# Genome-Wide Identification of the PHR Gene Family in Six Cucurbitaceae Species and Its Expression Analysis in Cucurbita moschata

## TL;DR

This study identifies and analyzes PHR genes in six Cucurbitaceae species, focusing on their role in phosphate regulation in pumpkin.

## Contribution

The first genome-wide identification and expression analysis of PHR genes in Cucurbitaceae species, particularly in pumpkin.

## Key findings

- 11 to 22 PHR genes were identified in six Cucurbitaceae species through genome-wide analysis.
- CmoPHR genes showed differential expression under varying phosphate concentrations.
- Four CmoPHR proteins exhibited transcriptional self-activating activity.

## Abstract

Phosphorus, as an essential nutrient, plays an important role in plant growth and development. Although Phosphate Starvation Response 1 (PHR1) or PHR1-like have been recognized as central regulators of phosphorus (Pi) homeostasis in several plants, they have not been systematically studied in Cucurbitaceae. In this study, 11, 10, 8, 12, 12, and 22 PHR genes were identified in cucumber, melon, bottle gourd, watermelon, wax gourd, and pumpkin, respectively, by genome-wide analysis. Phylogenetic analysis showed that the Cucurbitaceae PHR genes were divided into seven distinct subfamilies. These genes were further phylogenetically analyzed for their chromosomal localization, gene structure, protein structure, and synteny. Genomic homology analysis showed that many PHR genes existed in the corresponding homology blocks of six Cucurbitaceae species. qRT-PCR analysis showed that the CmoPHR genes exhibited differential expression under different concentrations of phosphate treatment. Transcriptional self-activation assays showed that CmoPHR2, CmoPHR9, CmoPHR16, and CmoPHR17 proteins had transcriptional self-activating activity. The results of this study provide a basis for the further cloning and functional validation of genes related to the phosphate regulatory network in pumpkin.