Agriculture Reference
In-Depth Information
Uptake of water by a dry seed is triphasic (Fig. 6) with a
rapid initial uptake (Phase I, i.e., imbibition) followed by a
plateau phase (Phase II). A further increase in water uptake
occurs only after germination is completed, as the embryo axis
elongates after having emerged from all seed covering layers.
Phase I covered 6h from the onset of imbibition followed by
a plateau (phase II) to 24h, and then the start of germination
(Phase III).
0.415
Phase - I
Phase - II
Phase - III
0.395
0.375
0.355
0.335
0.315
0.295
0.275
0.255
0.235
0.215
0
2
4
6
12
18
24
36
48
Imbibitions hours (h)
Fig. 6
Water uptake by dehusked rice seeds.
Although seed germination is a major subject in plant
physiological research, there is still a long way to go to elucidate
the mechanism of seed germination. Recently, functional
genomic strategies have been applied to study the germination
of plant seeds. A proteomic analysis of seed germination in
rice (CV. 9311) by comparison of 2DE maps showed that there
were 148 proteins displayed differently in the germination
of rice seeds. Among the changed proteins, 63 were down
regulated, 69 were upregulated (including 20 induced proteins).
The down regulated proteins were mainly storage proteins,
