title: Development of membrane- and calcium-gradients during pollen germination of Lilium longiflorum.
abstract: Chlorotetracyclin (10(-4)M) has been used to observe the distribution of membrane-associated calcium during pollen germination of Lilium longiflorum. For comparison, the general membrane distribution has been determined with 4·10(-5) M fluorescamine. The pollen grains show a calcium gradient with either weak or strong chlorotetracycline-fluorescence intensity, but always increasing toward the germination colpus. This gradient intensifies during germination, reaching a maximum before the pollen tube emerges. The typical tip-to-base calcium gradient of the tube does not change during growth. Independent of the developmental stage, the pollen grains show a flat fluorescamine-fluorescence gradient with the highest intensity in one half of the grain. Pollen tubes reveal a tip-to-base membrane gradient, independent of their length. As an additional marker for membrane distribution, the distribution of phosphorus, measured by proton-induced X-ray emission in chemically fixed tubes, has been used. A tip-to-base phosphorus gradient, distinct from the calcium gradient measured with the same method, was detected.
authors.affiliation: Zellenlehre, Universität Heidelberg, Im Neuenheimer Feld 230, D-6900, Heidelberg, Federal Republic of Germany.
authors.forename: H D
authors.initials: HD
authors.lastname: Reiss
authors.forename: W
authors.initials: W
authors.lastname: Herth
authors.forename: R
authors.initials: R
authors.lastname: Nobiling