Phosphorus in Plants

Information concerning the metabolic function of unusual naturally occurring plant constituents might be used to develop new growth regulators. An example of a development that arose in this way began with the observation by Tolbert (143) that as much as 30% of the total soluble phosphorus in plant roots, and sometimes in the leaves,... 

Phytic acid (inisitol hexakisphosphate) is the main storage form of phosphorus in plants. The phosphorus is not bioavailable to non-ruminants as they lack the enzymes to break it down. Novozyme has developed a commercial enzyme, phytase, that can be added to animal feed to release the phosphorus. No inorganic phosphorus needs to be added. This shift in the source of phosphorous has a large impact on the environmental footprint of pig farming. 

W. C. Plaxton, Metabolic aspects of phosphate starvation in plants. Phosphorus in Plant Biology Regulatory Roles in Molecular, Cellular, Organi.smic, and Eco.sy.s-lein Proces.ses (J. P. Lynch and J. Deikman eds.), American Society of Plant Physiologists, 1998, p. 229. 

Meat and such high protein plant foods as soy are excellent sources of phosphorus as well as protein. The phosphorus in meat is readily absorbed from the gastrointestinal tract however, much of the phosphorus in plant products is in a bound form which may inhibit the absorption of calcium as well as phosphorus. This study was designed to determine the effect of different levels of calcium and phosphorus with plant protein or animal protein on bone breaking strength and calcium and phosphorus utilization of weanling mice. 

Discussion 7.10. Determination of total phosphorus in plant material and feeding stuffs... 

Fig. 7.4. Flow diagram for determination of phosphorus in plant digest solutions... 

Armand Gautier and Paul Clausmann found fluorine to be a universal accompaniment of phosphorus in plant tissues (164). Although the unconditional necessity for fluorine for the plant has not been proved, it does occur in all plants and all plant parts (167). 

Phytase offers significant promise as a means to reduce phosphorus levels in animal waste by 30-35%, while also reducing the cost of phosphorus supplementation. The enzyme hydrolyzes phytate (myo-inositol hexakisphosphate), the primary storage form of phosphorus in plant seeds and pollen, in several steps into inositol and inorganic phosphorus, which is readily bioavailable to the farm animals. Phytases can also have non-specific phosphorus monoester activity. Addition of phytases to farm animals diets significantly enhances bioavailability of plant phosphorus for the animals while reducing phosphorus in the waste and simultaneously allowing a reduction of total phosphoms in the feed 500 units of phytase... 

Greipsson, S. (1995). Effect of iron plaque on roots of rice on growth of plants in excess zinc and accumulation of phosphorus in plants in excess copper or nickel. J. Plant. Nutr. 18, 1659-1665. 

J. Ruzicka, J.W.B. Stewart, Flow injection analysis. Part II. Ultrafast determination of phosphorus in plant material by continuous flow spectrophotometry, Anal. Chim. Acta 79 (1975) 79. 

B.F. Reis, E.A.G. Zagatto, A.O. Jacintho, F.J. Krug, H. Bergamin-Filho, Merging zones in flow injection analysis. Part 4. Simultaneous spectrophotometric determination of total nitrogen and phosphorus in plant material, Anal. Chim. Acta 119 (1980) 305. 

Although the percentage of phosphorus in plant material is relatively low, it is an essential component of plants. Phosphorus, like nitrogen, must be present in a simple inorganic form before it can be taken up by plants. In the case of phosphorus, the utilizable species is some form of orthophosphate ion. In the pH range that is present in most soils, H2PO4 and HP04 are the predominant orthophosphate species. 

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