Uptakes of phenolic acids

Blum U, Dalton BR, Shann JR (1985b) Effects of ferulic and />-coumaric acids in nutrient culture on cucumber leaf expansion as influenced by pH. J Chem Ecol 11 1567-1582 Blum U, Gerig TM (2005) Relationships between phenolic acid concentrations, transpiration, water utilization, leaf area expansion, and uptake of phenolic acids nutrient culture studies. JChem Ecol 31 1907-1932... 

Studies of the uptake of phenolic acids and related compounds by plants were reviewed by Flaig, v ho concluded that uptake occurred readily with organic compounds having a... 

Nutrient availability also plays a major role in exudation, with deficiencies in N, P, or K often increasing the rate of exudation (218). It is believed that nutrient deficiency may trigger the release of substances such as organic acids or nonproteinogenic amino acids (phytosiderophores), which may enhance the acquisition of the limiting nutrient (219,220). An example here might be the release of phenolic acids such as caffeic acid in response to iron deficiency, which results in an increase in uptake of the cation (221). 

Two studies have used single cells to study the effect of phenolic acids on mineral absorption. In sterile cell cultures of Paul s Scarlet rose, 100 pM ferulic acid inhibited Rb+ absorption in about 10 min when the cells were 4-5 days old (37). Uptake from 0.2 mM RbCl was inhibited about 25% and absorption from 5.0 mM RbCl was inhibited 45%. Absorption by 10-day-old cells was affected little. Salicylic acid at 10 pM inhibited PO - absorption by Scenedesmus, a unicellular green alga (38). These studies show that allelochemicals inhibit mineral absorption in cellular systems as well as tissue systems (Table I). 

Glass ADM. 1973. Influence of phenolic acids on ion uptake. J. Inhibition of phosphate uptake. Plant Physiology 51 1037-1041. 

Finally, several works have also implicated the nutrients P and Fe as possible inductors of changes in phenolic metabolism. However, studies of these relationships have been scarce. With regard to the former nutrient, P deficiency has been observed to raise the level of anthocyanins, but the reason for this rise remains unclear [4]. Meanwhile, low levels of Fe can increase the release of phenolic acids, presumably to help solubilize metals and thereby facilitate their uptake [135]. 

Andreasen MF, Kroon PA, Williamson G, Garcia-Conesa MT. 2001b. Intestinal release and uptake of phenolic antioxidant diferulic acids. Free Radio Biol Med 31 304-314. 

Action on the plasma membrane is the first and most fundamental of the bewildering array of deleterious effects of the cinnamic and benzoic acids. They reduce the transmembrane electrochemical potential with the immediacy and extent of that action depending on the concentration and lipid solubility of the compound.35,37,45,60 Rate of uptake also is concentration and pH-dependent, with transfer into and across the membrane greatest with lower pH conditions and higher external concentrations.60 Phenolic acid-induced depolarization of membranes causes a nonspecific efflux of both anions and cations accompanying the increased cell membrane permeability, and these membrane effects correlate with an inhibition of ion uptake. The phenolic acids suppress absorption of phosphate, potassium, nitrate, and magnesium ions, and overall changes in tissue... 

TABLE 25 Effect of pH on the Uptakes of Phenol and Benzoic Acid by Chemically Different Activated Carbons... 

The stimulation of amino acid uptake is oxygen dependent but is not inhibited by cyanide and dinitro-phenol. The effect of growth hormone on a-aminoiso-butyric acid has been extended to a number of natural amino acids, and it has been established that growth hormone stimulates the uptake of glycine, alanine, serine, proline, threonine, histidine, tryptophan, glutamine, and asparagine, but is without effect on the uptake of dicarboxylic acids, ethionine, valine, tyrosine, phenylalanine, leucine, lysine, and arginine. 

Although a great deal is still unknown regarding the roles of phenolic acids in plants, they have been connected with diverse functimis, including nutrient uptake, protein synthesis, enzyme activity, photosynthesis, stmctural components, and allelopathy [17]. 

Luy JF, Jiang H, Wu K, Zheng X, Cai Y, Katakowski M, Chopp M (2010) Effects of mixtures of phenolic acids on phosphorus uptake by cucumber seedlings. Eur J Pharmacol 641 102... 

Multiple additions of phenolic acids were used because phenolic acid concentrations in soil decline rapidly after each addition of phenolic acids (Blum et al. 1987 Blum and Gerig 2006). This was due to microbial metabolism, physical breakdown, root uptake, and/or soil particle sorption. Recovery of seedling processes, although considerably slower than in nutrient culture, also occurred in seedling-soil systems (Blum et al. 1987 Blum and Gerig 2006). To maintain inhibition for extended time periods multiple additions of phenolic acids were required. 

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