Journal of Plant Diseases and Protection

, Volume 125, Issue 4, pp 433–442 | Cite as

The role of pH for ionic solute uptake by the non-aerial hypocotyl of mung bean plants

  • John AponteEmail author
  • Peter Baur
Original Article


The non-aerial hypocotyl is an exceptional fast pathway for the uptake of soil-applied pre-emergent herbicides or systemic actives with soil mobility after release from coated seeds. The presence of charged groups at the interface of the non-aerial hypocotyl to the environment and its role for the penetration of likewise charged agrochemicals have not yet been investigated as a basis for the development of enhanced delivery systems. Recent work suggests pore-like structures having pore size diameters < 1.5 nm in mung bean hypocotyls, which is not associated with the existence of a real channel system having a continuous aqueous phase. The current work presents a detailed study on the role of pH for the sorption of ionic compounds by the non-aerial hypocotyl of mung bean plants. The presence of fixed dissociable charges on the surface of the non-aerial hypocotyl was characterized utilizing different methods, including local application of charged radiolabelled agrochemicals, incubation in osmotic solutions and differential dye staining experiments. The formation of a pH-dependent and continuous Donnan phase determined the adsorption or repulsion of compounds with opposite and equal ionic charge, which was shown for various ionic dyes and agrochemicals. Uptake via the non-aerial hypocotyl varied with the pH value of the test solution, indicating the presence of fixed charges in the membrane. This information is considered as essential for a better understanding of the transport properties through the non-aerial hypocotyl membrane.


Penetration pH Hypocotyl Agrochemicals Pores Ionic Staining 


  1. Aponte J, Baur P (2010) Penetration and translocation of coleoptile-applied systemic agrochemicals. In: Baur P, Bonnet M (eds) 9th International symposium on adjuvants for agrochemicals. ISAA Society, Wageningen, pp 371–378Google Scholar
  2. Aponte J, Baur P (2014) Transport properties of the mung bean (Vigna radiata) non-aerial hypocotyl membrane: permselectivity to hydrophilic compounds. Pest Manag Sci 70:148–155CrossRefPubMedGoogle Scholar
  3. Baur P (1998) Mechanistic aspects of foliar penetration of agrochemicals and the effects of adjuvants. Recent Res Dev Agric Food Chem 2:809–837Google Scholar
  4. Glaser R (1991) Biophysics. Springer, BerlinGoogle Scholar
  5. Gregor H, Hamilton M, Becher J, Bernstein F (1955) Studies on ion exchange resins. XIV. Titration capacity and swelling of methacrylic acid resins. J Phys Chem 59:874–881CrossRefGoogle Scholar
  6. Korner L, Kjellbom P, Larsson C, Moller I (1985) Surface properties of right side-out plasma membrane vesicles isolated from barley roots and leaves. Plant Physiol 79:72–79CrossRefPubMedPubMedCentralGoogle Scholar
  7. Larsson C, Moller I, Widell S (1990) Introduction to the plant plasma membrane, its molecular composition and organization. In: Larsson C, Moller I (eds) The plant plasma membrane. Structure, function and molecular biology. Springer, Berlin, pp 1–15CrossRefGoogle Scholar
  8. Luque P, Bruque S, Heredia A (1995) Water permeability of isolated cuticular membranes: a structural analysis. Arch Biochem Biophys 317:417–422CrossRefPubMedGoogle Scholar
  9. Martin J, Juniper B (1970) The cuticles of plants. Edward Arnold, EdinburghGoogle Scholar
  10. Patel S, Baur P (2009) Exploiting the full potential of tembotrione by means of formulation. Bayer CropSci J 62:17–34Google Scholar
  11. Schönherr J (1976a) Water permeability of cuticular membranes. In: Lange OL, Klappen L, Schulze E-D (eds) Water and plant life. Problems and modern approaches. Ecological studies. Analysis and synthesis, vol 19. Springer, Heidelberg, pp 148–159Google Scholar
  12. Schönherr J (1976b) Water permeability of isolated cuticular membranes: the effect of cuticular waxes on diffusion of water. Planta 131:159–164CrossRefPubMedGoogle Scholar
  13. Schönherr J (1976c) Water permeability of isolated cuticular membranes: the effect of pH and cations on diffusion, hydrodynamic permeability and size of polar pores in the cutin matrix. Planta 128:113–126CrossRefPubMedGoogle Scholar
  14. Schönherr J, Baur P (1994) Modelling penetration of plant cuticles by crop protection agents and effects of adjuvants on their rates of penetration. Pestic Sci 42:185–208CrossRefGoogle Scholar
  15. Schönherr J, Baur P (1996) Effects of temperature, surfactants and other adjuvants on rates of uptake of organic compounds. In: Kerstiens G (ed) Plant cuticles, an integrated functional approach. Bios Scientific Publishers Limited, Oxford, pp 135–155Google Scholar
  16. Schönherr J, Bukovac M (1973) Ion exchange properties of isolated tomato fruit cuticular membrane: exchange capacity, nature of fixed charges and cation selectivity. Planta 109:73–93CrossRefPubMedGoogle Scholar
  17. Schönherr J, Huber R (1977) Plant cuticles are polyelectrolytes with isoelectric points around three. Plant Physiol 59:145–150CrossRefPubMedPubMedCentralGoogle Scholar
  18. Silcox D, Holloway P (1986) A simple method for the removal and assessment of foliar deposits of agrochemicals using cellulose acetate film stripping. Asp Appl Biol 11:13–16Google Scholar
  19. Tyree MT, Scherbatskoy TD, Tabor CA (1990) Leaf cuticles behave as asymmetric membranes. Plant Physiol 92:103–109CrossRefPubMedPubMedCentralGoogle Scholar
  20. Van Almsick A, Benet-Bucholz J, Olenik B, Willms L (2009) Tembotrione, a new exceptionally safe cross-spectrum herbicide for corn production. Bayer CropSci J 62:5–16Google Scholar
  21. Westrin H, Shanbhag V, Albertsson P (1983) Isoelectric points of membrane surfaces of three spinach chloroplast classes determined by cross-partition. BBA Biomembr 732:83–91CrossRefGoogle Scholar

Copyright information

© Deutsche Phytomedizinische Gesellschaft 2018

Authors and Affiliations

  1. 1.Faculty of Natural SciencesLeibniz University of HannoverHannoverGermany
  2. 2.Formulation TechnologyBayer CropScience AGMonheimGermany
  3. 3.Clariant Industrial & Consumer SpecialtiesClariant Crop SolutionsFrankfurt am MainGermany
  4. 4.Clariant Industrial & Consumer SpecialtiesClariant International Ltd.MuttenzSwitzerland

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