of the wheat LEA gene family.