Functional biology of plant phosphate uptake at root and mycorrhiza interfaces

Abstract

Contents Summary 11 Introduction 11 Phosphate uptake and its regulation 14 Phosphate uptake assisted by the arbuscular–mycorrhizal 18 symbiosis Agricultural potential 21 Conclusions and perspectives 21 Acknowledgements 22 References 22 Summary Phosphorus (P) is an essential plant nutrient and one of the most limiting in natural habitats as well as in agricultural production world‐wide. The control of P acquisition efficiency and its subsequent uptake and translocation in vascular plants is complex. The physiological role of key cellular structures in plant P uptake and underlying molecular mechanisms are discussed in this review, with emphasis on phosphate transport across the cellular membrane at the root and arbuscular–mycorrhizal (AM) interfaces. The tools of molecular genetics have facilitated novel approaches and provided one of the major driving forces in the investigation of the basic transport mechanisms underlying plant P nutrition. Genetic engineering holds the potential to modify the system in a targeted way at the root–soil or AM symbiotic interface. Such approaches should assist in the breeding of crop plants that exhibit improved P acquisition efficiency and thus require lower inputs of P fertilizer for optimal growth. Whether engineering of P transport systems can contribute to enhanced P uptake will be discussed.

Regulation of plants' phosphate uptake in common mycorrhizal networks: Role of intraradical fungal phosphate transporters

“…5 There, it is taken up across the plant's periarbuscular membrane by specifically induced phosphate transporters belonging to the Pht1 family of plant Pi transporter. 6 Remarkably, these mycorrhiza-induced phosphate transporters have been found to be crucial for mycorrhizal Pi acquisition in several studies using mutants with reduced or inhibited mycorrhiza-inducible transporter gene expression. 7,8 In order to study the mycorrhiza-induced Pht1 genes in flax and sorghum, we characterized and analyzed the expression of Pi transporters of the Pht1 family in both plant species, and identified a set of mycorrhiza-inducible Pi transporters in both plants.…”

Live-Cell Imaging Reveals Periarbuscular Membrane Domains and Organelle Location in Medicago truncatula Roots during Arbuscular Mycorrhizal Symbiosis

“…TEM studies have shown that the periarbuscular membrane is continuous with the plasma membrane, but relatively little is known of its lipid or protein composition. Phosphate transporters that are expressed exclusively in AM roots in cells with arbuscules have been cloned from monocots and dicots (Harrison et al, 2002;Paszkowski et al, 2002;Glassop et al, 2005;Nagy et al, 2005;Bucher, 2007) including Medicago truncatula, where the phosphate transporter, MtPT4, was shown to reside exclusively in the periarbuscular membrane (Harrison et al, 2002). In addition, H + -ATPases, which create proton gradients necessary for secondary active transporters such as MtPT4, are induced in AM roots and have been localized to the periarbuscular membrane.…”

A Mycorrhizal-Specific Ammonium Transporter from Lotus japonicus Acquires Nitrogen Released by Arbuscular Mycorrhizal Fungi

“…The uptake of inorganic phosphate (Pi) is considered to be the key physiological process by which AM fungi improve plant growth (Bucher, 2007). AM fungi in fact possess active Pi transporters that acquire Pi from the soil and allow its delivery to the plant (Harrison and van Buuren, 1995).…”