Phosphate: the Silent Challenge

Document Type : Original Research Papers

Authors

1 Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology

2 Agriculture Department, Tabriz University, Tabriz, I.R. Iran

3 Agriculture Faculty, Tarbiat Modares University, Tehran, I.R. Iran

Abstract

Phosphorus (P) is one of the most vital elements for all living organisms which acts as a
constituent of essential biomolecules such as nucleic acids, phospholipids, and phosphosugars,
and as a major contributor to almost all metabolic reactions including photosynthesis,
respiration, and energy delivery. It is one of the most needed nutrients for plant growth and
development. Despite high levels of P in the soil, plants absorb it only in the soluble inorganic
form of free phosphate ion (Pi) which is scarce in soil. Therefore, there has been a large demand
for Pi fertilizers to secure crop yields, yet its deposition in soil and gradual run-off into water
reservoirs lead to chains of events that cause irreversible damages to ecosystems. Researches,
including genome-wide data analyses, have revealed interesting molecular aspects of plant
adaptive strategies to deal with low Pi concentrations in soil. These include the higher
expression of acid phosphatases and Pi transporters as well as the secretion of organic acids in
the rhizosphere that maintain cellular Pi homeostasis in order to keep metabolic reactions
running. Describing the cycle of Pi exchange between physical and biological worlds, the extent
to which current agricultural practices are disturbing the cycle, the necessity of introducing lessdestructive
methods of providing Pi, and alternative measures and solutions for sustainable
agriculture will be discussed in this review.

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