Activity › Discussion › History › Plants › Reply To: Plants
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Plants have evolved several strategies to survive droughts:
- Drought escape: Some plants complete their life cycle before the actual water deficit occurs, by rapidly developing and reproducing before the drought hits. This allows them to escape the drought.
- Drought avoidance: Plants can avoid drought by reducing water loss or increasing water uptake. Mechanisms include:
- Thick, waxy leaves to reduce evaporation
- Smaller leaves with fewer stomata (pores) to limit transpiration
- Shedding leaves to reduce water loss
- Extensive root systems to absorb more water from the soil
- Storing water in thick, fleshy leaves or stems (succulents)
- Opening stomata at night to take in CO2 for photosynthesis, while keeping them closed during the day to prevent water loss (CAM photosynthesis)
- Drought tolerance: Plants can tolerate low water potentials and desiccation by:
- Maintaining high tissue water content through osmotic adjustment
- Protecting cellular structures and membranes from damage
- Repairing damage once water becomes available again
- Integrated rhizosphere management: The plant’s interaction with its root microbiome can enhance drought tolerance. Beneficial bacteria can alter root architecture, produce osmoprotectants, induce systemic tolerance, and regulate stress response genes.
In summary, plants employ a combination of escape, avoidance and tolerance mechanisms, often in conjunction with their rhizosphere microbiome, to survive and thrive under drought conditions. The specific adaptations depend on the plant species and its evolutionary history.