Ubiquitin-Specific Protease 14 (UBP14) Is Involved in Root Responses to Phosphate Deficiency in Arabidopsis

Abstract

A mutant isolated from a screen of EMS-mutagenized Arabidopsis lines, per1, showed normal root hair development under control conditions but displayed an inhibited root hair elongation phenotype upon Pi deficiency. Additionally, the per1 mutant exhibited a pleiotropic phenotype under control conditions, resembling Pi-deficient plants in several aspects. Inhibition of root hair elongation upon growth on low Pi media was reverted by treatment with the Pi analog phosphite, suggesting that the mutant phenotype is not caused by a lack of Pi. Reciprocal grafting experiments revealed that the mutant rootstock is sufficient to cause the phenotype. Complementation analyses showed that the PER1 gene encodes an ubiquitin-specific protease, UBP14. The mutation caused a synonymous substitution in the 12th exon of this gene, resulting in a lower abundance of the UBP14 protein, probably as a consequence of reduced translation efficiency. Transcriptional profiling of per1 and wild-type plants subjected to short-term Pi starvation revealed genes that may be important for the signaling of Pi deficiency. We conclude that UBP14 function is crucial for adapting root development to the prevailing local availability of phosphate.

UBIQUITIN-SPECIFIC PROTEASE 14 interacts with ULTRAVIOLET-B INSENSITIVE 4 to regulate endoreduplication and cell and organ growth in Arabidopsis

“…A previous study showed that T-DNA insertion mutations (ubp14 and ttn6) in UBP14 resulted in an embryonic lethal phenotype, with the homologous embryos arresting at the globular stage (Doelling et al, 2001;Tzafrir et al, 2002). The per1 mutation resulted in a synonymous substitution in the UBP14 gene, and the per1 mutant had not been reported to influence plant growth and development under normal growth condition (Li et al, 2010). Thus, the functions of UBP14 in organ growth and development remain to be elucidated.…”

“…T-DNA insertion mutations (ubp14 and tnn6) inArabidopsis UBP14 result in an embryonic lethal phenotype (Doelling et al, 2001;Tzafrir et al, 2002). By contrast, the per1 mutation causes a synonymous substitution in the UBP14 gene, resulting in an inhibited root hair elongation phenotype upon phosphate deficiency (Li et al, 2010). However, this per1 mutation has not been shown to affect plant growth and development under normal growth conditions (Li et al, 2010).…”

“…By contrast, the per1 mutation causes a synonymous substitution in the UBP14 gene, resulting in an inhibited root hair elongation phenotype upon phosphate deficiency (Li et al, 2010). However, this per1 mutation has not been shown to affect plant growth and development under normal growth conditions (Li et al, 2010). Therefore, the biological functions of UBP14 in postembryonic development remain largely unknown.…”

UBIQUITIN-SPECIFIC PROTEASE16 Modulates Salt Tolerance in Arabidopsis by Regulating Na+/H+ Antiport Activity and Serine Hydroxymethyltransferase Stability

“…Although little is known about the specific substrates of each member, a few UBPs have been reported to be involved in the regulation of plant growth, development, and gene expression. For example, UBP14 is involved in root responses during phosphate deficiency (Li et al, 2010), while UBP26 is required for seed development and the repression of PHERES1 (Luo et al, 2008). UBP26 also plays a role in chromatin remodeling affecting small interfering RNA-mediated heterochromatin formation as well as FIS Polycomb repression (Sridhar et al, 2007).…”

Coexpression-Based Clustering of Arabidopsis Root Genes Predicts Functional Modules in Early Phosphate Deficiency Signaling

“…The latter trait is of particular importance when depletion zones, caused by the low mobility of Pi via mass flow and diffusion, develop around the root surface (Ma et al, 2001). UBIQUITIN-SPECIFIC PROTEASE14 (UBP14) has been shown to be crucial for root development under Pi-deficient conditions (Li et al, 2010). A mutant harboring a synonymous substitution in the UBC14 gene, presumably reducing the translation efficiency of the UBC14 transcript, forms short hairs under Pi-deficient conditions, while root hair development was indistinguishable from the wild type under control conditions.…”