Arabidopsis RING E3 ubiquitin ligase AtATL80 is negatively involved in phosphate mobilization and cold stress response in sufficient phosphate growth conditions

• Published in: Biochemical and biophysical research communications 2015-08, Vol.463 (4), p.793-799
• Main Authors: Suh, Ji Yeon, Kim, Woo Taek
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological; Arabidopsis - enzymology; Arabidopsis - metabolism; Arabidopsis - physiology; Arabidopsis thaliana; Biomass; Cell Membrane - enzymology; Cold stress response; Cold Temperature; Phosphate mobilization; Phosphates - metabolism; Phosphorus - metabolism; Phosphorus utilization efficiency; Plants, Genetically Modified - enzymology; Plants, Genetically Modified - growth & development; Plants, Genetically Modified - metabolism; RING E3 Ub ligase; Seed yield; Stress, Physiological; Ubiquitin-Protein Ligases - metabolism
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2015.06.015

Phosphate (Pi) remobilization in plants is critical to continuous growth and development. AtATL80 is a plasma membrane (PM)-localized RING E3 ubiquitin (Ub) ligase that belongs to the Arabidopsis Tóxicos en Levadura (ATL) family. AtATL80 was upregulated by long-term low Pi (0–0.02 mM KH2PO4) conditions in Arabidopsis seedlings. AtATL80-overexpressing transgenic Arabidopsis plants (35S:AtATL80-sGFP) displayed increased phosphorus (P) accumulation in the shoots and lower biomass, as well as reduced P-utilization efficiency (PUE) under high Pi (1 mM KH2PO4) conditions compared to wild-type plants. The loss-of-function atatl80 mutant line exhibited opposite phenotypic traits. The atatl80 mutant line bolted earlier than wild-type plants, whereas AtATL80-overexpressors bloomed significantly later and produced lower seed yields than wild-type plants under high Pi conditions. Thus, AtATL80 is negatively correlated not only with P content and PUE, but also with biomass and seed yield in Arabidopsis. In addition, AtATL80-overexpressors were significantly more sensitive to cold stress than wild-type plants, while the atatl80 mutant line exhibited an increased tolerance to cold stress. Taken together, our results suggest that AtATL80, a PM-localized ATL-type RING E3 Ub ligase, participates in the Pi mobilization and cold stress response as a negative factor in Arabidopsis. •AtATL80 is a RING E3 ubiquitin ligase in Arabidopsis.•AtATL80 is localized at the plasma membrane.•AtATL80 is involved in phosphate mobilization as a negative regulator.•AtATL80 is a negative factor of the cold stress tolerance response.