Old and young duplicate genes reveal different responses to environmental changes in Arachis duranensis.

Old and young duplicate genes have been reported in some organisms. However, little is known about the properties of old and young duplicate genes in Arachis. Here, we have identified old and young duplicate genes in Arachis duranensis, and analyzed the evolution, gene complexity, gene expression pattern, and functional divergence between old and young duplicate genes. Our results showed different evolutionary, gene complexity and gene expression patterns, as well as differing correlations between old and young duplicate genes. Gene ontology results showed that old duplicate genes play a crucial role in lipid and amino acid biosynthesis and the oxidation-reduction process and that young duplicate genes are preferentially involved in photosynthesis and response to biotic stimulus. Transcriptome data sets revealed that most old and young duplicate genes had asymmetric function, and only a few duplicate genes exhibited symmetric function under drought and nematode stress. We found that old duplicate genes are preferentially involved in lipid and amino acid metabolism and response to abiotic stress, while young duplicate genes are likely to participate in photosynthesis and response to biotic stress. This work provides a better understanding of the evolution and functional divergence of old and young duplicate genes in A. duranensis.