Identification of the GAox gene family in potato (Solanum tuberosum L.) and its expression analysis in response to drought stress

Background GAox is a key enzyme involved in GA biosynthesis pathway and plays an important role in regulating various processes in plant life cycle. However, it has not been systematic, studies have been conducted in potato, which is the world's fourth largest food crop. Methods In this work, we systematically identified GAox gene family (StGAox) in potato by analyzing the potato genome sequence using a set of bioinformatics approaches, and analyze their physical, chemical properties, distribution on chromosomes, gene structure, conserved motifs, gene duplication events and expression patterns were analyzed. Results The results showed that a total of 33 GAox proteins were identified and unevenly distributed on 10 chromosomes. Based on their protein structure and phylogenetic characteristics, these 33 StGAoxes were divided into 5 distinct subclasses. Collinearity analysis revealed that there were 5 pairs of duplicated genes in the StGAox gene family, and all of which evolved under purifying selection. Analysis of RNA-seq data of double haploid (DM) potatoes under different tissues, abiotic stresses and hormone treatments showed that PG0002068, PG0024249 and PG0027963 were higher expressed in leaves, PG009427, PG0026762, PG0009021 and PG0021095 were higher expressed in tubers, PG2003479, PG0024249, PG0005698, and PG0009021were higher expressed in shoots than those of other tissues. In addition, the expression of PG0002068, PG2003479, PG0032156, PG0024249, and PG0021292 were up-regulated under mannitol and drought stress. Conclusions Comparative genome-wide analysis of StGAox genes and their expression analyses revealed that members of this family may be involved in tissue-specific developmental and abiotic stress responses.