Permeability and Respiratory Properties of Germinating Pollen

Abstract

Abstract A study of permeability and respiration of germinating lily pollen ( Lilium longi‐florum , variety Ace) was conducted. Calcium was needed in the culture medium to maintain the integrity of the cell membranes. Carbohydrates leaked from pollen when calcium was absent, but little or no leakage occurred when calcium was present. A culture medium containing penlaerythritol was developed for this study. Pentaerythritol allowed normal germination and did not interfere with measurement of carbohydrates. Intact pollen grains possessed a β‐fructofuranosidase external to the cell membrane which hydrolyzed sucrose in the culture medium. External α‐ or β‐glucosidases were absent, although soluble α‐glucosidase was present within the pollen. Oligomycin, an inhibitor of oxidative phosphorylation, eliminated the 3‐phase patters of respiration associated with normal germination. O 2 uptake was inhibited by oligomycin while CO 2 output was stimulated. 2,4‐Dinitrophenol, an uncoupler of oxidative phosphorylation, reversed the inhibition of O 2 uptake caused by oligomycin.