The Plant Planet. Episode 6 - Plant Hormones, Tropisms & Turgor Movements

How do plants sense light, gravity, and touch without a brain or nervous system? 🌿 In Episode 6 of The Plant Planet, we explore internal chemical signaling (the 6 key plant hormones), environmental tropisms, and rapid cellular water-pressure movements. In this deep dive, we break down auxins (apical dominance & phototropism), gibberellins, cytokinins, abscisic acid (ABA), ethylene gas, brassinosteroids, statolith gravity sensing, and seismonastic leaf collapsing in Mimosa pudica. 🌱 IN THIS EPISODE YOU’LL LEARN: • How auxins migrate to shaded stem sides to cause directional phototropic bending • Why high cytokinin-to-auxin ratios trigger shoots, while high auxin-to-cytokinin ratios trigger roots • How ethylene gas accelerates fruit ripening and triggers autumn leaf abscission • How heavy starch statoliths (amyloplasts) sink to the bottom of root cells to sense gravity • The hydraulic mechanism behind Mimosa pudica: How rapid potassium ion loss collapses pulvini joint cells in milliseconds 0:00 - Introduction: Motion Without Muscles 0:55 - The 6 Key Plant Hormones (Auxins, GA, Cytokinins, ABA, Ethylene, Brassinosteroids) 2:50 - Directional Tropisms (Phototropism, Geotropism & Thigmotropism) 4:40 - Rapid Turgor Movements (*Mimosa pudica* & Sleep Movements) 6:15 - Outro & Summary 📚 REFERENCES & RESOURCES: Grounded in Botany & Horticulture diploma course materials and scientific plant data from Plants of the World Online (Royal Botanic Gardens, Kew). 🔔 SUBSCRIBE to follow along with the complete Botany & Plant Science Masterclass series! Drop a comment below: Have you ever touched a Sensitive Plant (Mimosa pudica)? #botany #plantscience #planthormones #auxin #mimosapudica #PlantNeurobiology #gardening #sciencedocumentary #nature