Main content area

Genome-wide survey and expression analysis of the stress-associated protein gene family in desert poplar, Populus euphratica

Jia, Huixia, Li, Jianbo, Zhang, Jin, Ren, Yiqiu, Hu, Jianjun, Lu, Mengzhu
Tree genetics & genomes 2016 v.12 no.4 pp. 78
Populus euphratica, abscisic acid, algorithms, cold, drought, genes, heat, heat stress, phylogeny, promoter regions, proteins, quantitative polymerase chain reaction, resistance mechanisms, single nucleotide polymorphism, stress response, stress tolerance, surveys, woody plants, zinc finger motif
Stress-associated proteins (SAPs) are a novel class of zinc finger proteins that extensively participate in abiotic stress responses. To date, no overall analysis and expression profiling of SAP genes in woody plants have been reported. Populus euphratica is distributed in desert regions and is extraordinarily adaptable to abiotic stresses. Thus, it is regarded as a promising candidate for studying abiotic stress resistance mechanisms of woody plants. In this study, 18 non-redundant SAP genes were identified from the genome of P. euphratica using basic local alignment search tool algorithms and functional domain verification. Among these 18 PeuSAP genes, 15 were intronless. To investigate the evolutionary relationships of SAP genes in P. euphratica and other Salicaceae plants, phylogenetic analyses were performed. Subsequently, the expression profiles of the 18 PeuSAP genes were analyzed in different tissues and under various stresses (drought, salt, heat, cold, and abscisic acid (ABA) treatment) using quantitative real-time PCR. Tissue expression analysis indicated that PeuSAPs showed no tissue specificity. PeuSAPs were induced by multiple abiotic stresses, especially drought, salt, and heat stresses, perhaps because of abundant cis-acting heat shock elements and drought-inducible elements in the promoter regions of the PeuSAPs. Moreover, single nucleotide polymorphisms (SNPs) variant analysis revealed many synonymous and non-synonymous SNPs in PeuSAP genes, but the zinc finger structure was conserved during evolution. These results provide an overview of the SAP gene family in P. euphratica and a reference for further functional research on PeuSAP genes.