The Polar Transport of Auxin

Abstract

THE POLAR SECRETION THEORy 440 A CHEMIOSMOTIC THEORY OF POLAR AUXIN DIFFUSION IN CELLS 441 pH Dependent Uptake of Indoleacetic Acid 441 Anion Permeability-Simple Diff usion or Carrier-Mediated Diff usion? 444 Displacement of the Curve of Uptake Versus pH... . . . . . . ... ...... . . . . . . . . . . . . . . . . . . . . . .. . . . . . .. ...... 444 POLAR TRANSPORT IN SECTIONS 445 Stimulation of Transport by Auxin..... . . . . . . . . . . ..... . . . . . . . ..... . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . ..... . . . . . . . 447 Relevance to lateral auxin movement 448 Relevance to electrical and transport oscillations 448 The Degree of Polarity of Single Cells 449 Auxin Movement Within and Between Cells . 450 Limitations of Microautoradiography for Determining the Path of Auxin Transport . .... 450 Number and Identity of Compartments Involved in Auxin Transport 452 Does Auxin Transport Have a Velocity?.. . . . . .... . . . . . . . . . . . . . . . . . . . . .... . . . . . . . . . . ...... . . . . . . . . . . ........ 454 The time course of auxin transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... . . . . . . 454 Pulse transport experiments ...... 455 Diff usion through a Series of Polar Cells 456 Polar Transport of Other Substances in Isolated Sections 458 Alternative Hypotheses also Involving Diff usion 462 TRANSPORT OF AUXIN IN INTACT PLANTS 463 DEVELOPMENT OF POLAR TRANSPORT 464