Biostimulants
Abiotic Stress
Abiotic stress is stress that is caused in plants by non-living environmental factors. This form of stress directly affects the physiology, growth, and productivity of plants and can, when it persists for a long time, lead to reduced yield or even plant death.
What is abiotic stress?
Abiotic stress includes all negative effects on plants resulting from physical or chemical environmental factors, such as water shortage, extreme temperatures, salt, light intensity, and nutrient imbalance. Unlike biotic stress, abiotic stress is not caused by living organisms.
- Affects plant growth and development
- Disrupts physiological processes
- Leads to energy loss and stress responses
- Increases susceptibility to diseases
Main forms of abiotic stress
Drought stress
Drought stress occurs when water uptake through the roots is insufficient to compensate for water loss by evaporation. This leads to reduced turgor pressure, growth inhibition, and closure of stomata.
Salt stress
Salt stress occurs at high concentrations of dissolved salts in the soil or irrigation water. This causes osmotic stress and ion toxicity, disrupting water uptake and cellular processes.
Temperature stress
Both heat and cold can be harmful to plants. High temperatures accelerate evaporation and denature proteins, while low temperatures stiffen membrane structures and slow enzymatic reactions.
Light stress
Too high or too low light intensity affects photosynthesis. Excessive irradiation can lead to photoinhibition and oxidative damage, while light shortage limits energy production.
Nutrient stress
A deficiency or excess of minerals causes disruption of metabolic processes, resulting in growth retardation, discoloration, and reduced vitality.
Physiological consequences of abiotic stress
Abiotic stress has direct effects on the internal processes of the plant:
- Reduced photosynthesis
- Increased respiratory activity
- Accumulating oxidative damage
- Disrupted water and nutrient management
Adaptation mechanisms of plants
Physiological adaptation
Plants respond to abiotic stress through processes such as osmoregulation, adjustment of stomatal activity, and modification of membrane composition.
Biochemical adaptation
The production of protective metabolites and antioxidants increases to protect cells from damage and oxidative stress.
Morphological adaptation
Prolonged stress can lead to changes in root depth, leaf surface, and tissue structure, allowing the plant to better adapt to adverse conditions.
Effect of abiotic stress on yield and quality
When abiotic stress is not adequately compensated, it results in:
- Lower biomass and yield
- Irregular growth
- Reduced product quality
- Delayed recovery after stress periods
Overview: impact of abiotic stress
| Stress factor | Effect on the plant |
|---|---|
| Water shortage | Loss of turgor and growth inhibition |
| Salt | Osmotic stress and ion toxicity |
| Temperature | Damage to enzymes and membranes |
| Light | Photoinhibition or energy shortage |
| Nutrients | Metabolic disruptions |