Etiolation
/iˌtaɪəˈleɪʃən/
Definition
Etiolation is a plant growth condition caused by too little light. Stems become unusually long and weak, leaves stay small, and the plant often looks pale because chlorophyll, the green pigment used in photosynthesis, develops poorly. It commonly occurs in seedlings grown in darkness or houseplants kept in insufficient light, and it differs from normal stretching by combining elongation with reduced leaf development and loss of strong green color.
Effects on Plants
- Light-seeking growth pattern: It redirects growth toward stem and leaf elongation, helping a seedling reach light quickly but leaving tissues thin and mechanically weak.
- Reduced photosynthetic capacity: Because chlorophyll production is limited in low light, affected plants capture less energy and often show slower recovery until brighter conditions return.
- Hormone-driven response: The process is regulated by light-sensitive signaling and growth hormones, especially auxin, which promotes cell expansion when light cues are insufficient.
- Common indoor warning sign: In houseplants and seedlings, it often signals that light intensity is too low or too far away, making plants leggy, pale, and less compact.
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