How Plants Sense the World

A pot plant on a windowsill quietly bends toward the light within days, with no eyes, brain or nervous system involved at all. This episode explores how plants detect light direction and colour, sense gravity through their roots, respond to touch, exchange chemical signals with their neighbours, and keep time well enough to know exactly when to flower — and takes an honest, evenhanded look at the ongoing scientific debate over whether any of this deserves to be called "intelligence."

You'll come away understanding how phototropism and photoreceptors let plants track light direction and quality, how statoliths let roots sense gravity, how touch responses range from a Mimosa leaf folding shut to a Venus flytrap snapping closed, how volatile chemical signals may let plants respond to threats detected in their neighbours, how circadian rhythms and day length govern flowering time, and why the "plant intelligence" debate is genuinely contested rather than settled among biologists.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Royal Botanic Gardens Kew – plant science explainers; Annual Review of Plant Biology – reviews on plant signalling and sensory biology; Nature Plants – research on plant-plant chemical communication; American Society of Plant Biologists – public education resources.