Effect of 8-hydroxyquinoline on flowering and endogenous levels of iron and copper in Lemna paucicostata, strain LP₆

Abstract

Lemna paucicostata LP₆, a strain of duckweed isolated locally, does not flower under any photoperiodic schedule when grown in Bonner and Devirian or other media routinely employed in various laboratories for studies on flowering in Lemnaceae. Flowering in this strain could be induced, however, by 8-hydroxyquinoline (8-HQ)-a well-known copper chelating agent-irrespective of the length of the photoperiod. To our knowledge, this is the first report where a direct induction of flowering in a duckweed by 8-HQ has been observed. Atomic absorption analysis of the plant material revealed that the endogenous level of copper is significantly higher in the plants treated with 8-HQ.. This is contrary to the general assumption that chelating agents influence flowering of duckweeds by causing a reduction in the uptake of copper ions and making them less available to the plants.