Phosphate and zinc transport and signalling in plants: toward a better understanding of their homeostasis interaction

Abstract

Inorganic phosphate (Pi) and zinc (Zn) are two essential nutrients for plant growth. In soils, these two minerals are either present in low amounts or are poorly available to plants. Consequently, worldwide agriculture has become dependent on external sources of Pi and Zn fertilizers to increase crop yields. However, this strategy is neither economically nor ecologically sustainable in the long term, particularly for Pi, which is a non-renewable resource. To date, research has emphasized the analysis of mineral nutrition considering each nutrient individually, and showed that Pi and Zn homeostasis is highly regulated in a complex process. Interestingly, numerous observations point to an unexpected interconnection between the homeostasis of the two nutrients. Nevertheless, despite their fundamental importance, the molecular bases and biological significance of these interactions remain largely unknown. Such interconnections can account for shortcomings of current agronomic models that typically focus on improving the assimilation of individual elements. Here, current knowledge on the regulation of the transport and signalling of Pi and Zn individually is reviewed, and then insights are provided on the recent progress made towards a better understanding of the Zn-Pi homeostasis interaction in plants.

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“…High content of phosphate in NPK and poultry manure-containing treatments at the end of the experiment could have played a role in zinc toxicity to the P. aquilinum which was similar to other reports. This was similar to the observations that despite its essentiality, high concentrations of zinc in the growth medium can cause toxicity in plants (Bouain et al, 2014). At cellular level, elevated zinc concentration causes oxidative stress, a decrease in accumulation of ATP, disintegration of cell organelle and development of vacuoles (Xu et al, 2013).…”

“…It is the only metal *Corresponding authors: E-mail: floraolaifa@yahoo.com represented in all six classes of enzymes-oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases (Bouain, et al, 2014). Its homeostasis is important for the functioning of the brain and central nervous system, electron transfer in catalytic reactions, growth and reproduction but can accumulate in tissues and become toxic when in excess (Javed, 2012).…”

Phosphorus Transport in Arabidopsis and Wheat: Emerging Strategies to Improve P Pool in Seeds

“…These observations indicate the existence of additional unknown genes and pathways regulating the Pi content in plants [8,52]. For instance, it is now well established that Pi content in plants is altered when plants are challenged by zinc limitation (−Zn) [6,[76][77][78][79]. Intriguingly, under single −Zn stress, an excess of Pi supply causes loss of wheat biomass in comparison with plants grown under -P-Zn simultaneous stress [78].…”

“…It is estimated that crop yield on 30-40% of the world's total arable land is limited by inorganic phosphate (Pi) bioavailability [4,5]. Many causes could explain the low availability of Pi to plants, such as the Pi (HPO 4 2− ) interaction with soil cations such as zinc (Zn 2+ ) or iron (Fe 2+ ), which form an insoluble complex [6][7][8]. In addition, and most importantly, global Pi reserves are rapidly decreasing due to an increase in its demand [2,[9][10][11].…”

TransDetect Identifies a New Regulatory Module Controlling Phosphate Accumulation

“…In Arabidopsis, the PHO1;H3 gene was demonstrated to be involved in the coordination of Pi and Zn 199 homeostasis (Khan et al, 2014). The expression of PHO1;3 is induced in response to -Zn treatments in 200 roots (Khan et al, 2014).…”