Agriculture Reference
In-Depth Information
Rice Plant
Proteins Stable enzymes
Low temperature
p
H
Polyamine
Polycation
Polyamine
Stable
Nucleicacids__RNAandDN
A
A
Phospholipids Stable membrane
Fig. 21
Protective mechanism under cold stress.
2-week old rice seedlings under 13/15°C for 14 days showed
that root and shoot dry weights were signifi cantly less from
the control condition (20/22°C), night and day temperature.
Results for stomatal conductance and the SPAD value from
the control condition were signifi cantly more than those from
the stress condition. The leaf glucose content from the stress
condition was more than that from the control indicating
restriction in GA3 synthesis. ABA increase led to a decrease
of leaf glucose and stomatal conductance. In addition, low
temperature stress caused a decrease of photosynthetic
capacity. High concentrations of glucose, increased ABA
biosynthesis. Glucose induced ABA biosynthesis and mediated
some signaling mechanisms for stomatal reactions. An increase
of leaf glucose from the stress condition caused IAA protection
against oxidative reaction in the stress tolerant genotypes.
ABA has a key role among plant hormones in controlling
damage from low temperature stress. Glucose has a direct
and extensive role in the regulation of ABA biosynthesis
