title: The emerging importance of the SPX domain-containing proteins in phosphate homeostasis.
abstract: Plant growth and development are strongly influenced by the availability of nutrients in the soil solution. Among them, phosphorus (P) is one of the most essential and most limiting macro-elements for plants. In the environment, plants are often confronted with P starvation as a result of extremely low concentrations of soluble inorganic phosphate (Pi) in the soil. To cope with these conditions, plants have developed a wide spectrum of mechanisms aimed at increasing P use efficiency. At the molecular level, recent studies have shown that several proteins carrying the SPX domain are essential for maintaining Pi homeostasis in plants. The SPX domain is found in numerous eukaryotic proteins, including several proteins from the yeast PHO regulon, involved in maintaining Pi homeostasis. In plants, proteins harboring the SPX domain are classified into four families based on the presence of additional domains in their structure, namely the SPX, SPX-EXS, SPX-MFS and SPX-RING families. In this review, we highlight the recent findings regarding the key roles of the proteins containing the SPX domain in phosphate signaling, as well as providing further research directions in order to improve our knowledge on P nutrition in plants, thus enabling the generation of plants with better P use efficiency.
authors.affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, WA 6009, Australia. david.secco@uwa.edu.au
authors.forename: David
authors.initials: D
authors.lastname: Secco
authors.forename: Chuang
authors.initials: C
authors.lastname: Wang
authors.forename: Bulak A
authors.initials: BA
authors.lastname: Arpat
authors.forename: Zhiye
authors.initials: Z
authors.lastname: Wang
authors.forename: Yves
authors.initials: Y
authors.lastname: Poirier
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Tyerman
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
authors.forename: Huixia
authors.initials: H
authors.lastname: Shou
authors.forename: James
authors.initials: J
authors.lastname: Whelan
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D006706:Homeostasis; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000502:physiology*; D010944:Plants / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000235:genetics; D015398:Signal Transduction; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D010710:Phosphates; D010940:Plant Proteins; D010758:Phosphorus