title: Influence of phytohormones on polar and hydrophobic parts of mixed phospholipid monolayers at water/air interface.
abstract: Surface parameters--the limiting area, collapse pressure, and compressibility modulus for monolayers of phospholipids containing a determined hydrophobic part (16:0) but different polar parts (PPL) and a determined polar part (PC) but different fatty acids (HPL), characteristic of nonembryogenic (NE) and embryogenic (E) winter wheat calli--were evaluated at 15 degrees C. These parameters were dependent on the kind of hydrophilic group and the size of the hydrophobic part of phospholipids. In the case of PPL, higher values of Alim and picoll were noticed for NE phospholipids. In the case of HPL, lower Alim and higher picoll were detected for NE than for E monolayers. All investigated phospholipid systems stimulated the adsorption of phytohormones from the water subphase. The influence of phytohormones of anionic (IAA, 2-4-D), cationic (kinetin, zeatin), and nonionic character (zearalenone) was examined. It appeared that the surface activity of phytohormones depended strongly on the kind of tissue from which the phospholipid mixture was extracted and, in a lesser degree, on their charge. In PPL systems with a determined hydrophobic part (16:0), no great differences in phytohormone influence on NE and E monolayers were observed (except of IAA). The greatest phytohormone influence on NE monolayers in HPL systems was related to the structure of the hydrophobic part of phospholipids. IAA, the most active (with the highest Alim values) among the phytohormones examined, influenced both HPL and PPL monolayers. This indicated the interactions of IAA with polar groups of phospholipids. Phytohormones also changed the monolayer stability against collapse process and the direction of changes depended on the kind of tissue (embryogenic or nonembryogenic).
authors.affiliation: Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland. gzyl@chemia.uj.edu.pl
authors.forename: Barbara
authors.initials: B
authors.lastname: Gzyl
authors.forename: Maria
authors.initials: M
authors.lastname: Filek
authors.forename: Anna
authors.initials: A
authors.lastname: Dudek
mesh_terms: D000388:Air; D057927:Hydrophobic and Hydrophilic Interactions; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D011312:Pressure; D013499:Surface Properties; D014908:Triticum / Q000737:chemistry / Q000187:drug effects / Q000196:embryology / Q000378:metabolism; D014867:Water / Q000737:chemistry*
chemical_list: D010743:Phospholipids; D010937:Plant Growth Regulators; D014867:Water