Phytochrome A (phyA) mRNA abundance decreased rapidly in total RNA samples isolated from 4-day-old etiolated oat seedlings following a red light pulse. Putative in vivo phyA mRNA degradation products were detectable both before and after red light treatment. Cordycepin-treated coleoptiles were unable to accumulate the chlorophyll a/b-binding protein mRNA in response to red light, indicating tha...

and an increased chlorophyll b to chlorophyll a ratio for better light capture in low light. Furthermore, an Ostreobium strain living in a coral skeleton, where nearly all of the red light has been captured by the zooxanthellae in the coral tissue, has been shown to have modified chlorophyll with a spectrum shifted towards far-red wavelengths. As zooxanthellae cannot use far-red light, more of ...

Light may be an important environmental signal for plant-associated bacteria, particularly those that live on leaves. An integrated network of red/far-red- and blue-light-responsive photosensory proteins is known to inhibit swarming motility in the foliar plant pathogen Pseudomonas syringae pv. syringae B728a. Here we elucidated factors in the red/far-red-light-sensing bacteriophytochrome BphP1...

Acclimation of the photosynthetic apparatus to light absorbed primarily by photosystem I (PSI) or by photosystem II (PSII) was studied in the unicellular red alga Porphyridium cruentum (ATCC 50161). Cultures grown under green light of 15 microeinsteins per square meter per second (PSII light; absorbed predominantly by the phycobilisomes) exhibited a PSII/PSI ratio of 0.26 +/- 0.05. Under red li...

We have used gene-specific DNA fragments as hybridization probes to quantitate the levels of transcripts encoding several phycobilisome polypeptides in the cyanobacterium Fremyella diplosiphon in response to changes in the light environment. While the levels of transcripts encoding allophycocyanin, the core linker polypeptide, and the constitutive phycocyanin subunits are similar in F. diplosip...

Z. Naturforsch. 46c, 542-548 (1991); received February 13, 1991 Blue-Light Photoreceptor, Chlorophyll Synthesis, Desmarestia aculeata, Green-Light Photo­ receptor, Nitrate The chlorophyll synthesis in the brown algae Desmarestia aculeata is affected by light quali­ ty and by the nutrient state in the medium before the illumination. Pulses of 5 min of red, green and blue light together with 200 ...

Discrete-time discrete-state finite Markov chains are versatile mathematical models for a wide range of real-life stochastic processes. One most common tasks in studies is computation the stationary distribution. Without loss generality, and drawing our motivation from applications to large networks, we interpret this problem as one computing distribution random walk on graph. We propose new co...

Every tenth lever-press of three morphine-dependent rhesus monkeys was reinforced with food. A red light, initially a neutral stimulus, was presented every third or fourth session for 5 min before and 5 min after an intravenous injection of nalorphine, a morphine antagonist that produces an immediate abstinence syndrome in morphine-dependent monkeys. After several pairings, conditioned suppress...

The low photosynthetic efficiency of chlorophyll in freshly collected red algae, can, in the case of Porphyra perforata, P. nereocystis, and Porphyridium cruentum, be increased by growing the algae for 10 days in red or blue light. Exposure to darkness or to green light maintains the algae in their originally low efficiency with respect to chlorophyll, while retaining the high efficiency of phy...