S-Adenosylmethionine Synthetase 3 Is Important for Pollen Tube Growth

An extracellular transglutaminase is required for apple pollen tube growth.

An extracellular form of the calcium-dependent protein-cross-linking enzyme TGase (transglutaminase) was demonstrated to be involved in the apical growth of Malus domestica pollen tube. Apple pollen TGase and its substrates were co-localized within aggregates on the pollen tube surface, as determined by indirect immunofluorescence staining and the in situ cross-linking of fluorescently labelled...

Phytohormonal regulation of S-adenosylmethionine synthetase and S-adenosylmethionine levels in dwarf pea epicotyls.

A significant stimulation (2- to 2.5-fold) of AdoMet synthetase was witnessed in glibberellicd acid (GA3, 1 microM)-treated epicotyls of the dwarf pea (Pisum sativum). This was accompanied by a 2.4-fold increase in the endogenous pool of S-adenosylmethionine. Both abscisic acid (10 microM) and cycloheximide (20 micrograms/ml) inhibited the GA3-mediated enhancement of AdoMet synthetase activity....

Actin polymerization is essential for pollen tube growth.

Actin microfilaments, which are prominent in pollen tubes, have been implicated in the growth process; however, their mechanism of action is not well understood. In the present work we have used profilin and DNAse I injections, as well as latrunculin B and cytochalasin D treatments, under quantitatively controlled conditions, to perturb actin microfilament structure and assembly in an attempt t...

Regulation of pollen tube growth

Ions and Pollen Tube Growth

Ions play a crucial role in the control of pollen tube growth. In this review we focus on four that seem especially important: calcium (Ca2+), protons (H+), potassium (K+), and chloride (Cl–). Ca2+ in the extracellular medium is essential for growth; it forms a steep intracellular tip-focused gradient, and exhibits a prominent extracellular tip-directed Ca2+ influx. pH is also essential for gro...