Agriculture Reference
In-Depth Information
Amino acids
Plant
Cell
Cold
Shock
311
metabolites
or mass
spectral
tags
Polyamine precursors
Compatible solutes
Fig.
22
Cold infl uence on metabolites.
targets specifi cally. Some of the two-component histidine
kinases function as stress sensors in bacteria and yeast. Each
environmental stimulus provides plant cells with specifi c yet
related informations.
Given a large number of potential stimuli, it is possible
that plants may monitor the unique attribute of stress signals
through different kinds of sensors. Once an extra cellular
stimulus is perceived, second messenger molecules, etc., e.g.,
Ca
2+
, inositol phosphates and reactive oxygen species (ROS)
are immediately generated. Second messengers subsequently
activate a downstream signal cascade that phosphorylates
transcription factors that regulate the expression of a set of genes
or proteins involved in stress adaptation. Phosphorylation by
protein kinases is the most common and important regulatory
mechanism in signal transduction (Gao et al. 2008).
Stimuli
Stiumuli
Low temperature (12°c)
12ºC
↓
Second Messenger
?
↓
P K ?
↓
MAPKK OsMEK 1
↓
MAPK OsMAP 1
