Transcription factors are special proteins in plants that control when, where, and how strongly genes are expressed.
They act like gene switches, turning genes on or off by binding to specific DNA sequences near those genes.
Here’s how they work and why they are important:
- Binding to DNA
- Transcription factors recognize and attach to specific short DNA regions called promoters or enhancers.
- By binding there, they help control whether RNA polymerase (the enzyme that copies DNA into RNA) can start transcription.
- Activating or repressing genes
- Some transcription factors are activators — they help RNA polymerase start working, which increases gene expression.
- Others are repressors — they block RNA polymerase or prevent other proteins from binding, which decreases gene expression.
- Responding to signals
- Transcription factors are often activated by hormones, light, stress, or environmental changes.
- For example:
- ABF (ABA-binding factors) activate stress-response genes when the hormone abscisic acid (ABA) increases during drought.
- PIFs (phytochrome-interacting factors) regulate genes in response to light.
- Regulating development
- They guide plant growth by controlling genes for flowering, leaf formation, seed development, and root growth.
- For instance, MADS-box transcription factors control flower organ formation.
- Cooperation and networks
- Transcription factors often work together in groups or networks to control complex processes.
- This coordination ensures genes are expressed at the right time and in the right cells.
In short, transcription factors are key regulators that turn genes on or off in plants.
They allow plants to grow properly, respond to hormones and environmental signals, and adapt to stress or changes in their surroundings.