Genome-wide Identification and Analysis of Late Embryogenesis Abundant (LEA) Genes in Musa acuminata

Abstract

Key Message Eighty four MaLEA genes were found coding for eighty five proteins, most of which are small and hydrophilic, and show ubiquitous distribution in the cell. MaLEA genes, having few introns, are distributed on all chromosomes, associated with abiotic stress-related cis-acting elements, and are differentially expressed under abiotic stress conditions. Musa acuminata (Banana) is a major fruit crop grown worldwide. M. acuminata production is often threatened by abiotic environmental stresses. Late Embryogenesis Abundant (LEA) proteins play significant roles in plant growth, development, and responses to stresses. However, no studies have been carried out to elucidate the number, location, structure, molecular phylogenetics, and expression of LEA genes in M. acuminata. In this study, a genomic census of LEA genes in M. acuminata was carried out. A total of 84 LEA genes were identified and grouped in to eight sub-families. The LEA_2 subfamily was the largest and most diverse, including 57 members. Repeated motifs corresponding to LEA groups were present in the M. acuminata LEA proteins. The majority of MaLEA proteins was hydrophilic, and contained amino acids such as alanine, glycine and serine in abundance. Various functions were predicted for these proteins including response to stress, binding, structural components, and embryo development. The majority of MaLEA proteins are associated with the cytoplasm and chloroplast, while others are present in different subcellular compartments. MaLEAs have few introns (< 3) and are distributed unevenly across all chromosomes indicating that a significant portion of these genes originated by tandem or segmental duplications. The upstream sequences of these genes contain cis-acting elements associated with stress responses. The large number and diversity of LEA genes found in banana indicates that they are important in abiotic stress tolerance. This investigation provides valuable insights for future functional studies of MaLEA genes which may be useful for developing drought-tolerant banana varieties.