Abstract
Background: Late embryogenesis abundant (LEA) proteins are a group of highly hydrophilic glycine-rich proteins, which accumulate in the late stage of seed maturation and are associated with many abiotic stresses. However, few peanut LEA genes had been reported, and the research on the number, location, structure, molecular phylogeny and expression of AhLEAs was very limited. Results: In this study, 126 LEA genes were identified in the peanut genome through genome-wide analysis and were further divided into eight groups. Sequence analysis showed that most of the AhLEAs (85.7 %) had no or only one intron. LEA genes were randomly distributed on 20 chromosomes. Compared with tandem duplication, segmental duplication played a more critical role in AhLEAs amplication, and 93 segmental duplication AhLEAs and 5 pairs of tandem duplication genes were identified. Synteny analysis showed that some AhLEAs genes come from a common ancestor, and genome rearrangement and translocation occurred among these genomes. Almost all promoters of LEAs contain ABRE, MYB recognition sites, MYC recognition sites, and ERE cis-acting elements, suggesting that the LEA genes were involved in stress response. Gene expression analyses revealed that most of the LEAs were expressed in the late stages of peanut embryonic development. LEA3 (AH16G06810.1, AH06G03960.1), and Dehydrin (AH07G18700.1, AH17G19710.1) were highly expressed in roots, stems, leaves and flowers. Moreover, 100 AhLEAs were involved in response to drought, low-temperature, or Al stresses. Some LEAs that were regulated by different abiotic stresses were also regulated by hormones including ABA, brassinolide, ethylene and salicylic acid. Interestingly, AhLEAs that were up-regulated by ethylene and salicylic acid showed obvious subfamily preferences.Conclusions: AhLEAs are involved in abiotic stress response, and segmental duplication plays an important role in the evolution and amplification of AhLEAs. The genome-wide identification, classification, evolutionary and expression analyses of the AhLEA gene family provide a foundation for further exploring the LEA genes’ function in response to abiotic stress in peanuts.
Genome-wide identification, and characterization of the CDPK gene family reveal their involvement in abiotic stress response in Fragaria x ananassa
