preview

Abiotic Stress Essay

Good Essays
Presence of plants under any abiotic stress causes the expression of different genes for tolerance and adaptation to the stress in its environment, plant undergoes several mechanisms for the expression of those stress induced genes. Date palm is considered as a halophytic plant. In order to determine its response to salinity, its adaptive mechanisms to salinity should be studied on a molecular level involving expressed genes and biochemical-molecular mechanisms (Wang et al., 2003).
Abiotic stress tolerance consists of genetically complex mechanisms involving multi-genes (Wang et al., 2003). The genes expressed as a result of abiotic stresses vary. These genes include three major categories: (i) those involved in signaling cascades and in
…show more content…
Mechanism of plant response to abiotic stress
Primary stresses, such as drought, cold, heat, salinity, chemical pollution, and salinity cause several secondary stresses, including osmotic and oxidative stresses. Initially, those stresses cause the disruption of cellular homeostasis (osmotic and ionic), denaturating structural and functional proteins and membranes, which trigger downstream signaling transduction processes, involving: Phospholipid cleaving enzymes (e.g. PLD), Osmosensors (e.g. AtHK), and second messengers (e.g. PtdOH, Ca2+ ions, and ROS), MAP Kinases, Ca2+ sensors (e.g. SOS3), calcium-dependent protein kinases (CDPKs), triggering various transcriptional factors (e.g. CBF/DREB, bZIP ABF, HSF, MYC/MYB) that activate stress-responsive mechanisms and expressing various stress-resistance genes with several functions such as: Detoxification functions (e.g. SOD), chaperone functions (e.g. SP1, Hsp, LEA, COR), osmolytes’ production (proline, GlyBet, sugar polyols), water and membrane ion transportation functions (aquaporin, ion transporter). This cascade of reactions causes the restoration of cellular homeostasis and protection of functional and structural proteins and membranes. That eventually lead to stress tolerance or resistance (Wang et al., 2003).

Significant factors in plant stress tolerance
Several factors are involved in mediating the
Get Access