Genome wide identification and expression analysis of patatin-like protein family members in peanut (Arachis hypogaea L.)

Abstract

Herein we performed bioinformatics analysis of patatin-like protein (PLP) family genes, including gene numbers, gene structure, chromosomal distribution, and expression levels, in order to establish a theoretical foundation for genes encoding PLPs in peanut (Arachis hypogaea L.). In total, 49 PLP family members were identified: 26 in A. hypogaea, 11 in A. duranansis (AA), and 12 in A. ipaënsis (BB). They were classified into four categories (class II, III, V and VI), and unevenly distributed on 20 chromosomes. Gene structure analysis revealed that the exon numbers varied from 2 to 14, and the length of amino acid ranged from 157 to 812 aa with isoelectric point (pI) ranged from 4.55 to 8.74. All the PLP family members contained the conserved patatin-like phospholipase domain, but none of them contained signal peptides, and only four contained transmembrane domains. Promoter analysis showed that PLP-encoding genes contained cis-acting regulatory elements related to hormone responses, environmental adaptability and stress response induction. RNA-seq data showed that these genes were expressed under different spatiotemporal conditions. The relative expression levels of PLP-encoding genes in different tissues were detected using quantitative real-time polymerase chain reaction (qRT-PCR). AhPLP1 and AhPLP10 expression levels in flowers were relatively high, while AhPLP4 expression level in roots, stems, and flowers was extremely low, which indicated the potential functions of PLPs in peanut.