Genome-wide systematic characterization of PHT gene family and its member involved in phosphate uptake in Orychophragmus violaceus.

Abstract

Background: Phosphorus (P) is an indispensable mineral element which plays crucial roles in plant development and production. While it is widely acknowledged that phosphate transporters (PHT) facilitate the absorption of P, detailed identification and characterization of the PHT genes in Orychophragmus violaceus remains unexplored.

Results: Here, a total of 22 OvPHT genes were identified from high-quality genome of O. violaceus and could be categorized into four distinct subfamilies, based on the phylogenetic analysis. Synteny analysis revealed that the OvPHT gene family underwent nine segmental duplication events and two tandem duplication events. Additionally, a detailed analysis of the Ka/Ks ratios indicated that these duplicated gene pairs primarily experienced purifying selection. Expression patterns of these OvPHT genes across various tissues, including leaves, roots, stems, and flowers, showed differential but partial-overlapping patterns. OvPHT1 members were predominantly expressed in roots and induced by P starvation. Conversely, OvPHT4 members showed high expression levels in all tested tissues, except for roots; the expression levels of OvPHT2 and OvPHT3 members were mainly detected in leaves and flowers, respectively. Moreover, OvPHT1;1 was localized in the plasma membrane. Overexpression of OvPHT1;1 in rice could enhance P uptake under low-P condition.

Conclusion: In summary, this systematic analysis provides detailed information for a better understanding of OvPHT genes and identifies candidate genes for further exploration of P-efficient utilization in O. violaceus.