The Release of Free Amino Acids From Germinating Pollen

Abstract

Synchronously germinating Petunia pollen in an aerated sucrose medium release free amino acids during the first minutes after contact with the aqueous medium. The release process between 1 minute and 6 hours follows an exponential equation. The content of free amino acids of the germinating pollen decreases sharply. Free amino acids set free from "dead" pollen reach their plateau after 40 minutes in the alcoholic extraction medium. Differences in the amino acid curves show that only a part of them is localized in the pollen wall, but the majority are peptide bound in the inner space of the microspore. Consideration of the data obtained by differential analysis of the amino acid curves suggests that amino acids and protein are synthesized in the early phase of pollen germination.

Pollen feeding in the butterfly Heliconius charitonia : isotopic evidence for essential amino acid transfer from pollen to eggs

“…The collected pollen mass is mixed on the proboscis with an exuded fluid and agitated for several hours. Pollen that is soaked releases a diversity of compounds, possibly via germination, including free amino acids and peptides (Linskens & Schrauwen 1969;Erhardt & Baker 1990). Thus, butterflies that re-ingest the fluid previously used to soak pollen could gain a dietary source of free amino acids.…”

Pollen Feeding and Reproductive Biology of Heliconius Butterflies

“…The present report discusses the evidence for an analogous development in certain members of the neotropical butterfly genus Heliconius (Nymphalinae), in which the source of amino acids and proteins for the adult butterfly is pollen rather than blood. Studies performed in the lab, in 6.0 nmol of arginine, leucine, lysine, and valine, respectively (6).…”

I. Development of suspension media

“…1) substantiate the findings of these workers, although we have found that the optimum moisture content to be attained during pre-humidification differs according to the pollen being treated. When dried pollen was suspended directly in liquid germination media, amino acids (Linskens & Schrauwen 1969) and soluble carbohydrates (Davies & Dickinson 1971) leaked out ofthe pollen into the media. Simon (1974) suggested that, on drying, the integrity of the pollen grain plasma membrane may be lost, and that this could be restored if dried pollen were hydrated in the absence of liquid water befo"re its incorporation into germination media.…”