Growth responses of rice seedlings to triacontanol in light and dark.

Triacontanol, a 30-carbon primary alcohol, applied in nutrient culture solutions to rice (Oryza sativa L.) seedlings at 2.3×10(-8) M (10 μg/l), caused an increase in dry weight and leaf area of the whole plants. The response could be observed as early as 3 h of treatment. It was observed at relatively high and low light intensities as well as in the dark where control plants lost but triacontanol-treated plants gained in dry weight. The dry weight gain in the dark was, however, eliminated by removing CO2 from the atmosphere. Triacontanol-treated plants also increased their content of Kjeldahl-N and contained 30% more total N per plant than controls after 6 h in the dark.