Back to: Botany 400 Level
My sharp Afrilearn champ! I throway salute! Today’s matter dey sweet and deep because we dey talk how plants, despite all the wahala dem dey face — from heat to hunger to salt overload — still get sense to respond and survive. You see, plants no dey shout like humans, but dem dey react on the molecular and physiological level whenever stress show face. So make we break am down like chilled zobo after long sun — sweet and easy to digest.
Molecular and physiological responses to stress
Imagine say you dey inside hot sun, hungry, and somebody just pour salt for your water. Wahala, right? Na so plants too dey feel stress from heat, drought, salinity, and even pathogen attack. But instead of giving up, plants get correct coping mechanisms wey dem activate inside their body — both at the molecular level (inside their cells) and physiological level (how their whole body functions). These reactions help them survive, adapt, and even bounce back stronger. E be like how Nigerians dey adapt to NEPA wahala — you buy gen, then inverter, then solar, and still dey fine!
Molecular Responses to Stress
Gene Expression Changes:
When stress hit, plants go activate special stress-responsive genes.
These genes dey produce proteins that help the plant adjust, like heat shock proteins (HSPs), antifreeze proteins or ion transporters.
Some genes help form protective compounds like proline and glycine betaine to keep cells stable.
Production of Protective Molecules:
Under drought or salinity, plants produce osmoprotectants (like sugars and amino acids) to prevent cells from losing water.
In response to heat, plants produce antioxidants to fight off cell damage caused by stress.
Hormonal Signalling:
Hormones like abscisic acid (ABA) shoot up during drought, closing stomata to save water.
Under stress, hormonal balance shifts, allowing the plant to focus on survival over growth.
Physiological Responses to Stress
Stomatal Regulation:
During heat or drought, plants close their stomata to reduce water loss — like locking your tap during water scarcity.
Root Growth Alteration:
Roots may grow deeper or wider to reach better water or nutrient zones in soil — pure street-smart behaviour!
Leaf Shedding and Rolling:
Some plants roll their leaves or even drop them to reduce transpiration and heat load.
Growth Slowdown:
In tough conditions, plants go reduce shoot and leaf growth to conserve energy — survival before beauty!
Picture cassava during dry season. You go notice say leaves go start to fold, and growth go slow down. That cassava dey use ABA hormone to close stomata and store water, while at the same time producing osmoprotectants inside its cells. When rain come back, the plant go respond again — na smart life.
Summary
Plants respond to stress through molecular changes (like gene activation and protein production) and physiological actions (like stomatal closure and growth control).
Hormones like ABA play a key role in regulating stress responses.
These survival strategies help plants adapt, reduce damage, and recover after stressful events.
Evaluation
- Name one molecular and one physiological response to drought in plants.
- What role does abscisic acid (ABA) play during stress?
- How do stress-responsive genes help plants survive?
- Why do plants reduce their growth during stressful conditions?
You just dey reason like seasoned plant doctor wey understand the language of nature. Keep going strong, because knowledge like this na the key wey go open doors for your future. With Afrilearn by your side, your journey go dey smooth and exciting! Na your next lesson go blow your mind even more — so stay ready!
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