Abstract
Background: Phosphorus (P) is an essential nutrient for plant growth and development. Phosphate transporter 1 (PHT1) is a transmembrane protein that mediates the uptake and translocation of inorganic phosphate (Pi) in plants. Despite extensive research on the PHT1 family across various species, the PHT1 genes in Eucalyptus grandis are poorly documented and not identified comprehensively. Results: In this study, a total of 21 EgrPHT1genes (EgrPHT1-1 ~ EgrPHT1-21) were identified for the comprehensive analysis of the whole genome of E. grandis. Gene structure showed that the number of exons ranges from 1 to 6, and 57% gene members lacking introns. Protein multi-sequence alignment analysis revealed that all members except the EgrPHT1-5 had 12 transmembrane domains. Chromosome localization analysis showed that all EgrPHT1 genes were unevenly distributed on 8 chromosomes. Collinearity result identified one pair of tandem duplication and two pairs of fragment duplications. Promoter cis-elements suggested that the expression of the EgrPHT1 genes was affected by various hormonal and abiotic stresses. Tissue-specific expression patterns indicated six genes (EgrPHT1-9/10/13/15/16/17) is specifically expressed in the roots, indicating that they may be involved in the formation and development of the root. Furthermore, 9 EgrPHT1 gene members (EgrPHT1-1/3/4/10/11/12/15/16/19) were upregulated in the root and EgrPHT1-1/3/4/1/16/19 was also upregulated in leaves under phosphorus deficiency. Conclusions: In this study, we identified and analyzed EgrPHT1 family genes using bioinformatics approaches, and also examined differential expression patterns of EgrPHT1 genes in various tissues and in response to Pi starvation stress, suggesting their involvement in P uptake, translocation, and homeostasis. This information provides a platform for further investigation of their biological functions.