"Perfumed" Plant Attracts Small Mammals

Professor Steven Johnson, from the University of KwaZulu-Natal (Durban, South Africa), in collaboration with researchers from the South African Biodiversity Institute (Pretoria, South Africa), the University of Calgary (Calgary, Canada), and the University of Bayreuth (Bayreuth, Germany), has used gas chromatography–mass spectrometry to study the scent of the Cytinus visseri and its effect on animals.

The Cytinaceae family of parasitic plants, which can be found in South Africa, does not produce its own chlorophyll. The Cytinus visseri buries itself in a host plant, allowing only dark maroon flowers and fruit to emerge as visual identifiers. The flowers of the Cytinus visseri require small, ground-dwelling mammals to disperse pollen, and use a distinct scent as an attractant.

Plants often use signals that are distinct from their surroundings to attract animals. Although animals generally learn these signals through associative conditioning, the team suggests that the most effective signals are those that elicit innate behavioral responses. Professor Johnson and his team, seeking to further understand these signals, determined the chemical basis for the plant’s attractive scent. The scent predominantly consists of two aliphatic ketones: 1-hexen-3-one and 3-hexanone. Combined, the two attract small animals, but when isolated, 3-hexanone remained an attractant while 1-hexen-3-one became a repellant.

This study was published in the online edition of the biological research journal Proceedings B on January 5, 2011.