Biology Reference
In-Depth Information
Fig. 1
Seasonal changes of lily pollen germination. (
a
) Mature pollen grains of
Lilium longifl orum
were either
cultivated immediately in medium B (fresh) or stored according to the described method at −80 °C (frozen).
Germination data were collected during the seasons and at locations as indicated (Karlsruhe, Germany, or
Salzburg, Austria). In seasons 2004-2005 and 2005-2006, the pollen grains were frozen in liquid nitrogen
during June and stored at −80 °C. Germination assays were performed once in a week until next year June.
A regression line drawn during the monthly average germination rate (
fi lled circle
) which was calculated from
both seasons clearly shows a higher germination frequency during April to September than in the months
October to March. (
b
) Detection of the plasma membrane H
+
ATPase and membrane-associated 14-3-3
proteins in microsomal fractions prepared from lily pollen grains. The time-dependent increase in the amount
of PM ATPases was only detectable and reproducible during April to September. In all other months with low
germination capability the pattern of PM ATPase expression varied irreproducibly
l in liquid medium [
3
] or germinate in 3 ml medium
in a 25 ml Erlenmeyer [
6
] (
see
Note 12
)).
4. Incubate for 6-16 h at RT (22 °C [
3
]). First pollen tubes
become visible after 1-2 h (Fig.
3
).
per 250
μ
1. Resuspend tobacco pollen grains from fi ve fl owers in 3-6 ml
germination medium in a small Petri dish (
see
Note 13
).
2. Incubate for 3-4 h. Pollen tubes can be observed after
30-60 min.
3.1.3 Tobacco Pollen
Culture
