Genome-Wide Analysis of Phosphorus Transporter Genes in and Their Roles in Heavy Metal Stress Tolerance.

Phosphorus transporter () genes encode HPO/H co-transporters that absorb and transport inorganic nutrient elements required for plant development and growth and protect plants from heavy metal stress. However, little is known about the roles of in compared to . In this study, we identified and extensively analyzed 336 PHTs from three diploid ( and ) and two allotetraploid ( and ) species. We categorized the into five phylogenetic clusters (-), including 201 homologs, 15 homologs, 40 homologs, 54 homologs, and 26 homologs, which are unevenly distributed on the corresponding chromosomes of the five species. All family genes from are more closely related to Arabidopsis in the same vs. other clusters, suggesting they are highly conserved and have similar functions. Duplication and synteny analysis revealed that segmental and tandem duplications led to the expansion of the gene family during the process of polyploidization and that members of this family have undergone purifying selection during evolution based on Ka/Ks values. Finally, we explored the expression profiles of family genes in specific tissues, at various developmental stages, and under heavy metal stress via RNA-seq analysis and qRT-PCR. that were induced by heavy metal treatment might mediate the response of rapeseed to this important stress. This study represents the first genome-wide analysis of family genes in species. Our findings improve our understanding of family genes and provide a basis for further studies of in plant tolerance to heavy metal stress.