WHEN certain typical plants, such as Cosmos (Cosmos bipinnatus), Salvia (Salvia splendens) and soybeans (Soja max) are exposed to a short photoperiod (7to 8-hour day) and a relatively long one (14to 15-hour day) they exhibit conspicuous differences in rate of growth, time of sexual reproduction and greenness of foliage. The short-day soybean plants, for instance, are lighter in color early in t...

We have investigated the importance of carotenoids on the accumulation and function of the photosynthetic apparatus using a mutant of the green alga Chlamydomonas reinhardtii lacking carotenoids. The FN68 mutant is deficient in phytoene synthase, the first enzyme of the carotenoid biosynthesis pathway, and therefore is unable to synthesize any carotenes and xanthophylls. We find that FN68 is un...

The only attempt at the isolation of carotene from mango fruit seems to have been made by Yamamoto Osima & Goma (1932) who obtained 60 mg. of a crystalline preparation from 38 kg., of fresh fruit pulp. From a study of its optical activity and absorption spectrum they concluded that it was a mixture of aand P-carotenes, which were, however, not separated. The inconclusive nature of their data ha...

Selected light wavebands promote plant development and/or the biosynthesis of targeted metabolites. This work offers new insights on effects red (R), green (G), blue (B), and white (W - R:G:B; 1:1:1) LED supplementation physiochemical traits strawberry leaves. Gas exchange chlorophyll fluorescence parameters, photosynthetic pigments, superoxide anion (*O2-) content were analysed in plants grown...

Leaf meals of the above-named tropical plants at 0.2,3,4 and 5% dietary levels were investigated for their values as feed ingredients egg yolk pigmenters in white maize based layer diets. Each diet was fed 5 replicates 15 hyaline layers 14 weeks. Pawpaw leaf meal (RM) 4% significantly (P<0.05) depressed intake without affecting production body weights. It, however, had no colouring yolk. Swo...

Thirty days old rice plants grown under low and moderate light conditions were transferred to full sunlight to observe the extent of photoinhibitory damage and protective mechanism, and the relationship between xanthophyll cycle and nonphotochemical quenching (qN) under changing light environment. Control plants (low, moderate and sun grown) exhibited similar Fv/Fm ratio, indicating similar pho...

Changes in biomass and photosynthesis of a diatom-dominated microphytobenthos (MPB) intertidal community were studied over a diel emersion period using a combination of O2 and scalar irradiance microprofiling, variable chlorophyll (Chl) fluorescence, and pigment analysis. The MPB biomass in the photic zone (0-0.5 mm) of the sediment exposed to low irradiance (150 μmol photons m(-2) s(-1)) showe...

Total carotenoids (TC) were determined as a measure of total xanthophylls in grain flours and grits, by new validated spectrophotometric method based on A1cm1%-approach. The general analytical procedure is easily adjustable to different samples, the number of extraction steps depending on TC concentration in the sample. Basically, two methods have been suggested: the rapid one for low-TC sample...

Carotenoid accumulation confers distinct colouration to plant tissues, with effects on plant response to light and as well as health benefits for consumers of plant products. The carotenoid pathway is controlled by flux of metabolites, rate-limiting enzyme steps, feed-back inhibition, and the strength of sink organelles, the plastids, in the cell. In apple (Malus × domestica Borkh), fruit carot...

The mutualistic relationship between corals and their unicellular dinoflagellate symbionts (Symbiodinium sp.) is a fundamental component within the ecology of coral reefs. Thermal stress causes the breakdown of the relationship between corals and their symbionts (bleaching). As with other organisms, this symbiosis may acclimate to changes in the environment, thereby potentially modifying the en...