Production of Free Indole by Some Aroids

Abstract

The production of free indole by several arum lily species(Araceae) was studied. The compound was identified by paper chromatography and thin-layer chromatography in several solvent systems, colour reactions with various reagents, enzymatic conversion to tryptophan, UV absorption spectrum, and formation of a complex with polynitrofluorenone.The presence of indole is restricted to certain floral parts and is correlated with the flowering sequence of these plants. In general, indole is present for not more than one day during the flowering cycle. In the case of Sauromatum guttatum Schott, production of indole by the appendix starts on the eve of flowering between 6 and 8 p.m, and ends about 24 hours later. At the peak of the metabolic flare-up period, about 0.3 umoles indole is present per gram fresh tissue.There is a close connection between the indole cycle and the production of heat and stench in the respiratory flare-up. Some of the indole formed is released as a constituent of the stench.

Mimicry in Plants

“…The primary model in this system is olfactory, i.e., the odor of decaying protein or feces. The chemistry of the fetid odors produced by these inflorescences was studied by Smith and Meeuse (1966) and Chen and Meeuse (1971). Various other aspects of the fascinating physiological characteristics of these plants were also studied by Meeuse and co-workers.…”

The Sauromatum guttatum appendix as an osmophore: excretory pathways, composition of volatiles and attractiveness to insects

“…Indole and 30 other nitrogenous compounds have already been identified by Smith & Meeuse (1966); these compounds, except for indole, could not be separated by our chromatographic protocol. The indole production is induced 7 h after the application of calorigen and salicylic acid, and before the emission of the odour (Chen & Meeuse, 1971, 1972. The nitrogen and the sulphur-containing compounds provide the distinctive vile aroma of the appendix, e.g.…”

“…were allowed to develop under the conditions described previously (Skubatz, Kunkel & Meeuse, 1993). The developmental stage of the appendix has been determined retrospectively with respect to the day of inflorescence-opening and heat-production (D-day; Chen & Meeuse, 1971).…”

Endothermy by flowers of Rhizanthes lowii (Rafflesiaceae)

“…Several hypotheses have been presented for the ecological relevance of elevated temperatures in plants (Moodie 1976;Uemura et al 1993): to protect the flowers from freezing (Camazine and Niklas 1984;Knutson 1974), to enhance the rate of flower development (Bermadinger-Stabentheiner and Stabentheiner 1995), to provide a direct energy reward for insect pollinators (Cooley 1995;Kevan 1975;Prance and Arias 1975;Seymour and Schultze-Motel 1997;Seymour et al 1983), to increase diffusion rates of carbon dioxide and volatilisation of specific chemicals that attract pollinators (Bahr and Bonner 1973;Chen and Meeuse 1971;Meeuse 1966Meeuse , 1975Moodie 1976;Nagy et al 1972;Schneider and Buchanan 1980;Skubatz et al 1990;Smith and Meeuse 1966;Uemura et al 1993), to enhance the growth of the pollen tube (Jewell et al 1994;Kudo 1995), to assure reproductive success (seed set) (Miller 1986) and to achieve mimicry of mammalian faeces and carrion to attract scavengers and carrion flies (Knutson 1972;Moodie 1976;Uemura et al 1993).…”