Agriculture Reference
In-Depth Information
18.3.2.2
Spatial Organisation
Oscillations may provide synchronisation of events widely separated in
space between different cells, or between subcellular compartments (Lloyd
and Stupfel 1991). At the whole-plant level, frequency-coded signals are
believed to play an important role in communication between the differ-
ent organs and tissues (Wagner et al. 1998). Oscillations may also provide
a specification of positional information during morphogenetical develop-
ment (Hejnowicz 1975; Lloyd and Stupfel 1991).
18.3.2.3
Prediction of Repetitive Events
Oscillatorysystemsareabletorespondrapidlytoinputsreceivedfromtheir
environmental surroundings (Lloyd and Stupfel 1991). A plant's ability to
utilise sunflecks is one such example (Pearcy 1990). Also consistent with
this idea, plant adaptation to a changing environment means resetting to
a new circadian and/or ultradian rhythm (Erdei et al. 1998).
18.3.2.4
Efficiency
Theoretical models show that the energetic efficiency of oscillatory pro-
cesses may be greater in the oscillatory mode than when steady-state be-
haviour prevails (Termonia and Ross 1982; Richter and Ross 1981), provid-
ing an evolutionary advantage over those organisms incapable of anything
other than steady-state behaviour. Another advantage of an oscillatory
strategy is that oscillations may enhance sensitivity to weak external stim-
uli (Dolmetsch et al. 1998).
18.3.2.5
Precision of Control
It is widely accepted that oscillations may act as a filter to discriminate true
signals from environmental noise (Tsien and Tsien 1990; Lloyd and Stupfel
1991). Theoretical findings by Rapp et al. (1981) suggest that, being more
robust to environmental perturbations, an oscillatory strategy provides
significant functional advantages for living cells.
18.3.3
Deterministic Chaos and “Strange” Behaviour
Theoretical studies show that non-linear systems will possess complex dy-
namics leading to “strange” behaviour such as bifurcation and chaos (com-
Search WWH ::
Custom Search