Molecular interaction between PHO2 and GIGANTEA reveals a new crosstalk between flowering time and phosphate homeostasis in Oryza sativa. (19th May 2017)

• Record Type: Journal Article
• Authors: Li, Shuai; Ying, Yinghui; Secco, David; Wang, Chuang; Narsai, Reena; Whelan, James; Shou, Huixia
• Is Part Of: Plant, cell and environment. Volume 40:Number 8(2017)
• Page Start: 1487
• Page End: 1499
• Publication Date: 2017-05-19
• Subjects: phospate signaling pathway -- UBC24 -- flowering regulation -- protein‐protein interaction; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.12945
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Plants are often confronted to nutrient limiting conditions, such as inorganic phosphate (Pi) deficiency, resulting in a reduction in growth and yield. PHO2, encoding a ubiquitin‐conjugating E2 enzyme, is a central component of the Pi‐starvation response signalling pathway. A yeast‐two‐hybrid screen using Oryza sativa (rice) PHO2 as bait, revealed an interaction between OsPHO2 and OsGIGANTEA, a key regulator of flowering time, which was confirmed using bimolecular fluorescence complementation (BiFC). Characterization of rice Osgi and Ospho2 mutants revealed that they displayed several similar phenotypic features supporting a physiological role for this interaction. Reduced growth, leaf tip necrosis, delayed flowering and over‐accumulation of Pi in leaves compared to wild type were shared features of Osgi and Ospho2 plants. Pi analysis of individual leaves demonstrated that Osgi, similar to Ospho2 mutants, were impaired in Pi remobilization from old to young leaves, albeit to a lesser extent. Transcriptome analyses revealed more than 55% of the genes differentially expressed in Osgi plants overlapped with the set of differentially expressed genes in Ospho2 plants . The interaction between OsPHO2 and OsGI links high‐level regulators of Pi homeostasis and development in rice. Abstract : PHO2, encoding a ubiquitin‐conjugating E2 enzyme, is a central component of the phosphate (Pi) starvation response signalling pathway. This study identified OsGIGANTEA, the key regulator controlling flowering time as a novel interacting partner of OsPHO2. Physiological and transcriptome analyses of Osgi and Ospho2 mutants suggest a crosstalk between Pi homeostasis and flowering time regulation in rice.