CROP IMPROVEMENT - Cold Tolerance in Rice Cultivation - page 162

Drought

Salinity

Secondary stress
Osmotic stress
Oxidative stress

Chemical
pollution

Heat

Heat

Cold

Disruption of osmotic and
ionic homeostasis;
Damage of functional and
structural proteins and
membranes

Signal sensing,
perception and
transduction

Osmosensor (e.g. AtHK1), phospholipid cleaving enzymes (e.g.
PLD), and second messengers (e.g. Ca 2+ , PtdOH, ROS) MAP
Kinases, Ca 2+ sensors (e.g. SOS3), calcium-dependant protein
kinases (e.g. CDPKs)

Transcriptional factors
(e.g. CBF/DREB, ABF, HSF, bZIP, MYC/MYB)

Transcription control

Chaperone functions
(Hsp, SP1, LEA, COR)

Detoxifi cation
(SOD, PX)

Stress responsive
mechanisms

Gene activation

Gene activation

Osmoprotection
(proline, GlyBet,
sugar polyols)

Water and ion
movement (aquaporin,
ion transporter)

Re-establishment of cellular homeostasis,
functional and structural protection of
proteins and membranes

Stress Tolerance or Resistance

Fig. 49 Stress response mechanism.

Color image of this figure appears in the color plate section at the end of the topic.

of the genotype, characterized as susceptible and tolerant to
cold were maintained at 10ºC for six hours. Specifi c primers
of 14 rice genes expected to be involved in cold tolerance were
designed to assess gene expression level by qRT-PCR. Tolerant