Photosynthesis, biomass partitioning and peroxisomicine A₁ production of Karwinskia species in response to nitrogen supply

Abstract

Species of the genus Karwinskia are medicinal woody plants producing secondary metabolites (anthracenones, peroxisomicine A1) with antitumour effects. We investigated the photosynthetic and growth characteristics of Karwinskia parvifolia Zucc. and Karwinskia humboldtiana Rose plants grown at two rates of nitrogen supply. There were significant differences in growth, CO2 exchange (photosynthesis, respiration), chlorophyll and nitrogen concentration between plants grown at high nitrogen supply (HN) and low nitrogen supply (LN). At HN, the plants of both species grew faster than those cultivated at LN. Rates of photosynthesis, leaf respiration and root respiration, quantum yield, the concentration of chlorophylls (a, b, a+b), specific leaf area, leaf mass ratio and peroxisomicine A1 concentration were higher in plants grown at HN. The species‐specific difference in the daily carbon budget was mainly due to variation in rates of carbon fixation. K. parvifolia responded more strongly to the nitrogen treatment than K. humboldtiana, in terms of growth, as well as with respect to photosynthesis and peroxisomicine A1 concentration.

Photosynthetic production of boreal ground vegetation after a forest clear-cut

“…The different composition and density of leaves may also explain the unexpected differences in the mass-specific expression of our results with E. angustifolium. In contrast to this study, several others found that the rates of photosynthesis and leaf respiration per leaf weight, specific leaf area and leaf mass ratio are higher in plants grown in high N soils (Field et al, 1983;Field and Mooney, 1983;Masarovicova et al, 2000;Poorter et al, 1995). Nevertheless, the difference in available nutrition did not significantly affect the rate of photosynthesis in this study.…”

“…Respiration accompanies the observable CO 2 exchange during daytimes. Therefore we fitted a Michaelis-Menten-type equation (Michaelis and Menten, 1913) for each set of our measurements as follows:…”

Carnivorous Syndrome in Asian Pitcher Plants of the Genus Nepenthes

“…2 mg g 21 in oak-hornbeam forest. Lower chlorophyll content is probably due to lower nitrogen content in carnivorous plants than in noncarnivorous plants, because a positive correlation between chlorophyll and nitrogen content is generally found for plants (Masarovičová et al, 2000).…”